[svn-r168] Changes since 19980122

----------------------

./MANIFEST
	Added new files.

./src/H5D.c
	Added support for partial datatype I/O which is needed when
	merging struct members between file and disk.  This isn't the
	efficient version because the merge requires an extra gather
	(step 1b in my pipeline diagram) that isn't turned off when it
	isn't needed.

./src/H5T.c
./src/H5Tpkg.h
./src/H5Tprivate.h
./src/H5Tpublic.h
	Conversion functions take an extra argument which is a pointer
	to a blob of private data that can be used by the conversion
	function to save anything that's expensive to compute and
	is constant for a particular conversion path.

./src/H5Tconv.c
	Compound data type conversion is beginning to work!  We can
	handle conversions between compound types that have members
	which are not arrays.  It also supports partial conversion so
	we can omit certain members of the source and not clobber
	extra members in the destination.

./test/Makefile.in
./test/cmpd_dset.c	[NEW]
	Added a test case that demonstrates how to use compound data
	types in a dataset.  The output doesn't match the output of
	the other test cases yet, the the entire example is more
	readable and written entirely with the API.

1 files changed, 32 insertions, 9 deletions

diff --git a/src/H5D.c b/src/H5D.c
index 2c947c0..dac599c 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -832,10 +832,12 @@ H5D_read(H5D_t *dataset, const H5T_t *mem_type, const H5P_t *mem_space,
 {
     size_t		nelmts	;		/*number of elements	*/
     uint8		*tconv_buf = NULL;	/*data type conv buffer	*/
+    uint8		*bkg_buf = NULL;	/*background buffer	*/
     H5T_conv_t		tconv_func = NULL;	/*conversion function	*/
     hid_t		src_id = -1, dst_id = -1;/*temporary type atoms */
     const H5P_conv_t	*sconv_func = NULL;	/*space conversion funcs*/
     H5P_number_t	numbering;		/*element numbering info*/
+    void		*cdata = NULL;		/*type conversion data	*/
     herr_t		ret_value = FAIL;
 
     FUNC_ENTER(H5D_read, FAIL);
@@ -863,7 +865,7 @@ H5D_read(H5D_t *dataset, const H5T_t *mem_type, const H5P_t *mem_space,
      * Locate the type conversion function and data space conversion
      * functions, and set up the element numbering information.
      */
-    if (NULL == (tconv_func = H5T_find(dataset->type, mem_type))) {
+    if (NULL == (tconv_func = H5T_find(dataset->type, mem_type, &cdata))) {
 	HGOTO_ERROR(H5E_DATASET, H5E_UNSUPPORTED, FAIL,
 		    "unable to convert between src and dest data types");
     }
@@ -893,23 +895,31 @@ H5D_read(H5D_t *dataset, const H5T_t *mem_type, const H5P_t *mem_space,
 	size_t src_size = nelmts * H5T_get_size(dataset->type);
 	size_t dst_size = nelmts * H5T_get_size(mem_type);
 	tconv_buf = H5MM_xmalloc(MAX(src_size, dst_size));
+	bkg_buf = H5MM_xmalloc (dst_size);
     }
 #endif
 
     /*
-     * Gather the data from disk into the data type conversion buffer.
+     * Gather the data from disk into the data type conversion buffer. Also
+     * gather data from application to background buffer (this step is not
+     * needed for most conversions, but we leave that as an exercise for
+     * later ;-)
      */
     if ((sconv_func->fgath)(dataset->ent.file, &(dataset->layout),
 			    H5T_get_size (dataset->type), file_space,
 			    &numbering, 0, nelmts,
 			    tconv_buf/*out*/)!=nelmts) {
-	HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "gather failed");
+	HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "file gather failed");
+    }
+    if ((sconv_func->mgath)(buf, H5T_get_size (mem_type), mem_space,
+			    &numbering, 0, nelmts, bkg_buf/*out*/)!=nelmts) {
+	HGOTO_ERROR (H5E_IO, H5E_READERROR, FAIL, "mem gather failed");
     }
 
     /*
      * Perform data type conversion.
      */
-    if ((tconv_func) (src_id, dst_id, nelmts, tconv_buf, NULL) < 0) {
+    if ((tconv_func) (src_id, dst_id, &cdata, nelmts, tconv_buf, bkg_buf)<0) {
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL,
 		    "data type conversion failed");
     }
@@ -919,7 +929,7 @@ H5D_read(H5D_t *dataset, const H5T_t *mem_type, const H5P_t *mem_space,
      */
     if ((sconv_func->mscat)(tconv_buf, H5T_get_size (mem_type), mem_space,
 			    &numbering, 0, nelmts, buf/*out*/)<0) {
-	HGOTO_ERROR (H5E_IO, H5E_WRITEERROR, FAIL, "scatter failed");
+	HGOTO_ERROR (H5E_IO, H5E_READERROR, FAIL, "scatter failed");
     }
     ret_value = SUCCEED;
     
