[svn-r8335] Purpose:

    Code optimization

Description:
    Change algorithm to directly use coordinates describing a chunk's position
in a dataspace instead of creating a dataspace with the chunk's position
selected.  This reduces the number of copies of dataspaces we need to keep
around.

Platforms tested:
    Solaris 2.7 (arabica)
    FreeBSD 4.9 (sleipnir) w/parallel
    too minor to require h5committest

3 files changed, 132 insertions, 19 deletions

diff --git a/src/H5Dio.c b/src/H5Dio.c
index 1008215..207efbf 100644
--- a/src/H5Dio.c
+++ b/src/H5Dio.c
@@ -2669,13 +2669,13 @@ done:
 static herr_t 
 H5D_create_chunk_file_map_hyper(const fm_map *fm)
 {
-    H5S_t       *tmp_fspace=NULL;           /* Temporary file dataspace */
     hssize_t    sel_points;                 /* Number of elements in file selection */
     hssize_t    sel_start[H5O_LAYOUT_NDIMS];   /* Offset of low bound of file selection */
     hssize_t    sel_end[H5O_LAYOUT_NDIMS];   /* Offset of high bound of file selection */
     hssize_t    start_coords[H5O_LAYOUT_NDIMS];   /* Starting coordinates of selection */
     hssize_t    coords[H5O_LAYOUT_NDIMS];   /* Current coordinates of chunk */
     hsize_t     count[H5O_LAYOUT_NDIMS];    /* Hyperslab count information */
+    hssize_t    end[H5O_LAYOUT_NDIMS];      /* Current coordinates of chunk */
     hsize_t     chunk_index;                /* Index of chunk */
     int         curr_dim;                   /* Current dimension to increment */
     unsigned    u;                          /* Local index variable */
@@ -2686,16 +2686,12 @@ H5D_create_chunk_file_map_hyper(const fm_map *fm)
     /* Sanity check */
     assert(fm->f_ndims>0);
 
-    /* Make a copy of file dataspace */
-    if((tmp_fspace = H5S_copy(fm->file_space))==NULL)
-        HGOTO_ERROR (H5E_DATASPACE, H5E_CANTCOPY, FAIL, "unable to copy memory space")
-
     /* Get number of elements selected in file */
-    if((sel_points=H5S_get_select_npoints(tmp_fspace))<0)
+    if((sel_points=H5S_get_select_npoints(fm->file_space))<0)
         HGOTO_ERROR(H5E_DATASPACE, H5E_CANTGET, FAIL, "can't get file selection # of elements")
 
     /* Get bounding box for selection (to reduce the number of chunks to iterate over) */
-    if(H5S_get_select_bounds(tmp_fspace, sel_start, sel_end)<0)
+    if(H5S_get_select_bounds(fm->file_space, sel_start, sel_end)<0)
         HGOTO_ERROR(H5E_DATASPACE, H5E_CANTGET, FAIL, "can't get file selection bound info")
 
     /* Set initial chunk location & hyperslab size */
@@ -2704,12 +2700,9 @@ H5D_create_chunk_file_map_hyper(const fm_map *fm)
         start_coords[u]=(sel_start[u]/(hssize_t)fm->layout->dim[u])*(hssize_t)fm->layout->dim[u];
         coords[u]=start_coords[u];
         count[u]=fm->layout->dim[u];
+        end[u]=(coords[u]+count[u])-1;
     } /* end for */
 
