[svn-r8670] Purpose:

    Code optimization

Description:
    Avoid a memory copy by directly reading from the variable-length sequence
buffer when there is no type conversion on the way to disk.

Platforms tested:
    Solaris 2.7 (arabica)
    FreeBSD 4.10 (sleipnir) w/parallel
    Too minor to require h5committest

3 files changed, 128 insertions, 16 deletions

diff --git a/src/H5Tconv.c b/src/H5Tconv.c
index 57ed1c3..8d3e44a 100644
--- a/src/H5Tconv.c
+++ b/src/H5Tconv.c
@@ -2429,6 +2429,7 @@ H5T_conv_vlen(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, hsize_t nelmts,
     H5T_vlen_alloc_info_t vl_alloc_info;/* VL allocation information         */
     H5T_path_t	*tpath;			/* Type conversion path		     */
     hbool_t     noop_conv=FALSE;        /* Flag to indicate a noop conversion */
+    hbool_t     write_to_file=FALSE;    /* Flag to indicate writing to file */
     hid_t   	tsrc_id = -1, tdst_id = -1;/*temporary type atoms	     */
     H5T_t	*src = NULL;		/*source data type		     */
     H5T_t	*dst = NULL;		/*destination data type		     */
@@ -2442,12 +2443,11 @@ H5T_conv_vlen(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, hsize_t nelmts,
     hssize_t 	seq_len;                /*the number of elements in the current sequence*/
     hsize_t	bg_seq_len=0, parent_seq_len=0;
     size_t	src_base_size, dst_base_size;/*source & destination base size*/
-    size_t	src_size, dst_size;     /*source & destination total size in bytes*/
     void	*conv_buf=NULL;     	/*temporary conversion buffer 	     */
     size_t	conv_buf_size=0;  	/*size of conversion buffer in bytes */
     void	*tmp_buf=NULL;     	/*temporary background buffer 	     */
     size_t	tmp_buf_size=0;	        /*size of temporary bkg buffer	     */
-    int         nested=0;               /*flag of nested VL case             */
+    hbool_t     nested=FALSE;           /*flag of nested VL case             */
     hsize_t	elmtno;			/*element number counter	     */
     hsize_t     i;
     herr_t      ret_value=SUCCEED;       /* Return value */
@@ -2530,8 +2530,12 @@ H5T_conv_vlen(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, hsize_t nelmts,
             if(H5T_vlen_get_alloc_info(dxpl_id,&vl_alloc_info)<0)
                 HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "unable to retrieve VL allocation info");
 
+            /* Set flags to indicate we are writing to or reading from the file */
+            if(dst->u.vlen.f!=NULL)
+                write_to_file=TRUE;
+
             /* Set the flag for nested VL case */
-            if(dst->u.vlen.f!=NULL && H5T_detect_class(dst->parent,H5T_VLEN) && bkg!=NULL)
+            if(write_to_file && H5T_detect_class(dst->parent,H5T_VLEN) && bkg!=NULL)
                 nested=1;
 
             /* The outer loop of the type conversion macro, controlling which */
@@ -2580,21 +2584,33 @@ H5T_conv_vlen(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, hsize_t nelmts,
                         /* Get length of element sequences */
                         if((seq_len=(*(src->u.vlen.getlen))(s))<0)
                             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "incorrect length");
-                        H5_CHECK_OVERFLOW(seq_len,hssize_t,size_t);
-                        src_size=(size_t)seq_len*src_base_size;
-                        dst_size=(size_t)seq_len*dst_base_size;
-
-                        /* Check if conversion buffer is large enough, resize if
-                         * necessary */      
-                        if(conv_buf_size<MAX3(src_size,dst_size,H5T_VLEN_MIN_CONF_BUF_SIZE)) {
-                            conv_buf_size=MAX3(src_size,dst_size,H5T_VLEN_MIN_CONF_BUF_SIZE);
-                            if((conv_buf=H5FL_BLK_REALLOC(vlen_seq,conv_buf, conv_buf_size))==NULL)
-                                HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for type conversion");
+
+                        /* If we are reading from memory and there is no conversion, just get the pointer to sequence */
+                        if(write_to_file && noop_conv) {
+                            /* Get direct pointer to sequence */
+                            if((conv_buf=(*(src->u.vlen.getptr))(s))==NULL)
+                                HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid source pointer");
                         } /* end if */
+                        else {
+                            size_t	src_size, dst_size;     /*source & destination total size in bytes*/
+
+                            H5_CHECK_OVERFLOW(seq_len,hssize_t,size_t);
+                            src_size=(size_t)seq_len*src_base_size;
+                            dst_size=(size_t)seq_len*dst_base_size;
+
+                            /* Check if conversion buffer is large enough, resize if
+                             * necessary */      
+                            if(conv_buf_size<MAX(src_size,dst_size)) {
+                                /* Only allocate conversion buffer in H5T_VLEN_MIN_CONF_BUF_SIZE increments */
+                                conv_buf_size=((MAX(src_size,dst_size)/H5T_VLEN_MIN_CONF_BUF_SIZE)+1)*H5T_VLEN_MIN_CONF_BUF_SIZE;
+                                if((conv_buf=H5FL_BLK_REALLOC(vlen_seq,conv_buf, conv_buf_size))==NULL)
+                                    HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for type conversion");
+                            } /* end if */
 
