[svn-r5152] Purpose:

    New Feature

Description:
    Added new H5Dfill() routine to fill the elements in a selection for a
    memory buffer with a fill value.  This is a user API wrapper around some
    internal routines which were needed for the fill-value modifications
    from Raymond as well as Pedro's code for reducing the size of a chunked
    dataset.

Platforms tested:
    FreeBSD 4.5 (sleipnir) [and IRIX64 6.5 (modi4) in parallel, in a few
    minutes]

10 files changed, 730 insertions, 46 deletions

diff --git a/src/H5D.c b/src/H5D.c
index 2b0b717..6345862 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -3597,6 +3597,90 @@ done:
 }   /* end H5Dvlen_get_buf_size() */
 
 
+/*--------------------------------------------------------------------------
+ NAME
+    H5Dfill
+ PURPOSE
+    Fill a selection in memory with a value
+ USAGE
+    herr_t H5Dfill(fill, fill_type, space, buf, buf_type)
+        const void *fill;       IN: Pointer to fill value to use
+        hid_t fill_type_id;     IN: Datatype of the fill value
+        void *buf;              IN/OUT: Memory buffer to fill selection within
+        hid_t buf_type_id;      IN: Datatype of the elements in buffer
+        hid_t space_id;         IN: Dataspace describing memory buffer &
+                                    containing selection to use.
+ RETURNS
+    Non-negative on success/Negative on failure.
+ DESCRIPTION
+    Use the selection in the dataspace to fill elements in a memory buffer.
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+herr_t
+H5Dfill(const void *fill, hid_t fill_type_id, void *buf, hid_t buf_type_id, hid_t space_id)
+{
+    H5S_t *space;               /* Dataspace */
+    H5T_t *fill_type;           /* Fill-value datatype */
+    H5T_t *buf_type;            /* Buffer datatype */
+    H5T_path_t *tpath = NULL;   /* Conversion information*/
+    uint8_t *tconv_buf = NULL;  /* Data type conv buffer */
+    uint8_t *bkg_buf = NULL;    /* Temp conversion buffer */
+    size_t src_type_size;       /* Size of source type	*/
+    size_t dst_type_size;       /* Size of destination type*/
+    size_t buf_size;            /* Desired buffer size	*/
+    herr_t ret_value=SUCCEED;   /* Return value */
+
+    FUNC_ENTER (H5Dfill, FAIL);
+
+    /* Check args */
+    if (fill==NULL)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid fill value");
+    if (buf==NULL)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid buffer");
+    if (H5I_DATASPACE != H5I_get_type(space_id) || NULL == (space=H5I_object(space_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "not a dataspace");
+    if (H5I_DATATYPE != H5I_get_type(fill_type_id) || NULL == (fill_type=H5I_object(fill_type_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "not a datatype");
+    if (H5I_DATATYPE != H5I_get_type(buf_type_id) || NULL == (buf_type=H5I_object(buf_type_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "not a datatype");
+
+    /* Get the memory and file datatype sizes */
+    src_type_size = H5T_get_size(fill_type);
+    dst_type_size = H5T_get_size(buf_type);
+
+    /* Get the maximum buffer size needed and allocate it */
+    buf_size=MAX(src_type_size,dst_type_size);
+    if (NULL==(tconv_buf = H5MM_malloc (buf_size)) || NULL==(bkg_buf = H5MM_calloc(buf_size)))
+        HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
+
+    /* Copy the user's data into the buffer for conversion */
+    HDmemcpy(tconv_buf,fill,src_type_size);
+
+    /* Convert memory buffer into disk buffer */
+    /* Set up type conversion function */
+    if (NULL == (tpath = H5T_path_find(fill_type, buf_type, NULL, NULL)))
+        HGOTO_ERROR(H5E_DATASET, H5E_UNSUPPORTED, FAIL, "unable to convert between src and dest data types");
+
+    /* Perform data type conversion */
+    if (H5T_convert(tpath, fill_type_id, buf_type_id, (hsize_t)1, 0, 0, tconv_buf, bkg_buf, H5P_DEFAULT)<0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTCONVERT, FAIL, "data type conversion failed");
+
+    /* Fill the selection in the memory buffer */
+    if(H5S_select_fill(tconv_buf, dst_type_size, space, buf)<0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTENCODE, FAIL, "filling selection failed");
+
+done:
+    if (tconv_buf)
+        H5MM_xfree(tconv_buf);
+    if (bkg_buf)
+        H5MM_xfree(bkg_buf);
+    FUNC_LEAVE (ret_value);
+}   /* H5Dfill() */
+
+
 /*-------------------------------------------------------------------------
  * Function:	H5Ddebug
  *
diff --git a/src/H5Dpublic.h b/src/H5Dpublic.h
index b889c35..41e479d 100644
--- a/src/H5Dpublic.h
+++ b/src/H5Dpublic.h
@@ -57,6 +57,8 @@ __DLL__ herr_t H5Diterate(void *buf, hid_t type_id, hid_t space_id,
             H5D_operator_t op, void *operator_data);
 __DLL__ herr_t H5Dvlen_reclaim(hid_t type_id, hid_t space_id, hid_t plist_id, void *buf);
 __DLL__ herr_t H5Dvlen_get_buf_size(hid_t dataset_id, hid_t type_id, hid_t space_id, hsize_t *size);
+__DLL__ herr_t H5Dfill(const void *fill, hid_t fill_type, void *buf,
+        hid_t buf_type, hid_t space);
 __DLL__ herr_t H5Ddebug(hid_t dset_id, unsigned int flags);
 
