[svn-r14860] Description:

	Omnibus raw data I/O revisions, with wide-ranging changes and
refactoring, in order to prepare for implementing "fast append" feature.

	These changes remove the majority of the code duplication for raw data
I/O which has crept in over the last ten years and introduces a more object-
oriented design for operating on different types of dataset storage.

	Chunked storage no longer has it's own I/O routines, it is now handled
as either contiguous (if chunk is not pulled into the cache) or compact (if the
chunk is cached in memory).

	No bug or feature changes, at least intentionally... :-)

Tested on:
        FreeBSD/32 6.2 (duty) in debug mode
        FreeBSD/64 6.2 (liberty) w/C++ & FORTRAN, in debug mode
        Linux/32 2.6 (kagiso) w/PGI compilers, w/C++ & FORTRAN, w/threadsafe,
                                in debug mode
        Linux/64-amd64 2.6 (smirom) w/default API=1.6.x, w/C++ & FORTRAN,
                                in production mode
        Linux/64-ia64 2.6 (cobalt) w/Intel compilers, w/C++ & FORTRAN,
                                in production mode
        Solaris/32 2.10 (linew) w/deprecated symbols disabled, w/C++ & FORTRAN,
                                w/szip filter, in production mode
        Mac OS X/32 10.5.2 (amazon) in debug mode
        Linux/64-ia64 2.4 (tg-login3) w/parallel, w/FORTRAN, in production mode
	

1 files changed, 41 insertions, 425 deletions

diff --git a/src/H5Dselect.c b/src/H5Dselect.c
index f08672f..947c81e 100644
--- a/src/H5Dselect.c
+++ b/src/H5Dselect.c
@@ -34,400 +34,37 @@
 #include "H5Eprivate.h"		/* Error handling		  	*/
 #include "H5FLprivate.h"	/* Free Lists                           */
 
+
 /****************/
 /* Local Macros */
 /****************/
 
+
 /******************/
 /* Local Typedefs */
 /******************/
 
+
 /********************/
 /* Local Prototypes */
 /********************/
 
-/* Struct for holding the vectorized I/O operation buffers "loosely" */
-typedef struct {
-    enum {
-        H5S_SELECT_READ,                /* Read selection */
-        H5S_SELECT_WRITE                /* Write selection */
-    } op_type;
-    union {
-        void *rbuf;                          /* Buffer for read */
-        const void *wbuf;                    /* Buffer to write */
-    } u;
-} H5D_select_buf_t;
 
 /*********************/
 /* Package Variables */
 /*********************/
 
+
 /*******************/
 /* Local Variables */
 /*******************/
 
 /* Declare a free list to manage sequences of size_t */
-H5FL_SEQ_DEFINE_STATIC(size_t);
+H5FL_SEQ_DEFINE(size_t);
 
