[svn-r26842] Description:

    Cache the dataset's rank & dimension sizes, instead of querying them
frequently, to speed up various checks & algorithms.  Also, a few minor
cleanups.

Tested on:
    MacOSX/64 10.10.2 (amazon) w/serial & parallel
    Linux/32 2.6.18 (jam) w/serial & parallel

1 files changed, 59 insertions, 16 deletions

diff --git a/src/H5Dint.c b/src/H5Dint.c
index 8e1fcec..c626475 100644
--- a/src/H5Dint.c
+++ b/src/H5Dint.c
@@ -62,6 +62,7 @@ static H5D_shared_t *H5D__new(hid_t dcpl_id, hbool_t creating,
     hbool_t vl_type);
 static herr_t H5D__init_type(H5F_t *file, const H5D_t *dset, hid_t type_id,
     const H5T_t *type);
+static herr_t H5D__cache_dataspace_info(const H5D_t *dset);
 static herr_t H5D__init_space(H5F_t *file, const H5D_t *dset, const H5S_t *space);
 static herr_t H5D__update_oh_info(H5F_t *file, hid_t dxpl_id, H5D_t *dset,
     hid_t dapl_id);
@@ -665,6 +666,41 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5D__cache_dataspace_info
+ *
+ * Purpose:	Cache dataspace info for a dataset
+ *
+ * Return:	Success:    SUCCEED
+ *		Failure:    FAIL
+ *
+ * Programmer:	Quincey Koziol
+ *		Wednesday, November 19, 2014
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D__cache_dataspace_info(const H5D_t *dset)
+{
+    int sndims;                         /* Signed number of dimensions of dataspace rank */
+    unsigned u;                         /* Local index value */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checking */
+    HDassert(dset);
+
+    /* Cache info for dataset's dataspace */
+    if((sndims = H5S_get_simple_extent_dims(dset->shared->space, dset->shared->curr_dims, dset->shared->max_dims)) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't cache dataspace dimensions")
+    dset->shared->ndims = (unsigned)sndims;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5D__cache_dataspace_info() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5D__init_space
  *
  * Purpose:	Copy a dataspace for a dataset's use, performing all the
@@ -698,6 +734,10 @@ H5D__init_space(H5F_t *file, const H5D_t *dset, const H5S_t *space)
     if(NULL == (dset->shared->space = H5S_copy(space, FALSE, TRUE)))
         HGOTO_ERROR(H5E_DATASET, H5E_CANTCOPY, FAIL, "can't copy dataspace")
 
+    /* Cache the dataset's dataspace info */
+    if(H5D__cache_dataspace_info(dset) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTCOPY, FAIL, "can't cache dataspace info")
+
     /* Set the latest format, if requested */
     if(use_latest_format)
         if(H5S_set_latest_version(dset->shared->space) < 0)
@@ -1251,6 +1291,10 @@ H5D__open_oid(H5D_t *dataset, hid_t dapl_id, hid_t dxpl_id)
     if(NULL == (dataset->shared->space = H5S_read(&(dataset->oloc), dxpl_id)))
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to load dataspace info from dataset header")
 
+    /* Cache the dataset's dataspace info */
+    if(H5D__cache_dataspace_info(dataset) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTCOPY, FAIL, "can't cache dataspace info")
+
     /* Get a datatype ID for the dataset's datatype */
     if((dataset->shared->type_id = H5I_register(H5I_DATATYPE, dataset->shared->type, FALSE)) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTREGISTER, FAIL, "unable to register type")
@@ -2161,9 +2205,7 @@ done:
 herr_t
 H5D__set_extent(H5D_t *dset, const hsize_t *size, hid_t dxpl_id)
 {
-    H5S_t   *space;                     /* Dataset's dataspace */
-    int     rank;                       /* Dataspace # of dimensions */
-    hsize_t curr_dims[H5O_LAYOUT_NDIMS];/* Current dimension sizes */
+    hsize_t curr_dims[H5S_MAX_RANK];    /* Current dimension sizes */
     htri_t  changed;                    /* Whether the dataspace changed size */
     herr_t  ret_value = SUCCEED;        /* Return value */
 
@@ -2187,29 +2229,30 @@ H5D__set_extent(H5D_t *dset, const hsize_t *size, hid_t dxpl_id)
     if(H5D__check_filters(dset) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "can't apply filters")
 
-    /* Get the data space */
-    space = dset->shared->space;
-
-    /* Check if we are shrinking or expanding any of the dimensions */
-    if((rank = H5S_get_simple_extent_dims(space, curr_dims, NULL)) < 0)
-        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get dataset dimensions")
+    /* Keep the current dataspace dimensions for later */
+    HDcompile_assert(sizeof(curr_dims) == sizeof(dset->shared->curr_dims));
+    HDmemcpy(curr_dims, dset->shared->curr_dims, H5S_MAX_RANK * sizeof(curr_dims[0]));
 
-    /* Modify the size of the data space */
-    if((changed = H5S_set_extent(space, size)) < 0)
-        HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to modify size of data space")
+    /* Modify the size of the dataspace */
+    if((changed = H5S_set_extent(dset->shared->space, size)) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to modify size of dataspace")
 
     /* Don't bother updating things, unless they've changed */
     if(changed) {
-        hbool_t shrink = FALSE;             /* Flag to indicate a dimension has shrank */
-        hbool_t expand = FALSE;             /* Flag to indicate a dimension has grown */
-        unsigned u;                         /* Local index variable */
+        hbool_t shrink = FALSE;         /* Flag to indicate a dimension has shrank */
+        hbool_t expand = FALSE;         /* Flag to indicate a dimension has grown */
+        unsigned u;                     /* Local index variable */
 
         /* Determine if we are shrinking and/or expanding any dimensions */
-        for(u = 0; u < (unsigned)rank; u++) {
+        for(u = 0; u < dset->shared->ndims; u++) {
+            /* Check for various status changes */
             if(size[u] < curr_dims[u])
                 shrink = TRUE;
             if(size[u] > curr_dims[u])
                 expand = TRUE;
+
+            /* Update the cached copy of the dataset's dimensions */
+            dset->shared->curr_dims[u] = size[u];
         } /* end for */
 
         /*-------------------------------------------------------------------------