 #ifdef __cplusplus
diff --git a/src/H5F.c b/src/H5F.c
index 71b009a..9c1fd21 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -3280,7 +3280,7 @@ H5F_get_fileno(const H5F_t *f, unsigned long *filenum)
 
     /* Retrieve the file's serial number */
     if(H5FD_get_fileno(f->shared->lf,filenum)<0)
-	HRETURN_ERROR(H5E_FILE, H5E_BADRANGE, FAIL, "can't retrieve fileno");
+	HGOTO_ERROR(H5E_FILE, H5E_BADRANGE, FAIL, "can't retrieve fileno");
 
 done:
     FUNC_LEAVE(ret_value);
diff --git a/src/H5Sall.c b/src/H5Sall.c
index ea5eac5..d988de2 100644
--- a/src/H5Sall.c
+++ b/src/H5Sall.c
@@ -1057,3 +1057,57 @@ H5S_all_select_iterate(void *buf, hid_t type_id, H5S_t *space, H5D_operator_t op
 
     FUNC_LEAVE (ret_value);
 }   /* H5S_all_select_iterate() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5S_all_select_fill
+ PURPOSE
+    Fill an "all" selection in memory with a value
+ USAGE
+    herr_t H5S_all_select_fill(fill,fill_size,space,buf)
+        const void *fill;       IN: Pointer to fill value to use
+        size_t fill_size;       IN: Size of elements in memory buffer & size of
+                                    fill value
+        H5S_t *space;           IN: Dataspace describing memory buffer &
+                                    containing selection to use.
+        void *buf;              IN/OUT: Memory buffer to fill selection in
+ RETURNS
+    Non-negative on success/Negative on failure.
+ DESCRIPTION
+    Use the selection in the dataspace to fill elements in a memory buffer.
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+    The memory buffer elements are assumed to have the same datatype as the
+    fill value being placed into them.
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+herr_t
+H5S_all_select_fill(const void *fill, size_t fill_size, H5S_t *space, void *buf)
+{
+    hssize_t nelemts;          /* Number of elements in dataspace */
+    herr_t ret_value=SUCCEED;  /* return value */
+
+    FUNC_ENTER (H5S_all_select_fill, FAIL);
+
+    /* Check args */
+    assert(fill);
+    assert(fill_size>0);
+    assert(space);
+    assert(buf);
+
+    /* Fill the selection in the memory buffer */
+
+    /* Get the number of elements to iterate through */
+    if((nelemts=H5S_get_simple_extent_npoints(space))<0)
+        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTCOUNT, FAIL, "can't get number of elements");
+
+    /* Fill the elements in the buffer */
+    H5_CHECK_OVERFLOW(nelemts,hssize_t,size_t);
+    H5V_array_fill(buf, fill, fill_size, (size_t)nelemts);
+
+done:
+    FUNC_LEAVE (ret_value);
+}   /* H5S_all_select_fill() */
+
diff --git a/src/H5Shyper.c b/src/H5Shyper.c
index 4c1f3f5..029b7d7 100644
--- a/src/H5Shyper.c
+++ b/src/H5Shyper.c
@@ -6047,18 +6047,17 @@ H5S_hyper_select_regular(const H5S_t *space)
     else
         ret_value=FALSE;
 
-done:
     FUNC_LEAVE (ret_value);
 }   /* H5S_hyper_select_regular() */
 
 
 /*--------------------------------------------------------------------------
  NAME
-    H5S_hyper_select_iterate_helper
+    H5S_hyper_select_iterate_mem_gen
  PURPOSE
     Internal routine to iterate over the elements of a span tree hyperslab selection
  USAGE
-    herr_t H5S_iterate_hyperslab_io(iter_info)
+    herr_t H5S_hyper_select_iterate_mem_gen(iter_info)
         H5S_hyper_iter_info_t *iter_info;   IN/OUT: Block of iteration parameters to pass into recursive calls
  RETURNS
     Non-negative on success, negative on failure
@@ -6071,7 +6070,7 @@ done:
  REVISION LOG
 --------------------------------------------------------------------------*/
 static herr_t
-H5S_hyper_select_iterate_helper(H5S_hyper_iter_info_t *iter_info)
+H5S_hyper_select_iterate_mem_gen(H5S_hyper_iter_info_t *iter_info)
 {
     const H5S_t *space; /* Dataspace operating with */
     H5S_sel_iter_t *iter;   /* Selection iterator */
@@ -6090,7 +6089,7 @@ H5S_hyper_select_iterate_helper(H5S_hyper_iter_info_t *iter_info)
     unsigned u;            /* Index variable */
     herr_t ret_value=FAIL;
 
-    FUNC_ENTER (H5S_hyper_select_iterate_helper, FAIL);
+    FUNC_ENTER (H5S_hyper_select_iterate_mem_gen, FAIL);
 
     /* Check args */
     assert(iter_info);
@@ -6244,7 +6243,7 @@ H5S_hyper_select_iterate_helper(H5S_hyper_iter_info_t *iter_info)
 done:
 #endif /* LATER */
     FUNC_LEAVE (ret_value);
-} /* end H5S_hyper_select_iterate_helper() */
+} /* end H5S_hyper_select_iterate_mem_gen() */
 
 
 /*--------------------------------------------------------------------------
@@ -6503,7 +6502,7 @@ H5S_hyper_select_iterate(void *buf, hid_t type_id, H5S_t *space, H5D_operator_t
         iter_info.op_data=operator_data;
 