 /* Declare a free list to manage sequences of hsize_t */
-H5FL_SEQ_DEFINE_STATIC(hsize_t);
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5D_select_fscat
- *
- * Purpose:	Scatters dataset elements from the type conversion buffer BUF
- *		to the file F where the data points are arranged according to
- *		the file dataspace FILE_SPACE and stored according to
- *		LAYOUT and EFL. Each element is ELMT_SIZE bytes.
- *		The caller is requesting that NELMTS elements are copied.
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:	Quincey Koziol
- *              Thursday, June 20, 2002
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5D_select_fscat (H5D_io_info_t *io_info,
-    const H5S_t *space, H5S_sel_iter_t *iter, size_t nelmts,
-    haddr_t chunk_addr, void *chunk/*in*/, const void *_buf)
-{
-    const uint8_t *buf=_buf;       /* Alias for pointer arithmetic */
-    hsize_t _off[H5D_IO_VECTOR_SIZE];             /* Array to store sequence offsets */
-    hsize_t *off=NULL;             /* Pointer to sequence offsets */
-    hsize_t mem_off;               /* Offset in memory */
-    size_t mem_curr_seq;           /* "Current sequence" in memory */
-    size_t dset_curr_seq;          /* "Current sequence" in dataset */
-    size_t _len[H5D_IO_VECTOR_SIZE];              /* Array to store sequence lengths */
-    size_t *len=NULL;              /* Array to store sequence lengths */
-    size_t orig_mem_len, mem_len;  /* Length of sequence in memory */
-    size_t  nseq;                  /* Number of sequences generated */
-    size_t  nelem;                 /* Number of elements used in sequences */
-    herr_t  ret_value=SUCCEED;     /* Return value */
-
-    FUNC_ENTER_NOAPI(H5D_select_fscat, FAIL);
-
-    /* Check args */
-    assert (io_info);
-    assert (space);
-    assert (iter);
-    assert (nelmts>0);
-    assert (_buf);
-    assert(TRUE==H5P_isa_class(io_info->dxpl_id,H5P_DATASET_XFER));
-
-    /* Allocate the vector I/O arrays */
-    if(io_info->dxpl_cache->vec_size != H5D_IO_VECTOR_SIZE) {
-        if((len = H5FL_SEQ_MALLOC(size_t,io_info->dxpl_cache->vec_size))==NULL)
-            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "can't allocate I/O length vector array");
-        if((off = H5FL_SEQ_MALLOC(hsize_t,io_info->dxpl_cache->vec_size))==NULL)
-            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "can't allocate I/O offset vector array");
-    } /* end if */
-    else {
-        len=_len;
-        off=_off;
-    } /* end else */
-
-    /* Loop until all elements are written */
-    while(nelmts>0) {
-        /* Get list of sequences for selection to write */
-        if(H5S_SELECT_GET_SEQ_LIST(space,H5S_GET_SEQ_LIST_SORTED,iter,io_info->dxpl_cache->vec_size,nelmts,&nseq,&nelem,off,len)<0)
-            HGOTO_ERROR (H5E_INTERNAL, H5E_UNSUPPORTED, FAIL, "sequence length generation failed");
-
-        /* Reset the current sequence information */
-        mem_curr_seq=dset_curr_seq=0;
-        orig_mem_len=mem_len=nelem*iter->elmt_size;
-        mem_off=0;
-
-        /* Write sequence list out */
-        if((*io_info->ops.writevv)(io_info, nseq, &dset_curr_seq, len, off, (size_t)1, &mem_curr_seq, &mem_len, &mem_off, chunk_addr, chunk, buf) < 0)
-            HGOTO_ERROR(H5E_DATASPACE, H5E_WRITEERROR, FAIL, "write error");
-
-        /* Update buffer */
-        buf += orig_mem_len;
-
-        /* Decrement number of elements left to process */
-        nelmts -= nelem;
-    } /* end while */
-
-done:
-    if(io_info->dxpl_cache->vec_size != H5D_IO_VECTOR_SIZE) {
-        if(len!=NULL)
-            H5FL_SEQ_FREE(size_t,len);
-        if(off!=NULL)
-            H5FL_SEQ_FREE(hsize_t,off);
-    } /* end if */
-    FUNC_LEAVE_NOAPI(ret_value);
-} /* H5D_select_fscat() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5D_select_fgath
- *
- * Purpose:	Gathers data points from file F and accumulates them in the
- *		type conversion buffer BUF.  The LAYOUT argument describes
- *		how the data is stored on disk and EFL describes how the data
- *		is organized in external files.  ELMT_SIZE is the size in
- *		bytes of a datum which this function treats as opaque.
- *		FILE_SPACE describes the dataspace of the dataset on disk
- *		and the elements that have been selected for reading (via
- *		hyperslab, etc).  This function will copy at most NELMTS
- *		elements.
- *
- * Return:	Success:	Number of elements copied.
- *		Failure:	0
- *
- * Programmer:	Quincey Koziol
- *              Monday, June 24, 2002
- *
- *-------------------------------------------------------------------------
- */
-size_t
-H5D_select_fgath (H5D_io_info_t *io_info,
-    const H5S_t *space, H5S_sel_iter_t *iter, size_t nelmts,
-    haddr_t chunk_addr, void *chunk/*in*/, void *_buf/*out*/)
-{
-    uint8_t *buf=(uint8_t*)_buf;          /* Alias for pointer arithmetic */
-    hsize_t _off[H5D_IO_VECTOR_SIZE];          /* Array to store sequence offsets */
-    hsize_t *off=NULL;          /* Pointer to sequence offsets */
-    hsize_t mem_off;            /* Offset in memory */
-    size_t mem_curr_seq;        /* "Current sequence" in memory */
-    size_t dset_curr_seq;       /* "Current sequence" in dataset */
