[svn-r12084] Purpose:

    Code checkpoint

Description:
    The fractal heap code is reasonably stable and is passing all its
current tests, so checkpoint everything with CVS.

    Also, add "statistics" module for v2 B-trees code, which is only a
stub right now.

Platforms tested:
    FreeBSD 4.11 (sleipnir)
    Mac OSX (amazon)
    Linux 2.4 (chicago)

15 files changed, 2153 insertions, 280 deletions

diff --git a/src/H5AC.c b/src/H5AC.c
index 86e9e17..7395e51 100644
--- a/src/H5AC.c
+++ b/src/H5AC.c
@@ -744,6 +744,7 @@ static const char * H5AC_entry_type_names[H5AC_NTYPES] =
     "v2 B-tree leaf nodes",
     "fractal heap headers",
     "fractal heap direct blocks",
+    "fractal heap indirect blocks",
     "test entry"	/* for testing only -- not used for actual files */
 };
 
diff --git a/src/H5ACprivate.h b/src/H5ACprivate.h
index e50c573..9d89621 100644
--- a/src/H5ACprivate.h
+++ b/src/H5ACprivate.h
@@ -52,6 +52,7 @@ typedef enum {
     H5AC_TEST_ID,	/*test entry -- not used for actual files    */
     H5AC_FHEAP_HDR_ID,	/*fractal heap header			     */
     H5AC_FHEAP_DBLOCK_ID, /*fractal heap direct block		     */
+    H5AC_FHEAP_IBLOCK_ID, /*fractal heap indirect block		     */
     H5AC_NTYPES		/* Number of types, must be last             */
 } H5AC_type_t;
 
diff --git a/src/H5B2stat.c b/src/H5B2stat.c
new file mode 100644
index 0000000..5b8cfc0
--- /dev/null
+++ b/src/H5B2stat.c
@@ -0,0 +1,107 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic HDF5 document set and   *
+ * is linked from the top-level documents page.  It can also be found at     *
+ * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html.  If you do not have     *
+ * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/* Programmer:  Quincey Koziol <koziol@ncsa.uiuc.edu>
+ *              Monday, March  6, 2006
+ *
+ * Purpose:	v2 B-tree metadata statistics functions.
+ *
+ */
+
+/****************/
+/* Module Setup */
+/****************/
+
+#define H5B2_PACKAGE		/*suppress error about including H5B2pkg  */
+
+/***********/
+/* Headers */
+/***********/
+#include "H5private.h"		/* Generic Functions			*/
+#include "H5B2pkg.h"		/* v2 B-trees				*/
+#include "H5Eprivate.h"		/* Error handling		  	*/
+
+/****************/
+/* Local Macros */
+/****************/
+
+
+/******************/
+/* Local Typedefs */
+/******************/
+
+
+/********************/
+/* Local Prototypes */
+/********************/
+
+
+/*********************/
+/* Package Variables */
+/*********************/
+
+
+/*****************************/
+/* Library Private Variables */
+/*****************************/
+
+
+/*******************/
+/* Local Variables */
+/*******************/
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5B2_stat_info
+ *
+ * Purpose:	Retrieve metadata statistics for the fractal heap
+ *
+ * Return:	Success:	non-negative
+ *
+ *		Failure:	negative
+ *
+ * Programmer:	Quincey Koziol
+ *              Monday, March  6, 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5B2_stat_info(H5F_t *f, hid_t dxpl_id, const H5B2_class_t *type,
+    haddr_t addr, H5B2_stat_t *info)
+{
+    H5B2_t	*bt2 = NULL;            /* Pointer to the B-tree header */
+    herr_t	ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5B2_get_root_addr_test)
+
+    /* Check arguments. */
+    HDassert(f);
+    HDassert(type);
+    HDassert(H5F_addr_defined(addr));
+    HDassert(info);
+
+    /* Look up the B-tree header */
+    if(NULL == (bt2 = H5AC_protect(f, dxpl_id, H5AC_BT2_HDR, addr, type, NULL, H5AC_READ)))
+	HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to load B-tree header")
+
+/* XXX: Fill in metadata statistics for the heap */
+
+done:
+    /* Release B-tree header node */
+    if(bt2 && H5AC_unprotect(f, dxpl_id, H5AC_BT2_HDR, addr, bt2, H5AC__NO_FLAGS_SET) < 0)
+        HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree header info")
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5B2_stat_info() */
+
diff --git a/src/H5Cpkg.h b/src/H5Cpkg.h
index 155c7f5..9a3cdcd 100644
--- a/src/H5Cpkg.h
+++ b/src/H5Cpkg.h
@@ -609,7 +609,7 @@
  ****************************************************************************/
 
 #define H5C__H5C_T_MAGIC	0x005CAC0E
-#define H5C__MAX_NUM_TYPE_IDS	11
+#define H5C__MAX_NUM_TYPE_IDS	12
 #define H5C__PREFIX_LEN		32
 
 struct H5C_t
diff --git a/src/H5HF.c b/src/H5HF.c
index 2577628..f183748 100644
--- a/src/H5HF.c
+++ b/src/H5HF.c
@@ -38,8 +38,8 @@
 /* Headers */
 /***********/
 #include "H5private.h"		/* Generic Functions			*/
-#include "H5HFpkg.h"		/* Fractal heaps			*/
 #include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5HFpkg.h"		/* Fractal heaps			*/
 #include "H5MFprivate.h"	/* File memory management		*/
 
 /****************/
@@ -160,7 +160,9 @@ H5HF_insert(H5F_t *f, hid_t dxpl_id, haddr_t addr, size_t size,
     herr_t ret_value = SUCCEED;
 
     FUNC_ENTER_NOAPI(H5HF_insert, FAIL)
+#ifdef QAK
 HDfprintf(stderr, "%s: size = %Zu\n", FUNC, size);
+#endif /* QAK */
 
     /*
      * Check arguments.
@@ -190,16 +192,23 @@ HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, FAIL, "standalone blocks not supported ye
         if(shared->write_once) {
 HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, FAIL, "'write once' managed blocks not supported yet")
         } /* end if */
-        else if(size <= shared->total_man_free) {
-HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, FAIL, "allocating internal managed blocks not supported yet")
-        } /* end if */
         else {
-            /* Allocate space at end of heap */
-            if(H5HF_man_alloc_end(fh->shared, dxpl_id, &hdr_flags, size, obj, id) < 0)
-                HGOTO_ERROR(H5E_HEAP, H5E_CANTALLOC, FAIL, "can't allocate space at end of managed blocks")
+            H5HF_section_free_node_t *sec_node;
+
+            /* Find free space in heap */
+            if(H5HF_man_find(fh->shared, dxpl_id, size, &sec_node) < 0)
+                HGOTO_ERROR(H5E_HEAP, H5E_CANTALLOC, FAIL, "can't allocate space in fractal heap")
+
+            /* Use free space for allocating object */
+            if(H5HF_man_insert(fh->shared, dxpl_id, sec_node, size, obj, id) < 0)
+                HGOTO_ERROR(H5E_HEAP, H5E_CANTALLOC, FAIL, "can't allocate space for object in fractal heap")
         } /* end else */
     } /* end else */
 
+    /* Check for making header dirty */
+    if(shared->dirty)
+        hdr_flags |= H5AC__DIRTIED_FLAG;
+
 done:
     if(fh && H5AC_unprotect(f, dxpl_id, H5AC_FHEAP_HDR, addr, fh, hdr_flags) < 0)
         HDONE_ERROR(H5E_HEAP, H5E_PROTECT, FAIL, "unable to release fractal heap header")
diff --git a/src/H5HFcache.c b/src/H5HFcache.c
index 735037b..348f9eb 100644
--- a/src/H5HFcache.c
+++ b/src/H5HFcache.c
@@ -33,8 +33,8 @@
 /* Headers */
 /***********/
 #include "H5private.h"		/* Generic Functions			*/
-#include "H5HFpkg.h"		/* Fractal heaps			*/
 #include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5HFpkg.h"		/* Fractal heaps			*/
 #include "H5Vprivate.h"		/* Vectors and arrays 			*/
 
 /****************/
@@ -44,9 +44,7 @@
 /* Fractal heap format version #'s */
 #define H5HF_HDR_VERSION        0               /* Header */
 #define H5HF_DBLOCK_VERSION     0               /* Direct block */
-
-/* Size of free space description in an absolute managed direct block */
-#define H5HF_MAN_ABS_FREE_NODE_SIZE(d) (2 * (d)->blk_off_size)
+#define H5HF_IBLOCK_VERSION     0               /* Indirect block */
 
 
 /******************/
@@ -58,18 +56,22 @@
 /********************/
 
 /* Metadata cache callbacks */
-static H5HF_t *H5HF_cache_hdr_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_type, void *udata);
+static H5HF_t *H5HF_cache_hdr_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *udata, void *udata2);
 static herr_t H5HF_cache_hdr_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5HF_t *fh);
 static herr_t H5HF_cache_hdr_clear(H5F_t *f, H5HF_t *fh, hbool_t destroy);
 static herr_t H5HF_cache_hdr_size(const H5F_t *f, const H5HF_t *fh, size_t *size_ptr);
-static H5HF_direct_t *H5HF_cache_dblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_type, void *udata);
+static H5HF_direct_t *H5HF_cache_dblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *udata, void *udata2);
 static herr_t H5HF_cache_dblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5HF_direct_t *dblock);
 static herr_t H5HF_cache_dblock_clear(H5F_t *f, H5HF_direct_t *dblock, hbool_t destroy);
 static herr_t H5HF_cache_dblock_size(const H5F_t *f, const H5HF_direct_t *dblock, size_t *size_ptr);
+static H5HF_indirect_t *H5HF_cache_iblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *udata, void *udata2);
+static herr_t H5HF_cache_iblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5HF_indirect_t *iblock);
+static herr_t H5HF_cache_iblock_clear(H5F_t *f, H5HF_indirect_t *iblock, hbool_t destroy);
+static herr_t H5HF_cache_iblock_size(const H5F_t *f, const H5HF_indirect_t *iblock, size_t *size_ptr);
 
 /* Local encode/decode routines */
-static herr_t H5HF_dtable_encode(H5F_t *f, uint8_t **pp, const H5HF_dtable_param_t *dt_param);
-static herr_t H5HF_dtable_decode(H5F_t *f, const uint8_t **pp, H5HF_dtable_param_t *dt_param);
+static herr_t H5HF_dtable_encode(H5F_t *f, uint8_t **pp, const H5HF_dtable_t *dtable);
+static herr_t H5HF_dtable_decode(H5F_t *f, const uint8_t **pp, H5HF_dtable_t *dtable);
 
 /*********************/
 /* Package Variables */
@@ -95,6 +97,17 @@ const H5AC_class_t H5AC_FHEAP_DBLOCK[1] = {{
     (H5AC_size_func_t)H5HF_cache_dblock_size,
 }};
 
+/* H5HF indirect block inherits cache-like properties from H5AC */
+const H5AC_class_t H5AC_FHEAP_IBLOCK[1] = {{
+    H5AC_FHEAP_IBLOCK_ID,
+    (H5AC_load_func_t)H5HF_cache_iblock_load,
+    (H5AC_flush_func_t)H5HF_cache_iblock_flush,
+    (H5AC_dest_func_t)H5HF_cache_iblock_dest,
+    (H5AC_clear_func_t)H5HF_cache_iblock_clear,
+    (H5AC_size_func_t)H5HF_cache_iblock_size,
+}};
+
+
 /*****************************/
 /* Library Private Variables */
 /*****************************/
@@ -110,6 +123,9 @@ H5FL_BLK_DEFINE_STATIC(header_block);
 /* Declare a free list to manage heap direct block data to/from disk */
 H5FL_BLK_DEFINE(direct_block);
 
+/* Declare a free list to manage heap indirect block data to/from disk */
+H5FL_BLK_DEFINE_STATIC(indirect_block);
+
 
 
 /*-------------------------------------------------------------------------
@@ -128,35 +144,44 @@ H5FL_BLK_DEFINE(direct_block);
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5HF_dtable_decode(H5F_t *f, const uint8_t **pp, H5HF_dtable_param_t *dt_param)
+H5HF_dtable_decode(H5F_t *f, const uint8_t **pp, H5HF_dtable_t *dtable)
 {
     FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_dtable_decode)
 
     /* Check arguments */
     HDassert(f);
     HDassert(pp && *pp);
-    HDassert(dt_param);
+    HDassert(dtable);
 
     /* Table width */
-    UINT16DECODE(*pp, dt_param->cparam.width);
+    UINT16DECODE(*pp, dtable->cparam.width);
 
     /* Starting block size */
-    H5F_DECODE_LENGTH(f, *pp, dt_param->cparam.start_block_size);
+    H5F_DECODE_LENGTH(f, *pp, dtable->cparam.start_block_size);
 
     /* Maximum direct block size */
-    H5F_DECODE_LENGTH(f, *pp, dt_param->cparam.max_direct_size);
+    H5F_DECODE_LENGTH(f, *pp, dtable->cparam.max_direct_size);
 
     /* Maximum heap size (as # of bits) */
-    UINT16DECODE(*pp, dt_param->cparam.max_index);
+    UINT16DECODE(*pp, dtable->cparam.max_index);
 
     /* Starting # of rows in root indirect block */
-    UINT16DECODE(*pp, dt_param->cparam.start_root_rows);
+    UINT16DECODE(*pp, dtable->cparam.start_root_rows);
 
     /* Address of table */
-    H5F_addr_decode(f, pp, &(dt_param->table_addr));
+    H5F_addr_decode(f, pp, &(dtable->table_addr));
 
     /* Current # of rows in root indirect block */
-    UINT16DECODE(*pp, dt_param->curr_root_rows);
+    UINT16DECODE(*pp, dtable->curr_root_rows);
+
+    /* Next direct block's heap offset */
+    H5F_DECODE_LENGTH(f, *pp, dtable->next_dir_block);
+
+    /* Next direct block size */
+    H5F_DECODE_LENGTH(f, *pp, dtable->next_dir_size);
+
+    /* Next direct block column */
+    UINT16DECODE(*pp, dtable->next_dir_col);
 
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* end H5HF_dtable_decode() */
@@ -178,35 +203,44 @@ H5HF_dtable_decode(H5F_t *f, const uint8_t **pp, H5HF_dtable_param_t *dt_param)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5HF_dtable_encode(H5F_t *f, uint8_t **pp, const H5HF_dtable_param_t *dt_param)
+H5HF_dtable_encode(H5F_t *f, uint8_t **pp, const H5HF_dtable_t *dtable)
 {
     FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_dtable_encode)
 
     /* Check arguments */
     HDassert(f);
     HDassert(pp && *pp);
-    HDassert(dt_param);
+    HDassert(dtable);
 
     /* Table width */
-    UINT16ENCODE(*pp, dt_param->cparam.width);
+    UINT16ENCODE(*pp, dtable->cparam.width);
 
     /* Starting block size */
-    H5F_ENCODE_LENGTH(f, *pp, dt_param->cparam.start_block_size);
+    H5F_ENCODE_LENGTH(f, *pp, dtable->cparam.start_block_size);
 
     /* Maximum direct block size */
-    H5F_ENCODE_LENGTH(f, *pp, dt_param->cparam.max_direct_size);
+    H5F_ENCODE_LENGTH(f, *pp, dtable->cparam.max_direct_size);
 
     /* Maximum heap size (as # of bits) */
-    UINT16ENCODE(*pp, dt_param->cparam.max_index);
+    UINT16ENCODE(*pp, dtable->cparam.max_index);
 
     /* Starting # of rows in root indirect block */
-    UINT16ENCODE(*pp, dt_param->cparam.start_root_rows);
+    UINT16ENCODE(*pp, dtable->cparam.start_root_rows);
 
     /* Address of table */
-    H5F_addr_encode(f, pp, dt_param->table_addr);
+    H5F_addr_encode(f, pp, dtable->table_addr);
 
     /* Current # of rows in root indirect block */
-    UINT16ENCODE(*pp, dt_param->curr_root_rows);
+    UINT16ENCODE(*pp, dtable->curr_root_rows);
+
+    /* Next direct block's heap offset */
+    H5F_ENCODE_LENGTH(f, *pp, dtable->next_dir_block);
+
+    /* Next direct block size */
+    H5F_ENCODE_LENGTH(f, *pp, dtable->next_dir_size);
+
+    /* Next direct block column */
+    UINT16ENCODE(*pp, dtable->next_dir_col);
 
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* end H5HF_dtable_encode() */
@@ -296,14 +330,21 @@ H5HF_cache_hdr_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void UNUSED *ud
     /* Min. size of standalone objects */
     UINT32DECODE(p, shared->standalone_size);
 
-    /* Length of fixed-length objects in heap */
-    UINT32DECODE(p, shared->fixed_len_size);
-
     /* Size of ref. count for objects in heap */
     shared->ref_count_size = *p++;
 
+    /* Internal management information */
+    H5F_DECODE_LENGTH(f, p, shared->total_man_free);
+    H5F_DECODE_LENGTH(f, p, shared->total_std_free);
+
+    /* Statistics information */
+    H5F_DECODE_LENGTH(f, p, shared->total_size);
+    H5F_DECODE_LENGTH(f, p, shared->man_size);
+    H5F_DECODE_LENGTH(f, p, shared->std_size);
+    H5F_DECODE_LENGTH(f, p, shared->nobjs);
+
     /* Managed objects' doubling-table info */
-    if(H5HF_dtable_decode(shared->f, &p, &(shared->man_dtable_info)) < 0)
+    if(H5HF_dtable_decode(shared->f, &p, &(shared->man_dtable)) < 0)
         HGOTO_ERROR(H5E_HEAP, H5E_CANTENCODE, NULL, "unable to encode managed obj. doubling table info")
 