         /* Call the recursive iterator routine */
-        ret_value=H5S_hyper_select_iterate_helper(&iter_info);
+        ret_value=H5S_hyper_select_iterate_mem_gen(&iter_info);
     } /* end else */
 
     /* Release selection iterator */
@@ -6571,6 +6570,402 @@ done:
 
 /*--------------------------------------------------------------------------
  NAME
+    H5S_hyper_select_fill_gen
+ PURPOSE
+    Fill a hyperslab selection in memory with a value
+ USAGE
+    herr_t H5S_hyper_select_fill_gen(fill,fill_size,space,buf)
+        const void *fill;       IN: Pointer to fill value to use
+        size_t fill_size;       IN: Size of elements in memory buffer & size of
+                                    fill value
+        H5S_t *space;           IN: Dataspace describing memory buffer &
+                                    containing selection to use.
+        void *buf;              IN/OUT: Memory buffer to fill selection in
+ RETURNS
+    Non-negative on success/Negative on failure.
+ DESCRIPTION
+    Use the selection in the dataspace to fill elements in a memory buffer.
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+    The memory buffer elements are assumed to have the same datatype as the
+    fill value being placed into them.
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+static herr_t
+H5S_hyper_select_fill_gen(const void *fill, size_t fill_size, H5S_t *space, void *buf)
+{
+    H5S_hyper_span_info_t *spans=NULL;      /* Pointer to copy of the span tree */
+    H5S_hyper_span_info_t *tmp_spans;       /* Temporary pointer to a span tree */
+    H5S_hyper_span_t *span[H5O_LAYOUT_NDIMS];   /* Array of pointers to span nodes */
+    H5S_hyper_span_t *curr_span;    /* Current hyperslab span node */
+    hsize_t slab[H5O_LAYOUT_NDIMS]; /* Cumulative size of each dimension in bytes */
+    hssize_t abs_arr[H5O_LAYOUT_NDIMS];  /* Absolute hyperslab span position */
+    hssize_t *off_arr;  /* Offset within the dataspace extent */
+    hsize_t acc;        /* Accumulator for computing cumulative sizes */
+    int fast_dim;       /* Rank of the fastest changing dimension for the dataspace */
+    int curr_dim;       /* Current dimension being operated on */
+    int ndims;          /* Number of dimensions of dataset */
+    hsize_t span_io;    /* Number of elements in current span to actually process */
+    hsize_t num_elem;   /* Number of elements in the selection */
+    uint8_t *loc;       /* Current element location pointer */
+    int i;              /* Index variable */
+    unsigned u;         /* Index variable */
+    herr_t ret_value=SUCCEED;   /* Return value */
+
+    FUNC_ENTER (H5S_hyper_select_fill_gen, FAIL);
+
+    /* Set the rank of the fastest changing dimension */
+    ndims=space->extent.u.simple.rank;
+    fast_dim=(ndims-1);
+
+    /* Set the pointer to the selection offset in the dataspace */
+    off_arr=space->select.offset;
+
+    /* Make a copy of the span tree to iterate over */
+    spans=H5S_hyper_copy_span(space->select.sel_info.hslab.span_lst);
+
+    /* Set the nelem & pstride values according to the element size */
+    H5S_hyper_span_precompute(spans,fill_size);
+
+    /* Build arrays of span heads & offsets in each dimension */
+    for(u=0, tmp_spans=spans; u<space->extent.u.simple.rank; u++) {
+        /* Set the pointers to the initial span in each dimension */
+        assert(tmp_spans);
+        assert(tmp_spans->head);
+
+        /* Set the pointer to the first span in the list for this node */
+        span[u] = tmp_spans->head;
+
+        /* Set the initial offset to low bound of span */
+        abs_arr[u]=span[u]->low;
+
+        /* Get the pointer to the next level down */
+        tmp_spans=tmp_spans->head->down;
+    } /* end for */
+
+    /* Compute sizes of "slab" in each dimension */
+    for(i=fast_dim, acc=fill_size; i>=0; i--) {
+        slab[i]=acc;
+        acc*=space->extent.u.simple.size[i];
+    } /* end for */
+
+    /* Set the offset of the first element iterated on */
+    for(i=0, loc=buf; i<ndims; i++)
+        /* Compute the sequential element offset */
+        loc+=(abs_arr[i]+off_arr[i])*slab[i];
+
+    /* Get the number of elements in selection */
+    num_elem=space->select.num_elem;
+
+    /* Get the pointer to the current span nodes */
+    curr_span=span[fast_dim];
+
+    /* Go iterate over the hyperslabs */
+    while(num_elem>0) {
+        /* Loop through the fastest dim's spans */
+        while(curr_span!=NULL) {
+            /* Compute the number of elements to attempt in this span */
+            span_io=(curr_span->high-curr_span->low)+1;
+
+            /* Double check that things haven't gotten out of sync */
+            assert(num_elem>0);
+
+            /* Fill the elements in the current block */
+            H5_CHECK_OVERFLOW(span_io,hsize_t,size_t);
+            H5V_array_fill(loc, fill, fill_size, (size_t)span_io);
+
+            /* Increment the buffer offset */
+            loc+=curr_span->pstride;
+
+            /* Decrement the number of elements left */
+            num_elem-=span_io;
+
+            /* Advance span in fastest dimension */
+            curr_span=curr_span->next;
+        } /* end while */
+
+        /* Check if there are more elements left */
+        if(num_elem>0) {
+            /* Recursively advance to next offset (not necessarily span) in next dimension up */