-                        /* Read in VL sequence */
-                        if((*(src->u.vlen.read))(src->u.vlen.f,dxpl_id,s,conv_buf,src_size)<0)
-                            HGOTO_ERROR(H5E_DATATYPE, H5E_READERROR, FAIL, "can't read VL data");
+                            /* Read in VL sequence */
+                            if((*(src->u.vlen.read))(src->u.vlen.f,dxpl_id,s,conv_buf,src_size)<0)
+                                HGOTO_ERROR(H5E_DATATYPE, H5E_READERROR, FAIL, "can't read VL data");
+                        } /* end else */
 
                         if(!noop_conv) {
                             /* Check if temporary buffer is large enough, resize if necessary */
@@ -2672,6 +2688,10 @@ H5T_conv_vlen(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, hsize_t nelmts,
                 nelmts-=safe;
             } /* end while */
 
+            /* Reset the conversion buffer pointer, so it doesn't get freed */
+            if(write_to_file && noop_conv)
+                conv_buf=NULL;
+
             /* Release the temporary datatype IDs used */
             if (tsrc_id >= 0)
                 H5I_dec_ref(tsrc_id);
diff --git a/src/H5Tpkg.h b/src/H5Tpkg.h
index 13118e0..68789bb 100644
--- a/src/H5Tpkg.h
+++ b/src/H5Tpkg.h
@@ -144,6 +144,7 @@ typedef struct H5T_enum_t {
 
 /* VL function pointers */
 typedef hssize_t (*H5T_vlen_getlenfunc_t)(void *vl_addr);
+typedef void * (*H5T_vlen_getptrfunc_t)(void *vl_addr);
 typedef htri_t (*H5T_vlen_isnullfunc_t)(H5F_t *f, void *vl_addr);
 typedef herr_t (*H5T_vlen_readfunc_t)(H5F_t *f, hid_t dxpl_id, void *_vl, void *buf, size_t len);
 typedef herr_t (*H5T_vlen_writefunc_t)(H5F_t *f, hid_t dxpl_id, const H5T_vlen_alloc_info_t *vl_alloc_info, void *_vl, void *buf, void *_bg, hsize_t seq_len, hsize_t base_size);
@@ -165,6 +166,7 @@ typedef struct H5T_vlen_t {
     H5T_str_t           pad;    /* For VL string.  space or null padding of 
                                  * extra bytes */                          
     H5F_t *f;                   /* File ID (if VL data is on disk) */
+    H5T_vlen_getptrfunc_t getptr;   /* Function to get VL sequence pointer */
     H5T_vlen_getlenfunc_t getlen;   /* Function to get VL sequence size (in element units, not bytes) */
     H5T_vlen_isnullfunc_t isnull;   /* Function to check if VL value is NIL */
     H5T_vlen_readfunc_t read;   /* Function to read VL sequence into buffer */
diff --git a/src/H5Tvlen.c b/src/H5Tvlen.c
index a2ef55a..bec8611 100644
--- a/src/H5Tvlen.c
+++ b/src/H5Tvlen.c
@@ -44,16 +44,19 @@ H5FL_EXTERN(H5T_t);
 /* Local functions */
 static herr_t H5T_vlen_reclaim_recurse(void *elem, const H5T_t *dt, H5MM_free_t free_func, void *free_info);
 static hssize_t H5T_vlen_seq_mem_getlen(void *_vl);
+static void * H5T_vlen_seq_mem_getptr(void *_vl);
 static htri_t H5T_vlen_seq_mem_isnull(H5F_t *f, void *_vl);
 static herr_t H5T_vlen_seq_mem_read(H5F_t *f, hid_t dxpl_id, void *_vl, void *_buf, size_t len);
 static herr_t H5T_vlen_seq_mem_write(H5F_t *f, hid_t dxpl_id, const H5T_vlen_alloc_info_t *vl_alloc_info, void *_vl, void *_buf, void *_bg, hsize_t seq_len, hsize_t base_size);
 static herr_t H5T_vlen_seq_mem_setnull(H5F_t *f, hid_t dxpl_id, void *_vl, void *_bg);
 static hssize_t H5T_vlen_str_mem_getlen(void *_vl);
+static void * H5T_vlen_str_mem_getptr(void *_vl);
 static htri_t H5T_vlen_str_mem_isnull(H5F_t *f, void *_vl);
 static herr_t H5T_vlen_str_mem_read(H5F_t *f, hid_t dxpl_id, void *_vl, void *_buf, size_t len);
 static herr_t H5T_vlen_str_mem_write(H5F_t *f, hid_t dxpl_id, const H5T_vlen_alloc_info_t *vl_alloc_info, void *_vl, void *_buf, void *_bg, hsize_t seq_len, hsize_t base_size);
 static herr_t H5T_vlen_str_mem_setnull(H5F_t *f, hid_t dxpl_id, void *_vl, void *_bg);
 static hssize_t H5T_vlen_disk_getlen(void *_vl);
+static void * H5T_vlen_disk_getptr(void *_vl);
 static htri_t H5T_vlen_disk_isnull(H5F_t *f, void *_vl);
 static herr_t H5T_vlen_disk_read(H5F_t *f, hid_t dxpl_id, void *_vl, void *_buf, size_t len);
 static herr_t H5T_vlen_disk_write(H5F_t *f, hid_t dxpl_id, const H5T_vlen_alloc_info_t *vl_alloc_info, void *_vl, void *_buf, void *_bg, hsize_t seq_len, hsize_t base_size);
@@ -229,6 +232,7 @@ H5T_vlen_set_loc(H5T_t *dt, H5F_t *f, H5T_loc_t loc)
 
