[svn-r13477] Description:

		The main purpose of this checkin was to eliminate the
space used for tracking creation time indices when there is no way they
can be used (i.e. attributes can't be shared in the file and the user hasn't
turned on attribute creation tracking), however there were some other minor
changes which crept in:
	- Fix a cache locking deadlock when a shared attribute and one of its
		components end up in the same fractal heap direct block.  
		(This is fixed the "slow" way for right now, until John has time
		to add support for readers/writer locking to the cache.
	- Optimize attribute copying when a copy will be kept during a v2 B-tree
		search.
	- When freeing a block on disk, attempt to merge it with the metadata
		and "small data" aggregators.

Tested on:
	Mac OS X/32 10.4.8 (amazon)
	FreeBSD/32 6.2 (duty)

1 files changed, 27 insertions, 6 deletions

diff --git a/src/H5Ocache.c b/src/H5Ocache.c
index c4430e6..7000e9e 100644
--- a/src/H5Ocache.c
+++ b/src/H5Ocache.c
@@ -150,7 +150,9 @@ H5O_flush_msgs(H5F_t *f, H5O_t *oh)
             } /* end for */
             /* Only encode creation index for version 2+ of format */
             else {
-                UINT16ENCODE(p, curr_msg->crt_idx);
+                /* Only encode creation index if they are being tracked */
+                if(oh->flags & H5O_HDR_ATTR_CRT_ORDER_TRACKED)
+                    UINT16ENCODE(p, curr_msg->crt_idx);
             } /* end else */
             HDassert(p == curr_msg->raw);
 
@@ -262,7 +264,7 @@ H5O_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void UNUSED * _udata1,
     if(NULL == (oh = H5FL_CALLOC(H5O_t)))
 	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
 
-    /* Generic, non-stored information */
+    /* File-specific, non-stored information */
     oh->sizeof_size = H5F_SIZEOF_SIZE(f);
     oh->sizeof_addr = H5F_SIZEOF_ADDR(f);
 
@@ -326,7 +328,12 @@ H5O_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void UNUSED * _udata1,
         H5F_addr_decode(f, &p, &(oh->attr_fheap_addr));
         H5F_addr_decode(f, &p, &(oh->name_bt2_addr));
         H5F_addr_decode(f, &p, &(oh->corder_bt2_addr));
-        UINT16DECODE(p, oh->max_attr_crt_idx);
+
+        /* Only encode max. creation index if they are being tracked */
+        if(oh->flags & H5O_HDR_ATTR_CRT_ORDER_TRACKED)
+            UINT16DECODE(p, oh->max_attr_crt_idx)
+        else
+            oh->max_attr_crt_idx = 0;
     } /* end if */
     else {
         /* Reset unused time fields */
@@ -449,17 +456,28 @@ H5O_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void UNUSED * _udata1,
             H5O_msg_crt_idx_t crt_idx = H5O_MAX_CRT_ORDER_IDX;  /* Creation index for current message */
 
             /* Decode message prefix info */
+
+            /* Version # */
             if(oh->version == H5O_VERSION_1)
                 UINT16DECODE(p, id)
             else
                 id = *p++;
+
+            /* Message size */
 	    UINT16DECODE(p, mesg_size);
 	    HDassert(mesg_size == H5O_ALIGN_OH(oh, mesg_size));
+
+            /* Message flags */
 	    flags = *p++;
+
+            /* Reserved bytes/creation index */
             if(oh->version == H5O_VERSION_1)
                 p += 3; /*reserved*/
-            else
-                UINT16DECODE(p, crt_idx);
+            else {
+                /* Only encode creation index if they are being tracked */
+                if(oh->flags & H5O_HDR_ATTR_CRT_ORDER_TRACKED)
+                    UINT16DECODE(p, crt_idx);
+            } /* end else */
 
             /* Try to detect invalidly formatted object header message that
              *  extends past end of chunk.
@@ -675,7 +693,10 @@ H5O_assert(oh);
             H5F_addr_encode(f, &p, oh->attr_fheap_addr);
             H5F_addr_encode(f, &p, oh->name_bt2_addr);
             H5F_addr_encode(f, &p, oh->corder_bt2_addr);
-            UINT16ENCODE(p, oh->max_attr_crt_idx);
+
+            /* Only encode max. creation index if they are being tracked */
+            if(oh->flags & H5O_HDR_ATTR_CRT_ORDER_TRACKED)
+                UINT16ENCODE(p, oh->max_attr_crt_idx);
 
             /* Chunk size */
             UINT32ENCODE(p, (oh->chunk[0].size - H5O_SIZEOF_HDR(oh)));