-    size_t _len[H5D_IO_VECTOR_SIZE];           /* Array to store sequence lengths */
-    size_t *len=NULL;           /* Pointer to sequence lengths */
-    size_t orig_mem_len, mem_len;       /* Length of sequence in memory */
-    size_t nseq;                /* Number of sequences generated */
-    size_t nelem;               /* Number of elements used in sequences */
-    size_t ret_value=nelmts;    /* Return value */
-
-    FUNC_ENTER_NOAPI(H5D_select_fgath, 0);
-
-    /* Check args */
-    assert (io_info);
-    assert (io_info->dset);
-    assert (io_info->store);
-    assert (space);
-    assert (iter);
-    assert (nelmts>0);
-    assert (_buf);
-
-    /* Allocate the vector I/O arrays */
-    if(io_info->dxpl_cache->vec_size != H5D_IO_VECTOR_SIZE) {
-        if((len = H5FL_SEQ_MALLOC(size_t,io_info->dxpl_cache->vec_size))==NULL)
-            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, 0, "can't allocate I/O length vector array");
-        if((off = H5FL_SEQ_MALLOC(hsize_t,io_info->dxpl_cache->vec_size))==NULL)
-            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, 0, "can't allocate I/O offset vector array");
-    } /* end if */
-    else {
-        len=_len;
-        off=_off;
-    } /* end else */
-
-    /* Loop until all elements are read */
-    while(nelmts>0) {
-        /* Get list of sequences for selection to read */
-        if(H5S_SELECT_GET_SEQ_LIST(space,H5S_GET_SEQ_LIST_SORTED,iter,io_info->dxpl_cache->vec_size,nelmts,&nseq,&nelem,off,len)<0)
-            HGOTO_ERROR (H5E_INTERNAL, H5E_UNSUPPORTED, 0, "sequence length generation failed");
-
-        /* Reset the current sequence information */
-        mem_curr_seq=dset_curr_seq=0;
-        orig_mem_len=mem_len=nelem*iter->elmt_size;
-        mem_off=0;
-
-        /* Read sequence list in */
-        if((*io_info->ops.readvv)(io_info, nseq, &dset_curr_seq, len, off, (size_t)1, 
-                                  &mem_curr_seq, &mem_len, &mem_off, chunk_addr, chunk, buf) < 0)
-            HGOTO_ERROR(H5E_DATASPACE, H5E_READERROR, 0, "read error");
-
-        /* Update buffer */
-        buf += orig_mem_len;
-
-        /* Decrement number of elements left to process */
-        nelmts -= nelem;
-    } /* end while */
-
-done:
-    if(io_info->dxpl_cache->vec_size != H5D_IO_VECTOR_SIZE) {
-        if(len!=NULL)
-            H5FL_SEQ_FREE(size_t,len);
-        if(off!=NULL)
-            H5FL_SEQ_FREE(hsize_t,off);
-    } /* end if */
-    FUNC_LEAVE_NOAPI(ret_value);
-} /* H5D_select_fgath() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5D_select_mscat
- *
- * Purpose:	Scatters NELMTS data points from the scatter buffer
- *		TSCAT_BUF to the application buffer BUF.  Each element is
- *		ELMT_SIZE bytes and they are organized in application memory
- *		according to SPACE.
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:	Quincey Koziol
- *              Monday, July 8, 2002
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5D_select_mscat (const void *_tscat_buf, const H5S_t *space,
-    H5S_sel_iter_t *iter, size_t nelmts, const H5D_dxpl_cache_t *dxpl_cache,
-    void *_buf/*out*/)
-{
-    uint8_t *buf=(uint8_t *)_buf;   /* Get local copies for address arithmetic */
-    const uint8_t *tscat_buf=(const uint8_t *)_tscat_buf;
-    hsize_t _off[H5D_IO_VECTOR_SIZE];          /* Array to store sequence offsets */
-    hsize_t *off=NULL;          /* Pointer to sequence offsets */
-    size_t _len[H5D_IO_VECTOR_SIZE];           /* Array to store sequence lengths */
-    size_t *len=NULL;           /* Pointer to sequence lengths */
-    size_t curr_len;            /* Length of bytes left to process in sequence */
-    size_t nseq;                /* Number of sequences generated */
-    size_t curr_seq;            /* Current sequence being processed */
-    size_t nelem;               /* Number of elements used in sequences */
-    herr_t ret_value=SUCCEED;   /* Number of elements scattered */
-
-    FUNC_ENTER_NOAPI(H5D_select_mscat, FAIL);
-
-    /* Check args */
-    assert (tscat_buf);
-    assert (space);
-    assert (iter);
-    assert (nelmts>0);
-    assert (buf);
-
-    /* Allocate the vector I/O arrays */
-    if(dxpl_cache->vec_size != H5D_IO_VECTOR_SIZE) {
-        if((len = H5FL_SEQ_MALLOC(size_t,dxpl_cache->vec_size))==NULL)
-            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "can't allocate I/O length vector array");
-        if((off = H5FL_SEQ_MALLOC(hsize_t,dxpl_cache->vec_size))==NULL)
-            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "can't allocate I/O offset vector array");
-    } /* end if */
-    else {
-        len=_len;
-        off=_off;
-    } /* end else */
-
-    /* Loop until all elements are written */
-    while(nelmts>0) {
-        /* Get list of sequences for selection to write */
-        if(H5S_SELECT_GET_SEQ_LIST(space,0,iter,dxpl_cache->vec_size,nelmts,&nseq,&nelem,off,len)<0)
-            HGOTO_ERROR (H5E_INTERNAL, H5E_UNSUPPORTED, 0, "sequence length generation failed");
-
-        /* Loop, while sequences left to process */
-        for(curr_seq=0; curr_seq<nseq; curr_seq++) {
-            /* Get the number of bytes in sequence */
-            curr_len=len[curr_seq];
+H5FL_SEQ_DEFINE(hsize_t);
 