                     /* Set up the function pointers to access the VL sequence in memory */
                     dt->u.vlen.getlen=H5T_vlen_seq_mem_getlen;
+                    dt->u.vlen.getptr=H5T_vlen_seq_mem_getptr;
                     dt->u.vlen.isnull=H5T_vlen_seq_mem_isnull;
                     dt->u.vlen.read=H5T_vlen_seq_mem_read;
                     dt->u.vlen.write=H5T_vlen_seq_mem_write;
@@ -239,6 +243,7 @@ H5T_vlen_set_loc(H5T_t *dt, H5F_t *f, H5T_loc_t loc)
 
                     /* Set up the function pointers to access the VL string in memory */
                     dt->u.vlen.getlen=H5T_vlen_str_mem_getlen;
+                    dt->u.vlen.getptr=H5T_vlen_str_mem_getptr;
                     dt->u.vlen.isnull=H5T_vlen_str_mem_isnull;
                     dt->u.vlen.read=H5T_vlen_str_mem_read;
                     dt->u.vlen.write=H5T_vlen_str_mem_write;
@@ -267,6 +272,7 @@ H5T_vlen_set_loc(H5T_t *dt, H5F_t *f, H5T_loc_t loc)
                 /* Set up the function pointers to access the VL information on disk */
                 /* VL sequences and VL strings are stored identically on disk, so use the same functions */
                 dt->u.vlen.getlen=H5T_vlen_disk_getlen;
+                dt->u.vlen.getptr=H5T_vlen_disk_getptr;
                 dt->u.vlen.isnull=H5T_vlen_disk_isnull;
                 dt->u.vlen.read=H5T_vlen_disk_read;
                 dt->u.vlen.write=H5T_vlen_disk_write;
@@ -315,6 +321,34 @@ H5T_vlen_seq_mem_getlen(void *_vl)
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5T_vlen_seq_mem_getptr
+ *
+ * Purpose:	Retrieves the pointer for a memory based VL element.
+ *
+ * Return:	Non-NULL on success/NULL on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		Saturday, June 12, 2004
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static void *
+H5T_vlen_seq_mem_getptr(void *_vl)
+{
+    hvl_t *vl=(hvl_t *)_vl;   /* Pointer to the user's hvl_t information */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5T_vlen_seq_mem_getptr)
+
+    /* check parameters */
+    assert(vl);
+
+    FUNC_LEAVE_NOAPI(vl->p)
+}   /* end H5T_vlen_seq_mem_getptr() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5T_vlen_seq_mem_isnull
  *
  * Purpose:	Checks if a memory sequence is the "null" sequence
@@ -499,6 +533,34 @@ H5T_vlen_str_mem_getlen(void *_vl)
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5T_vlen_str_mem_getptr
+ *
+ * Purpose:	Retrieves the pointer for a memory based VL string.
+ *
+ * Return:	Non-NULL on success/NULL on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		Saturday, June 12, 2004
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static void *
+H5T_vlen_str_mem_getptr(void *_vl)
+{
+    char *s=*(char **)_vl;   /* Pointer to the user's string information */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5T_vlen_str_mem_getptr)
+
+    /* check parameters */
+    assert(s);
+
+    FUNC_LEAVE_NOAPI(s)
+}   /* end H5T_vlen_str_mem_getptr() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5T_vlen_str_mem_isnull
  *
  * Purpose:	Checks if a memory string is a NULL pointer
@@ -669,6 +731,34 @@ H5T_vlen_disk_getlen(void *_vl)
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5T_vlen_disk_getptr
+ *
+ * Purpose:	Retrieves the pointer to a disk based VL element.
+ *
+ * Return:	Non-NULL on success/NULL on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		Saturday, June 12, 2004
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static void *
+H5T_vlen_disk_getptr(void *_vl)
+{
+    uint8_t *vl=(uint8_t *)_vl; /* Pointer to the disk VL information */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5T_vlen_disk_getptr)
+
+    /* check parameters */
+    assert(vl);
+
+    FUNC_LEAVE_NOAPI(NULL)
+}   /* end H5T_vlen_disk_getptr() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5T_vlen_disk_isnull
  *
  * Purpose:	Checks if a disk VL info object is the "nil" object