     HDassert((size_t)(p - buf) == size);
@@ -360,6 +401,9 @@ H5HF_cache_hdr_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5H
         uint8_t *p;                 /* Pointer into raw data buffer */
         size_t	size;               /* Header size on disk */
 
+        /* Sanity check */
+        HDassert(shared->dirty);
+
         /* Compute the size of the heap header on disk */
         size = H5HF_HEADER_SIZE(f);
 
@@ -391,14 +435,21 @@ H5HF_cache_hdr_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5H
         /* Min. size of standalone objects */
         UINT32ENCODE(p, shared->standalone_size);
 
-        /* Size of fixed-length objects in heap */
-        UINT32ENCODE(p, shared->fixed_len_size);
-
         /* Size of ref. count for objects in heap */
         *p++ = shared->ref_count_size;
 
+        /* Internal management information */
+        H5F_ENCODE_LENGTH(f, p, shared->total_man_free);
+        H5F_ENCODE_LENGTH(f, p, shared->total_std_free);
+
+        /* Statistics information */
+        H5F_ENCODE_LENGTH(f, p, shared->total_size);
+        H5F_ENCODE_LENGTH(f, p, shared->man_size);
+        H5F_ENCODE_LENGTH(f, p, shared->std_size);
+        H5F_ENCODE_LENGTH(f, p, shared->nobjs);
+
         /* Managed objects' doubling-table info */
-        if(H5HF_dtable_encode(shared->f, &p, &(shared->man_dtable_info)) < 0)
+        if(H5HF_dtable_encode(shared->f, &p, &(shared->man_dtable)) < 0)
 	    HGOTO_ERROR(H5E_HEAP, H5E_CANTENCODE, FAIL, "unable to encode managed obj. doubling table info")
 
 	/* Write the heap header. */
@@ -408,6 +459,7 @@ H5HF_cache_hdr_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5H
 
         H5FL_BLK_FREE(header_block, buf);
 
+	shared->dirty = FALSE;
 	fh->cache_info.is_dirty = FALSE;
     } /* end if */
 
@@ -545,7 +597,6 @@ H5HF_cache_dblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_size,
     H5RC_t 		*fh_shared = (H5RC_t *)_fh_shared;     /* Shared heap information */
     H5HF_shared_t       *shared = NULL; /* Shared fractal heap information */
     H5HF_direct_t	*dblock = NULL; /* Direct block info */
-    uint8_t		*buf = NULL;    /* Temporary buffer */
     const uint8_t	*p;             /* Pointer into raw data buffer */
     haddr_t             heap_addr;      /* Address of heap header in the file */
     uint32_t            metadata_chksum;        /* Metadata checksum value */
@@ -578,14 +629,14 @@ H5HF_cache_dblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_size,
 
     /* Allocate block buffer */
 /* XXX: Change to using free-list factories */
-    if((buf = H5FL_BLK_MALLOC(direct_block, (size_t)dblock->size)) == NULL)
+    if((dblock->blk = H5FL_BLK_MALLOC(direct_block, (size_t)dblock->size)) == NULL)
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
 
-    /* Read header from disk */
-    if(H5F_block_read(f, H5FD_MEM_FHEAP_HDR, addr, (size_t)dblock->size, dxpl_id, buf) < 0)
+    /* Read direct block from disk */
+    if(H5F_block_read(f, H5FD_MEM_FHEAP_DBLOCK, addr, (size_t)dblock->size, dxpl_id, dblock->blk) < 0)
 	HGOTO_ERROR(H5E_HEAP, H5E_READERROR, NULL, "can't read fractal heap direct block")
 
-    p = buf;
+    p = dblock->blk;
 
     /* Magic number */
     if(HDmemcmp(p, H5HF_DBLOCK_MAGIC, H5HF_SIZEOF_MAGIC))
@@ -622,9 +673,6 @@ H5HF_cache_dblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_size,
     /* (Defer deserializing the whole free list until we actually need to modify it) */
     UINT64DECODE_VAR(p, dblock->free_list_head, dblock->blk_off_size);
 
-    /* Keep pointer to block buffer */
-    dblock->blk = buf;
-
     /* Set return value */
     ret_value = dblock;
 
@@ -714,7 +762,7 @@ H5HF_cache_dblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr,
             node = dblock->free_list->first;
             while(node) {
                 /* Find first node which has enough room to describe free space */
-                while(node && node->size < H5HF_MAN_ABS_FREE_NODE_SIZE(dblock))
+                while(node && node->size < H5HF_MAN_ABS_DIRECT_FREE_NODE_SIZE(dblock))
                     node = node->next;
 
                 /* Check for free space node to encode */
@@ -723,7 +771,7 @@ H5HF_cache_dblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr,
 
                     /* Probe ahead for next node that is large enough to encode free space description */
                     next_node = node->next;
-                    while(next_node && next_node->size < H5HF_MAN_ABS_FREE_NODE_SIZE(dblock))
+                    while(next_node && next_node->size < H5HF_MAN_ABS_DIRECT_FREE_NODE_SIZE(dblock))
                         next_node = next_node->next;
 
                     /* Encode information for this node on free list */
@@ -741,8 +789,8 @@ H5HF_cache_dblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr,
             dblock->free_list->dirty = FALSE;
         } /* end if */
 
-	/* Write the heap header. */
-	if(H5F_block_write(f, H5FD_MEM_FHEAP_HDR, addr, (size_t)dblock->size, dxpl_id, dblock->blk) < 0)
+	/* Write the direct block */
+	if(H5F_block_write(f, H5FD_MEM_FHEAP_DBLOCK, addr, (size_t)dblock->size, dxpl_id, dblock->blk) < 0)
 	    HGOTO_ERROR(H5E_HEAP, H5E_CANTFLUSH, FAIL, "unable to save fractal heap direct block to disk")
 
 	dblock->cache_info.is_dirty = FALSE;
@@ -857,7 +905,7 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5HF_cache_block_size
+ * Function:	H5HF_cache_dblock_size
  *
  * Purpose:	Compute the size in bytes of a fractal heap direct block
  *		on disk, and return it in *size_ptr.  On failure,
@@ -886,3 +934,361 @@ H5HF_cache_dblock_size(const H5F_t UNUSED *f, const H5HF_direct_t *dblock, size_
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* H5HF_cache_dblock_size() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_cache_iblock_load
+ *
+ * Purpose:	Loads a fractal heap indirect block from the disk.
+ *
+ * Return:	Success:	Pointer to a new fractal heap indirect block
+ *
+ *		Failure:	NULL
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@ncsa.uiuc.edu
+ *		Feb 27 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+static H5HF_indirect_t *
+H5HF_cache_iblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_nrows, void *_fh_shared)
+{
+    const unsigned      *nrows = (const unsigned *)_nrows;     /* # of rows in indirect block */
+    H5RC_t 		*fh_shared = (H5RC_t *)_fh_shared;     /* Shared heap information */
+    H5HF_shared_t       *shared = NULL; /* Shared fractal heap information */
+    H5HF_indirect_t	*iblock = NULL; /* Indirect block info */
+    uint8_t		*buf = NULL;    /* Temporary buffer */
+    const uint8_t	*p;             /* Pointer into raw data buffer */
+    haddr_t             heap_addr;      /* Address of heap header in the file */
+    uint32_t            metadata_chksum;        /* Metadata checksum value */
+    size_t              u;              /* Local index variable */
+    H5HF_indirect_t	*ret_value;     /* Return value */
+
+    FUNC_ENTER_NOAPI(H5HF_cache_iblock_load, NULL)
+
+    /* Check arguments */
+    HDassert(f);
+    HDassert(H5F_addr_defined(addr));
+    HDassert(fh_shared);
+
+    /* Allocate space for the fractal heap indirect block */
+    if(NULL == (iblock = H5FL_MALLOC(H5HF_indirect_t)))
+	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
+    HDmemset(&iblock->cache_info, 0, sizeof(H5AC_info_t));
+
+    /* Share common heap information */
+    iblock->shared = fh_shared;
+    H5RC_INC(iblock->shared);
+
+    /* Get the pointer to the shared heap info */
+    shared = H5RC_GET_OBJ(iblock->shared);
+    HDassert(shared);
+
+    /* Set block's internal information */
+    iblock->nrows = *nrows;
+    if(iblock->nrows > shared->man_dtable.max_direct_rows) {
+        iblock->ndir_rows = shared->man_dtable.max_direct_rows;
+        iblock->nindir_rows = iblock->nrows - iblock->ndir_rows;
+    } /* end if */
+    else {
+        iblock->ndir_rows = iblock->nrows;
+        iblock->nindir_rows = 0;
+    } /* end else */
+
+    /* Compute size of indirect block */
+    iblock->size = H5HF_MAN_INDIRECT_SIZE(shared, iblock);
+
+    /* Allocate buffer to decode block */
+/* XXX: Use free list factories? */
+    if((buf = H5FL_BLK_MALLOC(indirect_block, iblock->size)) == NULL)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
+
+    /* Read indirect block from disk */
+    if(H5F_block_read(f, H5FD_MEM_FHEAP_IBLOCK, addr, iblock->size, dxpl_id, buf) < 0)
+	HGOTO_ERROR(H5E_HEAP, H5E_READERROR, NULL, "can't read fractal heap indirect block")
+
+    p = buf;
+
+    /* Magic number */
+    if(HDmemcmp(p, H5HF_IBLOCK_MAGIC, H5HF_SIZEOF_MAGIC))
+	HGOTO_ERROR(H5E_HEAP, H5E_CANTLOAD, NULL, "wrong fractal heap indirect block signature")
+    p += H5HF_SIZEOF_MAGIC;
+
+    /* Version */
+    if(*p++ != H5HF_IBLOCK_VERSION)
+	HGOTO_ERROR(H5E_HEAP, H5E_CANTLOAD, NULL, "wrong fractal heap direct block version")
+
+    /* Metadata flags (unused, currently) */
+/* XXX: Plan out metadata flags (including "read-only duplicate" feature) */
+    if(*p++ != 0)
+	HGOTO_ERROR(H5E_HEAP, H5E_CANTLOAD, NULL, "unknown metadata flag in fractal heap direct block")
+
+    /* Metadata checksum (unused, currently) */
+    UINT32DECODE(p, metadata_chksum);
+/* XXX: Verify checksum */
+    if(metadata_chksum != 0)
+	HGOTO_ERROR(H5E_HEAP, H5E_CANTLOAD, NULL, "incorrect metadata checksum for fractal heap direct block")
+
+    /* Address of heap that owns this block (skip) */
+    H5F_addr_decode(f, &p, &heap_addr);
+    if(H5F_addr_ne(heap_addr, shared->heap_addr))
+	HGOTO_ERROR(H5E_HEAP, H5E_CANTLOAD, NULL, "incorrect heap header address for direct block")
+    
+    /* Offset of heap within the heap's address space */
+    UINT64DECODE_VAR(p, iblock->block_off, shared->heap_off_size);
+
+    /* Allocate & decode indirect block entry tables */
+    HDassert(iblock->ndir_rows > 0);
+    if(NULL == (iblock->dblock_ents = H5FL_SEQ_MALLOC(H5HF_indirect_dblock_ent_t, (iblock->ndir_rows * shared->man_dtable.cparam.width))))
+	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for direct entries")
+    for(u = 0; u < (iblock->ndir_rows * shared->man_dtable.cparam.width); u++) {
+        H5F_addr_decode(f, &p, &(iblock->dblock_ents[u].addr));
+        UINT32DECODE_VAR(p, iblock->dblock_ents[u].free_space, shared->man_dtable.max_dir_blk_off_size);
+    } /* end for */
+    if(iblock->nindir_rows > 0) {
+        if(NULL == (iblock->iblock_ents = H5FL_SEQ_MALLOC(H5HF_indirect_iblock_ent_t, (iblock->nindir_rows * shared->man_dtable.cparam.width))))
+            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for indirect entries")
+
+        /* Decode indirect block-specific fields */
+        for(u = 0; u < (iblock->nindir_rows * shared->man_dtable.cparam.width); u++)
+            H5F_addr_decode(f, &p, &(iblock->iblock_ents[u].addr));
+    } /* end if */
+    else
+        iblock->iblock_ents = NULL;
+
+    /* Sanity check */
+    HDassert((size_t)(p - buf) == iblock->size);
+
+    /* Set return value */
+    ret_value = iblock;
+
+done:
+    /* Free buffer */
+/* XXX: Keep buffer around? */
+    H5FL_BLK_FREE(indirect_block, buf);
+
+    if(!ret_value && iblock)
+        (void)H5HF_cache_iblock_dest(f, iblock);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5HF_cache_iblock_load() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_cache_iblock_flush
+ *
+ * Purpose:	Flushes a dirty fractal heap indirect block to disk.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@ncsa.uiuc.edu
+ *		Mar  6 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5HF_cache_iblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5HF_indirect_t *iblock)
+{
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_NOAPI(H5HF_cache_iblock_flush, FAIL)
+
+    /* check arguments */
+    HDassert(f);
+    HDassert(H5F_addr_defined(addr));
+    HDassert(iblock);
+
+    if(iblock->cache_info.is_dirty) {
+        H5HF_shared_t *shared;      /* Shared fractal heap information */
+        uint8_t	*buf = NULL;        /* Temporary buffer */
+        uint8_t *p;                 /* Pointer into raw data buffer */
+        size_t u;                   /* Local index variable */
+
+        /* Get the pointer to the shared heap info */
+        shared = H5RC_GET_OBJ(iblock->shared);
+        HDassert(shared);
+
+        /* Allocate buffer to encode block */
+/* XXX: Use free list factories? */
+#ifdef QAK
+HDfprintf(stderr, "%s: iblock->nrows = %u\n", FUNC, iblock->nrows);
+HDfprintf(stderr, "%s: iblock->ndir_rows = %u\n", FUNC, iblock->ndir_rows);
+HDfprintf(stderr, "%s: iblock->nindir_rows = %u\n", FUNC, iblock->nindir_rows);
+HDfprintf(stderr, "%s: iblock->size = %Zu\n", FUNC, iblock->size);
+HDfprintf(stderr, "%s: iblock->block_off = %Hu\n", FUNC, iblock->block_off);
+HDfprintf(stderr, "%s: shared->man_dtable.cparam.width = %u\n", FUNC, shared->man_dtable.cparam.width);
+#endif /* QAK */
+        if((buf = H5FL_BLK_MALLOC(indirect_block, iblock->size)) == NULL)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
+
+        p = buf;
+
+        /* Magic number */
+        HDmemcpy(p, H5HF_IBLOCK_MAGIC, H5HF_SIZEOF_MAGIC);
+        p += H5HF_SIZEOF_MAGIC;
+
+        /* Version # */
+        *p++ = H5HF_IBLOCK_VERSION;
+
+        /* Metadata status flags */
+/* XXX: Set this? */
+        *p++ = 0;
+
+        /* Metadata checksum */
+/* XXX: Set this!  (After all the metadata is in the buffer) */
+        HDmemset(p, 0, 4);
+        p += 4;
+
+        /* Address of heap header for heap which owns this block */
+        H5F_addr_encode(f, &p, shared->heap_addr);
+
+        /* Offset of block in heap */
+        UINT64ENCODE_VAR(p, iblock->block_off, shared->heap_off_size);
+
+        /* Encode indirect block-specific fields */
+        HDassert(iblock->ndir_rows > 0);
+        for(u = 0; u < (iblock->ndir_rows * shared->man_dtable.cparam.width); u++) {
+            H5F_addr_encode(f, &p, iblock->dblock_ents[u].addr);
+            UINT32ENCODE_VAR(p, iblock->dblock_ents[u].free_space, shared->man_dtable.max_dir_blk_off_size);
+        } /* end for */
+        if(iblock->nindir_rows > 0)
+            for(u = 0; u < (iblock->nindir_rows * shared->man_dtable.cparam.width); u++)
+                H5F_addr_encode(f, &p, iblock->iblock_ents[u].addr);
+
+        /* Sanity check */
+        HDassert((size_t)(p - buf) == iblock->size);
+
+	/* Write the indirect block */
+	if(H5F_block_write(f, H5FD_MEM_FHEAP_IBLOCK, addr, iblock->size, dxpl_id, buf) < 0)
+	    HGOTO_ERROR(H5E_HEAP, H5E_CANTFLUSH, FAIL, "unable to save fractal heap indirect block to disk")
+
+        /* Free buffer */
+        H5FL_BLK_FREE(indirect_block, buf);
+
+	iblock->cache_info.is_dirty = FALSE;
+    } /* end if */
+
+    if(destroy)
+        if(H5HF_cache_iblock_dest(f, iblock) < 0)
+	    HGOTO_ERROR(H5E_HEAP, H5E_CANTFREE, FAIL, "unable to destroy fractal heap indirect block")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5HF_cache_iblock_flush() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_cache_iblock_dest
+ *
+ * Purpose:	Destroys a fractal heap indirect block in memory.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@ncsa.uiuc.edu
+ *		Mar  6 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+/* ARGSUSED */
+herr_t
+H5HF_cache_iblock_dest(H5F_t UNUSED *f, H5HF_indirect_t *iblock)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_cache_iblock_dest)
+
+    /*
+     * Check arguments.
+     */
+    HDassert(iblock);
+
+    /* Decrement reference count on shared fractal heap info */
+    if(iblock->shared)
+        H5RC_DEC(iblock->shared);
+
+    /* Release entry tables */
+    if(iblock->dblock_ents)
+        H5FL_SEQ_FREE(H5HF_indirect_dblock_ent_t, iblock->dblock_ents);
+    if(iblock->iblock_ents)
+        H5FL_SEQ_FREE(H5HF_indirect_iblock_ent_t, iblock->iblock_ents);
+
+    /* Free fractal heap indirect block info */
+    H5FL_FREE(H5HF_indirect_t, iblock);
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5HF_cache_iblock_dest() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_cache_iblock_clear
+ *
+ * Purpose:	Mark a fractal heap indirect block in memory as non-dirty.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@ncsa.uiuc.edu
+ *		Mar  6 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5HF_cache_iblock_clear(H5F_t *f, H5HF_indirect_t *iblock, hbool_t destroy)
+{
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5HF_cache_iblock_clear)
+
+    /*
+     * Check arguments.
+     */
+    HDassert(iblock);
+
+    /* Reset the dirty flag.  */
+    iblock->cache_info.is_dirty = FALSE;
+
+    if(destroy)
+        if(H5HF_cache_iblock_dest(f, iblock) < 0)
+	    HGOTO_ERROR(H5E_HEAP, H5E_CANTFREE, FAIL, "unable to destroy fractal heap indirect block")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5HF_cache_iblock_clear() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_cache_iblock_size
+ *
+ * Purpose:	Compute the size in bytes of a fractal heap indirect block
+ *		on disk, and return it in *size_ptr.  On failure,
+ *		the value of *size_ptr is undefined.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@ncsa.uiuc.edu
+ *		Mar  6 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5HF_cache_iblock_size(const H5F_t UNUSED *f, const H5HF_indirect_t *iblock, size_t *size_ptr)
+{
+    H5HF_shared_t *shared;      /* Shared fractal heap information */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_cache_iblock_size)
+
+    /* check arguments */
+    HDassert(iblock);
+    HDassert(size_ptr);
+
+    /* Get the pointer to the shared heap info */
+    shared = H5RC_GET_OBJ(iblock->shared);
+    HDassert(shared);
+
+    /* Set size value */
+    *size_ptr = iblock->size;
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* H5HF_cache_iblock_size() */
+
diff --git a/src/H5HFdbg.c b/src/H5HFdbg.c
index 2024402..977f40f 100644
--- a/src/H5HFdbg.c
+++ b/src/H5HFdbg.c
@@ -52,7 +52,7 @@
 /* Local Prototypes */
 /********************/
 