@@ -927,6 +937,7 @@ H5D_read(H5D_t *dataset, const H5T_t *mem_type, const H5P_t *mem_space,
     if (src_id >= 0) H5A_dec_ref(src_id);
     if (dst_id >= 0) H5A_dec_ref(dst_id);
     tconv_buf = H5MM_xfree(tconv_buf);
+    bkg_buf = H5MM_xfree (bkg_buf);
     FUNC_LEAVE(ret_value);
 }
 
@@ -954,10 +965,12 @@ H5D_write(H5D_t *dataset, const H5T_t *mem_type, const H5P_t *mem_space,
 {
     size_t		nelmts;
     uint8		*tconv_buf = NULL;	/*data type conv buffer	*/
+    uint8		*bkg_buf = NULL;	/*background buffer	*/
     H5T_conv_t		tconv_func = NULL;	/*conversion function	*/
     hid_t		src_id = -1, dst_id = -1;/*temporary type atoms */
     const H5P_conv_t	*sconv_func = NULL;	/*space conversion funcs*/
     H5P_number_t	numbering;		/*element numbering info*/
+    void		*cdata = NULL;		/*type conversion data	*/
     herr_t		ret_value = FAIL;
 
     FUNC_ENTER(H5D_write, FAIL);
@@ -985,7 +998,7 @@ H5D_write(H5D_t *dataset, const H5T_t *mem_type, const H5P_t *mem_space,
      * Locate the type conversion function and data space conversion
      * functions, and set up the element numbering information.
      */
-    if (NULL == (tconv_func = H5T_find(mem_type, dataset->type))) {
+    if (NULL == (tconv_func = H5T_find(mem_type, dataset->type, &cdata))) {
 	HGOTO_ERROR(H5E_DATASET, H5E_UNSUPPORTED, FAIL,
 		    "unable to convert between src and dest data types");
     }
@@ -1015,22 +1028,31 @@ H5D_write(H5D_t *dataset, const H5T_t *mem_type, const H5P_t *mem_space,
 	size_t src_size = nelmts * H5T_get_size(mem_type);
 	size_t dst_size = nelmts * H5T_get_size(dataset->type);
 	tconv_buf = H5MM_xmalloc(MAX(src_size, dst_size));
+	bkg_buf = H5MM_xmalloc (dst_size);
     }
 #endif
 
 
     /*
-     * Gather data into the data type conversion buffer.
+     * Gather data from application buffer into the data type conversion
+     * buffer. Also gather data from the file into the background buffer
+     * (this step is not needed for most conversions, but we leave that as an
+     * exercise for later ;-)
      */
     if ((sconv_func->mgath)(buf, H5T_get_size (mem_type), mem_space,
 			    &numbering, 0, nelmts, tconv_buf/*out*/)!=nelmts) {
-	HGOTO_ERROR (H5E_IO, H5E_WRITEERROR, FAIL, "gather failed");
+	HGOTO_ERROR (H5E_IO, H5E_WRITEERROR, FAIL, "mem gather failed");
+    }
+    if ((sconv_func->fgath)(dataset->ent.file, &(dataset->layout),
+			    H5T_get_size (dataset->type), file_space,
+			    &numbering, 0, nelmts, bkg_buf/*out*/)!=nelmts) {
+	HGOTO_ERROR (H5E_IO, H5E_WRITEERROR, FAIL, "file gather failed");
     }
 
     /*
      * Perform data type conversion.
      */
-    if ((tconv_func) (src_id, dst_id, nelmts, tconv_buf, NULL) < 0) {
+    if ((tconv_func) (src_id, dst_id, &cdata, nelmts, tconv_buf, bkg_buf)<0) {
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL,
 		    "data type conversion failed");
     }
@@ -1049,5 +1071,6 @@ H5D_write(H5D_t *dataset, const H5T_t *mem_type, const H5P_t *mem_space,
     if (src_id >= 0) H5A_dec_ref(src_id);
     if (dst_id >= 0) H5A_dec_ref(dst_id);
     tconv_buf = H5MM_xfree(tconv_buf);
+    bkg_buf = H5MM_xfree (bkg_buf);
     FUNC_LEAVE(ret_value);
 }