[svn-r13472] Description:

	Add new object header message to track attribute information (unused
currently).

Tested on:
	Mac OS X/32 10.4.8 (amazon)

8 files changed, 440 insertions, 24 deletions

diff --git a/MANIFEST b/MANIFEST
index 63fb2d7..806dd35 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -582,6 +582,7 @@
 ./src/H5MPprivate.h
 ./src/H5MPtest.c
 ./src/H5O.c
+./src/H5Oainfo.c
 ./src/H5Oalloc.c
 ./src/H5Oattr.c
 ./src/H5Oattribute.c
diff --git a/src/H5O.c b/src/H5O.c
index 48ee26e..94bfcc1 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -79,11 +79,11 @@ static herr_t H5O_obj_type_real(H5O_t *oh, H5O_type_t *obj_type);
 /* Header message ID to class mapping */
 const H5O_msg_class_t *const H5O_msg_class_g[] = {
     H5O_MSG_NULL,		/*0x0000 Null				*/
-    H5O_MSG_SDSPACE,		/*0x0001 Simple Dimensionality		*/
+    H5O_MSG_SDSPACE,		/*0x0001 Dataspace			*/
     H5O_MSG_LINFO,		/*0x0002 Link information		*/
-    H5O_MSG_DTYPE,		/*0x0003 Data Type			*/
+    H5O_MSG_DTYPE,		/*0x0003 Datatype			*/
     H5O_MSG_FILL,       	/*0x0004 Old data storage -- fill value */
-    H5O_MSG_FILL_NEW,		/*0x0005 New Data storage -- fill value */
+    H5O_MSG_FILL_NEW,		/*0x0005 New data storage -- fill value */
     H5O_MSG_LINK,		/*0x0006 Link 				*/
     H5O_MSG_EFL,		/*0x0007 Data storage -- external data files */
     H5O_MSG_LAYOUT,		/*0x0008 Data Layout			*/
@@ -92,7 +92,7 @@ const H5O_msg_class_t *const H5O_msg_class_g[] = {
 #else /* H5O_ENABLE_BOGUS */
     NULL,			/*0x0009 "Bogus" (for testing)		*/
 #endif /* H5O_ENABLE_BOGUS */
-    H5O_MSG_GINFO,		/*0x000A Group Information		*/
+    H5O_MSG_GINFO,		/*0x000A Group information		*/
     H5O_MSG_PLINE,		/*0x000B Data storage -- filter pipeline */
     H5O_MSG_ATTR,		/*0x000C Attribute list			*/
     H5O_MSG_NAME,		/*0x000D Object name			*/
@@ -103,6 +103,7 @@ const H5O_msg_class_t *const H5O_msg_class_g[] = {
     H5O_MSG_MTIME_NEW,		/*0x0012 New Object modification date and time */
     H5O_MSG_BTREEK,		/*0x0013 Non-default v1 B-tree 'K' values */
     H5O_MSG_DRVINFO,		/*0x0014 Driver info settings		*/
+    H5O_MSG_AINFO,		/*0x0015 Attribute information	*/
 };
 