+
+            /* Start at the fastest dim */
+            curr_dim=fast_dim-1;
+
+            /* Get the pointer to the correct dimension */
+            curr_span=span[curr_dim];
+
+            /* Work back up through the dimensions */
+            while(curr_dim>=0) {
+                /* Increment position in span */
+                abs_arr[curr_dim]++;
+
+                /* Check if we are still within the span */
+                if(abs_arr[curr_dim]<=curr_span->high) {
+                    break;
+                } /* end if */
+                /* If we walked off that span, advance to the next span */
+                else {
+                    /* Advance span in this dimension */
+                    curr_span=curr_span->next;
+
+                    /* Check if we have a valid span in this dimension still */
+                    if(curr_span!=NULL) {
+                        /* Reset the offset for the dim */
+                        abs_arr[curr_dim]=curr_span->low;
+
+                        break;
+                    } /* end if */
+                    else {
+                        /* If we finished the span list in this dimension, decrement the dimension worked on and loop again */
+                        curr_dim--;
+
+                        /* Reset the curr_span to the next dim */
+                        if(curr_dim>=0)
+                            curr_span=span[curr_dim];
+                    } /* end else */
+                } /* end else */
+            } /* end while */
+
+            /* Reset the span in the current dimension */
+            span[curr_dim]=curr_span;
+
+            /* Walk back down the iterator positions, reseting them */
+            while(curr_dim<fast_dim) {
+                assert(curr_span);
+                assert(curr_span->down);
+                assert(curr_span->down->head);
+
+                /* Set the new span for this dimension */
+                span[curr_dim+1]=curr_span->down->head;
+
+                /* Advance span down the tree */
+                curr_span=curr_span->down->head;
+
+                /* Reset the offset for the dim */
+                abs_arr[curr_dim+1]=curr_span->low;
+
+                /* Increment current dimension */
+                curr_dim++;
+            } /* end while */
+
+            /* Verify that the curr_span points to the fastest dim */
+            assert(curr_span==span[fast_dim]);
+
+            /* Verify that the offset is correct for the fastest dim */
+            assert(abs_arr[fast_dim]==curr_span->low);
+
+            /* Recompute offset in buffer */
+            for(i=0, loc=buf; i<ndims; i++)
+                loc+=(abs_arr[i]+off_arr[i])*slab[i];
+        } /* end if */
+    } /* end while */
+
+#ifdef LATER
+done:
+#endif /* LATER */
+    /* Free the copy of the selections span tree */
+    if(spans!=NULL)
+        H5S_hyper_free_span_info(spans);
+
+    FUNC_LEAVE (ret_value);
+} /* end H5S_hyper_select_fill_gen() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5S_hyper_select_fill_opt
+ PURPOSE
+    Fill a hyperslab selection in memory with a value
+ USAGE
+    herr_t H5S_hyper_select_fill_opt(fill,fill_size,space,buf)
+        const void *fill;       IN: Pointer to fill value to use
+        size_t fill_size;       IN: Size of elements in memory buffer & size of
+                                    fill value
+        H5S_t *space;           IN: Dataspace describing memory buffer &
+                                    containing selection to use.
+        void *buf;              IN/OUT: Memory buffer to fill selection in
+ RETURNS
+    Non-negative on success/Negative on failure.
+ DESCRIPTION
+    Use the selection in the dataspace to fill elements in a memory buffer.
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+    The memory buffer elements are assumed to have the same datatype as the
+    fill value being placed into them.
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+static herr_t
+H5S_hyper_select_fill_opt(const void *fill, size_t fill_size, H5S_t *space, void *buf)
+{
+    H5S_hyper_dim_t *diminfo;               /* Alias for dataspace's diminfo information */
+    hsize_t tmp_count[H5O_LAYOUT_NDIMS];    /* Temporary hyperslab counts */
+    hsize_t tmp_block[H5O_LAYOUT_NDIMS];    /* Temporary hyperslab blocks */
+    hsize_t slab[H5O_LAYOUT_NDIMS];         /* Size of objects in buffer */
+    hsize_t acc;                /* Size accumulator */
+    hsize_t num_elem;           /* Number of elements in the selection */
+    hsize_t fast_elem;          /* Block size in the fastest dimension */
+    hsize_t fast_stride;        /* Stride in the fastest dimension */
+    hssize_t temp_off;          /* Offset in a given dimension */
+    uint8_t *loc;               /* Current element location */
+    int i;                      /* Counter */
+    unsigned u;                 /* Counter */
+    int fast_dim;               /* Rank of the fastest changing dimension for the dataspace */
+    int temp_dim;               /* Temporary rank holder */
+    unsigned ndims;             /* Rank of the dataspace */
+    herr_t ret_value=SUCCEED;   /* Return value */
+
+    FUNC_ENTER (H5S_hyper_select_fill_opt, FAIL);
+
+    /* Set some convienence values */
+    ndims=space->extent.u.simple.rank;
+    fast_dim=ndims-1;
+    diminfo=space->select.sel_info.hslab.diminfo;