-            HDmemcpy(buf+off[curr_seq],tscat_buf,curr_len);
-
-            /* Advance offset in destination buffer */
-            tscat_buf+=curr_len;
-        } /* end for */
-
-        /* Decrement number of elements left to process */
-        nelmts -= nelem;
-    } /* end while */
-
-done:
-    if(dxpl_cache->vec_size != H5D_IO_VECTOR_SIZE) {
-        if(len!=NULL)
-            H5FL_SEQ_FREE(size_t,len);
-        if(off!=NULL)
-            H5FL_SEQ_FREE(hsize_t,off);
-    } /* end if */
-    FUNC_LEAVE_NOAPI(ret_value);
-}   /* H5D_select_mscat() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5D_select_mgath
- *
- * Purpose:	Gathers dataset elements from application memory BUF and
- *		copies them into the gather buffer TGATH_BUF.
- *		Each element is ELMT_SIZE bytes and arranged in application
- *		memory according to SPACE.
- *		The caller is requesting that at most NELMTS be gathered.
- *
- * Return:	Success:	Number of elements copied.
- *		Failure:	0
- *
- * Programmer:	Quincey Koziol
- *              Monday, June 24, 2002
- *
- *-------------------------------------------------------------------------
- */
-size_t
-H5D_select_mgath (const void *_buf, const H5S_t *space,
-    H5S_sel_iter_t *iter, size_t nelmts, const H5D_dxpl_cache_t *dxpl_cache,
-    void *_tgath_buf/*out*/)
-{
-    const uint8_t *buf=(const uint8_t *)_buf;   /* Get local copies for address arithmetic */
-    uint8_t *tgath_buf=(uint8_t *)_tgath_buf;
-    hsize_t _off[H5D_IO_VECTOR_SIZE];          /* Array to store sequence offsets */
-    hsize_t *off=NULL;          /* Pointer to sequence offsets */
-    size_t _len[H5D_IO_VECTOR_SIZE];           /* Array to store sequence lengths */
-    size_t *len=NULL;           /* Pointer to sequence lengths */
-    size_t curr_len;            /* Length of bytes left to process in sequence */
-    size_t nseq;                /* Number of sequences generated */
-    size_t curr_seq;            /* Current sequence being processed */
-    size_t nelem;               /* Number of elements used in sequences */
-    size_t ret_value=nelmts;    /* Number of elements gathered */
-
-    FUNC_ENTER_NOAPI(H5D_select_mgath, 0);
-
-    /* Check args */
-    assert (buf);
-    assert (space);
-    assert (iter);
-    assert (nelmts>0);
-    assert (tgath_buf);
-
-    /* Allocate the vector I/O arrays */
-    if(dxpl_cache->vec_size != H5D_IO_VECTOR_SIZE) {
-        if((len = H5FL_SEQ_MALLOC(size_t,dxpl_cache->vec_size))==NULL)
-            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, 0, "can't allocate I/O length vector array");
-        if((off = H5FL_SEQ_MALLOC(hsize_t,dxpl_cache->vec_size))==NULL)
-            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, 0, "can't allocate I/O offset vector array");
-    } /* end if */
-    else {
-        len=_len;
-        off=_off;
-    } /* end else */
-
-    /* Loop until all elements are written */
-    while(nelmts>0) {
-        /* Get list of sequences for selection to write */
-        if(H5S_SELECT_GET_SEQ_LIST(space,0,iter,dxpl_cache->vec_size,nelmts,&nseq,&nelem,off,len)<0)
-            HGOTO_ERROR (H5E_INTERNAL, H5E_UNSUPPORTED, 0, "sequence length generation failed");
-
-        /* Loop, while sequences left to process */
-        for(curr_seq=0; curr_seq<nseq; curr_seq++) {
-            /* Get the number of bytes in sequence */
-            curr_len=len[curr_seq];
-
-            HDmemcpy(tgath_buf,buf+off[curr_seq],curr_len);
-
-            /* Advance offset in gather buffer */
-            tgath_buf+=curr_len;
-        } /* end for */
-
-        /* Decrement number of elements left to process */
-        nelmts -= nelem;
-    } /* end while */
-
-done:
-    if(dxpl_cache->vec_size != H5D_IO_VECTOR_SIZE) {
-        if(len!=NULL)
-            H5FL_SEQ_FREE(size_t,len);
-        if(off!=NULL)
-            H5FL_SEQ_FREE(hsize_t,off);
-    } /* end if */
-    FUNC_LEAVE_NOAPI(ret_value);
-}   /* H5D_select_mgath() */
 