 /* Header object ID to class mapping */
diff --git a/src/H5Oainfo.c b/src/H5Oainfo.c
new file mode 100644
index 0000000..514d451
--- /dev/null
+++ b/src/H5Oainfo.c
@@ -0,0 +1,392 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * 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://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have          *
+ * access to either file, you may request a copy from help@hdfgroup.org.     *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*-------------------------------------------------------------------------
+ *
+ * Created:             H5Oainfo.c
+ *                      Mar  6 2007
+ *                      Quincey Koziol <koziol@hdfgroup.org>
+ *
+ * Purpose:             Attribute Information messages.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#define H5O_PACKAGE		/*suppress error about including H5Opkg	  */
+
+#include "H5private.h"		/* Generic Functions			*/
+#include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5FLprivate.h"	/* Free lists                           */
+#include "H5Opkg.h"             /* Object headers			*/
+
+
+/* PRIVATE PROTOTYPES */
+static void *H5O_ainfo_decode(H5F_t *f, hid_t dxpl_id, unsigned mesg_flags, const uint8_t *p);
+static herr_t H5O_ainfo_encode(H5F_t *f, hbool_t disable_shared, uint8_t *p, const void *_mesg);
+static void *H5O_ainfo_copy(const void *_mesg, void *_dest);
+static size_t H5O_ainfo_size(const H5F_t *f, hbool_t disable_shared, const void *_mesg);
+static herr_t H5O_ainfo_free(void *_mesg);
+static herr_t H5O_ainfo_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg);
+static herr_t H5O_ainfo_debug(H5F_t *f, hid_t dxpl_id, const void *_mesg,
+			     FILE * stream, int indent, int fwidth);
+
+/* This message derives from H5O message class */
+const H5O_msg_class_t H5O_MSG_AINFO[1] = {{
+    H5O_AINFO_ID,            	/*message id number             */
+    "ainfo",                 	/*message name for debugging    */
+    sizeof(H5O_ainfo_t),     	/*native message size           */
+    FALSE,			/* messages are sharable?       */
+    H5O_ainfo_decode,        	/*decode message                */
+    H5O_ainfo_encode,        	/*encode message                */
+    H5O_ainfo_copy,          	/*copy the native value         */
+    H5O_ainfo_size,          	/*size of symbol table entry    */
+    NULL,                   	/*default reset method          */
+    H5O_ainfo_free,	        /* free method			*/
+    H5O_ainfo_delete,	        /* file delete method		*/
+    NULL,			/* link method			*/
+    NULL, 			/*set share method		*/
+    NULL,		    	/*can share method		*/
+    NULL,			/* pre copy native value to file */
+    NULL,			/* copy native value to file    */
+    NULL,			/* post copy native value to file */
+    NULL,			/* get creation index		*/
+    NULL,			/* set creation index		*/
+    H5O_ainfo_debug          	/*debug the message             */
+}};
+
+/* Current version of attribute info information */
+#define H5O_AINFO_VERSION 	0
+
+/* Flags for attribute info index flag encoding */
+#define H5O_AINFO_INDEX_NAME            0x01
+#define H5O_AINFO_INDEX_CORDER          0x02
+#define H5O_AINFO_ALL_FLAGS             (H5O_AINFO_INDEX_NAME | H5O_AINFO_INDEX_CORDER)
+
+/* Declare a free list to manage the H5O_ainfo_t struct */
+H5FL_DEFINE_STATIC(H5O_ainfo_t);
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5O_ainfo_decode
+ *
+ * Purpose:     Decode a message and return a pointer to a newly allocated one.
+ *
+ * Return:      Success:        Ptr to new message in native form.
+ *              Failure:        NULL
+ *
+ * Programmer:  Quincey Koziol
+ *              koziol@hdfgroup.org
+ *              Mar  6 2007
+ *
+ *-------------------------------------------------------------------------
+ */
+static void *
+H5O_ainfo_decode(H5F_t *f, hid_t UNUSED dxpl_id, unsigned UNUSED mesg_flags,
+    const uint8_t *p)
+{
+    H5O_ainfo_t	*ainfo = NULL;  /* Attribute info */
+    unsigned char index_flags;  /* Flags for encoding link index info */
+    void        *ret_value;     /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5O_ainfo_decode)
+
+    /* check args */
+    HDassert(f);
+    HDassert(p);
+
+    /* Version of message */
+    if(*p++ != H5O_AINFO_VERSION)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "bad version number for message")
+
+    /* Allocate space for message */
+    if(NULL == (ainfo = H5FL_MALLOC(H5O_ainfo_t)))
