[svn-r17582] Description:

	Bring changes from file free space branch back to the trunk.  *yay!*

Tested on:
        FreeBSD/32 6.3 (duty) in debug mode
        FreeBSD/64 6.3 (liberty) w/C++ & FORTRAN, in debug mode
        Linux/32 2.6 (jam) w/PGI compilers, w/default API=1.8.x,
                w/C++ & FORTRAN, w/threadsafe, in debug mode
        Linux/64-amd64 2.6 (smirom) w/Intel compilers, w/default API=1.6.x,
                w/C++ & FORTRAN, in production mode
        Solaris/32 2.10 (linew) w/deprecated symbols disabled, w/C++ & FORTRAN,
                w/szip filter, in production mode
        Linux/64-ia64 2.6 (cobalt) w/Intel compilers, w/C++ & FORTRAN,
                in production mode
        Linux/64-ia64 2.4 (tg-login3) w/parallel, w/FORTRAN, in debug mode
        Linux/64-amd64 2.6 (abe) w/parallel, w/FORTRAN, in production mode
        Mac OS X/32 10.5.8 (amazon) in debug mode
        Mac OS X/32 10.5.8 (amazon) w/C++ & FORTRAN, w/threadsafe,
                in production mode

1 files changed, 65 insertions, 0 deletions

diff --git a/src/H5FSsection.c b/src/H5FSsection.c
index 26ff7b9..30885a9 100644
--- a/src/H5FSsection.c
+++ b/src/H5FSsection.c
@@ -1562,6 +1562,71 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5FS_sect_try_merge
+ *
+ * Purpose:	Try to merge/shrink a block 
+ *
+ * Return:	TRUE:		merged/shrunk
+ *		FALSE: 	 	not merged/not shrunk
+ *		Failure:	negative
+ *
+ * Programmer:	Vailin Choi; June 10, 2009
+ *
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5FS_sect_try_merge(H5F_t *f, hid_t dxpl_id, H5FS_t *fspace, H5FS_section_info_t *sect,
+    unsigned flags, void *op_data)
+{
+    hbool_t sinfo_valid = FALSE;        /* Whether the section info is valid */
+    hbool_t sinfo_modified = FALSE;     /* Whether the section info was modified */
+    hsize_t saved_fs_size;		/* copy the free-space section size */
+    htri_t ret_value = FALSE;           /* Return value */
+
+    FUNC_ENTER_NOAPI(H5FS_sect_try_merge, FAIL)
+
+    /* Check arguments. */
+    HDassert(f);
+    HDassert(fspace);
+    HDassert(sect);
+    HDassert(H5F_addr_defined(sect->addr));
+    HDassert(sect->size);
+
+    /* Get a pointer to the section info */
+    if(H5FS_sinfo_lock(f, dxpl_id, fspace, H5AC_WRITE) < 0)
+	HGOTO_ERROR(H5E_FSPACE, H5E_CANTGET, FAIL, "can't get section info")
+    sinfo_valid = TRUE;
+    saved_fs_size = sect->size;
+
+    /* Attempt to merge/shrink section with existing sections */
+    if(H5FS_sect_merge(fspace, &sect, op_data) < 0)
+	HGOTO_ERROR(H5E_FSPACE, H5E_CANTMERGE, FAIL, "can't merge sections")
+
+    /* Check if section is shrunk and/or merged away completely */
+    if(!sect) {
+	sinfo_modified = TRUE;
+	HGOTO_DONE(TRUE)
+    } /* end if */
+    else {
+        /* Check if section is merged */
+        if(sect->size > saved_fs_size) {
+            if(H5FS_sect_link(fspace, sect, flags) < 0)
+                HGOTO_ERROR(H5E_FSPACE, H5E_CANTINSERT, FAIL, "can't insert free space section into skip list")
+            sinfo_modified = TRUE;
+            HGOTO_DONE(TRUE)
+        } /* end if */
+    } /* end else */
+
+done:
+    /* Release the section info */
+    if(sinfo_valid && H5FS_sinfo_unlock(f, dxpl_id, fspace, sinfo_modified) < 0)
+        HDONE_ERROR(H5E_FSPACE, H5E_CANTRELEASE, FAIL, "can't release section info")
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5FS_sect_try_merge() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5FS_sect_find_node
  *
  * Purpose:	Locate a section of free space (in existing free space list