 
 /*-------------------------------------------------------------------------
@@ -443,11 +80,8 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5D_select_io(H5D_io_info_t *io_info,
-    size_t nelmts, size_t elmt_size,
-    const H5S_t *file_space, const H5S_t *mem_space,
-    haddr_t addr, void *chunk/*in*/,
-    const H5D_select_buf_t *io_buf)
+H5D_select_io(const H5D_io_info_t *io_info, size_t elmt_size,
+    size_t nelmts, const H5S_t *file_space, const H5S_t *mem_space)
 {
     H5S_sel_iter_t mem_iter;    /* Memory selection iteration info */
     hbool_t mem_iter_init = 0;  /* Memory selection iteration info has been initialized */
@@ -475,10 +109,10 @@ H5D_select_io(H5D_io_info_t *io_info,
     HDassert(io_info->dset);
     HDassert(io_info->store);
     HDassert(TRUE == H5P_isa_class(io_info->dxpl_id, H5P_DATASET_XFER));
-    HDassert(io_buf->u.rbuf);
+    HDassert(io_info->u.rbuf);
 
     /* Allocate the vector I/O arrays */
-    if(io_info->dxpl_cache->vec_size != H5D_IO_VECTOR_SIZE) {
+    if(io_info->dxpl_cache->vec_size > H5D_IO_VECTOR_SIZE) {
         if(NULL == (mem_len = H5FL_SEQ_MALLOC(size_t,io_info->dxpl_cache->vec_size)))
             HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "can't allocate I/O length vector array")
         if(NULL == (mem_off = H5FL_SEQ_MALLOC(hsize_t,io_info->dxpl_cache->vec_size)))
@@ -511,19 +145,17 @@ H5D_select_io(H5D_io_info_t *io_info,
         *file_len = *mem_len = elmt_size;
 
