[svn-r22282] Issue 7934 - The data sieve buffer size was for all the datasets in the file. It

      could waste memory if any dataset size is smaller than the sieve buffer
      size.  Now the library picks the smaller one between the dataset size
      and the sieve buffer size from the file access property. (There is no change
      to hl/ and fortran/ directories.  They were property changes during the merge
      from the trunk)

Tested on jam, koala, and ostrich.

3 files changed, 34 insertions, 9 deletions

diff --git a/release_docs/RELEASE.txt b/release_docs/RELEASE.txt
index 284d23d..56ea41e 100644
--- a/release_docs/RELEASE.txt
+++ b/release_docs/RELEASE.txt
@@ -1,4 +1,4 @@
-HDF5 version 1.8.10-snap0 currently under development
+HF5 version 1.8.10-snap0 currently under development
 ================================================================================
 
 INTRODUCTION
@@ -60,7 +60,11 @@ New Features
     
     Library
     -------
-    - None
+    - The data sieve buffer size was for all the datasets in the file.  It
+      could waste memory if any dataset size is smaller than the sieve buffer
+      size.  Now the library picks the smaller one between the dataset size
+      and the sieve buffer size from the file access property. See Issue 7934.
+      (SLU - 2012/4/11)
  
     Parallel Library
     ----------------
diff --git a/src/H5Dcontig.c b/src/H5Dcontig.c
index cafa4a4..c6b9a6c 100644
--- a/src/H5Dcontig.c
+++ b/src/H5Dcontig.c
@@ -420,6 +420,7 @@ H5D_contig_construct(H5F_t *f, H5D_t *dset)
     hsize_t nelmts;                     /* Number of elements in dataspace */
     size_t dt_size;                     /* Size of datatype */
     hsize_t tmp_size;                   /* Temporary holder for raw data size */
+    size_t tmp_sieve_buf_size;          /* Temporary holder for sieve buffer size */
     hsize_t dim[H5O_LAYOUT_NDIMS];	/* Current size of data in elements */
     hsize_t max_dim[H5O_LAYOUT_NDIMS];  /* Maximum size of data in elements */
     int ndims;                          /* Rank of dataspace */
@@ -464,8 +465,15 @@ H5D_contig_construct(H5F_t *f, H5D_t *dset)
     /* Assign the dataset's contiguous storage size */
     dset->shared->layout.storage.u.contig.size = tmp_size;
 
-    /* Get the sieve buffer size for this dataset */
-    dset->shared->cache.contig.sieve_buf_size = H5F_SIEVE_BUF_SIZE(f);
+    /* Get the sieve buffer size for the file */
+    tmp_sieve_buf_size = H5F_SIEVE_BUF_SIZE(f);
+
+    /* Adjust the sieve buffer size to the smaller one between the dataset size and the buffer size
+     * from the file access property. (SLU - 2012/3/30) */
+    if(tmp_size < tmp_sieve_buf_size)
+        dset->shared->cache.contig.sieve_buf_size = tmp_size;
+    else
+        dset->shared->cache.contig.sieve_buf_size = tmp_sieve_buf_size;
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -965,6 +973,7 @@ H5D_contig_writevv_sieve_cb(hsize_t dst_off, hsize_t src_off, size_t len,
             /* Allocate room for the data sieve buffer */
             if(NULL == (dset_contig->sieve_buf = H5FL_BLK_MALLOC(sieve_buf, dset_contig->sieve_buf_size)))
                 HGOTO_ERROR(H5E_DATASET, H5E_CANTALLOC, FAIL, "memory allocation failed")
+
 #ifdef H5_CLEAR_MEMORY
 if(dset_contig->sieve_size > len)
     HDmemset(dset_contig->sieve_buf + len, 0, (dset_contig->sieve_size - len));
diff --git a/src/H5Dlayout.c b/src/H5Dlayout.c
index fa25305..177f2b4 100644
--- a/src/H5Dlayout.c
+++ b/src/H5Dlayout.c
@@ -384,6 +384,10 @@ H5D_layout_oh_read(H5D_t *dataset, hid_t dxpl_id, hid_t dapl_id, H5P_genplist_t
 
     switch(dataset->shared->layout.type) {
         case H5D_CONTIGUOUS:
+        {
+            hsize_t tmp_size;                   /* Temporary holder for raw data size */
+            size_t tmp_sieve_buf_size;          /* Temporary holder for sieve buffer size */
+
             /* Compute the size of the contiguous storage for versions of the
              * layout message less than version 3 because versions 1 & 2 would
              * truncate the dimension sizes to 32-bits of information. - QAK 5/26/04
@@ -392,7 +396,6 @@ H5D_layout_oh_read(H5D_t *dataset, hid_t dxpl_id, hid_t dapl_id, H5P_genplist_t
                 hssize_t snelmts;                   /* Temporary holder for number of elements in dataspace */
                 hsize_t nelmts;                     /* Number of elements in dataspace */
                 size_t dt_size;                     /* Size of datatype */
-                hsize_t tmp_size;                   /* Temporary holder for raw data size */
 
                 /* Retrieve the number of elements in the dataspace */
                 if((snelmts = H5S_GET_EXTENT_NPOINTS(dataset->shared->space)) < 0)
@@ -412,10 +415,19 @@ H5D_layout_oh_read(H5D_t *dataset, hid_t dxpl_id, hid_t dapl_id, H5P_genplist_t
 
                 /* Assign the dataset's contiguous storage size */
                 dataset->shared->layout.storage.u.contig.size = tmp_size;
-            } /* end if */
-
-            /* Get the sieve buffer size for this dataset */
-            dataset->shared->cache.contig.sieve_buf_size = H5F_SIEVE_BUF_SIZE(dataset->oloc.file);
+            } else
+                tmp_size = dataset->shared->layout.storage.u.contig.size;
+
+	    /* Get the sieve buffer size for the file */
+	    tmp_sieve_buf_size = H5F_SIEVE_BUF_SIZE(dataset->oloc.file);
+
+	    /* Adjust the sieve buffer size to the smaller one between the dataset size and the buffer size
+	     * from the file access property.  (SLU - 2012/3/30) */
+	    if(tmp_size < tmp_sieve_buf_size)
+		dataset->shared->cache.contig.sieve_buf_size = tmp_size;
+	    else
+		dataset->shared->cache.contig.sieve_buf_size = tmp_sieve_buf_size;
+        }
             break;
 
         case H5D_CHUNKED: