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authorQuincey Koziol <koziol@hdfgroup.org>2000-08-16 20:08:23 (GMT)
committerQuincey Koziol <koziol@hdfgroup.org>2000-08-16 20:08:23 (GMT)
commit68203c788ab9266b28a4e95dd061434fa94e501d (patch)
treeee6a722b1ccaff3d46f9134f063c2e37bd170311 /src/H5O.c
parente6cc5a8c5eb1cc378d8c1781e832b5d4e9f10044 (diff)
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[svn-r2472] Combine object header prefix and first object header chunk when possible.
Diffstat (limited to 'src/H5O.c')
-rw-r--r--src/H5O.c75
1 files changed, 55 insertions, 20 deletions
diff --git a/src/H5O.c b/src/H5O.c
index 5d1fe99..a064da1 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -542,6 +542,7 @@ H5O_flush(H5F_t *f, hbool_t destroy, haddr_t addr, H5O_t *oh)
intn i, id;
H5O_cont_t *cont = NULL;
herr_t (*encode)(H5F_t*, uint8_t*, const void*) = NULL;
+ uintn combine=0; /* Whether to combine the object header prefix & the first chunk */
FUNC_ENTER(H5O_flush, FAIL);
@@ -572,16 +573,22 @@ H5O_flush(H5F_t *f, hbool_t destroy, haddr_t addr, H5O_t *oh)
/* zero to alignment */
HDmemset (p, 0, H5O_SIZEOF_HDR(f)-12);
- /* write the object header header */
+ /* write the object header prefix */
+ /* Check if we can combine the object header prefix & the first chunk into one I/O operation */
+ if(oh->chunk[0].dirty && (addr+H5O_SIZEOF_HDR(f))==oh->chunk[0].addr) {
+ combine=1;
+ } /* end if */
+ else {
#ifdef H5_HAVE_PARALLEL
- if (IS_H5FD_MPIO(f))
- H5FD_mpio_tas_allsame(f->shared->lf, TRUE); /*only p0 will write*/
+ if (IS_H5FD_MPIO(f))
+ H5FD_mpio_tas_allsame(f->shared->lf, TRUE); /*only p0 will write*/
#endif /* H5_HAVE_PARALLEL */
- if (H5F_block_write(f, addr, (hsize_t)H5O_SIZEOF_HDR(f),
- H5P_DEFAULT, buf) < 0) {
- HRETURN_ERROR(H5E_OHDR, H5E_WRITEERROR, FAIL,
- "unable to write object header hdr to disk");
- }
+ if (H5F_block_write(f, addr, (hsize_t)H5O_SIZEOF_HDR(f),
+ H5P_DEFAULT, buf) < 0) {
+ HRETURN_ERROR(H5E_OHDR, H5E_WRITEERROR, FAIL,
+ "unable to write object header hdr to disk");
+ }
+ } /* end else */
/* encode messages */
for (i = 0; i < oh->nmesgs; i++) {
@@ -649,20 +656,48 @@ H5O_flush(H5F_t *f, hbool_t destroy, haddr_t addr, H5O_t *oh)
/* write each chunk to disk */
for (i = 0; i < oh->nchunks; i++) {
if (oh->chunk[i].dirty) {
- assert(H5F_addr_defined(oh->chunk[i].addr));
+ assert(H5F_addr_defined(oh->chunk[i].addr));
+ if(i==0 && combine) {
+ /* Allocate space for the combined prefix and first chunk */
+ if((p=H5FL_BLK_ALLOC(chunk_image,H5O_SIZEOF_HDR(f)+oh->chunk[i].size,0))==NULL)
+ HRETURN_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
+
+ /* Copy in the prefix */
+ HDmemcpy(p,buf,H5O_SIZEOF_HDR(f));
+
+ /* Copy in the first chunk */
+ HDmemcpy(p+H5O_SIZEOF_HDR(f),oh->chunk[i].image,oh->chunk[i].size);
+
+ /* Write the combined prefix/chunk out */
#ifdef H5_HAVE_PARALLEL
- if (IS_H5FD_MPIO(f))
- H5FD_mpio_tas_allsame(f->shared->lf, TRUE); /*only p0 write*/
+ if (IS_H5FD_MPIO(f))
+ H5FD_mpio_tas_allsame(f->shared->lf, TRUE); /*only p0 write*/
#endif /* H5_HAVE_PARALLEL */
- if (H5F_block_write(f, oh->chunk[i].addr,
- (hsize_t)(oh->chunk[i].size),
- H5P_DEFAULT, oh->chunk[i].image) < 0) {
- HRETURN_ERROR(H5E_OHDR, H5E_WRITEERROR, FAIL,
- "unable to write object header data to disk");
- }
- oh->chunk[i].dirty = FALSE;
- }
- }
+ if (H5F_block_write(f, addr,
+ (hsize_t)(H5O_SIZEOF_HDR(f)+oh->chunk[i].size),
+ H5P_DEFAULT, p) < 0) {
+ HRETURN_ERROR(H5E_OHDR, H5E_WRITEERROR, FAIL,
+ "unable to write object header data to disk");
+ } /* end if */
+
+ /* Release the memory for the combined prefix/chunk */
+ p = H5FL_BLK_FREE(chunk_image,p);
+ } /* end if */
+ else {
+#ifdef H5_HAVE_PARALLEL
+ if (IS_H5FD_MPIO(f))
+ H5FD_mpio_tas_allsame(f->shared->lf, TRUE); /*only p0 write*/
+#endif /* H5_HAVE_PARALLEL */
+ if (H5F_block_write(f, oh->chunk[i].addr,
+ (hsize_t)(oh->chunk[i].size),
+ H5P_DEFAULT, oh->chunk[i].image) < 0) {
+ HRETURN_ERROR(H5E_OHDR, H5E_WRITEERROR, FAIL,
+ "unable to write object header data to disk");
+ } /* end if */
+ } /* end else */
+ oh->chunk[i].dirty = FALSE;
+ } /* end if */
+ } /* end for */
oh->dirty = FALSE;
}