+
+    /* Build the table of next-dimension down 'element' sizes */
+    for(i=fast_dim, acc=fill_size; i>=0; i--) {
+        slab[i]=acc;
+        acc*=space->extent.u.simple.size[i];
+    } /* end for */
+
+    /* Build the tables of count & block sizes as well as the initial starting location */
+    for(u=0, loc=buf; u<ndims; u++) {
+        tmp_count[u]=diminfo[u].count;
+        tmp_block[u]=diminfo[u].block;
+        loc+=(diminfo[u].start+space->select.offset[u])*slab[u];
+    } /* end for */
+
+    /* Get the number of elements in selection */
+    num_elem=space->select.num_elem;
+
+    /* Get the number of elements in the fastest dimension of the selection */
+    fast_elem=tmp_block[fast_dim];
+    fast_stride=diminfo[fast_dim].stride;
+
+    /* Go iterate over the hyperslabs */
+    while(num_elem>0) {
+        /* Iterate over the blocks in the fastest dimension */
+        while(tmp_count[fast_dim]>0) {
+            /* Double check that things haven't gotten out of sync */
+            assert(num_elem>0);
+
+            /* Fill the elements in the current block */
+            H5_CHECK_OVERFLOW(fast_elem,hsize_t,size_t);
+            H5V_array_fill(loc, fill, fill_size, (size_t)fast_elem);
+
+            /* Advance the pointer in the memory buffer */
+            loc+=(fast_stride*fill_size);
+
+            /* Decrement the block count */
+            tmp_count[fast_dim]--;
+
+            /* Decrement the number of elements to process */
+            num_elem-=fast_elem;
+        } /* end while */
+
+        /* Work on other dimensions if necessary */
+        if(num_elem>0) {
+            /* Reset the sequence and block counts */
+            tmp_count[fast_dim]=diminfo[fast_dim].count;
+
+            /* Bubble up the decrement to the slower changing dimensions */
+            temp_dim=fast_dim-1;
+            while(temp_dim>=0) {
+                /* Decrement the sequence count in this dimension */
+                tmp_block[temp_dim]--;
+
+                /* Check if we are still in the sequence */
+                if(tmp_block[temp_dim]>0)
+                    break;
+
+                /* Reset the sequence count in this dimension */
+                tmp_block[temp_dim]=diminfo[temp_dim].block;
+
+                /* Decrement the block count */
+                tmp_count[temp_dim]--;
+
+                /* Check if we have more blocks left */
+                if(tmp_count[temp_dim]>0)
+                    break;
+
+                /* Reset the block count in this dimension */
+                tmp_count[temp_dim]=diminfo[temp_dim].count;
+            
+                /* Wrapped a dimension, go up to next dimension */
+                temp_dim--;
+            } /* end while */
+
+            /* Re-compute buffer location */
+            for(loc=buf,u=0; u<ndims; u++) {
+                temp_off=(diminfo[u].start+space->select.offset[u])
+                    +diminfo[u].stride*(diminfo[u].count-tmp_count[u])
+                        +(diminfo[u].block-tmp_block[u]);
+                loc+=temp_off*slab[u];
+            } /* end for */
+        } /* end if */
+    } /* end while */
+
+#ifdef LATER
+done:
+#endif /* LATER */
+    FUNC_LEAVE (ret_value);
+} /* end H5S_hyper_select_fill_opt() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5S_hyper_select_fill
+ PURPOSE
+    Fill a hyperslab selection in memory with a value
+ USAGE
+    herr_t H5S_hyper_select_fill(fill,fill_size,space,buf)
+        const void *fill;       IN: Pointer to fill value to use
+        size_t fill_size;       IN: Size of elements in memory buffer & size of
+                                    fill value
+        H5S_t *space;           IN: Dataspace describing memory buffer &
+                                    containing selection to use.
+        void *buf;              IN/OUT: Memory buffer to fill selection in
+ RETURNS
+    Non-negative on success/Negative on failure.
+ DESCRIPTION
+    Use the selection in the dataspace to fill elements in a memory buffer.
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+    The memory buffer elements are assumed to have the same datatype as the
+    fill value being placed into them.
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+herr_t
+H5S_hyper_select_fill(const void *fill, size_t fill_size, H5S_t *space, void *buf)
+{
+    herr_t ret_value=SUCCEED;  /* return value */
+
+    FUNC_ENTER (H5S_hyper_select_fill, FAIL);
+
+    /* Check args */
+    assert(fill);
+    assert(fill_size>0);
+    assert(space);
+    assert(buf);
+
+    /* Fill the selection in the memory buffer */
+
+    /* Check for the special case of just one H5Sselect_hyperslab call made */
+    if(space->select.sel_info.hslab.diminfo!=NULL)
+        /* Use optimized call to fill regular hyperslab */
+        ret_value=H5S_hyper_select_fill_opt(fill, fill_size, space, buf);
+    else
+        /* Call the general fill routine */
+        ret_value=H5S_hyper_select_fill_gen(fill, fill_size, space, buf);
+
+    FUNC_LEAVE (ret_value);
+}   /* H5S_hyper_select_fill() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
     H5S_hyper_recover_span
  PURPOSE
     Recover a generated span, if appropriate
@@ -6703,7 +7098,7 @@ H5S_hyper_append_span (H5S_hyper_span_t **prev_span, H5S_hyper_span_info_t ** sp
                 } /* end if */
             } /* end if */
 