+	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
+
+    /* Get the index flags for the object */
+    index_flags = *p++;
+    HDassert(index_flags & H5O_AINFO_INDEX_NAME);
+    if(index_flags & ~H5O_AINFO_ALL_FLAGS)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "bad flag value for message")
+    ainfo->index_corder = (index_flags & H5O_AINFO_INDEX_CORDER) ? TRUE : FALSE;
+
+    /* Number of attributes on the object */
+    H5F_DECODE_LENGTH(f, p, ainfo->nattrs)
+
+    /* Max. creation order value for the object */
+    UINT16DECODE(p, ainfo->max_crt_idx);
+
+    /* Address of fractal heap to store "dense" attributes */
+    H5F_addr_decode(f, &p, &(ainfo->fheap_addr));
+
+    /* Address of v2 B-tree to index names of attributes (names are always indexed) */
+    H5F_addr_decode(f, &p, &(ainfo->name_bt2_addr));
+
+    /* Address of v2 B-tree to index creation order of links, if there is one */
+    if(ainfo->index_corder)
+        H5F_addr_decode(f, &p, &(ainfo->corder_bt2_addr));
+    else
+        ainfo->corder_bt2_addr = HADDR_UNDEF;
+
+    /* Set return value */
+    ret_value = ainfo;
+
+done:
+    if(ret_value == NULL)
+        if(ainfo != NULL)
+            H5FL_FREE(H5O_ainfo_t, ainfo);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_ainfo_decode() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5O_ainfo_encode
+ *
+ * Purpose:     Encodes a message.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Quincey Koziol
+ *              koziol@hdfgroup.org
+ *              Mar  6 2007
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5O_ainfo_encode(H5F_t *f, hbool_t UNUSED disable_shared, uint8_t *p, const void *_mesg)
+{
+    const H5O_ainfo_t   *ainfo = (const H5O_ainfo_t *)_mesg;
+    unsigned char       index_flags;          /* Flags for encoding attribute index info */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5O_ainfo_encode)
+
+    /* check args */
+    HDassert(f);
+    HDassert(p);
+    HDassert(ainfo);
+
+    /* Message version */
+    *p++ = H5O_AINFO_VERSION;
+
+    /* The flags for the attribute indices */
+    index_flags = H5O_AINFO_INDEX_NAME;       /* Names are always indexed */
+    index_flags |= ainfo->index_corder ? H5O_AINFO_INDEX_CORDER : 0;
+    *p++ = index_flags;
+
+    /* Number of attributes on the object */
+    H5F_ENCODE_LENGTH(f, p, ainfo->nattrs)
+
+    /* Max. creation order value for the object */
+    UINT16ENCODE(p, ainfo->max_crt_idx);
+
+    /* Address of fractal heap to store "dense" attributes */
+    H5F_addr_encode(f, &p, ainfo->fheap_addr);
+
+    /* Address of v2 B-tree to index names of attributes */
+    H5F_addr_encode(f, &p, ainfo->name_bt2_addr);
+
+    /* Address of v2 B-tree to index creation order of attributes, if they are indexed */
+    if(ainfo->index_corder)
+        H5F_addr_encode(f, &p, ainfo->corder_bt2_addr);
+    else
+        HDassert(!H5F_addr_defined(ainfo->corder_bt2_addr));
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5O_ainfo_encode() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5O_ainfo_copy
+ *
+ * Purpose:     Copies a message from _MESG to _DEST, allocating _DEST if
+ *              necessary.
+ *
+ * Return:      Success:        Ptr to _DEST
+ *              Failure:        NULL
+ *
+ * Programmer:  Quincey Koziol
+ *              koziol@hdfgroup.org
+ *              Mar  6 2007
+ *
+ *-------------------------------------------------------------------------
+ */
+static void *
+H5O_ainfo_copy(const void *_mesg, void *_dest)
+{
+    const H5O_ainfo_t   *ainfo = (const H5O_ainfo_t *)_mesg;
+    H5O_ainfo_t         *dest = (H5O_ainfo_t *) _dest;
+    void                *ret_value;     /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5O_ainfo_copy)
+
+    /* check args */
+    HDassert(ainfo);
+    if(!dest && NULL == (dest = H5FL_MALLOC(H5O_ainfo_t)))
+	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
+
+    /* copy */
+    *dest = *ainfo;
+
+    /* Set return value */
+    ret_value = dest;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_ainfo_copy() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5O_ainfo_size
+ *
+ * Purpose:     Returns the size of the raw message in bytes not counting
+ *              the message type or size fields, but only the data fields.
+ *              This function doesn't take into account alignment.
+ *
+ * Return:      Success:        Message data size in bytes without alignment.
+ *              Failure:        zero