-static herr_t H5HF_dtable_debug(H5HF_dtable_param_t *dt_param, FILE *stream,
+static herr_t H5HF_dtable_debug(H5HF_dtable_t *dtable, FILE *stream,
     int indent, int fwidth);
 
 
@@ -85,14 +85,14 @@ static herr_t H5HF_dtable_debug(H5HF_dtable_param_t *dt_param, FILE *stream,
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5HF_dtable_debug(H5HF_dtable_param_t *dt_param, FILE *stream, int indent, int fwidth)
+H5HF_dtable_debug(H5HF_dtable_t *dtable, FILE *stream, int indent, int fwidth)
 {
     FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_dtable_debug)
 
     /*
      * Check arguments.
      */
-    HDassert(dt_param);
+    HDassert(dtable);
     HDassert(stream);
     HDassert(indent >= 0);
     HDassert(fwidth >= 0);
@@ -100,27 +100,50 @@ H5HF_dtable_debug(H5HF_dtable_param_t *dt_param, FILE *stream, int indent, int f
     /*
      * Print the values.
      */
+    /* Creation parameter values */
     HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
 	      "Doubling table width:",
-	      dt_param->cparam.width);
+	      dtable->cparam.width);
     HDfprintf(stream, "%*s%-*s %Zu\n", indent, "", fwidth,
 	      "Starting block size:",
-	      dt_param->cparam.start_block_size);
+	      dtable->cparam.start_block_size);
     HDfprintf(stream, "%*s%-*s %Zu\n", indent, "", fwidth,
 	      "Max. direct block size:",
-	      dt_param->cparam.max_direct_size);
+	      dtable->cparam.max_direct_size);
     HDfprintf(stream, "%*s%-*s %u (bits)\n", indent, "", fwidth,
 	      "Max. index size:",
-	      dt_param->cparam.max_index);
+	      dtable->cparam.max_index);
     HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
 	      "Starting # of rows in root indirect block:",
-	      dt_param->cparam.start_root_rows);
+	      dtable->cparam.start_root_rows);
+
+    /* Run-time varying parameter values */
     HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
 	      "Table's root address:",
-	      dt_param->table_addr);
+	      dtable->table_addr);
     HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
 	      "Current # of rows in root indirect block:",
-	      dt_param->curr_root_rows);
+	      dtable->curr_root_rows);
+    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
+	      "Next direct block size:",
+	      dtable->next_dir_size);
+    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
+	      "Next direct block column:",
+	      dtable->next_dir_col);
+
+    /* Computed values */
+    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
+	      "Max. # of rows in root indirect block:",
+	      dtable->max_root_indirect_rows);
+    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
+	      "Max. # of direct rows in any indirect block:",
+	      dtable->max_direct_rows);
+    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
+	      "# of bits for IDs in first row:",
+	      dtable->first_row_bits);
+    HDfprintf(stream, "%*s%-*s %Hu\n", indent, "", fwidth,
+	      "# of IDs in first row:",
+	      dtable->num_id_first_row);
 
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* end H5HF_dtable_debug() */
@@ -181,15 +204,31 @@ H5HF_hdr_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream, int indent,
     HDfprintf(stream, "%*s%-*s %lu\n", indent, "", fwidth,
 	      "Min. size of standalone object:",
 	      (unsigned long)shared->standalone_size);
-    HDfprintf(stream, "%*s%-*s %lu\n", indent, "", fwidth,
-	      "Fixed length object size:",
-	      (unsigned long)shared->fixed_len_size);
-    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
-	      "Ref. count size:",
-	      (unsigned)shared->ref_count_size);
+    HDfprintf(stream, "%*s%-*s %u%s\n", indent, "", fwidth,
+              "Ref. count size:",
+              (unsigned)shared->ref_count_size,
+              (shared->ref_count_size == 0 ? " (ref. count not stored)" : ""));
+    HDfprintf(stream, "%*s%-*s %Hu\n", indent, "", fwidth,
+	      "Total free space in managed blocks:",
+	      shared->total_man_free);
+    HDfprintf(stream, "%*s%-*s %Hu\n", indent, "", fwidth,
+	      "Total # of free entries for standalone blocks:",
+	      shared->total_std_free);
+    HDfprintf(stream, "%*s%-*s %Hu\n", indent, "", fwidth,
+	      "Total data block size:",
+	      shared->total_size);
+    HDfprintf(stream, "%*s%-*s %Hu\n", indent, "", fwidth,
+	      "Total managed space data block size:",
+	      shared->man_size);
+    HDfprintf(stream, "%*s%-*s %Hu\n", indent, "", fwidth,
+	      "Total standalone space data block size:",
+	      shared->std_size);
+    HDfprintf(stream, "%*s%-*s %Hu\n", indent, "", fwidth,
+	      "Number of objects in heap:",
+	      shared->nobjs);
 
     HDfprintf(stream, "%*sManaged Objects Doubling-Table Info...\n", indent, "");
-    H5HF_dtable_debug(&shared->man_dtable_info, stream, indent + 3, MAX(0, fwidth -3));
+    H5HF_dtable_debug(&shared->man_dtable, stream, indent + 3, MAX(0, fwidth -3));
 
 done:
     if(fh && H5AC_unprotect(f, dxpl_id, H5AC_FHEAP_HDR, addr, fh, H5AC__NO_FLAGS_SET) < 0)
@@ -225,7 +264,7 @@ H5HF_dblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream,
     size_t	amount_free = 0;        /* Amount of free space in block */
     uint8_t	*marker = NULL;         /* Track free space for block */
     size_t	overlap;                /* Number of free space overlaps */
-    size_t	u, v;                   /* Local index variable */
+    size_t	u;                      /* Local index variable */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_NOAPI(H5HF_dblock_debug, FAIL)
@@ -276,7 +315,7 @@ H5HF_dblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream,
 	      dblock->block_off);
     blk_prefix_size = H5HF_MAN_ABS_DIRECT_OVERHEAD_DBLOCK(shared, dblock);
     HDfprintf(stream, "%*s%-*s %Zu\n", indent, "", fwidth,
-	      "Size of prefix:",
+	      "Size of block header:",
               blk_prefix_size);
     HDfprintf(stream, "%*s%-*s %Zu\n", indent, "", fwidth,
 	      "Size of block offsets:",
@@ -290,7 +329,7 @@ H5HF_dblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream,
 
     /* Check for valid free list */
     if(!dblock->free_list)
-        if(H5HF_man_dblock_build_freelist(dblock) < 0)
+        if(H5HF_man_dblock_build_freelist(dblock, addr) < 0)
             HGOTO_ERROR(H5E_HEAP, H5E_CANTDECODE, FAIL, "can't decode free list for block")
     HDassert(dblock->free_list);
 
@@ -333,8 +372,8 @@ H5HF_dblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream,
     } /* end while */
 
     HDfprintf(stream, "%*s%-*s %.2f%%\n", indent, "", fwidth,
-            "Percent of block used:",
-            (100.0 * (double)(dblock->size - (blk_prefix_size + amount_free)) / (double)dblock->size));
+            "Percent of available space for data used:",
+            (100.0 * (double)((dblock->size - blk_prefix_size) - amount_free) / (double)(dblock->size - blk_prefix_size)));
 