-            /* Indicate elements to previous span */
+            /* Indicate elements from previous span */
             new_span->pstride=low-(*prev_span)->low;
 
             /* Append to end of merged spans list */
diff --git a/src/H5Spkg.h b/src/H5Spkg.h
index 0fc4513..668e9a6 100644
--- a/src/H5Spkg.h
+++ b/src/H5Spkg.h
@@ -138,6 +138,8 @@ __DLL__ herr_t H5S_select_elements (H5S_t *space, H5S_seloper_t op,
             size_t num_elem, const hssize_t **coord);
 __DLL__ herr_t H5S_point_select_iterate(void *buf, hid_t type_id, H5S_t *space,
                             H5D_operator_t op, void *operator_data);
+__DLL__ herr_t H5S_point_select_fill(const void *fill, size_t fill_size,
+                H5S_t *space, void *buf);
 
 /* "All" select functions */
 __DLL__ herr_t H5S_all_release(H5S_t *space);
@@ -159,6 +161,8 @@ __DLL__ herr_t H5S_all_write(H5F_t *f, const struct H5O_layout_t *layout,
 			    hid_t dxpl_id, const void *buf);
 __DLL__ herr_t H5S_all_select_iterate(void *buf, hid_t type_id, H5S_t *space,
                             H5D_operator_t op, void *operator_data);
+__DLL__ herr_t H5S_all_select_fill(const void *fill, size_t fill_size,
+                H5S_t *space, void *buf);
 __DLL__ htri_t H5S_all_opt_possible(const H5S_t *mem_space,
                             const H5S_t *file_space, const unsigned flags);
 
@@ -179,6 +183,8 @@ __DLL__ htri_t H5S_hyper_select_single(const H5S_t *space);
 __DLL__ htri_t H5S_hyper_select_regular(const H5S_t *space);
 __DLL__ herr_t H5S_hyper_select_iterate(void *buf, hid_t type_id, H5S_t *space,
                 H5D_operator_t op, void *operator_data);
+__DLL__ herr_t H5S_hyper_select_fill(const void *fill, size_t fill_size,
+                H5S_t *space, void *buf);
 
 /* "None" selection functions */
 __DLL__ herr_t H5S_select_none(H5S_t *space);
diff --git a/src/H5Spoint.c b/src/H5Spoint.c
index 7ca1bed..883dfae 100644
--- a/src/H5Spoint.c
+++ b/src/H5Spoint.c
@@ -520,11 +520,11 @@ H5S_point_mgath (const void *_buf, size_t elmt_size,
 #ifdef QAK
     printf("%s: check 1.0\n",FUNC);
 #endif /* QAK */
-    if ((space_ndims=H5S_get_simple_extent_dims (mem_space, mem_size, NULL))<0) {
-        HRETURN_ERROR (H5E_DATASPACE, H5E_CANTINIT, 0,
-		       "unable to retrieve data space dimensions");
-    }
+    /* Get the dataspace dimensions */
+    if ((space_ndims=H5S_get_simple_extent_dims (mem_space, mem_size, NULL))<0)
+        HRETURN_ERROR (H5E_DATASPACE, H5E_CANTINIT, 0, "unable to retrieve data space dimensions");
 
+    /* Loop through all the points selected */
     for(num_gath=0; num_gath<nelmts; num_gath++) {
         if(mem_iter->pnt.elmt_left>0) {
             /* Compute the location of the point to get */
@@ -596,17 +596,11 @@ H5S_point_mscat (const void *_tconv_buf, size_t elmt_size,
 #ifdef QAK
     printf("%s: check 1.0\n",FUNC);
 #endif /* QAK */
-    /*
-     * Retrieve hyperslab information to determine what elements are being
-     * selected (there might be other selection methods in the future).  We
-     * only handle hyperslabs with unit sample because there's currently no
-     * way to pass sample information to H5V_hyper_copy().
-     */
-    if ((space_ndims=H5S_get_simple_extent_dims (mem_space, mem_size, NULL))<0) {
-        HRETURN_ERROR (H5E_DATASPACE, H5E_CANTINIT, FAIL,
-		       "unable to retrieve data space dimensions");
-    }
+    /* Get the dataspace dimensions */
+    if ((space_ndims=H5S_get_simple_extent_dims (mem_space, mem_size, NULL))<0)
+        HRETURN_ERROR (H5E_DATASPACE, H5E_CANTINIT, FAIL, "unable to retrieve data space dimensions");
 
+    /* Loop through all the points selected */
     for(num_scat=0; num_scat<nelmts; num_scat++) {
         if(mem_iter->pnt.elmt_left>0) {
             /* Compute the location of the point to get */
@@ -1202,7 +1196,6 @@ H5S_point_select_regular(const H5S_t *space)
     else
     	ret_value=FALSE;
 
-done:
     FUNC_LEAVE (ret_value);
 }   /* H5S_point_select_regular() */
 
@@ -1384,18 +1377,21 @@ done:
  COMMENTS, BUGS, ASSUMPTIONS
  EXAMPLES
  REVISION LOG
+    QAK - 2002/4/5 - Wasn't using selection offset in calculation, corrected.
 --------------------------------------------------------------------------*/
 herr_t
 H5S_point_select_iterate(void *buf, hid_t type_id, H5S_t *space, H5D_operator_t op,
         void *operator_data)
 {
-    hsize_t	mem_size[H5O_LAYOUT_NDIMS]; /* Dataspace size */
-    hssize_t	mem_offset[H5O_LAYOUT_NDIMS];   /* Point offset */
-    hsize_t offset;             /* offset of region in buffer */
-    void *tmp_buf;              /* temporary location of the element in the buffer */
+    hsize_t mem_size[H5O_LAYOUT_NDIMS]; /* Dataspace size */
+    hsize_t acc;            /* Size accumulator */
+    hsize_t offset;         /* Offset of region in buffer */
+    hsize_t elmt_size;      /* Size of datatype */
+    void *tmp_buf;          /* Temporary location of the element in the buffer */
     H5S_pnt_node_t *node;   /* Point node */
-    unsigned rank;             /* Dataspace rank */
-    H5T_t *dt;                  /* Datatype structure */
+    unsigned rank;          /* Dataspace rank */
+    H5T_t *dt;              /* Datatype structure */
+    int i;                  /* Index variable */
     herr_t ret_value=0;     /* return value */
 