+ *
+ * Programmer:  Quincey Koziol
+ *              koziol@hdfgroup.org
+ *              Mar  6 2007
+ *
+ *-------------------------------------------------------------------------
+ */
+static size_t
+H5O_ainfo_size(const H5F_t *f, hbool_t UNUSED disable_shared, const void *_mesg)
+{
+    const H5O_ainfo_t   *ainfo = (const H5O_ainfo_t *)_mesg;
+    size_t ret_value;   /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5O_ainfo_size)
+
+    /* Set return value */
+    ret_value = 1                       /* Version */
+                + 1                     /* Index flags */
+                + H5F_SIZEOF_SIZE(f)    /* Number of attributes */
+                + 2                     /* Curr. max. creation order value */
+                + H5F_SIZEOF_ADDR(f)    /* Address of fractal heap to store "dense" attributes */
+                + H5F_SIZEOF_ADDR(f)    /* Address of v2 B-tree for indexing names of attributes */
+                + (ainfo->index_corder ? H5F_SIZEOF_ADDR(f) : 0);   /* Address of v2 B-tree for indexing creation order values of attributes */
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_ainfo_size() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5O_ainfo_free
+ *
+ * Purpose:	Free's the message
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *              Tuesday, March  6, 2007
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5O_ainfo_free(void *mesg)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5O_ainfo_free)
+
+    HDassert(mesg);
+
+    H5FL_FREE(H5O_ainfo_t, mesg);
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5O_ainfo_free() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5O_ainfo_delete
+ *
+ * Purpose:     Free file space referenced by message
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Quincey Koziol
+ *              Tuesday, March  6, 2007
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5O_ainfo_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg)
+{
+    const H5O_ainfo_t *ainfo = (const H5O_ainfo_t *)_mesg;
+    herr_t ret_value = SUCCEED;   /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5O_ainfo_delete)
+
+    /* check args */
+    HDassert(f);
+    HDassert(ainfo);
+
+    /* If the object is using "dense" attribute storage, delete it */
+#ifdef NOT_YET
+    if(H5F_addr_defined(ainfo->fheap_addr))
+        if(H5G_dense_delete(f, dxpl_id, (H5O_linfo_t *)linfo, TRUE) < 0)   /* Casting away const OK - QAK */
+            HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to free dense link storage")
+#endif /* NOT_YET */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_ainfo_delete() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5O_ainfo_debug
+ *
+ * Purpose:     Prints debugging info for a message.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Quincey Koziol
+ *              koziol@hdfgroup.org
+ *              Mar  6 2007
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5O_ainfo_debug(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, const void *_mesg, FILE * stream,
+	       int indent, int fwidth)
+{
+    const H5O_ainfo_t       *ainfo = (const H5O_ainfo_t *) _mesg;
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5O_ainfo_debug)
+
+    /* check args */
+    HDassert(f);
+    HDassert(ainfo);
+    HDassert(stream);
+    HDassert(indent >= 0);
+    HDassert(fwidth >= 0);
+
+    HDfprintf(stream, "%*s%-*s %t\n", indent, "", fwidth,
+	      "Index creation order of links:", ainfo->index_corder);
+    HDfprintf(stream, "%*s%-*s %Hu\n", indent, "", fwidth,
+	      "Number of attributes:", ainfo->nattrs);
+    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
+	      "Max. creation index value:", (unsigned)ainfo->max_crt_idx);
+    HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
+	      "'Dense' attribute storage fractal heap address:", ainfo->fheap_addr);
+    HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
+	      "'Dense' attribute storage name index v2 B-tree address:", ainfo->name_bt2_addr);
+    HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
+	      "'Dense' attribute storage creation order index v2 B-tree address:", ainfo->corder_bt2_addr);
+
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5O_ainfo_debug() */
+
diff --git a/src/H5Olinfo.c b/src/H5Olinfo.c
index 6184d07..e3ea8fd 100644
--- a/src/H5Olinfo.c
+++ b/src/H5Olinfo.c
@@ -77,8 +77,9 @@ const H5O_msg_class_t H5O_MSG_LINFO[1] = {{
 #define H5O_LINFO_VERSION 	0
 