     /*
      * Print the data in a VMS-style octal dump.
@@ -348,3 +387,131 @@ done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5HF_dblock_debug() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_iblock_debug
+ *
+ * Purpose:	Prints debugging info about a fractal heap indirect block.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@ncsa.uiuc.edu
+ *		Mar  7 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5HF_iblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream,
+    int indent, int fwidth, haddr_t hdr_addr, unsigned nrows)
+{
+    H5HF_t	*fh = NULL;             /* Fractal heap header info */
+    H5HF_shared_t *shared;              /* Shared fractal heap information */
+    H5HF_indirect_t *iblock = NULL;     /* Fractal heap direct block info */
+    char temp_str[64];                  /* Temporary string, for formatting */
+    size_t	u, v;                   /* Local index variable */
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_NOAPI(H5HF_iblock_debug, FAIL)
+
+    /*
+     * Check arguments.
+     */
+    HDassert(f);
+    HDassert(H5F_addr_defined(addr));
+    HDassert(stream);
+    HDassert(indent >= 0);
+    HDassert(fwidth >= 0);
+    HDassert(H5F_addr_defined(hdr_addr));
+    HDassert(nrows > 0);
+
+    /*
+     * Load the fractal heap header.
+     */
+    if(NULL == (fh = H5AC_protect(f, dxpl_id, H5AC_FHEAP_HDR, hdr_addr, NULL, NULL, H5AC_READ)))
+	HGOTO_ERROR(H5E_HEAP, H5E_CANTLOAD, FAIL, "unable to load fractal heap header")
+
+    /* Get the pointer to the shared fractal heap info */
+    shared = H5RC_GET_OBJ(fh->shared);
+    HDassert(shared);
+
+    /*
+     * Load the heap direct block
+     */
+    if(NULL == (iblock = H5AC_protect(f, dxpl_id, H5AC_FHEAP_IBLOCK, addr, &nrows, fh->shared, H5AC_READ)))
+	HGOTO_ERROR(H5E_HEAP, H5E_CANTLOAD, FAIL, "unable to load fractal heap indirect block")
+
+    /* Release the heap header */
+    if(H5AC_unprotect(f, dxpl_id, H5AC_FHEAP_HDR, hdr_addr, fh, H5AC__NO_FLAGS_SET) < 0)
+        HDONE_ERROR(H5E_HEAP, H5E_PROTECT, FAIL, "unable to release fractal heap header")
+    fh = NULL;
+
+    /* Print opening message */
+    HDfprintf(stream, "%*sFractal Heap Indirect Block...\n", indent, "");
+
+    /*
+     * Print the values.
+     */
+    HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
+	      "Address of fractal heap that owns this block:",
+	      shared->heap_addr);
+    HDfprintf(stream, "%*s%-*s %Hu\n", indent, "", fwidth,
+	      "Offset of indirect block in heap:",
+	      iblock->block_off);
+    HDfprintf(stream, "%*s%-*s %Zu\n", indent, "", fwidth,
+	      "Size of indirect block:",
+	      iblock->size);
+    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
+	      "Total # of rows:",
+	      iblock->nrows);
+    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
+	      "# of direct rows:",
+	      iblock->ndir_rows);
+    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
+	      "# of indirect rows:",
+	      iblock->nindir_rows);
+
+    /* Print the entry tables */
+    HDfprintf(stream, "%*sDirect Block Entries (address, free space):\n", indent, "");
+    for(u = 0; u < iblock->ndir_rows; u++) {
+        sprintf(temp_str, "Row #%u:", (unsigned)u);
+        HDfprintf(stream, "%*s%-*s\n", indent + 3, "", MAX(0, fwidth - 3),
+                temp_str);
+        for(v = 0; v < shared->man_dtable.cparam.width; v++) {
+            size_t off = (u * shared->man_dtable.cparam.width) + v;
+
+            sprintf(temp_str, "Col #%u:", (unsigned)v);
+            HDfprintf(stream, "%*s%-*s %8a, %8Zu\n", indent + 6, "", MAX(0, fwidth - 6),
+                    temp_str,
+                    iblock->dblock_ents[off].addr,
+                    iblock->dblock_ents[off].free_space);
+        } /* end for */
+    } /* end for */
+    HDfprintf(stream, "%*sIndirect Block Entries:\n", indent, "");
+    if(iblock->nindir_rows > 0) {
+        for(u = 0; u < iblock->nindir_rows; u++) {
+            sprintf(temp_str, "Row #%u:", (unsigned)u);
+            HDfprintf(stream, "%*s%-*s\n", indent + 3, "", MAX(0, fwidth - 3),
+                    temp_str);
+            for(v = 0; v < shared->man_dtable.cparam.width; v++) {
+                size_t off = (u * shared->man_dtable.cparam.width) + v;
+
+                sprintf(temp_str, "Col #%u:", (unsigned)v);
+                HDfprintf(stream, "%*s%-*s %8a\n", indent + 6, "", MAX(0, fwidth - 6),
+                        temp_str,
+                        iblock->iblock_ents[off].addr);
+            } /* end for */
+        } /* end for */
+    } /* end if */
+    else
+        HDfprintf(stream, "%*s%-*s\n", indent + 3, "", MAX(0, fwidth - 3),
+                  "<none>");
+
+
+done:
+    if(iblock && H5AC_unprotect(f, dxpl_id, H5AC_FHEAP_IBLOCK, addr, iblock, H5AC__NO_FLAGS_SET) < 0)
+        HDONE_ERROR(H5E_HEAP, H5E_PROTECT, FAIL, "unable to release fractal heap direct block")
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5HF_iblock_debug() */
+
diff --git a/src/H5HFflist.c b/src/H5HFflist.c
new file mode 100644
index 0000000..361bb37
--- /dev/null
+++ b/src/H5HFflist.c
@@ -0,0 +1,367 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic HDF5 document set and   *
+ * is linked from the top-level documents page.  It can also be found at     *
+ * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html.  If you do not have     *
+ * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/* Programmer:  Quincey Koziol <koziol@ncsa.uiuc.edu>
+ *              Tuesday, March  7, 2006
+ *
+ * Purpose:	Fractal heap free space functions.
+ *
+ */
+
+/****************/
+/* Module Setup */
+/****************/
+
+#define H5HF_PACKAGE		/*suppress error about including H5HFpkg  */
+
+/***********/
+/* Headers */
+/***********/
+#include "H5private.h"		/* Generic Functions			*/
+#include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5HFpkg.h"		/* Fractal heaps			*/
+#include "H5Vprivate.h"		/* Vectors and arrays 			*/
+
+/****************/
+/* Local Macros */
+/****************/
+
+/* Max. height of the skip list holding free list nodes */
+#define H5HF_FLIST_DEFAULT_SKIPLIST_HEIGHT     16
+
+/******************/
+/* Local Typedefs */
+/******************/
+
+/* Free list node for free list sections of the same size */
+typedef struct H5HF_flist_node_t {
+    size_t sec_size;            /* Size of all sections on list */
+    H5SL_t *sec_list;           /* Skip list to hold pointers to actual free list section node */
+} H5HF_flist_node_t;
+
+
+/********************/
+/* Package Typedefs */
+/********************/
+
+/* Main free list info */
+struct H5HF_freelist_t {
+    hsize_t tot_space;          /* Total amount of space in free list         */
+    unsigned nbins;             /* Number of bins                             */
+    H5SL_operator_t node_free_op;       /* Callback for freeing nodes when free list is destroyed */
+    H5SL_t **bins;              /* Pointer to array of lists of free nodes    */
+};
+
+
+/********************/
+/* Local Prototypes */
+/********************/
+static herr_t H5HF_flist_node_free_cb(void *item, void *key, void *op_data);
+
+
+/*********************/
+/* Package Variables */
+/*********************/
+
+/* Declare a free list to manage the H5HF_freelist_t struct */
+H5FL_DEFINE_STATIC(H5HF_freelist_t);
+
+/* Declare a free list to manage the H5HF_flist_node_t struct */
+H5FL_DEFINE_STATIC(H5HF_flist_node_t);
+
+/* Declare a free list to manage the 'H5SL_t *' sequence information */
+typedef H5SL_t *H5SL_ptr_t;
+H5FL_SEQ_DEFINE_STATIC(H5SL_ptr_t);
+
+
+/*****************************/
+/* Library Private Variables */
+/*****************************/
+
+
+/*******************/
+/* Local Variables */
+/*******************/
+
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_flist_create
+ *
+ * Purpose:	Allocate & initialize free list for heap
+ *
+ * Return:	Success:	Pointer to free list structure
+ *
+ *		Failure:	NULL
+ *
+ * Programmer:	Quincey Koziol
+ *              Tuesday, March  7, 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+H5HF_freelist_t *
+H5HF_flist_create(size_t max_block_size, H5SL_operator_t node_free_op)
+{
+    H5HF_freelist_t *flist;             /* New free list structure */
+    H5HF_freelist_t *ret_value;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5HF_flist_create)
+
+    /* Check arguments. */
+
+    /*
+     * Allocate top free list structure
+     */
+    if(NULL == (flist = H5FL_MALLOC(H5HF_freelist_t)))
+	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for fractal heap free list")
+
+    /* Set free list parameters */
+    flist->tot_space = 0;
+    flist->nbins = H5V_log2_of2(max_block_size);
+    flist->node_free_op = node_free_op;
+
+    /* Allocate the bins for free space sizes */
+    if(NULL == (flist->bins = H5FL_SEQ_CALLOC(H5SL_ptr_t, flist->nbins)))
+	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for free list bins")
+
+    /* Set return value */
+    ret_value = flist;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5HF_flist_create() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_flist_add
+ *
+ * Purpose:	Add a section of free space in a direct block to the free list
+ *
+ * Return:	Success:	non-negative
+ *
+ *		Failure:	negative
+ *
+ * Programmer:	Quincey Koziol
+ *              Tuesday, March  7, 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5HF_flist_add(H5HF_freelist_t *flist, void *node, size_t *size_key, haddr_t *addr_key)
+{
+    H5HF_flist_node_t *flist_node = NULL;   /* Pointer to free list node of the correct size */
+    unsigned bin;                       /* Bin to put the free space section in */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5HF_flist_add)
+#ifdef QAK
+HDfprintf(stderr, "%s: *size_key = %Zu, *addr_key = %a\n", FUNC, *size_key, *addr_key);
+#endif /* QAK */
+
+    /* Check arguments. */
+    HDassert(flist);
+    HDassert(node);
+    HDassert(size_key);
+    HDassert(addr_key);
+
+    /* Determine correct bin which holds items of the section's size */
+    bin = H5V_log2_gen((hsize_t)*size_key);
+    if(flist->bins[bin] == NULL) {
+        if(NULL == (flist->bins[bin] = H5SL_create(H5SL_TYPE_SIZE, 0.5, H5HF_FLIST_DEFAULT_SKIPLIST_HEIGHT)))
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTCREATE, FAIL, "can't create skip list for free list nodes")
+    } /* end if */
+    else {
+        /* Check for node list of the correct size already */
+        flist_node = H5SL_search(flist->bins[bin], size_key);
+    } /* end else */
+
+    /* Check if we need to create a new skip list for nodes of this size */
+    if(flist_node == NULL) {
+        /* Allocate new free list size node */
+        if(NULL == (flist_node = H5FL_MALLOC(H5HF_flist_node_t)))
+            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for fractal heap free list")
+
+        /* Initialize the free list size node */
+        flist_node->sec_size = *size_key;
+        if(NULL == (flist_node->sec_list = H5SL_create(H5SL_TYPE_HADDR, 0.5, H5HF_FLIST_DEFAULT_SKIPLIST_HEIGHT)))
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTCREATE, FAIL, "can't create skip list for free list nodes")
+
+        /* Insert new free list size node into bin's list */
+        if(H5SL_insert(flist->bins[bin], flist_node, &flist_node->sec_size) < 0)
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTINSERT, FAIL, "can't insert free list node into skip list")
+    } /* end if */
+
+    /* Insert free list node into correct skip list */
+    if(H5SL_insert(flist_node->sec_list, node, addr_key) < 0)
+        HGOTO_ERROR(H5E_HEAP, H5E_CANTINSERT, FAIL, "can't insert free list node into skip list")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5HF_flist_add() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_flist_find
+ *
+ * Purpose:	Locate a section of free space (in existing free list) that
+ *              is large enough to fulfill request.
+ *
+ * Return:	Success:	non-negative
+ *
+ *		Failure:	negative
+ *
+ * Programmer:	Quincey Koziol
+ *              Tuesday, March  7, 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5HF_flist_find(H5HF_freelist_t *flist, size_t request, void **node)
+{
+    H5HF_flist_node_t *flist_node;      /* Free list size node */
+    unsigned bin;                       /* Bin to put the free space section in */
+    herr_t ret_value = FALSE;           /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5HF_flist_find)
+
+    /* Check arguments. */
+    HDassert(flist);
+    HDassert(request > 0);
+    HDassert(node);
+
+    /* Determine correct bin which holds items of at least the section's size */
+    bin = H5V_log2_gen((hsize_t)request);
+    while(bin < flist->nbins && flist->bins[bin] == NULL)
+        bin++;
+
+    /* Find the first free space section that is large enough to fulfill request */
+    /* (Since the bins use skip lists to track the sizes of the address-ordered
+     *  lists, this is actually a "best fit" algorithm)
+     */
+#ifdef QAK
+HDfprintf(stderr, "%s: flist->nbins = %u\n", FUNC, flist->nbins);
+HDfprintf(stderr, "%s: bin = %u\n", FUNC, bin);
+#endif /* QAK */
+    if(bin < flist->nbins)
+        do {
+            /* Look for large enough free list section in this bin */
+            if(flist->bins[bin])
+                /* Check for large enough list of sections on list */
+                if((flist_node = H5SL_greater(flist->bins[bin], &request))) {
+                    /* Take first node off of the list (ie. node w/lowest address) */
+                    if(NULL == (*node = H5SL_remove_first(flist_node->sec_list)))
+                        HGOTO_ERROR(H5E_HEAP, H5E_CANTDELETE, FAIL, "can't remove free list node from skip list")
+
+                    /* Check for no more nodes on list of that size */
+                    if(H5SL_count(flist_node->sec_list) == 0) {
+                        H5HF_flist_node_t *tmp_flist_node;      /* Free list size node */
+
+                        /* Remove size tracking list from bin */
+                        tmp_flist_node = H5SL_remove(flist->bins[bin], &flist_node->sec_size);
+                        if(tmp_flist_node == NULL || tmp_flist_node != flist_node)
+                            HGOTO_ERROR(H5E_HEAP, H5E_CANTDELETE, FAIL, "can't remove free list node from skip list")
+
+                        /* Destroy skip list for size tracking node */
+                        if(H5SL_close(flist_node->sec_list) < 0)
+                            HGOTO_ERROR(H5E_HEAP, H5E_CANTCLOSEOBJ, FAIL, "can't destroy size tracking node's skip list")
+
+                        /* Release free list node */
+                        H5FL_FREE(H5HF_flist_node_t, flist_node);
+                    } /* end if */
+
+                    HGOTO_DONE(TRUE)
+                } /* end if */
+
+            /* Advance to next larger bin */
+            bin++;
+        } while(bin < flist->nbins);
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5HF_flist_find() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_flist_node_free_cb
+ *
+ * Purpose:	Free a size-tracking node for a bin
+ *
+ * Return:	Success:	non-negative
+ *
+ *		Failure:	negative
+ *
+ * Programmer:	Quincey Koziol
+ *              Saturday, March 11, 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5HF_flist_node_free_cb(void *item, void UNUSED *key, void *op_data)
+{
+    H5HF_flist_node_t *flist_node = (H5HF_flist_node_t *)item;       /* Temporary pointer to free list node */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_flist_node_free_cb)
+
+    HDassert(flist_node);
+
+    /* Release the skip list for sections of this size */
+    H5SL_destroy(flist_node->sec_list, (H5SL_operator_t)op_data, NULL);
+
+    /* Release free list node */
+    H5FL_FREE(H5HF_flist_node_t, flist_node);
+
+    FUNC_LEAVE_NOAPI(0)
+}   /* H5HF_flist_node_free_cb() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_flist_free
+ *
+ * Purpose:	Destroy & deallocate free list structure
+ *
+ * Return:	Success:	non-negative
+ *
+ *		Failure:	negative
+ *
+ * Programmer:	Quincey Koziol
+ *              Tuesday, March  7, 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5HF_flist_free(H5HF_freelist_t *flist)
+{
+    unsigned u;                 /* Local index variable */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_flist_free)
+
+    /* Check arguments. */
+    HDassert(flist);
+
+    /* Clear out lists of nodes */
+    for(u = 0; u < flist->nbins; u++)
+        if(flist->bins[u]) {
+            H5SL_destroy(flist->bins[u], H5HF_flist_node_free_cb, (void *)flist->node_free_op);
+            flist->bins[u] = NULL;
+        } /* end if */
+
+    /* Release bins for skip lists */
+    H5FL_SEQ_FREE(H5SL_ptr_t, flist->bins);
+
+    /* Free fractal heap free list info */
+    H5FL_FREE(H5HF_freelist_t, flist);
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* H5HF_flist_free() */
+
diff --git a/src/H5HFint.c b/src/H5HFint.c
index 151b19f..fce8640 100644
--- a/src/H5HFint.c
+++ b/src/H5HFint.c
@@ -33,9 +33,10 @@
 /* Headers */
 /***********/
 #include "H5private.h"		/* Generic Functions			*/
-#include "H5HFpkg.h"		/* Fractal heaps			*/
 #include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5HFpkg.h"		/* Fractal heaps			*/
 #include "H5MFprivate.h"	/* File memory management		*/
+#include "H5MMprivate.h"	/* Memory management			*/
 #include "H5Vprivate.h"		/* Vectors and arrays 			*/
 
 /****************/
@@ -44,7 +45,8 @@
 
 /* Limit on the size of the max. direct block size */
 /* (This is limited to 32-bits currently, because I think it's unlikely to
- *      need to be larger, and the 32-bit limit for H5V_log2_of2(n)  - QAK)
+ *      need to be larger, the 32-bit limit for H5V_log2_of2(n), and
+ *      some offsets/sizes are encoded with a maxiumum of 32-bits  - QAK)
  */
 #define H5HL_MAX_DIRECT_SIZE_LIMIT ((hsize_t)2 * 1024 * 1024 * 1024)
 
@@ -54,15 +56,45 @@
 
 
 /********************/
+/* Package Typedefs */
+/********************/
+
+/* Direct block free list section node */
+struct H5HF_section_free_node_t {
+    haddr_t     sect_addr;                      /* Address of free list section in the file */
+                                                /* (Not actually used as address, used as unique ID for free list node) */
+    haddr_t     block_addr;                     /* Address of direct block for free section */
+    size_t      sect_size;                      /* Size of free space section */
+                                                /* (section size is "object size", without the metadata overhead, since metadata overhead varies from block to block) */
+    size_t      block_size;                     /* Size of direct block */
+                                                /* (Needed to retrieve direct block) */
+};
+
+
+/********************/
 /* Local Prototypes */
 /********************/
 
+/* Doubling table routines */
+static herr_t H5HF_dtable_init(const H5HF_shared_t *shared, H5HF_dtable_t *dtable);
+static herr_t H5HF_dtable_lookup(const H5HF_dtable_t *dtable, hsize_t off,
+    unsigned *row, unsigned *col);
+
+/* Shared heap header routines */
 static herr_t H5HF_shared_free(void *_shared);
+
+/* Direct block routines */
+static herr_t H5HF_dblock_section_node_free_cb(void *item, void UNUSED *key,
+    void UNUSED *op_data);
+static herr_t H5HF_man_dblock_inc_size(H5HF_shared_t *shared);
 static herr_t H5HF_man_dblock_create(H5RC_t *fh_shared, hid_t dxpl_id,
     size_t block_size, hsize_t block_off, haddr_t *addr_p);
-static herr_t H5HF_man_dblock_insert(H5RC_t *fh_shared, hid_t dxpl_id,
-    haddr_t block_addr, size_t block_size, size_t obj_size, const void *obj,
-    void *id);
+static herr_t H5HF_man_dblock_new(H5RC_t *fh_shared, hid_t dxpl_id,
+    size_t request);
+
+/* Indirect block routines */
+static herr_t H5HF_man_iblock_create(H5RC_t *fh_shared, hid_t dxpl_id,
+    hsize_t block_off, unsigned nrows, haddr_t *addr_p);
 
 /*********************/
 /* Package Variables */
@@ -77,6 +109,18 @@ H5FL_DEFINE(H5HF_direct_free_head_t);
 /* Declare a free list to manage the H5HF_direct_free_node_t struct */
 H5FL_DEFINE(H5HF_direct_free_node_t);
 
+/* Declare a free list to manage the H5HF_section_free_node_t struct */
+H5FL_DEFINE(H5HF_section_free_node_t);
+
+/* Declare a free list to manage the H5HF_indirect_t struct */
+H5FL_DEFINE(H5HF_indirect_t);
+
+/* Declare a free list to manage the H5HF_indirect_dblock_ent_t sequence information */
+H5FL_SEQ_DEFINE(H5HF_indirect_dblock_ent_t);
+
+/* Declare a free list to manage the H5HF_indirect_iblock_ent_t sequence information */
+H5FL_SEQ_DEFINE(H5HF_indirect_iblock_ent_t);
+
 
 /*****************************/
 /* Library Private Variables */
@@ -93,6 +137,101 @@ H5FL_DEFINE_STATIC(H5HF_shared_t);
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5HF_dtable_init
+ *
+ * Purpose:	Initialize values for doubling table
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@ncsa.uiuc.edu
+ *		Mar  6 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5HF_dtable_init(const H5HF_shared_t *shared, H5HF_dtable_t *dtable)
+{
+    hsize_t tmp_block_size;             /* Temporary block size */
+    size_t u;                           /* Local index variable */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5HF_dtable_init)
+
+    /*
+     * Check arguments.
+     */
+    HDassert(shared);
+    HDassert(dtable);
+
+    /* Compute/cache some values */
+    dtable->first_row_bits = H5V_log2_of2(dtable->cparam.start_block_size) +
+            H5V_log2_of2(dtable->cparam.width);
+    dtable->max_root_indirect_rows = (dtable->cparam.max_index - dtable->first_row_bits) + 1;
+    dtable->max_direct_rows = (H5V_log2_of2(dtable->cparam.max_direct_size) -
+            H5V_log2_of2(dtable->cparam.start_block_size)) + 2;
+    dtable->num_id_first_row = dtable->cparam.start_block_size * dtable->cparam.width;
+    dtable->max_dir_blk_off_size = H5HF_SIZEOF_OFFSET_LEN(dtable->cparam.max_direct_size);
+    dtable->next_dir_size = dtable->cparam.start_block_size;
+
+    /* Build table of block sizes for each row */
+    if(NULL == (dtable->row_block_size = H5MM_malloc(dtable->max_root_indirect_rows * sizeof(hsize_t))))
+	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "can't create doubling table block size table")
+    tmp_block_size = dtable->cparam.start_block_size;
+    dtable->row_block_size[0] = dtable->cparam.start_block_size;
+    for(u = 1; u < dtable->max_root_indirect_rows; u++) {
+        dtable->row_block_size[u] = tmp_block_size;
+        tmp_block_size *= 2;
+    } /* end for */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5HF_dtable_init() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_dtable_lookup
+ *
+ * Purpose:	Compute the row & col of an offset in a doubling-table
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@ncsa.uiuc.edu
+ *		Mar  6 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5HF_dtable_lookup(const H5HF_dtable_t *dtable, hsize_t off, unsigned *row, unsigned *col)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_dtable_lookup)
+
+    /*
+     * Check arguments.
+     */
+    HDassert(dtable);
+    HDassert(row);
+    HDassert(col);
+
+    /* Check for offset in first row */
+    if(off < dtable->num_id_first_row) {
+        *row = 0;
+        *col = off / dtable->cparam.start_block_size;
+    } /* end if */
+    else {
+        unsigned high_bit = H5V_log2_gen(off);  /* Determine the high bit in the offset */
+        hsize_t off_mask = 1 << high_bit;       /* Compute mask for determining column */
+
+        *row = (high_bit - dtable->first_row_bits) + 1;
+        *col = (off - off_mask) / dtable->row_block_size[*row];
+    } /* end else */
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5HF_dtable_lookup() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5HF_shared_alloc
  *
  * Purpose:	Allocate shared fractal heap info 
@@ -153,7 +292,7 @@ done:
 herr_t
 H5HF_shared_own(H5HF_t *fh, H5HF_shared_t *shared)
 {
-    herr_t ret_value = SUCCEED;           /* Return value */
+    herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT(H5HF_shared_own)
 
@@ -164,9 +303,14 @@ H5HF_shared_own(H5HF_t *fh, H5HF_shared_t *shared)
     HDassert(shared);
 
     /* Compute/cache some values */
-    shared->fixed_len_obj = (shared->fixed_len_size > 0);
     shared->ref_count_obj = (shared->ref_count_size > 0);
-    shared->heap_off_size = H5HF_SIZEOF_OFFSET_BITS(shared->man_dtable_info.cparam.max_index);
+    shared->heap_off_size = H5HF_SIZEOF_OFFSET_BITS(shared->man_dtable.cparam.max_index);
+    if(H5HF_dtable_init(shared, &shared->man_dtable) < 0)
+	HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, FAIL, "can't initialize doubling table info")
+
+    /* Create the free-list structure for the heap */
+    if(NULL == (shared->flist = H5HF_flist_create(shared->man_dtable.cparam.max_direct_size, H5HF_dblock_section_node_free_cb)))
+	HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, FAIL, "can't initialize free list info")
 
