[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, 8 insertions, 4 deletions

diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index 9b40eeb..6f08ca4 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -239,10 +239,14 @@ H5_DLL size_t H5O_layout_meta_size(H5F_t *f, const void *_mesg);
 
 /* EFL operators */
 H5_DLL hsize_t H5O_efl_total_size(H5O_efl_t *efl);
-H5_DLL herr_t H5O_efl_read(H5F_t *f, const H5O_efl_t *efl, haddr_t addr,
-			    size_t size, uint8_t *buf);
-H5_DLL herr_t H5O_efl_write(H5F_t *f, const H5O_efl_t *efl, haddr_t addr,
-			     size_t size, const uint8_t *buf);
+H5_DLL ssize_t H5O_efl_readvv(const H5O_efl_t *efl,
+    size_t dset_max_nseq, size_t *dset_curr_seq, size_t dset_len_arr[], hsize_t dset_offset_arr[],
+    size_t mem_max_nseq, size_t *mem_curr_seq, size_t mem_len_arr[], hsize_t mem_offset_arr[],
+    void *buf);
+H5_DLL ssize_t H5O_efl_writevv(const H5O_efl_t *efl,
+    size_t dset_max_nseq, size_t *dset_curr_seq, size_t dset_len_arr[], hsize_t dset_offset_arr[],
+    size_t mem_max_nseq, size_t *mem_curr_seq, size_t mem_len_arr[], hsize_t mem_offset_arr[],
+    const void *buf);
 
 /* Fill value operators */
 H5_DLL herr_t H5O_fill_convert(void *_fill, H5T_t *type, hid_t dxpl_id);