 /* Flags for link info index flag encoding */
-#define H5O_LINFO_INDEX_NAME          0x01
-#define H5O_LINFO_INDEX_CORDER        0x02
+#define H5O_LINFO_INDEX_NAME            0x01
+#define H5O_LINFO_INDEX_CORDER          0x02
+#define H5O_LINFO_ALL_FLAGS             (H5O_LINFO_INDEX_NAME | H5O_LINFO_INDEX_CORDER)
 
 /* Data exchange structure to use when copying links from src to dst */
 typedef struct {
@@ -89,18 +90,16 @@ typedef struct {
     H5O_copy_t  *cpy_info;              /* Information for copy operation */
 } H5O_linfo_postcopy_ud_t;
 
-/* Declare a free list to manage the hsize_t struct */
+/* Declare a free list to manage the H5O_linfo_t struct */
 H5FL_DEFINE_STATIC(H5O_linfo_t);
 
 
 /*-------------------------------------------------------------------------
  * Function:    H5O_linfo_decode
  *
- * Purpose:     Decode a message and return a pointer to
- *              a newly allocated one.
- *
- * Return:      Success:        Ptr to new message in native order.
+ * Purpose:     Decode a message and return a pointer to a newly allocated one.
  *
+ * Return:      Success:        Ptr to new message in native form.
  *              Failure:        NULL
  *
  * Programmer:  Quincey Koziol
@@ -113,8 +112,8 @@ static void *
 H5O_linfo_decode(H5F_t *f, hid_t UNUSED dxpl_id, unsigned UNUSED mesg_flags,
     const uint8_t *p)
 {
-    unsigned char index_flags;  /* Flags for encoding link index info */
     H5O_linfo_t	*linfo = NULL;  /* Link info */
+    unsigned char index_flags;  /* Flags for encoding link index info */
     void        *ret_value;     /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT(H5O_linfo_decode)
@@ -134,6 +133,8 @@ H5O_linfo_decode(H5F_t *f, hid_t UNUSED dxpl_id, unsigned UNUSED mesg_flags,
     /* Get the index flags for the group */
     index_flags = *p++;
     HDassert(index_flags & H5O_LINFO_INDEX_NAME);
+    if(index_flags & ~H5O_LINFO_ALL_FLAGS)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "bad flag value for message")
     linfo->index_corder = (index_flags & H5O_LINFO_INDEX_CORDER) ? TRUE : FALSE;
 
     /* Number of links in the group */
@@ -231,7 +232,6 @@ H5O_linfo_encode(H5F_t *f, hbool_t UNUSED disable_shared, uint8_t *p, const void
  *              necessary.
  *
  * Return:      Success:        Ptr to _DEST
- *
  *              Failure:        NULL
  *
  * Programmer:  Quincey Koziol
@@ -273,7 +273,6 @@ done:
  *              This function doesn't take into account alignment.
  *
  * Return:      Success:        Message data size in bytes without alignment.
- *
  *              Failure:        zero
  *
  * Programmer:  Quincey Koziol
diff --git a/src/H5Opkg.h b/src/H5Opkg.h
index e3626fe..716260e 100644
--- a/src/H5Opkg.h
+++ b/src/H5Opkg.h
@@ -31,7 +31,7 @@
 #define H5O_NMESGS	8 		/*initial number of messages	     */
 #define H5O_NCHUNKS	2		/*initial number of chunks	     */
 #define H5O_MIN_SIZE	32		/*min obj header data size	     */
-#define H5O_MSG_TYPES   21              /* # of types of messages            */
+#define H5O_MSG_TYPES   22              /* # of types of messages            */
 #define H5O_MAX_CRT_ORDER_IDX 65535     /* Max. creation order index value   */
 
 /* Versions of object header structure */
@@ -259,7 +259,7 @@ struct H5O_t {
     /* Attribute information (stored, for versions > 1) */
     unsigned	max_compact;		/* Maximum # of compact attributes   */
     unsigned	min_dense;		/* Minimum # of "dense" attributes   */
-    hsize_t     nattrs;                 /* Number of attributes in the group */
+    hsize_t     nattrs;                 /* Number of attributes on the object */
     haddr_t     attr_fheap_addr;        /* Address of fractal heap for storing "dense" attributes */
     haddr_t     name_bt2_addr;          /* Address of v2 B-tree for indexing names of attributes */
     haddr_t     corder_bt2_addr;        /* Address of v2 B-tree for indexing creation order of attributes */
@@ -435,6 +435,9 @@ H5_DLLVAR const H5O_msg_class_t H5O_MSG_BTREEK[1];
  */
 H5_DLLVAR const H5O_msg_class_t H5O_MSG_DRVINFO[1];
 