     /* Make shared heap info reference counted */
     if(NULL == (fh->shared = H5RC_create(shared, H5HF_shared_free)))
@@ -214,6 +358,8 @@ H5HF_shared_create(H5F_t *f, H5HF_t *fh, haddr_t fh_addr, H5HF_create_t *cparam)
     if(!POWER_OF_TWO(cparam->managed.max_direct_size) ||
             (cparam->managed.max_direct_size == 0 || cparam->managed.max_direct_size > H5HL_MAX_DIRECT_SIZE_LIMIT))
 	HGOTO_ERROR(H5E_HEAP, H5E_BADVALUE, FAIL, "max. direct block size not power of two")
+    if(cparam->managed.max_direct_size < cparam->standalone_size)
+	HGOTO_ERROR(H5E_HEAP, H5E_BADVALUE, FAIL, "max. direct block size not large enough to hold all managed blocks")
     if(cparam->managed.max_index > (8 * H5F_SIZEOF_SIZE(f)) || cparam->managed.max_index == 0)
 	HGOTO_ERROR(H5E_HEAP, H5E_BADVALUE, FAIL, "max. direct block size not power of two")
 #endif /* NDEBUG */
@@ -226,9 +372,11 @@ H5HF_shared_create(H5F_t *f, H5HF_t *fh, haddr_t fh_addr, H5HF_create_t *cparam)
     shared->heap_addr = fh_addr;
     shared->addrmap = cparam->addrmap;
     shared->standalone_size = cparam->standalone_size;
-    shared->fixed_len_size = cparam->fixed_len_size;
     shared->ref_count_size = cparam->ref_count_size;
-    HDmemcpy(&(shared->man_dtable_info.cparam), &(cparam->managed), sizeof(H5HF_dtable_cparam_t));
+    HDmemcpy(&(shared->man_dtable.cparam), &(cparam->managed), sizeof(H5HF_dtable_cparam_t));
+
+    /* Note that the shared info is dirty (it's not written to the file yet) */
+    shared->dirty = TRUE;
 
     /* Make shared heap info reference counted */
     if(H5HF_shared_own(fh, shared) < 0)
@@ -266,6 +414,13 @@ H5HF_shared_free(void *_shared)
     /* Sanity check */
     HDassert(shared);
 
+    /* Free the free list information for the heap */
+    if(shared->flist)
+        H5HF_flist_free(shared->flist);
+
+    /* Free the block size lookup table for the doubling table */
+    H5MM_xfree(shared->man_dtable.row_block_size);
+
     /* Free the shared info itself */
     H5FL_FREE(H5HF_shared_t, shared);
 
@@ -274,84 +429,49 @@ H5HF_shared_free(void *_shared)
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5HF_man_alloc_end
+ * Function:	H5HF_man_dblock_inc_size
  *
- * Purpose:	Allocate space for an object at the end of the managed obj. heap
+ * Purpose:	Increment size of next direct block
  *
- * Return:	Non-negative on success (with heap ID of new object
- *              filled in), negative on failure
+ * Return:	SUCCEED/FAIL
  *
  * Programmer:	Quincey Koziol
  *		koziol@ncsa.uiuc.edu
- *		Feb 27 2006
+ *		Mar  6 2006
  *
  *-------------------------------------------------------------------------
  */
-herr_t
-H5HF_man_alloc_end(H5RC_t *fh_shared, hid_t dxpl_id, unsigned *fh_flags_ptr,
-    size_t size, const void *obj, void *id/*out*/)
+static herr_t
+H5HF_man_dblock_inc_size(H5HF_shared_t *shared)
 {
-    H5HF_shared_t *shared;              /* Shared heap information */
-    herr_t ret_value = SUCCEED;
-
-    FUNC_ENTER_NOAPI_NOINIT(H5HF_man_alloc_end)
-HDfprintf(stderr, "%s: size = %Zu\n", FUNC, size);
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_man_dblock_inc_size)
 
     /*
      * Check arguments.
      */
-    HDassert(fh_shared);
-    HDassert(fh_flags_ptr);
-    HDassert(size > 0);
-    HDassert(obj);
-    HDassert(id);
-
-    /* Get the pointer to the shared heap info */
-    shared = H5RC_GET_OBJ(fh_shared);
     HDassert(shared);
 
-    /* Check if this is the first object in the heap */
-    if(shared->next_man_block == 0) {
-        /* Check if the object can fit in a direct block of the starting block size */
-#ifndef QAK
-HDfprintf(stderr, "%s: H5HF_MAN_ABS_DIRECT_OVERHEAD_SIZE = %u\n", FUNC, H5HF_MAN_ABS_DIRECT_OVERHEAD_SIZE(shared, shared->man_dtable_info.cparam.start_block_size));
-HDfprintf(stderr, "%s: H5HF_MAN_ABS_DIRECT_OBJ_PREFIX_LEN_SIZE = %u\n", FUNC, H5HF_MAN_ABS_DIRECT_OBJ_PREFIX_LEN_SIZE(shared, shared->man_dtable_info.cparam.start_block_size));
-#endif /* QAK */
-        if((size + H5HF_MAN_ABS_DIRECT_OVERHEAD_SIZE(shared, shared->man_dtable_info.cparam.start_block_size)
-                    + H5HF_MAN_ABS_DIRECT_OBJ_PREFIX_LEN_SIZE(shared, shared->man_dtable_info.cparam.start_block_size))
-                <= shared->man_dtable_info.cparam.start_block_size) {
-            haddr_t dblock_addr;        /* Address of new direct block */
-            size_t dblock_size;         /* Size of new direct block */
-
-            /* Allocate initial direct block */
-            dblock_size = shared->man_dtable_info.cparam.start_block_size;
-            if(H5HF_man_dblock_create(fh_shared, dxpl_id, dblock_size, (hsize_t)0, &dblock_addr) < 0)
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "can't allocate fractal heap direct block")
-HDfprintf(stderr, "%s: dblock_addr = %a\n", FUNC, dblock_addr);
-
-            /* Point root at new direct block */
-            shared->next_man_block = dblock_size;
-            shared->man_dtable_info.curr_root_rows = 0;
-            shared->man_dtable_info.table_addr = dblock_addr;
-
-            /* Mark heap header as modified */
-            *fh_flags_ptr |= H5AC__DIRTIED_FLAG;
-
-            /* Attempt to insert object into direct block */
-            if(H5HF_man_dblock_insert(fh_shared, dxpl_id, dblock_addr, dblock_size, size, obj, id) < 0)
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "can't insert object into fractal heap direct block")
-        } /* end if */
-        else {
-HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, FAIL, "first object doesn't fit into starting direct block")
-        } /* end else */
+    /* Check for another block of the same size, in the same row */
+    if(shared->man_dtable.next_dir_col < shared->man_dtable.cparam.width) {
+        /* Move to next column in doubling table */
+        shared->man_dtable.next_dir_col++;
     } /* end if */
     else {
-HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, FAIL, "allocating objects at end of heap not supported yet")
+        /* Check for "doubling" block to next row or resetting to initial size */
+/* XXX: The maximum size will vary for different indirect blocks... */
+        if(shared->man_dtable.next_dir_size < shared->man_dtable.cparam.max_direct_size)
+            /* Double block size */
+            shared->man_dtable.next_dir_size *= 2;
+        else
+            /* Reset to starting block size */
+            shared->man_dtable.next_dir_size = shared->man_dtable.cparam.start_block_size;
+
+        /* Set next column */
+        shared->man_dtable.next_dir_col = 0;
     } /* end else */
 
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5HF_man_alloc_end() */
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5HF_man_dblock_inc_size() */
 
 
 /*-------------------------------------------------------------------------
@@ -368,10 +488,11 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5HF_man_dblock_create(H5RC_t *fh_shared, hid_t dxpl_id, size_t block_size,
-    hsize_t block_off, haddr_t *addr_p)
+H5HF_man_dblock_create(H5RC_t *fh_shared, hid_t dxpl_id, 
+    size_t block_size, hsize_t block_off, haddr_t *addr_p)
 {
     H5HF_direct_free_node_t *node;      /* Pointer to free list node for block */
+    H5HF_section_free_node_t *sec_node; /* Pointer to free list section for block */
     H5HF_shared_t *shared;              /* Pointer to shared heap info */
     H5HF_direct_t *dblock = NULL;       /* Pointer to direct block */
     herr_t ret_value = SUCCEED;         /* Return value */
@@ -389,7 +510,7 @@ H5HF_man_dblock_create(H5RC_t *fh_shared, hid_t dxpl_id, size_t block_size,
      * Allocate file and memory data structures.
      */
     if(NULL == (dblock = H5FL_MALLOC(H5HF_direct_t)))
-	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for fractal heap header")
+	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for fractal heap direct block")
 
     /* Reset the metadata cache info for the heap header */
     HDmemset(&dblock->cache_info, 0, sizeof(H5AC_info_t));
@@ -403,7 +524,9 @@ H5HF_man_dblock_create(H5RC_t *fh_shared, hid_t dxpl_id, size_t block_size,
     HDassert(shared);
 
     /* Set info for direct block */
+#ifdef QAK
 HDfprintf(stderr, "%s: size = %Zu, block_off = %Hu\n", FUNC, block_size, block_off);
+#endif /* QAK */
     dblock->size = block_size;
     dblock->block_off = block_off;
     dblock->blk_off_size = H5HF_SIZEOF_OFFSET_LEN(block_size);
@@ -434,15 +557,39 @@ HDmemset(dblock->blk, 0, dblock->size);
     node->prev = node->next = NULL;
 
     /* Attach to free list head */
+/* XXX: Convert this list to a skip list? */
     dblock->free_list->first = node;
 
     /* Allocate space for the header on disk */
     if(HADDR_UNDEF == (*addr_p = H5MF_alloc(shared->f, H5FD_MEM_FHEAP_DBLOCK, dxpl_id, (hsize_t)block_size)))
-	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "file allocation failed for fractal heap header")
+	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "file allocation failed for fractal heap direct block")
 
-    /* Cache the new fractal heap header */
+    /* Create free list section node */
+    if(NULL == (sec_node = H5FL_MALLOC(H5HF_section_free_node_t)))
+        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for direct block free list section")
+
+    /* Set section's information */
+    sec_node->block_addr = *addr_p;
+    sec_node->block_size = block_size;
+    sec_node->sect_addr = *addr_p + node->my_offset;
+    /* (section size is "object size", without the metadata overhead) */
+    sec_node->sect_size = node->size - H5HF_MAN_ABS_DIRECT_OBJ_PREFIX_LEN_DBLOCK(shared, dblock);
+
+    /* Add new free space to the global list of space */
+    if(H5HF_flist_add(shared->flist, sec_node, &sec_node->sect_size, &sec_node->sect_addr) < 0)
+	HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, FAIL, "can't add direct block free space to global list")
+
+    /* Update shared heap info */
+    shared->total_man_free += dblock->blk_free_space;
+    shared->total_size += dblock->size;
+    shared->man_size += dblock->size;
+
+    /* Mark heap header as modified */
+    shared->dirty = TRUE;
+
+    /* Cache the new fractal heap direct block */
     if(H5AC_set(shared->f, dxpl_id, H5AC_FHEAP_DBLOCK, *addr_p, dblock, H5AC__NO_FLAGS_SET) < 0)
-	HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, FAIL, "can't add fractal heap header to cache")
+	HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, FAIL, "can't add fractal heap direct block to cache")
 
 done:
     if(ret_value < 0)
@@ -454,6 +601,34 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5HF_dblock_section_node_free_cb
+ *
+ * Purpose:	Free a section node for a block
+ *
+ * Return:	Success:	non-negative
+ *
+ *		Failure:	negative
+ *
+ * Programmer:	Quincey Koziol
+ *              Monday, March 13, 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5HF_dblock_section_node_free_cb(void *item, void UNUSED *key, void UNUSED *op_data)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_dblock_section_node_free_cb)
+
+    HDassert(item);
+
+    /* Release the sections */
+    H5FL_FREE(H5HF_section_free_node_t, item);
+
+    FUNC_LEAVE_NOAPI(0)
+}   /* H5HF_dblock_section_node_free_cb() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5HF_man_dblock_build_freelist
  *
  * Purpose:	Parse the free list information for a direct block and build
@@ -468,9 +643,10 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5HF_man_dblock_build_freelist(H5HF_direct_t *dblock)
+H5HF_man_dblock_build_freelist(H5HF_direct_t *dblock, haddr_t dblock_addr)
 {
     H5HF_direct_free_head_t *head = NULL;       /* Pointer to free list head for block */
+    H5HF_shared_t *shared;                      /* Pointer to shared heap info */
     herr_t ret_value = SUCCEED;                 /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT(H5HF_man_dblock_build_freelist)
@@ -489,6 +665,7 @@ H5HF_man_dblock_build_freelist(H5HF_direct_t *dblock)
     if(dblock->free_list_head == 0)
         head->first = NULL;
     else {
+        H5HF_section_free_node_t *sec_node;     /* Pointer to free list section for block */
         H5HF_direct_free_node_t *node = NULL;   /* Pointer to free list node for block */
         H5HF_direct_free_node_t *prev_node;     /* Pointer to previous free list node for block */
         hsize_t free_len;       /* Length of free list info */
@@ -496,6 +673,10 @@ H5HF_man_dblock_build_freelist(H5HF_direct_t *dblock)
         hsize_t prev_off;       /* Prev node offset in block */
         uint8_t *p;             /* Temporary pointer to free node info */
 
+        /* Get the pointer to the shared B-tree info */
+        shared = H5RC_GET_OBJ(dblock->shared);
+        HDassert(shared);
+
         /* Point to first node in free list */
         p = dblock->blk + dblock->free_list_head;
 
@@ -516,6 +697,21 @@ H5HF_man_dblock_build_freelist(H5HF_direct_t *dblock)
         /* Attach to free list head */
         head->first = node;
 
+        /* Create free list section node */
+        if(NULL == (sec_node = H5FL_MALLOC(H5HF_section_free_node_t)))
+            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for direct block free list section")
+
+        /* Set section's information */
+        sec_node->block_addr = dblock_addr;
+        sec_node->block_size = dblock->size;
+        sec_node->sect_addr = dblock_addr + node->my_offset;
+        /* (section size is "object size", without the metadata overhead) */
+        sec_node->sect_size = node->size - H5HF_MAN_ABS_DIRECT_OBJ_PREFIX_LEN_DBLOCK(shared, dblock);
+
+        /* Add new free space to the global list of space */
+        if(H5HF_flist_add(shared->flist, sec_node, &sec_node->sect_size, &sec_node->sect_addr) < 0)
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, FAIL, "can't add direct block free space to global list")
+
         /* Set up trailing node pointer */
         prev_node = node;
         prev_off = next_off;
@@ -540,6 +736,21 @@ H5HF_man_dblock_build_freelist(H5HF_direct_t *dblock)
             node->prev = prev_node;
             node->next = NULL;
 
