[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, 76 insertions, 0 deletions

diff --git a/src/H5Dpkg.h b/src/H5Dpkg.h
new file mode 100644
index 0000000..093360b
--- /dev/null
+++ b/src/H5Dpkg.h
@@ -0,0 +1,76 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic HDF5 document set and   *
+ * is linked from the top-level documents page.  It can also be found at     *
+ * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html.  If you do not have     *
+ * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * Programmer:	Quincey Koziol <koziol@ncsa.uiuc.edu>
+ *		Monday, April 14, 2003
+ *
+ * Purpose:	This file contains declarations which are visible only within
+ *		the H5D package.  Source files outside the H5D package should
+ *		include H5Dprivate.h instead.
+ */
+#ifndef H5D_PACKAGE
+#error "Do not include this file outside the H5D package!"
+#endif
+
+#ifndef _H5Dpkg_H
+#define _H5Dpkg_H
+
+/* Get package's private header */
+#include "H5Dprivate.h"
+
+/* Other private headers needed by this file */
+#include "H5Gprivate.h"		/* Group headers		  	*/
+#include "H5Oprivate.h"		/* Object headers		  	*/
+#include "H5Sprivate.h"		/* Dataspace functions			*/
+#include "H5Tprivate.h"		/* Datatype functions			*/
+
+/* The number of reserved IDs in dataset ID group */
+#define H5D_RESERVED_ATOMS  0
+
+/* Set the minimum object header size to create objects with */
+#define H5D_MINHDR_SIZE 256
+
+/****************************/
+/* Package Private Typedefs */
+/****************************/
+
+/*
+ * A dataset is the following struct.
+ */
+struct H5D_t {
+    H5G_entry_t         ent;            /* cached object header stuff   */
+    H5T_t              *type;           /* datatype of this dataset     */
+    H5S_t              *space;          /* dataspace of this dataset    */
+    hid_t               dcpl_id;        /* dataset creation property id */
+    H5O_layout_t        layout;         /* data layout                  */
+    /* Cache some frequently accessed values from the DCPL */
+    H5O_efl_t           efl;            /* External file list information */
+    H5D_alloc_time_t    alloc_time;     /* Dataset allocation time      */
+    H5D_fill_time_t	fill_time;	/* Dataset fill value writing time */
+    H5O_fill_t          fill;           /* Dataset fill value information */
+};
+
+/* Enumerated type for allocating dataset's storage */
+typedef enum {
+    H5D_ALLOC_CREATE,           /* Dataset is being created */
+    H5D_ALLOC_OPEN,             /* Dataset is being opened */
+    H5D_ALLOC_EXTEND,           /* Dataset's dataspace is being extended */
+    H5D_ALLOC_WRITE             /* Dataset is being extended */
+} H5D_time_alloc_t;
+
+/* Package-private functions defined in H5D package */
+H5_DLL herr_t H5D_alloc_storage (H5F_t *f, hid_t dxpl_id, H5D_t *dset, H5D_time_alloc_t time_alloc,
+                        hbool_t update_time, hbool_t full_overwrite);
+#endif /*_H5Dpkg_H*/