         /* Perform I/O on memory and file sequences */
-        if(io_buf->op_type == H5S_SELECT_READ) {
-            if((tmp_file_len = (*io_info->ops.readvv)(io_info,
+        if(io_info->op_type == H5D_IO_OP_READ) {
+            if((tmp_file_len = (*io_info->layout_ops.readvv)(io_info,
                     file_nseq, &curr_file_seq, file_len, file_off,
-                    mem_nseq, &curr_mem_seq, mem_len, mem_off,
-                    addr, chunk, io_buf->u.rbuf)) < 0)
+                    mem_nseq, &curr_mem_seq, mem_len, mem_off)) < 0)
                 HGOTO_ERROR(H5E_DATASPACE, H5E_READERROR, FAIL, "read error")
         } /* end if */
         else {
-            HDassert(io_buf->op_type == H5S_SELECT_WRITE);
-            if((tmp_file_len = (*io_info->ops.writevv)(io_info,
+            HDassert(io_info->op_type == H5D_IO_OP_WRITE);
+            if((tmp_file_len = (*io_info->layout_ops.writevv)(io_info,
                     file_nseq, &curr_file_seq, file_len, file_off,
-                    mem_nseq, &curr_mem_seq, mem_len, mem_off,
-                    addr, chunk, io_buf->u.wbuf)) < 0)
+                    mem_nseq, &curr_mem_seq, mem_len, mem_off)) < 0)
                 HGOTO_ERROR(H5E_DATASPACE, H5E_WRITEERROR, FAIL, "write error")
         } /* end else */
 
@@ -571,19 +203,17 @@ H5D_select_io(H5D_io_info_t *io_info,
             } /* end if */
 
             /* Perform I/O on memory and file sequences */
-            if(io_buf->op_type == H5S_SELECT_READ) {
-                if((tmp_file_len = (*io_info->ops.readvv)(io_info,
+            if(io_info->op_type == H5D_IO_OP_READ) {
+                if((tmp_file_len = (*io_info->layout_ops.readvv)(io_info,
                         file_nseq, &curr_file_seq, file_len, file_off,
-                        mem_nseq, &curr_mem_seq, mem_len, mem_off,
-                        addr, chunk, io_buf->u.rbuf)) < 0)
+                        mem_nseq, &curr_mem_seq, mem_len, mem_off)) < 0)
                     HGOTO_ERROR(H5E_DATASPACE, H5E_READERROR, FAIL, "read error")
             } /* end if */
             else {
-                HDassert(io_buf->op_type == H5S_SELECT_WRITE);
-                if((tmp_file_len = (*io_info->ops.writevv)(io_info,
+                HDassert(io_info->op_type == H5D_IO_OP_WRITE);
+                if((tmp_file_len = (*io_info->layout_ops.writevv)(io_info,
                         file_nseq, &curr_file_seq, file_len, file_off,
-                        mem_nseq, &curr_mem_seq, mem_len, mem_off,
-                        addr, chunk, io_buf->u.wbuf)) < 0)
+                        mem_nseq, &curr_mem_seq, mem_len, mem_off)) < 0)
                     HGOTO_ERROR(H5E_DATASPACE, H5E_WRITEERROR, FAIL, "write error")
             } /* end else */
 