+/* Attribute Information Message. (0x0015) */
+H5_DLLVAR const H5O_msg_class_t H5O_MSG_AINFO[1];
+
 
 /*
  * Object header "object" types
diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index 3fb2255..0d1f918 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -1,4 +1,4 @@
-/* * * * * * * * * * * * * * * * * * * * * * *fs * * * * * * * * * * * * * * * *
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
  * Copyright by The HDF Group.                                               *
  * Copyright by the Board of Trustees of the University of Illinois.         *
  * All rights reserved.                                                      *
@@ -114,8 +114,8 @@ typedef struct H5O_copy_t {
 
 /* Header message IDs */
 #define H5O_NULL_ID	0x0000          /* Null Message.  */
-#define H5O_SDSPACE_ID	0x0001          /* Simple Dataspace Message.  */
-#define H5O_LINFO_ID    0x0002          /* Link Info Message. */
+#define H5O_SDSPACE_ID	0x0001          /* Dataspace Message. */
+#define H5O_LINFO_ID    0x0002          /* Link info Message. */
 #define H5O_DTYPE_ID	0x0003          /* Datatype Message.  */
 #define H5O_FILL_ID     0x0004          /* Fill Value Message. (Old)  */
 #define H5O_FILL_NEW_ID 0x0005          /* Fill Value Message. (New)  */
@@ -123,7 +123,7 @@ typedef struct H5O_copy_t {
 #define H5O_EFL_ID	0x0007          /* External File List Message  */
 #define H5O_LAYOUT_ID	0x0008          /* Data Storage Layout Message.  */
 #define H5O_BOGUS_ID	0x0009          /* "Bogus" Message.  */
-#define H5O_GINFO_ID	0x000a          /* Group Info Message.  */
+#define H5O_GINFO_ID	0x000a          /* Group info Message.  */
 #define H5O_PLINE_ID	0x000b          /* Filter pipeline message.  */
 #define H5O_ATTR_ID	0x000c          /* Attribute Message.  */
 #define H5O_NAME_ID	0x000d          /* Object name message.  */
@@ -134,6 +134,7 @@ typedef struct H5O_copy_t {
 #define H5O_MTIME_NEW_ID 0x0012         /* Modification time message. (New)  */
 #define H5O_BTREEK_ID   0x0013          /* v1 B-tree 'K' values message.  */
 #define H5O_DRVINFO_ID  0x0014          /* Driver info message.  */
+#define H5O_AINFO_ID    0x0015          /* Attribute info message.  */
 
 
 /* Shared object message flags.
@@ -407,6 +408,23 @@ typedef struct H5O_drvinfo_t {
     uint8_t            *buf;                    /* Buffer for encoded info */
 } H5O_drvinfo_t;
 
+/*
+ * Attribute Info Message.
+ * (Contains dynamic information about attributes on an object)
+ * (Data structure in memory)
+ */
+typedef struct H5O_ainfo_t {
+    /* (creation order info) */
+    hbool_t     index_corder;           /* Are creation order values indexed on attributes? */
+    H5O_msg_crt_idx_t max_crt_idx;      /* Maximum attribute creation index used */
+    haddr_t     corder_bt2_addr;        /* Address of v2 B-tree for indexing creation order values of "dense" attributes */
+
+    /* (storage management info) */
+    hsize_t     nattrs;                 /* Number of attributes on the object */
+    haddr_t     fheap_addr;             /* Address of fractal heap for storing "dense" attributes */
+    haddr_t     name_bt2_addr;          /* Address of v2 B-tree for indexing names of "dense" attributes */
+} H5O_ainfo_t;
+
 