     FUNC_ENTER (H5S_point_select_iterate, 0);
@@ -1414,17 +1410,18 @@ H5S_point_select_iterate(void *buf, hid_t type_id, H5S_t *space, H5D_operator_t
     /* Set the size of the datatype */
     if (NULL==(dt=H5I_object(type_id)))
         HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an valid base datatype");
-    mem_size[rank]=H5T_get_size(dt);
+    mem_size[rank]=elmt_size=H5T_get_size(dt);
 
     /* Iterate through the node, checking the bounds on each element */
     node=space->select.sel_info.pnt_lst->head;
     while(node!=NULL && ret_value==0) {
-        /* Set up the location of the point */
-        HDmemcpy(mem_offset, node->pnt, rank*sizeof(hssize_t));
-        mem_offset[rank]=0;
+        /* Compute the offset of each selected point in the buffer */
+        for(i=rank-1,acc=elmt_size,offset=0; i>=0; i--) {
+            offset+=(node->pnt[i]+space->select.offset[i])*acc;
+            acc*=mem_size[i];
+        } /* end for */
 
         /* Get the offset in the memory buffer */
-        offset=H5V_array_offset(rank+1,mem_size,(const hssize_t *)mem_offset);
         tmp_buf=((char *)buf+offset);
 
         ret_value=(*op)(tmp_buf,type_id,(hsize_t)rank,node->pnt,operator_data);
@@ -1434,3 +1431,75 @@ H5S_point_select_iterate(void *buf, hid_t type_id, H5S_t *space, H5D_operator_t
 
     FUNC_LEAVE (ret_value);
 }   /* H5S_point_select_iterate() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5S_point_select_fill
+ PURPOSE
+    Fill a point selection in memory with a value
+ USAGE
+    herr_t H5S_point_select_fill(fill,fill_size,space,buf)
+        const void *fill;       IN: Pointer to fill value to use
+        size_t fill_size;       IN: Size of elements in memory buffer & size of
+                                    fill value
+        H5S_t *space;           IN: Dataspace describing memory buffer &
+                                    containing selection to use.
+        void *buf;              IN/OUT: Memory buffer to fill selection in
+ RETURNS
+    Non-negative on success/Negative on failure.
+ DESCRIPTION
+    Use the selection in the dataspace to fill elements in a memory buffer.
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+    The memory buffer elements are assumed to have the same datatype as the
+    fill value being placed into them.
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+herr_t
+H5S_point_select_fill(const void *fill, size_t fill_size, H5S_t *space, void *_buf)
+{
+    hsize_t size[H5O_LAYOUT_NDIMS];     /* Total size of memory buf */
+    uint8_t *buf=(uint8_t *)_buf;   /* Alias for memory buffer */
+    hsize_t	acc;            /* Coordinate accumulator */
+    hsize_t	off;            /* Coordinate offset */
+    H5S_pnt_node_t *node;       /* Point node */
+    int	ndims;                  /* Dimensionality of space*/
+    int i;                  /* Index variable */
+    herr_t ret_value=SUCCEED;   /* return value */
+
+    FUNC_ENTER (H5S_point_select_fill, FAIL);
+
+    /* Check args */
+    assert(fill);
+    assert(fill_size>0);
+    assert(space);
+    assert(buf);
+
+    /* Fill the selection in the memory buffer */
+
+    /* Get the dataspace dimensions */
+    if ((ndims=H5S_get_simple_extent_dims (space, size, NULL))<0)
+        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTINIT, FAIL, "unable to retrieve data space dimensions");
+
+    /* Loop through all the points selected */
+    node=space->select.sel_info.pnt_lst->head;
+    while(node!=NULL) {
+        /* Compute the offset of each selected point in the buffer */
+        for(i=ndims-1,acc=fill_size,off=0; i>=0; i--) {
+            off+=(node->pnt[i]+space->select.offset[i])*acc;
+            acc*=size[i];
+        } /* end for */
+
+        /* Set the selected point to the fill value */
+        HDmemcpy(buf+off,fill,fill_size);
+
+        /* Advance to the next point */
+        node=node->next;
+      } /* end while */
+
+done:
+    FUNC_LEAVE (ret_value);
+}   /* H5S_point_select_fill() */
+
diff --git a/src/H5Sprivate.h b/src/H5Sprivate.h
index 5af635d..0380d36 100644
--- a/src/H5Sprivate.h
+++ b/src/H5Sprivate.h
@@ -223,6 +223,8 @@ __DLL__ herr_t H5S_select_iterate(void *buf, hid_t type_id, H5S_t *space,
 				  H5D_operator_t op, void *operator_data);
 __DLL__ herr_t H5S_sel_iter_release(const H5S_t *space,
 				    H5S_sel_iter_t *sel_iter);
+__DLL__ herr_t H5S_select_fill(const void *fill, size_t fill_size, H5S_t *space,
+                                    void *buf);
 
 #ifdef H5_HAVE_PARALLEL
 
diff --git a/src/H5Sselect.c b/src/H5Sselect.c
index 92f9832..8d18e5c 100644
--- a/src/H5Sselect.c
+++ b/src/H5Sselect.c
@@ -1220,7 +1220,7 @@ H5S_select_contiguous(const H5S_t *space)
 