+            /* Create free list section node */
+            if(NULL == (sec_node = H5FL_MALLOC(H5HF_section_free_node_t)))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for direct block free list section")
+
+            /* Set section's information */
+            sec_node->block_addr = dblock_addr;
+            sec_node->block_size = dblock->size;
+            sec_node->sect_addr = dblock_addr + node->my_offset;
+            /* (section size is "object size", without the metadata overhead) */
+            sec_node->sect_size = node->size - H5HF_MAN_ABS_DIRECT_OBJ_PREFIX_LEN_DBLOCK(shared, dblock);
+
+            /* Add new free space to the global list of space */
+            if(H5HF_flist_add(shared->flist, sec_node, &sec_node->sect_size, &sec_node->sect_addr) < 0)
+                HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, FAIL, "can't add direct block free space to global list")
+
             /* Update trailing info */
             prev_node->next = node;
             prev_off = next_off;
@@ -559,34 +770,260 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5HF_man_dblock_insert
+ * Function:	H5HF_man_dblock_new
  *
- * Purpose:	Allocate space in a managed direct block
+ * Purpose:	Create a direct block large enough to hold an object of
+ *              the requested size
  *
  * Return:	SUCCEED/FAIL
  *
  * Programmer:	Quincey Koziol
  *		koziol@ncsa.uiuc.edu
- *		Feb 28 2006
+ *		Mar 13 2006
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5HF_man_dblock_insert(H5RC_t *fh_shared, hid_t dxpl_id, haddr_t block_addr,
-    size_t block_size, size_t obj_size, const void *obj, void *id)
+H5HF_man_dblock_new(H5RC_t *fh_shared, hid_t dxpl_id, size_t request)
+{
+    size_t min_dblock_size;             /* Min. size of direct block to allocate */
+    H5HF_shared_t *shared;              /* Shared heap information */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5HF_man_dblock_new)
+#ifdef QAK
+HDfprintf(stderr, "%s: request = %Zu\n", FUNC, request);
+#endif /* QAK */
+
+    /*
+     * Check arguments.
+     */
+    HDassert(fh_shared);
+    HDassert(request > 0);
+
+    /* Get the pointer to the shared heap info */
+    shared = H5RC_GET_OBJ(fh_shared);
+    HDassert(shared);
+
+    /* Compute the min. size of the direct block needed to fulfill the request */
+    if(request < shared->man_dtable.cparam.start_block_size)
+        min_dblock_size = shared->man_dtable.cparam.start_block_size;
+    else {
+        min_dblock_size = 2 * H5V_log2_gen((hsize_t)request);
+        HDassert(min_dblock_size <= shared->man_dtable.cparam.max_direct_size);
+    } /* end else */
+
+    /* Adjust the size of block needed to fulfill request, with overhead */
+#ifdef QAK
+HDfprintf(stderr, "%s: H5HF_MAN_ABS_DIRECT_OVERHEAD_SIZE = %u\n", FUNC, H5HF_MAN_ABS_DIRECT_OVERHEAD_SIZE(shared, shared->man_dtable.cparam.start_block_size));
+HDfprintf(stderr, "%s: H5HF_MAN_ABS_DIRECT_OBJ_PREFIX_LEN_SIZE = %u\n", FUNC, H5HF_MAN_ABS_DIRECT_OBJ_PREFIX_LEN_SIZE(shared, shared->man_dtable.cparam.start_block_size));
+#endif /* QAK */
+    if((min_dblock_size - request) < (H5HF_MAN_ABS_DIRECT_OVERHEAD_SIZE(shared, min_dblock_size)
+            + H5HF_MAN_ABS_DIRECT_OBJ_PREFIX_LEN_SIZE(shared, min_dblock_size)))
+        min_dblock_size *= 2;
+#ifdef QAK
+HDfprintf(stderr, "%s: min_dblock_size = %Zu\n", FUNC, min_dblock_size);
+HDfprintf(stderr, "%s: shared->man_dtable.next_dir_size = %Zu\n", FUNC, shared->man_dtable.next_dir_size);
+#endif /* QAK */
+
+    /* Add direct block to heap */
+    if(min_dblock_size <= shared->man_dtable.next_dir_size) {
+        haddr_t dblock_addr;            /* Address of new direct block */
+        size_t dblock_size;             /* SIze of new direct block */
+
+        /* Create new direct block */
+        dblock_size = shared->man_dtable.next_dir_size;
+        if(H5HF_man_dblock_create(fh_shared, dxpl_id, dblock_size, shared->man_dtable.next_dir_block, &dblock_addr) < 0)
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTALLOC, FAIL, "can't allocate fractal heap direct block")
+#ifdef QAK
+HDfprintf(stderr, "%s: dblock_addr = %a\n", FUNC, dblock_addr);
+HDfprintf(stderr, "%s: shared->man_dtable.next_dir_block = %Hu\n", FUNC, shared->man_dtable.next_dir_block);
+#endif /* QAK */
+
+        /* Check if this is the first block in the heap */
+        if(shared->man_dtable.next_dir_block == 0) {
+            /* Point root at new direct block */
+            shared->man_dtable.curr_root_rows = 0;
+            shared->man_dtable.table_addr = dblock_addr;
+        } /* end if */
+        /* Check for the second block in the heap */
+        else if(shared->man_dtable.curr_root_rows == 0) {
+            H5HF_indirect_t *iblock = NULL; /* Pointer to indirect block to create */
+            H5HF_direct_t *dblock = NULL;   /* Pointer to direct block to query */
+            haddr_t iblock_addr;            /* Indirect block's address */
+            unsigned nrows;                 /* Number of rows for root indirect block */
+
+            /* Check for allocating entire root indirect block initially */
+            if(shared->man_dtable.cparam.start_root_rows == 0)
+                nrows = shared->man_dtable.max_root_indirect_rows;
+            else
+                nrows = shared->man_dtable.cparam.start_root_rows;
+
+            /* Allocate root indirect block */
+            if(H5HF_man_iblock_create(fh_shared, dxpl_id, (hsize_t)0, nrows, &iblock_addr) < 0)
+                HGOTO_ERROR(H5E_HEAP, H5E_CANTALLOC, FAIL, "can't allocate fractal heap indirect block")
+#ifdef QAK
+HDfprintf(stderr, "%s: iblock_addr = %a\n", FUNC, iblock_addr);
+#endif /* QAK */
+
+            /* Lock indirect block */
+            if(NULL == (iblock = H5AC_protect(shared->f, dxpl_id, H5AC_FHEAP_IBLOCK, iblock_addr, &nrows, fh_shared, H5AC_WRITE)))
+                HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, FAIL, "unable to protect fractal heap indirect block")
+
+            /* Lock first (root) direct block */
+            if(NULL == (dblock = H5AC_protect(shared->f, dxpl_id, H5AC_FHEAP_DBLOCK, shared->man_dtable.table_addr, &shared->man_dtable.cparam.start_block_size, fh_shared, H5AC_READ)))
+                HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, FAIL, "unable to protect fractal heap direct block")
+
+            /* Point indirect block at direct block to add */
+            iblock->dblock_ents[0].addr = shared->man_dtable.table_addr;
+            iblock->dblock_ents[0].free_space = dblock->blk_free_space;
+
+            /* Unlock first (root) direct block */
+            if(H5AC_unprotect(shared->f, dxpl_id, H5AC_FHEAP_DBLOCK, shared->man_dtable.table_addr, dblock, H5AC__NO_FLAGS_SET) < 0)
+                HDONE_ERROR(H5E_HEAP, H5E_CANTUNPROTECT, FAIL, "unable to release fractal heap direct block")
+            dblock = NULL;
+
+            /* Lock new direct block */
+            if(NULL == (dblock = H5AC_protect(shared->f, dxpl_id, H5AC_FHEAP_DBLOCK, dblock_addr, &shared->man_dtable.cparam.start_block_size, fh_shared, H5AC_READ)))
+                HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, FAIL, "unable to protect fractal heap direct block")
+
+            /* Point indirect block at new direct block */
+            iblock->dblock_ents[1].addr = dblock_addr;
+            iblock->dblock_ents[1].free_space = dblock->blk_free_space;
+
+            /* Unlock new direct block */
+            if(H5AC_unprotect(shared->f, dxpl_id, H5AC_FHEAP_DBLOCK, dblock_addr, dblock, H5AC__NO_FLAGS_SET) < 0)
+                HDONE_ERROR(H5E_HEAP, H5E_CANTUNPROTECT, FAIL, "unable to release fractal heap direct block")
+            dblock = NULL;
+
+            /* Point heap header at new indirect block */
+            shared->man_dtable.curr_root_rows = nrows;
+            shared->man_dtable.table_addr = iblock_addr;
+
+            /* Mark heap header as modified */
+            shared->dirty = TRUE;
+
+            /* Release the indirect block (marked as dirty) */
+            if(H5AC_unprotect(shared->f, dxpl_id, H5AC_FHEAP_IBLOCK, iblock_addr, iblock, H5AC__DIRTIED_FLAG) < 0)
+                HDONE_ERROR(H5E_HEAP, H5E_CANTUNPROTECT, FAIL, "unable to release fractal heap indirect block")
+        } /* end if */
+        else {
+HDfprintf(stderr, "%s: Adding >2nd direct block to heap not supported\n", FUNC);
+HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, FAIL, "allocating objects from non root block not supported yet")
+        } /* end else */
+
+        /* Update shared info */
+        shared->man_dtable.next_dir_block += dblock_size;
+
+        /* Increment size of next block */
+        H5HF_man_dblock_inc_size(shared);
+    } /* end if */
+    else {
+HDfprintf(stderr, "%s: Skipping direct block sizes not supported\n", FUNC);
+HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, FAIL, "allocating objects from non root block not supported yet")
+    } /* end else */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5HF_man_dblock_new() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_man_find
+ *
+ * Purpose:	Find space for an object in a managed obj. heap
+ *
+ * Return:	Non-negative on success (with direct block info
+ *              filled in), negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@ncsa.uiuc.edu
+ *		Mar 13 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5HF_man_find(H5RC_t *fh_shared, hid_t dxpl_id, size_t request,
+    H5HF_section_free_node_t **sec_node/*out*/)
+{
+    H5HF_shared_t *shared;              /* Shared heap information */
+    htri_t node_found;                  /* Whether an existing free list node was found */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5HF_man_find)
+#ifdef QAK
+HDfprintf(stderr, "%s: request = %Zu\n", FUNC, request);
+#endif /* QAK */
+
+    /*
+     * Check arguments.
+     */
+    HDassert(fh_shared);
+    HDassert(request > 0);
+    HDassert(sec_node);
+
+    /* Get the pointer to the shared heap info */
+    shared = H5RC_GET_OBJ(fh_shared);
+    HDassert(shared);
+
+    /* Look for free space in global free list */
+    if((node_found = H5HF_flist_find(shared->flist, request, (void **)sec_node)) < 0)
+        HGOTO_ERROR(H5E_HEAP, H5E_CANTALLOC, FAIL, "can't locate free space in fractal heap direct block")
+
+/* XXX: Make certain we've loaded all the direct blocks in the heap */
+
+    /* If we didn't find a node, go make one big enough to hold the requested block */
+    if(!node_found) {
+        /* Allocate direct block big enough to hold requested size */
+        if(H5HF_man_dblock_new(fh_shared, dxpl_id, request) < 0)
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTCREATE, FAIL, "can't create fractal heap direct block")
+
+        /* Request space from the free list */
+        /* (Ought to be able to be filled, now) */
+        if(H5HF_flist_find(shared->flist, request, (void **)sec_node) <= 0)
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTALLOC, FAIL, "can't locate free space in fractal heap direct block")
+    } /* end if */
+    HDassert(*sec_node);
+#ifdef QAK
+HDfprintf(stderr, "%s: (*sec_node)->block_addr = %a\n", FUNC, (*sec_node)->block_addr);
+HDfprintf(stderr, "%s: (*sec_node)->block_size = %Zu\n", FUNC, (*sec_node)->block_size);
+HDfprintf(stderr, "%s: (*sec_node)->sect_addr = %a\n", FUNC, (*sec_node)->sect_addr);
+HDfprintf(stderr, "%s: (*sec_node)->sect_size = %Zu\n", FUNC, (*sec_node)->sect_size);
+#endif /* QAK */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5HF_man_find() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_man_insert
+ *
+ * Purpose:	Insert an object in a managed direct block
+ *
+ * Return:	SUCCEED/FAIL
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@ncsa.uiuc.edu
+ *		Mar 13 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5HF_man_insert(H5RC_t *fh_shared, hid_t dxpl_id, H5HF_section_free_node_t *sec_node,
+    size_t obj_size, const void *obj, void *id)
 {
-    H5HF_direct_t *dblock = NULL;       /* Pointer to direct block to modify */
     H5HF_shared_t *shared;              /* Pointer to shared heap info */
+    H5HF_direct_t *dblock = NULL;       /* Pointer to direct block to modify */
+    haddr_t dblock_addr;                /* Direct block address */
     herr_t ret_value = SUCCEED;         /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5HF_man_dblock_insert)
+    FUNC_ENTER_NOAPI_NOINIT(H5HF_man_insert)
 
     /*
      * Check arguments.
      */
     HDassert(fh_shared);
-    HDassert(H5F_addr_defined(block_addr));
-    HDassert(block_size > 0);
     HDassert(obj_size > 0);
     HDassert(obj);
     HDassert(id);
@@ -596,127 +1033,268 @@ H5HF_man_dblock_insert(H5RC_t *fh_shared, hid_t dxpl_id, haddr_t block_addr,
     HDassert(shared);
 
     /* Lock direct block */
-    if(NULL == (dblock = H5AC_protect(shared->f, dxpl_id, H5AC_FHEAP_DBLOCK, block_addr, &block_size, fh_shared, H5AC_WRITE)))
+    dblock_addr = sec_node->block_addr;
+    if(NULL == (dblock = H5AC_protect(shared->f, dxpl_id, H5AC_FHEAP_DBLOCK, dblock_addr, &sec_node->block_size, fh_shared, H5AC_WRITE)))
         HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, FAIL, "unable to load fractal heap direct block")
 
+    /* Insert object into block */
+
     /* Check for address mapping type */
     if(shared->addrmap == H5HF_ABSOLUTE) {
-        H5HF_direct_free_node_t *node;      /* Pointer to free list node for block */
-        size_t full_obj_size;               /* Size of object including metadata */
-        size_t obj_off;                     /* Offset of object within block */
-        hbool_t found;                      /* Flag to indicate we found a node with enough free space */
+        H5HF_direct_free_node_t *node;  /* Block's free list node */
+        uint8_t *p;                     /* Temporary pointer to obj info in block */
+        size_t obj_off;                 /* Offset of object within block */
+        size_t full_obj_size;           /* Size of object including metadata */
+        size_t alloc_obj_size;          /* Size of object including metadata & any free space fragment */
+        unsigned char free_frag_size;   /* Size of free space fragment */
+
+        /* Locate "local" free list node for section */
+/* XXX: Change to using skip list */
+        obj_off = sec_node->sect_addr - sec_node->block_addr;
+        node = dblock->free_list->first;
+        while(node->my_offset != obj_off)
+            node = node->next;
 
         /* Compute full object size, with metadata for object */
         full_obj_size = obj_size + H5HF_MAN_ABS_DIRECT_OBJ_PREFIX_LEN_DBLOCK(shared, dblock);
 
-        /* Sanity check */
+        /* Sanity checks */
         HDassert(dblock->blk_free_space >= full_obj_size);
-
-        /* Check for valid free list */
-        if(!dblock->free_list)
-            if(H5HF_man_dblock_build_freelist(dblock) < 0)
-                HGOTO_ERROR(H5E_HEAP, H5E_CANTDECODE, FAIL, "can't decode free list for block")
         HDassert(dblock->free_list);
-
-        /* Search free list for block large enough to fit object */
-        node = dblock->free_list->first;
-        found = FALSE;
-        while(node) {
-            /* Check if this node is large enough to hold object */
-            if(node->size >= full_obj_size) {
-                /* Check for using exact free space available */
-                if(node->size == full_obj_size) {
-                    /* Set the offset of the object within the block */
-                    obj_off = node->my_offset;
-
-                    /* Check for allocating from first node in list */
-                    if(node->prev == NULL) {
-                        /* Make the next node in the free list the list head */
-                        dblock->free_list->first = node->next;
-                        dblock->free_list_head = node->next_offset;
-                    } /* end if */
-                    else {
-                        H5HF_direct_free_node_t *prev_node;          /* Pointer to previous free list node for block */
-
-                        /* Excise node from list */
-                        prev_node = node->prev;
-                        prev_node->next = node->next;
-                        if(node->next) {
-                            H5HF_direct_free_node_t *next_node;          /* Pointer to next free list node for block */
-
-                            next_node = node->next;
-                            next_node->prev = prev_node;
-                            prev_node->next_offset = next_node->my_offset;
-                        } /* end if */
-                        else
-                            prev_node->next_offset = 0;
-                    } /* end if */
-
-                    /* Release the memory for the free list node */
-                    H5FL_FREE(H5HF_direct_free_node_t, node);
+        HDassert(node->size >= full_obj_size);
+
+        /* Check for using entire node */
+        free_frag_size = 0;
+        if(node->size <= (full_obj_size + H5HF_MAN_ABS_DIRECT_FREE_NODE_SIZE(dblock))) {
+            /* Set the offset of the object within the block */
+            obj_off = node->my_offset;
+
+            /* Check for allocating from first node in list */
+            if(node->prev == NULL) {
+                /* Make the next node in the free list the list head */
+                dblock->free_list->first = node->next;
+                dblock->free_list_head = node->next_offset;
+            } /* end if */
+            else {
+                H5HF_direct_free_node_t *prev_node;          /* Pointer to previous free list node for block */
+
+                /* Excise node from list */
+                prev_node = node->prev;
+                prev_node->next = node->next;
+                if(node->next) {
+                    H5HF_direct_free_node_t *next_node;          /* Pointer to next free list node for block */
+
+                    next_node = node->next;
+                    next_node->prev = prev_node;
+                    prev_node->next_offset = next_node->my_offset;
                 } /* end if */
-                else {
-                    /* Allocate object from end of free space node */
-                    /* (so we don't have to play with the other node's info */
-                    obj_off = (node->my_offset + node->size) - full_obj_size;
-                    node->size -= full_obj_size;
-                } /* end else */
-
-                /* Reduce space available in block */
-                dblock->blk_free_space -= full_obj_size;
-
-                /* Mark free list as dirty */
-                dblock->free_list->dirty = TRUE;
-                found = TRUE;
+                else
+                    prev_node->next_offset = 0;
             } /* end if */
 
-            /* Avance to next node */
-            node = node->next;
-        } /* end while */
+            /* Set the free fragment size */
+            free_frag_size = (unsigned char )(node->size - full_obj_size);
+
+            /* Release the memory for the free list node & section */
+            H5FL_FREE(H5HF_direct_free_node_t, node);
+            H5FL_FREE(H5HF_section_free_node_t, sec_node);
+        } /* end if */
+        else {
+            /* Allocate object from end of free space node */
+            /* (so we don't have to adjust with any other node's info */
+            obj_off = (node->my_offset + node->size) - full_obj_size;
+            node->size -= full_obj_size;
+
+            /* Adjust information for section node */
+            sec_node->sect_size -= full_obj_size;
+
+            /* Re-insert section node onto global list */
+            if(H5HF_flist_add(shared->flist, sec_node, &sec_node->sect_size, &sec_node->sect_addr) < 0)
+                HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, FAIL, "can't add direct block free space to global list")
+        } /* end else */
+
+        /* Compute the size of the space to actually allocate */
+        /* (includes the metadata for the object & the free space fragment) */
+        alloc_obj_size = full_obj_size + free_frag_size;
 
-        /* Encode metadata & copy object into block */
-        if(found) {
-            uint8_t *p;             /* Temporary pointer to obj info */
+        /* Reduce space available in block */
+        dblock->blk_free_space -= alloc_obj_size;
 
-            /* Point to location for object */
+        /* Mark free list as dirty */
+        dblock->free_list->dirty = TRUE;
+
+        /* Point to location for object */
+#ifdef QAK
 HDfprintf(stderr, "%s: obj_off = %Zu\n", FUNC, obj_off);
+HDfprintf(stderr, "%s: free_frag_size = %Zu\n", FUNC, free_frag_size);
 HDfprintf(stderr, "%s: full_obj_size = %Zu\n", FUNC, full_obj_size);
-            p = dblock->blk + obj_off;
+HDfprintf(stderr, "%s: alloc_obj_size = %Zu\n", FUNC, alloc_obj_size);
+#endif /* QAK */
+        p = dblock->blk + obj_off;
+
+        /* Encode the length */
+        UINT64ENCODE_VAR(p, obj_size, dblock->blk_off_size);
 
