[svn-r6825] Purpose:

    New feature/enhancement

Description:
    Chunked datasets are handled poorly in several circumstances involving
certain selections and chunks that are too large for the chunk cache and/or
chunks with filters, causing the chunk to be read from disk multiple times.

Solution:
    Rearrange raw data I/O infrastructure to handle chunked datasets in a much
more friendly way by creating a selection in memory and on disk for each chunk
in a chunked dataset and performing all of the I/O on that chunk at one time.

    There are still some scalability (the current code attempts to
create a selection for all the chunks in the dataset, instead of just the
chunks that are accessed, requiring portions of the istore.c and fillval.c
tests to be commented out) and performance issues, but checking this in will
allow the changes to be tested by a much wider audience while I address the
remaining issues.


Platforms tested:
    h5committested, FreeBSD 4.8 (sleipnir) serial & parallel, Linux 2.4 (eirene)

1 files changed, 1 insertions, 1 deletions

diff --git a/src/H5Z.c b/src/H5Z.c
index f8265d3..b5e0e52 100644
--- a/src/H5Z.c
+++ b/src/H5Z.c
@@ -529,7 +529,7 @@ H5Z_prelude_callback(hid_t dcpl_id, hid_t type_id, H5Z_prelude_type_t prelude_ty
 
             /* Check if the chunks have filters */
             if(dcpl_pline.nfilters > 0) {
-                int chunk_ndims;        /* # of chunk dimensions */
+                unsigned chunk_ndims;   /* # of chunk dimensions */
                 hsize_t chunk_size[H5O_LAYOUT_NDIMS];       /* Size of chunk dimensions */
                 H5S_t *space;           /* Dataspace describing chunk */
                 hid_t space_id;         /* ID for dataspace describing chunk */