[svn-r5126] Purpose:

    Bug Fix (sorta)
Description:
    "small" contiguous hyperslabs were not being detected correctly by
    H5S_hyper_select_contigous() leading to poorer performance than possible.
Solution:
    Corrected check for small hyperslabs.  Also cleaned up the H5S_find() code.
Platforms tested:
    FreeBSD 4.5 (sleipnir)

1 files changed, 18 insertions, 30 deletions

diff --git a/src/H5S.c b/src/H5S.c
index 877de5d..0b6632c 100644
--- a/src/H5S.c
+++ b/src/H5S.c
@@ -1496,9 +1496,9 @@ H5S_set_extent_simple (H5S_t *space, unsigned rank, const hsize_t *dims,
 H5S_conv_t *
 H5S_find (const H5S_t *mem_space, const H5S_t *file_space)
 {
-    size_t	i;
-    htri_t c1,c2;
-    H5S_conv_t	*path;
+    H5S_conv_t	*path;  /* Space conversion path */
+    htri_t c1,c2;       /* Flags whether a selection is contiguous */
+    size_t	i;      /* Index variable */
     
     FUNC_ENTER (H5S_find, NULL);
 
@@ -1512,11 +1512,8 @@ H5S_find (const H5S_t *mem_space, const H5S_t *file_space)
      * We can't do conversion if the source and destination select a
      * different number of data points.
      */
-    if (H5S_get_select_npoints(mem_space) !=
-	H5S_get_select_npoints (file_space)) {
-        HRETURN_ERROR (H5E_DATASPACE, H5E_BADRANGE, NULL,
-		       "memory and file data spaces are different sizes");
-    }
+    if (H5S_get_select_npoints(mem_space) != H5S_get_select_npoints (file_space))
+        HRETURN_ERROR (H5E_DATASPACE, H5E_BADRANGE, NULL, "memory and file data spaces are different sizes");
 
     /*
      * Is this path already present in the data space conversion path table?
@@ -1524,15 +1521,14 @@ H5S_find (const H5S_t *mem_space, const H5S_t *file_space)
      */
     for (i=0; i<H5S_nconv_g; i++) {
         if (H5S_conv_g[i]->f->type==file_space->select.type &&
-            H5S_conv_g[i]->m->type==mem_space->select.type) {
+                H5S_conv_g[i]->m->type==mem_space->select.type) {
             /*
              * Initialize direct read/write functions
              */
             c1=H5S_select_contiguous(file_space);
             c2=H5S_select_contiguous(mem_space);
             if(c1==FAIL || c2==FAIL)
-                HRETURN_ERROR(H5E_DATASPACE, H5E_BADRANGE, NULL,
-                      "invalid check for contiguous dataspace ");
+                HRETURN_ERROR(H5E_DATASPACE, H5E_BADRANGE, NULL, "invalid check for contiguous dataspace ");
 
             if (c1==TRUE && c2==TRUE) {
                 H5S_conv_g[i]->read = H5S_all_read;
@@ -1551,20 +1547,16 @@ H5S_find (const H5S_t *mem_space, const H5S_t *file_space)
      * The path wasn't found.  Do we have enough information to create a new
      * path?
      */
-    if (NULL==H5S_fconv_g[file_space->select.type] ||
-            NULL==H5S_mconv_g[mem_space->select.type]) {
-        HRETURN_ERROR(H5E_DATASPACE, H5E_UNSUPPORTED, NULL,
-		      "unable to convert between data space selections");
-    }
+    if (NULL==H5S_fconv_g[file_space->select.type] || NULL==H5S_mconv_g[mem_space->select.type])
+        HRETURN_ERROR(H5E_DATASPACE, H5E_UNSUPPORTED, NULL, "unable to convert between data space selections");
 
     /*
      * Create a new path.
      */
-    if (NULL==(path = H5MM_calloc(sizeof(*path)))) {
-        HRETURN_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL,
-		      "memory allocation failed for data space conversion "
-		      "path");
-    }
+    if (NULL==(path = H5MM_calloc(sizeof(*path))))
+        HRETURN_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for data space conversion path");
+
+    /* Initialize file & memory conversion functions */
     path->f = H5S_fconv_g[file_space->select.type];
     path->m = H5S_mconv_g[mem_space->select.type];
 
@@ -1574,13 +1566,12 @@ H5S_find (const H5S_t *mem_space, const H5S_t *file_space)
     c1=H5S_select_contiguous(file_space);
     c2=H5S_select_contiguous(mem_space);
     if(c1==FAIL || c2==FAIL)
-        HRETURN_ERROR(H5E_DATASPACE, H5E_BADRANGE, NULL,
-		      "invalid check for contiguous dataspace ");
+        HRETURN_ERROR(H5E_DATASPACE, H5E_BADRANGE, NULL, "invalid check for contiguous dataspace ");
 
     if (c1==TRUE && c2==TRUE) {
         path->read = H5S_all_read;
         path->write = H5S_all_write;
-    }
+    } /* end if */
     
     /*
      * Add the new path to the table.
@@ -1589,14 +1580,11 @@ H5S_find (const H5S_t *mem_space, const H5S_t *file_space)
         size_t n = MAX(10, 2*H5S_aconv_g);
         H5S_conv_t **p = H5MM_realloc(H5S_conv_g, n*sizeof(H5S_conv_g[0]));
 
-        if (NULL==p) {
-            HRETURN_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL,
-                  "memory allocation failed for data space conversion "
-                  "path table");
-        }
+        if (NULL==p)
+            HRETURN_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for data space conversion path table");
         H5S_aconv_g = n;
         H5S_conv_g = p;
-    }
+    } /* end if */
     H5S_conv_g[H5S_nconv_g++] = path;
 
     FUNC_LEAVE(path);