 /*--------------------------------------------------------------------------
  NAME
-    H5S_iterate
+    H5S_select_iterate
  PURPOSE
     Iterate over the selected elements in a memory buffer.
  USAGE
@@ -1536,7 +1536,72 @@ H5S_select_regular(const H5S_t *space)
             break;
     } /* end switch */
 
-done:
     FUNC_LEAVE (ret_value);
 }   /* H5S_select_regular() */
 
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5S_select_fill
+ PURPOSE
+    Fill a selection in memory with a value
+ USAGE
+    herr_t H5S_select_fill(fill,fill_size,space,buf)
+        const void *fill;       IN: Pointer to fill value to use
+        size_t fill_size;       IN: Size of elements in memory buffer & size of
+                                    fill value
+        H5S_t *space;           IN: Dataspace describing memory buffer &
+                                    containing selection to use.
+        void *buf;              IN/OUT: Memory buffer to fill selection in
+ RETURNS
+    Non-negative on success/Negative on failure.
+ DESCRIPTION
+    Use the selection in the dataspace to fill elements in a memory buffer.
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+    The memory buffer elements are assumed to have the same datatype as the
+    fill value being placed into them.
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+herr_t
+H5S_select_fill(const void *fill, size_t fill_size, H5S_t *space, void *buf)
+{
+    herr_t ret_value=FAIL;  /* return value */
+
+    FUNC_ENTER (H5S_select_fill, FAIL);
+
+    /* Check args */
+    assert(fill);
+    assert(fill_size>0);
+    assert(space);
+    assert(buf);
+
+    /* Fill the selection in the memory buffer */
+    /* [Defer (mostly) to the selection routines] */
+    switch(space->select.type) {
+        case H5S_SEL_POINTS:         /* Sequence of points selected */
+            ret_value=H5S_point_select_fill(fill,fill_size,space,buf);
+            break;
+
+        case H5S_SEL_HYPERSLABS:     /* Hyperslab selection defined */
+            ret_value=H5S_hyper_select_fill(fill,fill_size,space,buf);
+            break;
+
+        case H5S_SEL_ALL:            /* Entire extent selected */
+            ret_value=H5S_all_select_fill(fill,fill_size,space,buf);
+            break;
+
+        case H5S_SEL_NONE:           /* Nothing selected */
+            ret_value=SUCCEED;
+            break;
+
+        case H5S_SEL_ERROR:
+        case H5S_SEL_N:
+            assert(0 && "Invalid selection type!");
+            break;
+    } /* end switch */
+
+    FUNC_LEAVE (ret_value);
+}   /* H5S_select_fill() */
+
diff --git a/src/H5V.c b/src/H5V.c
index d4ac850..50b937f 100644
--- a/src/H5V.c
+++ b/src/H5V.c
@@ -80,6 +80,9 @@ H5V_stride_optimize1(unsigned *np/*in,out*/, hsize_t *elmt_size/*in,out*/,
  *		Saturday, October 11, 1997
  *
  * Modifications:
+ *              Unrolled loops for common cases
+ *              Quincey Koziol
+ *		?, ? ?, 2001?
  *
  *-------------------------------------------------------------------------
  */
@@ -224,6 +227,9 @@ H5V_stride_optimize2(unsigned *np/*in,out*/, hsize_t *elmt_size/*in,out*/,
  *		Saturday, October 11, 1997
  *
  * Modifications:
+ *              Unrolled loops for common cases
+ *              Quincey Koziol
+ *		?, ? ?, 2001?
  *
  *-------------------------------------------------------------------------
  */
@@ -491,6 +497,9 @@ H5V_hyper_fill(unsigned n, const hsize_t *_size,
  *		Friday, October 10, 1997
  *
  * Modifications:
+ *              Unrolled loops for common cases
+ *              Quincey Koziol
+ *		?, ? ?, 2001?
  *
  *-------------------------------------------------------------------------
  */
@@ -901,13 +910,11 @@ H5V_array_fill(void *_dst, const void *src, size_t size, size_t count)
  * Purpose:	Given a coordinate description of a location in an array, this
  *      function returns the byte offset of the coordinate.
  *
- *		The dimensionality of the whole array, the hyperslab, and the
- *		returned stride array is N.  The whole array dimensions are
- *		TOTAL_SIZE and the coordinate is at offset OFFSET.
- *
- * Return:	Success: Byte offset from beginning of array to start
- *				of striding.
+ *		The dimensionality of the whole array, and the offset is N.
+ *              The whole array dimensions are TOTAL_SIZE and the coordinate
+ *              is at offset OFFSET.
  *
+ * Return:	Success: Byte offset from beginning of array to element offset
  *		Failure: abort() -- should never fail
  *
  * Programmer:	Quincey Koziol
@@ -924,7 +931,7 @@ H5V_array_offset(unsigned n, const hsize_t *total_size, const hssize_t *offset)
     hsize_t	    acc;	/*accumulator				*/
     int	    i;		/*counter				*/
 
-    FUNC_ENTER(H5V_array_stride, (HDabort(), 0));
+    FUNC_ENTER(H5V_array_offset, (HDabort(), 0));
 
     assert(n <= H5V_HYPER_NDIMS);
     assert(total_size);
@@ -934,8 +941,8 @@ H5V_array_offset(unsigned n, const hsize_t *total_size, const hssize_t *offset)
     for (i=(int)(n-1), acc=1, skip=0; i>=0; --i) {
         skip += acc * offset[i];
         acc *= total_size[i];
-    }
+    } /* end for */
 
     FUNC_LEAVE(skip);
-}
+} /* end H5V_array_offset() */