-    /* Select initial chunk as hyperslab */
-    if(H5S_select_hyperslab(tmp_fspace,H5S_SELECT_SET,coords,NULL,count,NULL)<0) /*lint !e772 The coords and count arrays should always be initialized */
-        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTSELECT, FAIL, "can't create hyperslab selection")
-
     /* Calculate the index of this chunk */
     if(H5V_chunk_index(fm->f_ndims,coords,fm->layout->dim,fm->chunks,fm->down_chunks,&chunk_index)<0)
         HGOTO_ERROR (H5E_DATASPACE, H5E_BADRANGE, FAIL, "can't get chunk index")
@@ -2717,7 +2710,7 @@ H5D_create_chunk_file_map_hyper(const fm_map *fm)
     /* Iterate through each chunk in the dataset */
     while(sel_points) {
         /* Check for intersection of temporary chunk and file selection */
-        if(H5S_hyper_intersect(tmp_fspace,fm->file_space)==TRUE) {
+        if(H5S_hyper_intersect_block(fm->file_space,coords,end)==TRUE) {
             H5S_t *tmp_fchunk;                  /* Temporary file dataspace */
             H5D_chunk_info_t *new_chunk_info; /* chunk information to insert into tree */
             hssize_t    chunk_points;           /* Number of elements in chunk selection */
@@ -2797,6 +2790,7 @@ H5D_create_chunk_file_map_hyper(const fm_map *fm)
         /* Increment chunk location in fastest changing dimension */
         H5_CHECK_OVERFLOW(count[curr_dim],hsize_t,hssize_t);
         coords[curr_dim]+=(hssize_t)count[curr_dim];
+        end[curr_dim]+=(hssize_t)count[curr_dim];
 
         /* Bring chunk location back into bounds, if necessary */
         if(coords[curr_dim]>sel_end[curr_dim]) {
@@ -2809,22 +2803,16 @@ H5D_create_chunk_file_map_hyper(const fm_map *fm)
 
                 /* Increment chunk location in current dimension */
                 coords[curr_dim]+=(hssize_t)count[curr_dim];
+                end[curr_dim]=(coords[curr_dim]+(hssize_t)count[curr_dim])-1;
             } while(coords[curr_dim]>sel_end[curr_dim]);
 
             /* Re-Calculate the index of this chunk */
             if(H5V_chunk_index(fm->f_ndims,coords,fm->layout->dim,fm->chunks,fm->down_chunks,&chunk_index)<0)
                 HGOTO_ERROR (H5E_DATASPACE, H5E_BADRANGE, FAIL, "can't get chunk index")
         } /* end if */
-
-        /* Move template chunk's offset to current location of chunk */
-        if(H5S_hyper_move(tmp_fspace,coords)<0)
-            HGOTO_ERROR(H5E_DATASPACE, H5E_CANTSELECT, FAIL, "can't move chunk selection")
     } /* end while */
 
 done:
-    if(tmp_fspace)
-        if(H5S_close(tmp_fspace)<0)
-            HDONE_ERROR(H5E_DATASPACE, H5E_CANTRELEASE, FAIL, "can't release file dataspace copy")
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5D_create_chunk_file_map_hyper() */
 
diff --git a/src/H5Shyper.c b/src/H5Shyper.c
index 589ddd0..6a6d604 100644
--- a/src/H5Shyper.c
+++ b/src/H5Shyper.c
@@ -3624,6 +3624,7 @@ done:
     FUNC_LEAVE_NOAPI(ret_value);
 }   /* H5S_hyper_convert() */
 
+#ifdef LATER
 
 /*--------------------------------------------------------------------------
  NAME
@@ -3740,6 +3741,127 @@ H5S_hyper_intersect (H5S_t *space1, H5S_t *space2)
 done:
     FUNC_LEAVE_NOAPI(ret_value);
 }   /* H5S_hyper_intersect() */
+#endif /* LATER */
+
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5S_hyper_intersect_block_helper
+ PURPOSE
+    Helper routine to detect intersections in span trees
+ USAGE
+    htri_t H5S_hyper_intersect_block_helper(spans, start, end)
+        H5S_hyper_span_info_t *spans;     IN: First span tree to operate with
+        hssize_t *offset;   IN: Selection offset coordinate
+        hssize_t *start;    IN: Starting coordinate for block
+        hssize_t *end;      IN: Ending coordinate for block
+ RETURNS
+    Non-negative on success, negative on failure
+ DESCRIPTION
+    Quickly detect intersections between span tree and block
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+static htri_t
+H5S_hyper_intersect_block_helper (const H5S_hyper_span_info_t *spans, hssize_t *offset, hssize_t *start, hssize_t *end)
+{
+    H5S_hyper_span_t *curr;     /* Pointer to current span in 1st span tree */
+    htri_t status;              /* Status from recursive call */
+    htri_t ret_value=FALSE;     /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5S_hyper_intersect_block_helper);
+
+    /* Sanity check */
+    assert(spans);
+    assert(offset);
+    assert(start);
+    assert(end);
+
+    /* Get the span list for spans in this tree */
+    curr=spans->head;
+
+    /* Iterate over the spans in the tree */
+    while(curr!=NULL) {
+        /* Check for span entirely before block */
+        if((curr->high+*offset)<*start)
+            /* Advance to next span in this dimension */
+            curr=curr->next;
+        /* If this span is past the end of the block, then we're done in this dimension */
+        else if((curr->low+*offset)>*end)
+            HGOTO_DONE(FALSE)
+        /* block & span overlap */
+        else {
+            if(curr->down==NULL)
+                HGOTO_DONE(TRUE)
+            else {
+                /* Recursively check spans in next dimension down */
+                if((status=H5S_hyper_intersect_block_helper(curr->down,offset+1,start+1,end+1))<0)
+                    HGOTO_ERROR(H5E_DATASPACE, H5E_BADSELECT, FAIL, "can't perform hyperslab intersection check");
+
+                /* If there is a span intersection in the down dimensions, the span trees overlap */
+                if(status==TRUE)
+                    HGOTO_DONE(TRUE);
+
+                /* No intersection in down dimensions, advance to next span */
+                curr=curr->next;
+            } /* end else */
+        } /* end else */
+    } /* end while */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+}   /* H5S_hyper_intersect_block_helper() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5S_hyper_intersect_block
+ PURPOSE
+    Detect intersections in span trees
+ USAGE
+    htri_t H5S_hyper_intersect_block(space, start, end)
+        H5S_t *space;       IN: First dataspace to operate on span tree
+        hssize_t *start;    IN: Starting coordinate for block
+        hssize_t *end;      IN: Ending coordinate for block
+ RETURNS
+    Non-negative on success, negative on failure
+ DESCRIPTION
+    Quickly detect intersections between span tree and block
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+htri_t 
+H5S_hyper_intersect_block (const H5S_t *space, hssize_t *start, hssize_t *end)
+{
+    htri_t ret_value=FAIL;      /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5S_hyper_intersect_block);
+
+    /* Sanity check */
+    assert(space);
+    assert(start);
+    assert(end);
+
+    /* Check for 'all' selection, instead of a hyperslab selection */
+    /* (Technically, this shouldn't be in the "hyperslab" routines...) */
+    if(space->select.type==H5S_SEL_ALL)
+        HGOTO_DONE(TRUE);
+
+    /* Check that the space selections both have span trees */
+    if(space->select.sel_info.hslab.span_lst==NULL)
+        HGOTO_ERROR(H5E_DATASPACE, H5E_UNINITIALIZED, FAIL, "dataspace does not have span tree");
+
+    /* Perform the span-by-span intersection check */
+    if((ret_value=H5S_hyper_intersect_block_helper(space->select.sel_info.hslab.span_lst,space->select.offset,start,end))<0)
+        HGOTO_ERROR(H5E_DATASPACE, H5E_BADSELECT, FAIL, "can't perform hyperslab intersection check");
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+}   /* H5S_hyper_intersect_block() */
 
 
 /*--------------------------------------------------------------------------
diff --git a/src/H5Sprivate.h b/src/H5Sprivate.h
index 2fcdad7..94510b2 100644
--- a/src/H5Sprivate.h
+++ b/src/H5Sprivate.h
@@ -241,7 +241,10 @@ H5_DLL herr_t H5S_hyper_add_span_element(H5S_t *space, unsigned rank,
     hssize_t *coords);
 H5_DLL herr_t H5S_hyper_reset_scratch(H5S_t *space);
 H5_DLL herr_t H5S_hyper_convert(H5S_t *space);
+#ifdef LATER
 H5_DLL htri_t H5S_hyper_intersect (H5S_t *space1, H5S_t *space2);
+#endif /* LATER */
+H5_DLL htri_t H5S_hyper_intersect_block (const H5S_t *space, hssize_t *start, hssize_t *end);
 H5_DLL herr_t H5S_hyper_adjust(H5S_t *space, const hssize_t *offset);
 H5_DLL herr_t H5S_hyper_move(H5S_t *space, const hssize_t *offset);
 H5_DLL herr_t H5S_hyper_normalize_offset(H5S_t *space);