 /* Typedef for iteration operations */
 typedef herr_t (*H5O_operator_t)(const void *mesg/*in*/, unsigned idx,
diff --git a/src/Makefile.am b/src/Makefile.am
index 9120544..8375f3a1 100755
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -59,8 +59,9 @@ libhdf5_la_SOURCES= H5.c H5checksum.c H5dbg.c H5system.c H5timer.c H5trace.c \
         H5HF.c H5HFbtree2.c H5HFcache.c H5HFdbg.c H5HFdblock.c H5HFdtable.c \
         H5HFhdr.c H5HFhuge.c H5HFiblock.c H5HFiter.c H5HFman.c H5HFsection.c \
         H5HFspace.c H5HFstat.c H5HFtest.c H5HFtiny.c \
-        H5HG.c H5HGdbg.c H5HL.c H5HLdbg.c H5HP.c H5I.c H5MF.c H5MM.c \
-        H5MP.c H5MPtest.c H5L.c H5Lexternal.c H5O.c H5Oalloc.c H5Oattr.c \
+        H5HG.c H5HGdbg.c H5HL.c H5HLdbg.c H5HP.c H5I.c H5L.c H5Lexternal.c \
+        H5MF.c H5MM.c H5MP.c H5MPtest.c \
+        H5O.c H5Oainfo.c H5Oalloc.c H5Oattr.c \
         H5Oattribute.c H5Obogus.c H5Obtreek.c H5Ocache.c \
         H5Ocont.c H5Ocopy.c H5Odbg.c H5Odrvinfo.c H5Odtype.c H5Oefl.c \
         H5Ofill.c H5Oginfo.c \
diff --git a/src/Makefile.in b/src/Makefile.in
index d86d395..57e0112 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -100,7 +100,7 @@ am_libhdf5_la_OBJECTS = H5.lo H5checksum.lo H5dbg.lo H5system.lo \
 	H5HFiblock.lo H5HFiter.lo H5HFman.lo H5HFsection.lo \
 	H5HFspace.lo H5HFstat.lo H5HFtest.lo H5HFtiny.lo H5HG.lo \
 	H5HGdbg.lo H5HL.lo H5HLdbg.lo H5HP.lo H5I.lo H5MF.lo H5MM.lo \
-	H5MP.lo H5MPtest.lo H5L.lo H5Lexternal.lo H5O.lo H5Oalloc.lo \
+	H5MP.lo H5MPtest.lo H5L.lo H5Lexternal.lo H5O.lo H5Oainfo.lo H5Oalloc.lo \
 	H5Oattr.lo H5Oattribute.lo H5Obogus.lo H5Obtreek.lo H5Ocache.lo H5Ocont.lo \
 	H5Ocopy.lo H5Odbg.lo H5Odrvinfo.lo H5Odtype.lo H5Oefl.lo H5Ofill.lo \
 	H5Oginfo.lo H5Olayout.lo H5Olinfo.lo H5Olink.lo H5Omessage.lo \
@@ -418,7 +418,7 @@ libhdf5_la_SOURCES = H5.c H5checksum.c H5dbg.c H5system.c H5timer.c H5trace.c \
         H5HFhdr.c H5HFhuge.c H5HFiblock.c H5HFiter.c H5HFman.c H5HFsection.c \
         H5HFspace.c H5HFstat.c H5HFtest.c H5HFtiny.c \
         H5HG.c H5HGdbg.c H5HL.c H5HLdbg.c H5HP.c H5I.c H5MF.c H5MM.c \
-        H5MP.c H5MPtest.c H5L.c H5Lexternal.c H5O.c H5Oalloc.c H5Oattr.c \
+        H5MP.c H5MPtest.c H5L.c H5Lexternal.c H5O.c H5Oainfo.c H5Oalloc.c H5Oattr.c \
         H5Oattribute.c H5Obogus.c H5Obtreek.c H5Ocache.c \
         H5Ocont.c H5Ocopy.c H5Odbg.c H5Odrvinfo.c H5Odtype.c H5Oefl.c H5Ofill.c H5Oginfo.c \
         H5Olayout.c \
@@ -668,6 +668,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5MP.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5MPtest.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5O.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Oainfo.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Oalloc.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Oattr.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Oattribute.Plo@am__quote@