@@ -604,17 +234,15 @@ done:
         if(H5S_SELECT_ITER_RELEASE(&mem_iter) < 0)
             HDONE_ERROR(H5E_DATASPACE, H5E_CANTRELEASE, FAIL, "unable to release selection iterator")
 
-    /* Free vector arrays */
-    if(io_info->dxpl_cache->vec_size != H5D_IO_VECTOR_SIZE) {
-        if(file_len != NULL)
-            H5FL_SEQ_FREE(size_t, file_len);
-        if(file_off != NULL)
-            H5FL_SEQ_FREE(hsize_t, file_off);
-        if(mem_len != NULL)
-            H5FL_SEQ_FREE(size_t, mem_len);
-        if(mem_off != NULL)
-            H5FL_SEQ_FREE(hsize_t, mem_off);
-    } /* end if */
+    /* Release vector arrays, if allocated */
+    if(file_len && file_len != _file_len)
+        H5FL_SEQ_FREE(size_t, file_len);
+    if(file_off && file_off != _file_off)
+        H5FL_SEQ_FREE(hsize_t, file_off);
+    if(mem_len && mem_len != _mem_len)
+        H5FL_SEQ_FREE(size_t, mem_len);
+    if(mem_off && mem_off != _mem_off)
+        H5FL_SEQ_FREE(hsize_t, mem_off);
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5D_select_io() */
@@ -633,23 +261,17 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5D_select_read(H5D_io_info_t *io_info,
-    size_t nelmts, size_t elmt_size,
-    const H5S_t *file_space, const H5S_t *mem_space,
-    haddr_t addr, void *chunk/*in*/,
-    void *buf/*out*/)
+H5D_select_read(const H5D_io_info_t *io_info, const H5D_type_info_t *type_info,
+    hsize_t nelmts, const H5S_t *file_space, const H5S_t *mem_space)
 {
-    H5D_select_buf_t io_buf;      /* Selection I/O operation to perform */
     herr_t ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_NOAPI(H5D_select_read, FAIL)
 
-    /* Construct proper I/O operation */
-    io_buf.op_type = H5S_SELECT_READ;
-    io_buf.u.rbuf = buf;
-
     /* Call generic selection operation */
-    if(H5D_select_io(io_info, nelmts, elmt_size, file_space, mem_space, addr, chunk, &io_buf) < 0)
+    H5_CHECK_OVERFLOW(nelmts, hsize_t, size_t);
+    if(H5D_select_io(io_info, type_info->src_type_size, (size_t)nelmts,
+            file_space, mem_space) < 0)
         HGOTO_ERROR(H5E_DATASPACE, H5E_READERROR, FAIL, "read error")
 
 done:
@@ -670,23 +292,17 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5D_select_write(H5D_io_info_t *io_info,
-    size_t nelmts, size_t elmt_size,
-    const H5S_t *file_space, const H5S_t *mem_space,
-    haddr_t addr, void *chunk/*in*/,
-    const void *buf/*out*/)
+H5D_select_write(const H5D_io_info_t *io_info, const H5D_type_info_t *type_info,
+    hsize_t nelmts, const H5S_t *file_space, const H5S_t *mem_space)
 {
-    H5D_select_buf_t io_buf;      /* Selection I/O operation to perform */
     herr_t ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_NOAPI(H5D_select_write, FAIL)
 
-    /* Construct proper I/O operation */
-    io_buf.op_type = H5S_SELECT_WRITE;
-    io_buf.u.wbuf = buf;
-
     /* Call generic selection operation */
-    if(H5D_select_io(io_info, nelmts, elmt_size, file_space, mem_space, addr, chunk, &io_buf) < 0)
+    H5_CHECK_OVERFLOW(nelmts, hsize_t, size_t);
+    if(H5D_select_io(io_info, type_info->dst_type_size, (size_t)nelmts,
+            file_space, mem_space) < 0)
         HGOTO_ERROR(H5E_DATASPACE, H5E_WRITEERROR, FAIL, "write error")
 
 done: