[svn-r13757]

h5repack and h5diff hyperslab I/O

changed the limit on which  hyperslab I/O is done from 1GB to 128MB

h5repack currently tests this feature by defining a dataset with dimensions of 128MB + 1byte (the datum being 1 byte integer), in which a 1Kb hyperslab was written.

tested: linux
there were some errors in running the tests, but these were in the library, due to a recent check-in that will be fixed shortly (at least we hope :-) )

2 files changed, 66 insertions, 48 deletions

diff --git a/tools/h5repack/h5repack_copy.c b/tools/h5repack/h5repack_copy.c
index 4253678..54e9dd2 100644
--- a/tools/h5repack/h5repack_copy.c
+++ b/tools/h5repack/h5repack_copy.c
@@ -155,7 +155,47 @@ out:
  *                  with the requested filter, use the input one
  *
  *  October 2006:  Read/write using the file type by default.
- *                 Read/write by hyperslabs for big datasets.
+ *
+ *  October 2006:  Read by hyperslabs for big datasets.
+ *
+ *  A threshold of H5TOOLS_MALLOCSIZE (128 MB) is the limit upon which I/O hyperslab is done
+ *  i.e., if the memory needed to read a dataset is greater than this limit, 
+ *  then hyperslab I/O is done instead of one operation I/O 
+ *  For each dataset, the memory needed is calculated according to
+ *
+ *  memory needed = number of elements * size of each element
+ *
+ *  if the memory needed is lower than H5TOOLS_MALLOCSIZE, then the following operations 
+ *  are done
+ *
+ *  H5Dread( input_dataset1 )
+ *  H5Dread( input_dataset2 )
+ *
+ *  with all elements in the datasets selected. If the memory needed is greater than 
+ *  H5TOOLS_MALLOCSIZE, then the following operations are done instead:
+ *
+ *  a strip mine is defined for each dimension k (a strip mine is defined as a 
+ *  hyperslab whose size is memory manageable) according to the formula
+ *
+ *  (1) strip_mine_size[k ] = MIN(dimension[k ], H5TOOLS_BUFSIZE / size of memory type)
+ *
+ *  where H5TOOLS_BUFSIZE is a constant currently defined as 1MB. This formula assures 
+ *  that for small datasets (small relative to the H5TOOLS_BUFSIZE constant), the strip 
+ *  mine size k is simply defined as its dimension k, but for larger datasets the 
+ *  hyperslab size is still memory manageable.
+ *  a cycle is done until the number of elements in the dataset is reached. In each 
+ *  iteration, two parameters are defined for the function H5Sselect_hyperslab, 
+ *  the start and size of each hyperslab, according to
+ *
+ *  (2) hyperslab_size [k] = MIN(dimension[k] - hyperslab_offset[k], strip_mine_size [k])
+ *
+ *  where hyperslab_offset [k] is initially set to zero, and later incremented in 
+ *  hyperslab_size[k] offsets. The reason for the operation 
+ *
+ *  dimension[k] - hyperslab_offset[k]
+ *
+ *  in (2) is that, when using the strip mine size, it assures that the "remaining" part 
+ *  of the dataset that does not fill an entire strip mine is processed.
  *
  *  November 2006:  Use H5Ocopy in the copy of objects. The logic for using 
  *   H5Ocopy or not is if a change of filters or layout is requested by the user 
@@ -273,7 +313,7 @@ int do_copy_objects(hid_t fidin,
        options->all_filter==1 || options->all_layout==1 
        || is_ref
        )
-   {
+   {       
     int j;
 
     if ((dset_in=H5Dopen(fidin,travt->objs[i].name))<0)
diff --git a/tools/h5repack/h5repacktst.c b/tools/h5repack/h5repacktst.c
index 38e050c..6d1feaf 100644
--- a/tools/h5repack/h5repacktst.c
+++ b/tools/h5repack/h5repacktst.c
@@ -104,7 +104,7 @@ int make_nbit(hid_t loc_id);
 int make_scaleoffset(hid_t loc_id);
 int make_all(hid_t loc_id);
 int make_fill(hid_t loc_id);
-int make_big(hid_t loc_id, int set_chunk);
+int make_big(hid_t loc_id);
 int make_testfiles(void);
 void write_dset_in(hid_t loc_id,const char* dset_name,hid_t file_id,int make_diffs );
 void write_attr_in(hid_t loc_id,const char* dset_name,hid_t fid,int make_diffs );
@@ -1480,7 +1480,7 @@ int make_testfiles(void)
  */
  if((loc_id = H5Fcreate(FNAME14,H5F_ACC_TRUNC,H5P_DEFAULT,H5P_DEFAULT))<0)
   return -1;
- if (make_big(loc_id, 1)<0)
+ if (make_big(loc_id)<0)
   goto out;
  if(H5Fclose(loc_id)<0)
   return -1;
@@ -2592,49 +2592,42 @@ out:
 /*-------------------------------------------------------------------------
  * Function: make_big 
  *
- * Purpose: used in test read by hyperslabs. Can create 1GB datasets, either with 
- *  chunk layout or with contiguous layout, by iterating trough 1MB hyperslabs.
- *  Only 1 hyperslab is written. Only the chunk case is called.
+ * Purpose: used in test read by hyperslabs. Creates a 128MB dataset.
+ *  Only 1 1024Kb hyperslab is written.
  *
  *-------------------------------------------------------------------------
  */
 