-            /* Encode the length, if required */
-            if(!shared->fixed_len_obj)
-                UINT64ENCODE_VAR(p, obj_size, dblock->blk_off_size);
+        /* Encode the free fragment size */
+        *p++ = free_frag_size;
 
-            /* Encode a ref. count (of 1), if required */
-            if(shared->ref_count_obj)
-                UINT64ENCODE_VAR(p, 1, shared->ref_count_size);
+        /* Encode a ref. count (of 1), if required */
+        if(shared->ref_count_obj)
+            UINT64ENCODE_VAR(p, 1, shared->ref_count_size);
 
-            /* Copy the object's data into the heap */
-            HDmemcpy(p, obj, obj_size);
+        /* Copy the object's data into the heap */
+        HDmemcpy(p, obj, obj_size);
+        p += obj_size;
+
+#ifdef H5_USING_PURIFY
+        /* Zero out the free space fragment */
+        HDmemset(p, 0, free_frag_size);
+#endif /* H5_USING_PURIFY */
 #ifndef NDEBUG
-            p += obj_size;
+        p += free_frag_size;
 #endif /* NDEBUG */
 
-            /* Sanity check */
-            HDassert((size_t)(p - (dblock->blk  + obj_off)) == full_obj_size);
+        /* Sanity check */
+        HDassert((size_t)(p - (dblock->blk  + obj_off)) == alloc_obj_size);
 
-            /* Set the head ID for the new object */
+        /* Set the heap ID for the new object */
+#ifdef QAK
 HDfprintf(stderr, "%s: dblock->block_off = %Hu\n", FUNC, dblock->block_off);
-            UINT64ENCODE_VAR(id, (dblock->block_off + obj_off), shared->heap_off_size);
-        } /* end if */
-        else
-            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "no space for object in block")
+#endif /* QAK */
+        UINT64ENCODE_VAR(id, (dblock->block_off + obj_off), shared->heap_off_size);
+
+        /* Update shared heap info */
+        shared->total_man_free -= alloc_obj_size;
 
     } /* end if */
     else {
 HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, FAIL, "inserting within mapped managed blocks not supported yet")
     } /* end else */
 
+    /* Update statistics about heap */
+    shared->nobjs++;
+
+    /* Mark heap header as modified */
+    shared->dirty = TRUE;
+
 done:
     /* Release the direct block (marked as dirty) */
-    if(dblock && H5AC_unprotect(shared->f, dxpl_id, H5AC_FHEAP_DBLOCK, block_addr, dblock, H5AC__DIRTIED_FLAG) < 0)
+    if(dblock && H5AC_unprotect(shared->f, dxpl_id, H5AC_FHEAP_DBLOCK, dblock_addr, dblock, H5AC__DIRTIED_FLAG) < 0)
         HDONE_ERROR(H5E_HEAP, H5E_CANTUNPROTECT, FAIL, "unable to release fractal heap direct block")
 
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5HF_man_dblock_insert() */
+} /* end H5HF_man_insert() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_man_iblock_create
+ *
+ * Purpose:	Allocate & initialize a managed indirect block
+ *
+ * Return:	Pointer to new direct block on success, NULL on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@ncsa.uiuc.edu
+ *		Mar  6 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5HF_man_iblock_create(H5RC_t *fh_shared, hid_t dxpl_id,
+    hsize_t block_off, unsigned nrows, haddr_t *addr_p)
+{
+    H5HF_shared_t *shared;              /* Pointer to shared heap info */
+    H5HF_indirect_t *iblock = NULL;     /* Pointer to indirect block */
+    size_t u;                           /* Local index variable */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5HF_man_iblock_create)
+
+    /*
+     * Check arguments.
+     */
+    HDassert(fh_shared);
+    HDassert(nrows > 0);
+    HDassert(addr_p);
+
+    /*
+     * Allocate file and memory data structures.
+     */
+    if(NULL == (iblock = H5FL_MALLOC(H5HF_indirect_t)))
+	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for fractal heap indirect block")
+
+    /* Reset the metadata cache info for the heap header */
+    HDmemset(&iblock->cache_info, 0, sizeof(H5AC_info_t));
+
+    /* Share common heap information */
+    iblock->shared = fh_shared;
+    H5RC_INC(iblock->shared);
+
+    /* Get the pointer to the shared B-tree info */
+    shared = H5RC_GET_OBJ(iblock->shared);
+    HDassert(shared);
+
+#ifdef QAK
+HDfprintf(stderr, "%s: nrows = %u\n", FUNC, nrows);
+#endif /* QAK */
+    /* Set info for direct block */
+    iblock->block_off = block_off;
+    iblock->nrows = nrows;
+    if(iblock->nrows > shared->man_dtable.max_direct_rows) {
+        iblock->ndir_rows = shared->man_dtable.max_direct_rows;
+        iblock->nindir_rows = iblock->nrows - iblock->ndir_rows;
+    } /* end if */
+    else {
+        iblock->ndir_rows = iblock->nrows;
+        iblock->nindir_rows = 0;
+    } /* end else */
+
+    /* Compute size of buffer needed for indirect block */
+    iblock->size = H5HF_MAN_INDIRECT_SIZE(shared, iblock);
+
+    /* Allocate indirect block entry tables */
+    if(NULL == (iblock->dblock_ents = H5FL_SEQ_MALLOC(H5HF_indirect_dblock_ent_t, (iblock->ndir_rows * shared->man_dtable.cparam.width))))
+	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for direct entries")
+    if(iblock->nindir_rows > 0) {
+        if(NULL == (iblock->iblock_ents = H5FL_SEQ_MALLOC(H5HF_indirect_iblock_ent_t, (iblock->nindir_rows * shared->man_dtable.cparam.width))))
+            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for indirect entries")
+    } /* end if */
+    else
+        iblock->iblock_ents = NULL;
+
+    /* Initialize indirect block entry tables */
+    for(u = 0; u < (iblock->ndir_rows * shared->man_dtable.cparam.width); u++) {
+        iblock->dblock_ents[u].addr = HADDR_UNDEF;
+        iblock->dblock_ents[u].free_space = 0;
+    } /* end for */
+    for(u = 0; u < (iblock->nindir_rows * shared->man_dtable.cparam.width); u++)
+        iblock->iblock_ents[u].addr = HADDR_UNDEF;
+
+    /* Allocate space for the header on disk */
+    if(HADDR_UNDEF == (*addr_p = H5MF_alloc(shared->f, H5FD_MEM_FHEAP_IBLOCK, dxpl_id, (hsize_t)iblock->size)))
+	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "file allocation failed for fractal heap header")
+
+/* XXX: Update indirect statistics when they are added */
+#ifdef LATER
+    /* Update shared heap info */
+    shared->total_man_free += dblock->blk_free_space;
+    shared->man_dtable.next_dir_block += dblock->size;
+    shared->total_size += dblock->size;
+    shared->man_size += dblock->size;
+
+    /* Mark heap header as modified */
+    shared->dirty = TRUE;
+#endif /* LATER */
+
+    /* Cache the new fractal heap header */
+    if(H5AC_set(shared->f, dxpl_id, H5AC_FHEAP_IBLOCK, *addr_p, iblock, H5AC__NO_FLAGS_SET) < 0)
+	HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, FAIL, "can't add fractal heap indirect block to cache")
+
+done:
+    if(ret_value < 0)
+        if(iblock)
+            (void)H5HF_cache_iblock_dest(shared->f, iblock);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5HF_man_iblock_create() */
 
diff --git a/src/H5HFpkg.h b/src/H5HFpkg.h
index c633919..27085fd 100644
--- a/src/H5HFpkg.h
+++ b/src/H5HFpkg.h
@@ -34,6 +34,7 @@
 #include "H5ACprivate.h"	/* Metadata cache			*/
 #include "H5FLprivate.h"	/* Free Lists                           */
 #include "H5RCprivate.h"	/* Reference counted object functions	*/
+#include "H5SLprivate.h"	/* Skip lists				*/
 
 /**************************/
 /* Package Private Macros */
@@ -45,6 +46,7 @@
 /* Fractal heap signatures */
 #define H5HF_HDR_MAGIC                  "FRHP"          /* Header */
 #define H5HF_DBLOCK_MAGIC               "FHDB"          /* Direct block */
+#define H5HF_IBLOCK_MAGIC               "FHIB"          /* Indirect block */
 
 /* "Standard" size of prefix information for fractal heap metadata */
 #define H5HF_METADATA_PREFIX_SIZE (                                           \
@@ -63,6 +65,9 @@
     + 2 /* Starting # of rows in root indirect block */                       \
     + H5F_SIZEOF_ADDR(f) /* File address of table managed */                  \
     + 2 /* Current # of rows in root indirect block */                        \
+    + H5F_SIZEOF_SIZE(f) /* Next direct block's heap offset */                \
+    + H5F_SIZEOF_SIZE(f) /* Next direct block's size */                       \
+    + 2 /* Next direct block's column */                                      \
     )
 
 /* Size of the fractal heap header on disk */
@@ -73,18 +78,28 @@
     /* Fractal heap header specific fields */                                 \
     + 1 /* Address mapping */                                                 \
     + 4 /* Min. size of standalone object */                                  \
-    + 4 /* Length of fixed-size objects */                                    \
     + 1 /* Size of ref. count for objects */                                  \
+    + H5F_SIZEOF_SIZE(f) /* Total man. free space */                          \
+    + H5F_SIZEOF_SIZE(f) /* Total std. free entries */                        \
+    + H5F_SIZEOF_SIZE(f) /* Total size of heap */                             \
+    + H5F_SIZEOF_SIZE(f) /* Size of man. space in heap */                     \
+    + H5F_SIZEOF_SIZE(f) /* Size of std. space in heap */                     \
+    + H5F_SIZEOF_SIZE(f) /* Number of objects in heap */                      \
     + H5HF_DTABLE_INFO_SIZE(f) /* Size of managed obj. doubling-table info */ \
     )
 
+/* Size of free space description in an absolute managed direct block */
+#define H5HF_MAN_ABS_DIRECT_FREE_NODE_SIZE(d) (2 * (d)->blk_off_size)
+
 /* Size of header for each object in an absolute managed direct block */
 #define H5HF_MAN_ABS_DIRECT_OBJ_PREFIX_LEN_SIZE(s, o) (                       \
-    ((s)->fixed_len_obj ? 0 : H5HF_SIZEOF_OFFSET_LEN(o))  /* Length of object in block */ \
+    H5HF_SIZEOF_OFFSET_LEN(o)   /* Length of object in block */               \
+    + 1                         /* Free space fragment length */              \
     + (s)->ref_count_size       /* Ref. count of object in block */           \
     )
 #define H5HF_MAN_ABS_DIRECT_OBJ_PREFIX_LEN_DBLOCK(s, d) (                     \
-    ((s)->fixed_len_obj ? 0 : (d)->blk_off_size)  /* Length of object in block */ \
+    (d)->blk_off_size           /* Length of object in block */               \
+    + 1                         /* Free space fragment length */              \
     + (s)->ref_count_size       /* Ref. count of object in block */           \
     )
 
@@ -110,6 +125,19 @@
     + (d)->blk_off_size         /* Offset of first descriptor in free list */ \
     )
 
+/* Size of managed indirect block (absolute & mapped) */
+#define H5HF_MAN_INDIRECT_SIZE(s, i) (                                        \
+    /* General metadata fields */                                             \
+    H5HF_METADATA_PREFIX_SIZE                                                 \
+                                                                              \
+    /* Fractal heap managed, absolutely mapped indirect block specific fields */ \
+    + H5F_SIZEOF_ADDR((s)->f)   /* File address of heap owning the block */   \
+    + (s)->heap_off_size        /* Offset of the block in the heap */         \
+    + ((i)->ndir_rows * (s)->man_dtable.cparam.width * (H5F_SIZEOF_ADDR((s)->f) + (s)->man_dtable.max_dir_blk_off_size)) /* Size of entries for direct blocks */ \
+    + ((i)->nindir_rows * (s)->man_dtable.cparam.width * H5F_SIZEOF_ADDR((s)->f)) /* Size of entries for indirect blocks */ \
+    )
+
+
 /* Compute the # of bytes required to store an offset into a given buffer size */
 #define H5HF_SIZEOF_OFFSET_BITS(b)   (((b) + 7) / 8)
 #define H5HF_SIZEOF_OFFSET_LEN(l)   H5HF_SIZEOF_OFFSET_BITS(H5V_log2_of2((unsigned)(l)))
@@ -119,11 +147,11 @@
 /****************************/
 
 /* Doubling-table info */
-typedef struct H5HF_dtable_param_t {
+typedef struct H5HF_dtable_t {
     /* Immutable, pre-set information for table */
     H5HF_dtable_cparam_t    cparam;     /* Creation parameters for table */
 
-    /* Derived information (varies during lifetime of table) */
+    /* Derived information (stored, vary during lifetime of table) */
     haddr_t     table_addr;     /* Address of first block for table */
                                 /* Undefined if no space allocated for table */
     unsigned    curr_root_rows; /* Current number of rows in the root indirect block */
@@ -131,39 +159,60 @@ typedef struct H5HF_dtable_param_t {
                                  * to direct block (of START_BLOCK_SIZE) instead
                                  * of indirect root block.
                                  */
-} H5HF_dtable_param_t;
+    hsize_t     next_dir_block; /* Offset of next direct managed block */
+    size_t      next_dir_size;  /* Size of next managed direct block */
+    unsigned    next_dir_col;   /* "Column" of next managed direct block (in doubling table) */
+
+    /* Computed information (not stored) */
+    unsigned    max_root_indirect_rows; /* Maximum # of rows in root indirect block */
+    unsigned    max_direct_rows; /* Maximum # of direct rows in any indirect block */
+    unsigned    max_dir_blk_off_size;   /* Max. size of offsets in direct blocks */
+    unsigned    first_row_bits;  /* # of bits in address of first row */
+    hsize_t     num_id_first_row;   /* Number of IDs in first row of table */
+    hsize_t     *row_block_size;    /* Block size per row of indirect block */
+} H5HF_dtable_t;
+
+/* Fractal heap free list info (forward decl - defined in H5HFflist.c) */
+typedef struct H5HF_freelist_t H5HF_freelist_t;
+
+/* Fractal heap free list section info (forward decl - defined in H5HFint.c) */
+typedef struct H5HF_section_free_node_t H5HF_section_free_node_t;
 
 /* Each fractal heap has certain information that can be shared across all
  * the instances of blocks in that fractal heap.
  */
 typedef struct H5HF_shared_t {
     /* Shared internal information (varies during lifetime of heap) */
-    hsize_t     next_man_block; /* Offset of next direct managed block */
-    hsize_t     next_std_block; /* Offset of next direct standalone block */
     hsize_t     total_man_free; /* Total amount of free space in managed blocks */
     hsize_t     total_std_free; /* Total # of free standalone ID entries */
 
-    /* Cached/computed values */
+    /* Statistics for heap */
+    hsize_t     total_size;     /* Total amount of space used by heap (managed & standalone) */
+    hsize_t     man_size;       /* Total amount of managed space in heap */
+    hsize_t     std_size;       /* Total amount of standalone space in heap */
+    hsize_t     nobjs;          /* Number of objects in heap */
+
+    /* Cached/computed values (not stored in header) */
+    hbool_t     dirty;          /* Shared info is modified */
     haddr_t     heap_addr;      /* Address of heap header in the file */
     H5F_t      *f;              /* Pointer to file for heap */
+    H5HF_freelist_t *flist;     /* Free list for objects in heap */
 
     /* Doubling table information */
     /* (Partially set by user, partially derived/updated internally) */
-    H5HF_dtable_param_t man_dtable_info;        /* Doubling-table info for managed objects */
-    H5HF_dtable_param_t std_dtable_info;        /* Doubling-table info for standalone objects */
+    H5HF_dtable_t man_dtable;   /* Doubling-table info for managed objects */
+    H5HF_dtable_t std_dtable;   /* Doubling-table info for standalone objects */
 
     /* Information set by user */
     H5HF_addrmap_t addrmap;     /* Type of address mapping */
     uint32_t standalone_size;   /* Size of object to store standalone */
-    uint32_t fixed_len_size;    /* Size of objects (only for heaps w/fixed-length objects) */
     unsigned char ref_count_size; /* Size of ref. count for objects (only for heaps w/ref. counted objects) */
 
-    /* Information derived from user parameters */
-    hbool_t     fixed_len_obj;  /* Are objects in the heap fixed length? */
+    /* Information derived from user parameters (not stored in header) */
+    unsigned char heap_off_size; /* Size of heap offsets (in bytes) */
     hbool_t     ref_count_obj;  /* Are objects in the heap ref. counted? */
     hbool_t     have_io_filter; /* Does the heap have I/O filters for the direct blocks? */
     hbool_t     write_once;     /* Is heap being written in "write once" mode? */
-    unsigned char heap_off_size; /* Size of heap offsets (in bytes) */
 } H5HF_shared_t;
 
 /* The fractal heap header information */
@@ -177,6 +226,7 @@ typedef struct H5HF_t {
 