-int make_big(hid_t loc_id, int set_chunk)
+int make_big(hid_t loc_id)
 {
  hid_t   did=-1;
  hid_t   f_sid=-1;
  hid_t   m_sid=-1;
  hid_t   tid;
  hid_t   dcpl;
- hsize_t dims[1]={GBLL};               /* dataset dimensions */
- hsize_t hs_size[1]={GBLL/1024};       /* hyperslab dimensions */
- hsize_t chunk_dims[1]={GBLL/1024};    /* chunk dimensions */
- hsize_t hs_start[1];
+ hsize_t dims[1]={ H5TOOLS_MALLOCSIZE + 1}; /* dataset dimensions */
+ hsize_t hs_size[1];                     /* hyperslab dimensions */
+ hsize_t hs_start[1];                    /* hyperslab start */
+ hsize_t chunk_dims[1]={1024};           /* chunk dimensions */
  size_t  size;
- size_t  nelmts=(size_t)GBLL/1024;
+ size_t  nelmts=(size_t)1024;
  signed  char fillvalue=-1;
  signed  char *buf=NULL;
- int     i, j, s;
- char    c;
- char    name[20];
 
- strcpy(name,"conti");
+ /* write one 1024 byte hyperslab */
+ hs_start[0] = 0;
+ hs_size[0]  = 1024;
 
  /* create */ 
  if ((dcpl = H5Pcreate(H5P_DATASET_CREATE))<0)
   goto out;
  if (H5Pset_fill_value(dcpl, H5T_NATIVE_SCHAR, &fillvalue)<0)
   goto out;
-
- if (set_chunk)
- {
-  strcpy(name,"chunk");
-  if(H5Pset_chunk(dcpl, 1, chunk_dims)<0)
-   goto out;
- }
+ if(H5Pset_chunk(dcpl, 1, chunk_dims)<0)
+  goto out;
  if ((f_sid = H5Screate_simple(1,dims,NULL))<0)
   goto out;
- if ((did = H5Dcreate(loc_id,name,H5T_NATIVE_SCHAR,f_sid,dcpl))<0)
+ if ((did = H5Dcreate(loc_id,"dset",H5T_NATIVE_SCHAR,f_sid,dcpl))<0)
   goto out;
  if ((m_sid = H5Screate_simple(1, hs_size, hs_size))<0) 
   goto out;
@@ -2643,30 +2636,14 @@ int make_big(hid_t loc_id, int set_chunk)
  if ((size = H5Tget_size(tid))<=0)
   goto out;
  
- /* create a evenly divided buffer from 0 to 127  */
- buf=(signed  char *) HDmalloc((unsigned)(nelmts*size));
- s = 1024 / 127;
- for (i=0, j=0, c=0; i<1024; j++, i++) 
- {
-  if ( j==s)
-  {
-   c++;
-   j=0;
-  };
-
-  HDmemset(buf, c, nelmts);
-  
-  hs_start[0] = i * GBLL/1024;
-  if (H5Sselect_hyperslab (f_sid,H5S_SELECT_SET,hs_start,NULL,hs_size, NULL)<0) 
-   goto out;
-  if (H5Dwrite (did,H5T_NATIVE_SCHAR,m_sid,f_sid,H5P_DEFAULT,buf)<0) 
-   goto out;
+ /* initialize buffer to 0  */
+ buf=(signed  char *) calloc( nelmts, size);
+ 
+ if (H5Sselect_hyperslab (f_sid,H5S_SELECT_SET,hs_start,NULL,hs_size, NULL)<0) 
+  goto out;
+ if (H5Dwrite (did,H5T_NATIVE_SCHAR,m_sid,f_sid,H5P_DEFAULT,buf)<0) 
+  goto out;
 
-  /* write only one hyperslab */
-  if (i==0) 
-   break;
-  
- }
  free(buf);
  buf=NULL;
 
@@ -2693,6 +2670,7 @@ out:
 
 }
 
+
 /*-------------------------------------------------------------------------
  * Function: make_external 
  *