 /* Direct block free list node */
 typedef struct H5HF_direct_free_node_t {
+    /* Direct block free list info */
     size_t      size;                           /* Size of free space */
     size_t      my_offset;                      /* Offset of free space in block */
     size_t      next_offset;                    /* Offset of next free space in block */
@@ -198,7 +248,7 @@ typedef struct H5HF_direct_t {
     /* Internal heap information */
     H5RC_t	*shared;	/* Ref-counted shared info	              */
     size_t      size;           /* Size of direct block                       */
-    size_t      blk_off_size;   /* Size of offsets in the block               */
+    unsigned    blk_off_size;   /* Size of offsets in the block               */
     H5HF_direct_free_head_t *free_list; /* Pointer to free list for block     */
     uint8_t     *blk;           /* Pointer to buffer containing block data    */
 
@@ -208,6 +258,45 @@ typedef struct H5HF_direct_t {
     size_t      free_list_head; /* Offset of head of free list in block       */
 } H5HF_direct_t;
 
+/* Indirect block direct block entry */
+typedef struct H5HF_indirect_dblock_ent_t {
+    haddr_t     addr;           /* Direct block's address                     */
+    size_t      free_space;     /* Amount of free space in direct block       */
+/* XXX: Will need space for block size, for blocks with I/O filters */
+} H5HF_indirect_dblock_ent_t;
+
+/* Indirect block indirect block entry */
+typedef struct H5HF_indirect_iblock_ent_t {
+    haddr_t     addr;           /* Indirect block's address                   */
+} H5HF_indirect_iblock_ent_t;
+
+/* Fractal heap indirect block */
+typedef struct H5HF_indirect_t {
+    /* Information for H5AC cache functions, _must_ be first field in structure */
+    H5AC_info_t cache_info;
+
+    /* Internal heap information */
+    H5RC_t	*shared;	/* Ref-counted shared info	              */
+    unsigned    nrows;          /* Total # of rows in indirect block          */
+    unsigned    ndir_rows;      /* # of direct rows in indirect block         */
+    unsigned    nindir_rows;    /* # of indirect rows in indirect block       */
+    size_t      size;           /* Size of indirect block on disk             */
+    H5HF_indirect_dblock_ent_t *dblock_ents;    /* Pointer to direct block entry table */
+    H5HF_indirect_iblock_ent_t *iblock_ents;    /* Pointer to indirect block entry table */
+
+    /* Stored values */
+    hsize_t     block_off;      /* Offset of the block within the heap's address space */
+} H5HF_indirect_t;
+
+/* Fractal heap metadata statistics info */
+typedef struct H5HF_stat_t {
+    hsize_t total_size;         /* Total size of heap allocated (man & std)   */
+    hsize_t man_size;           /* Total size of managed space in heap        */
+    hsize_t std_size;           /* Total size of standalone space in heap     */
+    hsize_t man_free_space;     /* Free space within heap                     */
+    hsize_t nobjs;              /* Number of objects in heap                  */
+} H5HF_stat_t;
+
 
 /*****************************/
 /* Package Private Variables */
@@ -219,6 +308,9 @@ H5_DLLVAR const H5AC_class_t H5AC_FHEAP_HDR[1];
 /* H5HF direct block inherits cache-like properties from H5AC */
 H5_DLLVAR const H5AC_class_t H5AC_FHEAP_DBLOCK[1];
 
+/* H5HF indirect block inherits cache-like properties from H5AC */
+H5_DLLVAR const H5AC_class_t H5AC_FHEAP_IBLOCK[1];
+
 /* Declare a free list to manage the H5HF_t struct */
 H5FL_EXTERN(H5HF_t);
 
@@ -234,6 +326,14 @@ H5FL_EXTERN(H5HF_direct_free_node_t);
 /* Declare a free list to manage heap direct block data to/from disk */
 H5FL_BLK_EXTERN(direct_block);
 
+/* Declare a free list to manage the H5HF_indirect_t struct */
+H5FL_EXTERN(H5HF_indirect_t);
+
+/* Declare a free list to manage the H5HF_indirect_dblock_ent_t sequence information */
+H5FL_SEQ_EXTERN(H5HF_indirect_dblock_ent_t);
+
+/* Declare a free list to manage the H5HF_indirect_iblock_ent_t sequence information */
+H5FL_SEQ_EXTERN(H5HF_indirect_iblock_ent_t);
 
 
 /******************************/
@@ -246,19 +346,38 @@ H5_DLL herr_t H5HF_shared_create(H5F_t *f, H5HF_t *fh, haddr_t heap_addr, H5HF_c
 H5_DLL herr_t H5HF_shared_own(H5HF_t *fh, H5HF_shared_t *shared);
 
 /* Routines for allocating space */
-H5_DLL herr_t H5HF_man_alloc_end(H5RC_t *fh_shared, hid_t dxpl_id, unsigned *fh_flags_ptr,
-    size_t size, const void *obj, void *id/*out*/);
-H5_DLL herr_t H5HF_man_dblock_build_freelist(H5HF_direct_t *dblock);
+H5_DLL herr_t H5HF_man_dblock_build_freelist(H5HF_direct_t *dblock, haddr_t dblock_addr);
+H5_DLL herr_t H5HF_man_find(H5RC_t *fh_shared, hid_t dxpl_id, size_t request,
+    H5HF_section_free_node_t **sec_node/*out*/);
+H5_DLL herr_t H5HF_man_insert(H5RC_t *fh_shared, hid_t dxpl_id,
+    H5HF_section_free_node_t *sec_node, size_t obj_size, const void *obj,
+    void *id);
 
 /* Metadata cache callbacks */
 H5_DLL herr_t H5HF_cache_hdr_dest(H5F_t *f, H5HF_t *fh);
 H5_DLL herr_t H5HF_cache_dblock_dest(H5F_t *f, H5HF_direct_t *dblock);
+H5_DLL herr_t H5HF_cache_iblock_dest(H5F_t *f, H5HF_indirect_t *iblock);
 
 /* Debugging routines for dumping file structures */
 H5_DLL herr_t H5HF_hdr_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr,
     FILE *stream, int indent, int fwidth);
 H5_DLL herr_t H5HF_dblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr,
     FILE *stream, int indent, int fwidth, haddr_t hdr_addr, size_t nrec);
+H5_DLL herr_t H5HF_iblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr,
+    FILE *stream, int indent, int fwidth, haddr_t hdr_addr, unsigned nrows);
+
+/* Statistics routines */
+H5_DLL herr_t H5HF_stat_info(H5F_t *f, hid_t dxpl_id, haddr_t fh_addr,
+    H5HF_stat_t *stats);
+
+/* Free list routines */
+H5_DLL H5HF_freelist_t * H5HF_flist_create(size_t max_block_size,
+    H5SL_operator_t node_free_op);
+H5_DLL herr_t H5HF_flist_add(H5HF_freelist_t *flist, void *node, size_t *size_key,
+    haddr_t *addr_key);
+H5_DLL htri_t H5HF_flist_find(H5HF_freelist_t *flist, size_t request,
+    void **node);
+H5_DLL herr_t H5HF_flist_free(H5HF_freelist_t *flist);
 
 /* Testing routines */
 #ifdef H5HF_TESTING
diff --git a/src/H5HFprivate.h b/src/H5HFprivate.h
index 984d717..b5abe9e 100644
--- a/src/H5HFprivate.h
+++ b/src/H5HFprivate.h
@@ -65,8 +65,6 @@ typedef struct H5HF_create_t {
     H5HF_addrmap_t addrmap;     /* Type of address mapping for objects in heap */
     uint32_t standalone_size;   /* Size of object to store standalone */
                                 /* (i.e. max. size of object to manage) */
-    uint32_t fixed_len_size;    /* Size of objects, in bytes (0 means variable-sized objects) */
-                                /* (only for heaps w/fixed-length objects) */
     unsigned char ref_count_size; /* Size of ref. count field for objects, in bytes (0 means no ref. counts for objects) */
                                 /* (only for heaps w/ref. counted objects) */
 } H5HF_create_t;
diff --git a/src/H5HFstat.c b/src/H5HFstat.c
new file mode 100644
index 0000000..78be450
--- /dev/null
+++ b/src/H5HFstat.c
@@ -0,0 +1,117 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic HDF5 document set and   *
+ * is linked from the top-level documents page.  It can also be found at     *
+ * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html.  If you do not have     *
+ * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/* Programmer:  Quincey Koziol <koziol@ncsa.uiuc.edu>
+ *              Monday, March  6, 2006
+ *
+ * Purpose:	Fractal heap metadata statistics functions.
+ *
+ */
+
+/****************/
+/* Module Setup */
+/****************/
+
+#define H5HF_PACKAGE		/*suppress error about including H5HFpkg  */
+
+/***********/
+/* Headers */
+/***********/
+#include "H5private.h"		/* Generic Functions			*/
+#include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5HFpkg.h"		/* Fractal heaps			*/
+
+/****************/
+/* Local Macros */
+/****************/
+
+
+/******************/
+/* Local Typedefs */
+/******************/
+
+
+/********************/
+/* Local Prototypes */
+/********************/
+
+
+/*********************/
+/* Package Variables */
+/*********************/
+
+
+/*****************************/
+/* Library Private Variables */
+/*****************************/
+
+
+/*******************/
+/* Local Variables */
+/*******************/
+
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_stat_info
+ *
+ * Purpose:	Retrieve metadata statistics for the fractal heap
+ *
+ * Return:	Success:	non-negative
+ *
+ *		Failure:	negative
+ *
+ * Programmer:	Quincey Koziol
+ *              Monday, March  6, 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5HF_stat_info(H5F_t *f, hid_t dxpl_id, haddr_t fh_addr, H5HF_stat_t *stats)
+{
+    H5HF_t	*fh = NULL;             /* Pointer to the B-tree header */
+    H5HF_shared_t *shared;              /* Shared fractal heap information */
+    herr_t	ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5HF_stat_info)
+
+    /* Check arguments. */
+    HDassert(f);
+    HDassert(H5F_addr_defined(fh_addr));
+    HDassert(stats);
+
+    /* Look up the fractal heap header */
+    if(NULL == (fh = H5AC_protect(f, dxpl_id, H5AC_FHEAP_HDR, fh_addr, NULL, NULL, H5AC_READ)))
+	HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, FAIL, "unable to load fractal heap header")
+
+    /* Get the pointer to the shared fractal heap info */
+    shared = H5RC_GET_OBJ(fh->shared);
+    HDassert(shared);
+
+    /* Report statistics for fractal heap */
+    stats->total_size = shared->total_size;
+    stats->man_size = shared->man_size;
+    stats->std_size = shared->std_size;
+    stats->man_free_space = shared->total_man_free;
+    stats->nobjs = shared->nobjs;
+/* XXX: Add more metadata statistics for the heap */
+
+done:
+    /* Release fractal heap header node */
+    if(fh && H5AC_unprotect(f, dxpl_id, H5AC_FHEAP_HDR, fh_addr, fh, H5AC__NO_FLAGS_SET) < 0)
+        HDONE_ERROR(H5E_HEAP, H5E_CANTUNPROTECT, FAIL, "unable to release fractal heap header info")
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5HF_stat_info() */
+
diff --git a/src/H5HFtest.c b/src/H5HFtest.c
index d17f804..43c9573 100644
--- a/src/H5HFtest.c
+++ b/src/H5HFtest.c
@@ -13,9 +13,10 @@
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 /* Programmer:  Quincey Koziol <koziol@ncsa.uiuc.edu>
- *              Thursday, February  3, 2005
+ *              Thursday, February  3, 2006
  *
  * Purpose:	Fractal heap testing functions.
+ *
  */
 
 /****************/
@@ -29,8 +30,8 @@
 /* Headers */
 /***********/
 #include "H5private.h"		/* Generic Functions			*/
-#include "H5HFpkg.h"		/* Fractal heaps			*/
 #include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5HFpkg.h"		/* Fractal heaps			*/
 
 /****************/
 /* Local Macros */
@@ -102,9 +103,8 @@ H5HF_get_cparam_test(H5F_t *f, hid_t dxpl_id, haddr_t fh_addr, H5HF_create_t *cp
     /* Get fractal heap creation parameters */
     cparam->addrmap = shared->addrmap;
     cparam->standalone_size = shared->standalone_size;
-    cparam->fixed_len_size = shared->fixed_len_size;
     cparam->ref_count_size = shared->ref_count_size;
-    HDmemcpy(&(cparam->managed), &(shared->man_dtable_info.cparam), sizeof(H5HF_dtable_cparam_t));
+    HDmemcpy(&(cparam->managed), &(shared->man_dtable.cparam), sizeof(H5HF_dtable_cparam_t));
 
 done:
     /* Release fractal heap header node */
diff --git a/src/Makefile.am b/src/Makefile.am
index d6ebcfb..32e4ed5 100755
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -38,7 +38,7 @@ MOSTLYCLEANFILES=H5Tinit.c
 
 # library sources
 libhdf5_la_SOURCES= H5.c H5dbg.c H5A.c H5AC.c H5B.c H5Bcache.c \
-        H5B2.c H5B2cache.c H5B2dbg.c H5B2int.c H5B2test.c \
+        H5B2.c H5B2cache.c H5B2dbg.c H5B2int.c H5B2stat.c H5B2test.c \
         H5C.c \
         H5D.c \
         H5Dcompact.c \
@@ -54,7 +54,7 @@ libhdf5_la_SOURCES= H5.c H5dbg.c H5A.c H5AC.c H5B.c H5Bcache.c \
         H5Gstab.c  \
         H5Gtest.c  \
         H5Gtraverse.c  \
-        H5HF.c H5HFcache.c H5HFdbg.c H5HFint.c H5HFtest.c \
+        H5HF.c H5HFcache.c H5HFdbg.c H5HFflist.c H5HFint.c H5HFstat.c H5HFtest.c \
         H5HG.c H5HGdbg.c H5HL.c H5HLdbg.c H5HP.c H5I.c H5MF.c H5MM.c \
         H5MP.c H5MPtest.c \
         H5O.c \
diff --git a/src/Makefile.in b/src/Makefile.in
index 2ac3a81..abd3096 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -83,7 +83,7 @@ libLTLIBRARIES_INSTALL = $(INSTALL)
 LTLIBRARIES = $(lib_LTLIBRARIES)
 libhdf5_la_LIBADD =
 am_libhdf5_la_OBJECTS = H5.lo H5dbg.lo H5A.lo H5AC.lo H5B.lo \
-	H5Bcache.lo H5B2.lo H5B2cache.lo H5B2dbg.lo H5B2int.lo \
+	H5Bcache.lo H5B2.lo H5B2cache.lo H5B2dbg.lo H5B2int.lo H5B2stat.lo \
 	H5B2test.lo H5C.lo H5D.lo H5Dcompact.lo H5Dcontig.lo H5Defl.lo \
 	H5Dio.lo H5Distore.lo H5Dmpio.lo H5Doh.lo H5Dselect.lo \
 	H5Dtest.lo H5E.lo H5F.lo H5Fdbg.lo H5Fmount.lo H5Fsfile.lo \
@@ -93,7 +93,7 @@ am_libhdf5_la_OBJECTS = H5.lo H5dbg.lo H5A.lo H5AC.lo H5B.lo \
 	H5FPclient.lo H5FPserver.lo H5FS.lo H5G.lo H5Gent.lo \
 	H5Glink.lo H5Gloc.lo H5Gname.lo H5Gnode.lo H5Gobj.lo H5Goh.lo \
 	H5Gstab.lo H5Gtest.lo H5Gtraverse.lo H5HF.lo H5HFcache.lo \
-	H5HFdbg.lo H5HFint.lo H5HFtest.lo H5HG.lo H5HGdbg.lo H5HL.lo \
+	H5HFdbg.lo H5HFflist.lo H5HFint.lo H5HFstat.lo H5HFtest.lo H5HG.lo H5HGdbg.lo H5HL.lo \
 	H5HLdbg.lo H5HP.lo H5I.lo H5MF.lo H5MM.lo H5MP.lo H5MPtest.lo \
 	H5O.lo H5Oattr.lo H5Obogus.lo H5Ocache.lo H5Ocont.lo \
 	H5Odtype.lo H5Oefl.lo H5Ofill.lo H5Oginfo.lo H5Olayout.lo \
@@ -390,7 +390,7 @@ MOSTLYCLEANFILES = H5Tinit.c
 
 # library sources
 libhdf5_la_SOURCES = H5.c H5dbg.c H5A.c H5AC.c H5B.c H5Bcache.c \
-        H5B2.c H5B2cache.c H5B2dbg.c H5B2int.c H5B2test.c \
+        H5B2.c H5B2cache.c H5B2dbg.c H5B2int.c H5B2stat.c H5B2test.c \
         H5C.c \
         H5D.c \
         H5Dcompact.c \
@@ -406,7 +406,7 @@ libhdf5_la_SOURCES = H5.c H5dbg.c H5A.c H5AC.c H5B.c H5Bcache.c \
         H5Gstab.c  \
         H5Gtest.c  \
         H5Gtraverse.c  \
-        H5HF.c H5HFcache.c H5HFdbg.c H5HFint.c H5HFtest.c \
+        H5HF.c H5HFcache.c H5HFdbg.c H5HFflist.c H5HFint.c H5HFstat.c H5HFtest.c \
         H5HG.c H5HGdbg.c H5HL.c H5HLdbg.c H5HP.c H5I.c H5MF.c H5MM.c \
         H5MP.c H5MPtest.c \
         H5O.c \
@@ -567,6 +567,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5B2cache.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5B2dbg.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5B2int.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5B2stat.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5B2test.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Bcache.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5C.Plo@am__quote@
@@ -618,7 +619,9 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5HF.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5HFcache.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5HFdbg.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5HFflist.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5HFint.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5HFstat.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5HFtest.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5HG.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5HGdbg.Plo@am__quote@