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authorQuincey Koziol <koziol@hdfgroup.org>1997-10-08 22:11:46 (GMT)
committerQuincey Koziol <koziol@hdfgroup.org>1997-10-08 22:11:46 (GMT)
commitcdb316b7e0b247977d667edac7b98486e3a9b46c (patch)
tree694437667c157739f46921fed4fd4df9975270cd /src
parent2721bb475869900135de0fe14cde6ac1d4d73d8d (diff)
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[svn-r117] Added "seek position caching" code to shared file-records, which trimmed 20%
off the run-time for the current tests. (4.77s down to 3.89s)
Diffstat (limited to 'src')
-rw-r--r--src/H5F.c30
-rw-r--r--src/H5Fprivate.h14
2 files changed, 36 insertions, 8 deletions
diff --git a/src/H5F.c b/src/H5F.c
index 88e4581..25cb336 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -1295,14 +1295,20 @@ H5F_block_read (H5F_t *f, haddr_t addr, size_t size, void *buf)
if (0==size) return 0;
addr += f->shared->file_create_parms.userblock_size;
- if (H5F_SEEK (f->shared->file_handle, addr)<0) {
- /* low-level seek failure */
- HRETURN_ERROR (H5E_IO, H5E_SEEKERROR, FAIL);
- }
+ /* Check for switching file access operations or mis-placed seek offset */
+ if(f->shared->last_op!=OP_READ || f->shared->f_cur_off!=addr)
+ {
+ f->shared->last_op=OP_READ;
+ if (H5F_SEEK (f->shared->file_handle, addr)<0) {
+ /* low-level seek failure */
+ HRETURN_ERROR (H5E_IO, H5E_SEEKERROR, FAIL);
+ } /* end if */
+ } /* end if */
if (H5F_READ (f->shared->file_handle, buf, size)<0) {
/* low-level read failure */
HRETURN_ERROR (H5E_IO, H5E_READERROR, FAIL);
}
+ f->shared->f_cur_off=addr+size;
FUNC_LEAVE (SUCCEED);
}
@@ -1343,14 +1349,22 @@ H5F_block_write (H5F_t *f, haddr_t addr, size_t size, void *buf)
/* no write intent */
HRETURN_ERROR (H5E_IO, H5E_WRITEERROR, FAIL);
}
- if (H5F_SEEK (f->shared->file_handle, addr)<0) {
- /* low-level seek failure */
- HRETURN_ERROR (H5E_IO, H5E_SEEKERROR, FAIL);
- }
+
+ /* Check for switching file access operations or mis-placed seek offset */
+ if(f->shared->last_op!=OP_WRITE || f->shared->f_cur_off!=addr)
+ {
+ f->shared->last_op=OP_WRITE;
+ if (H5F_SEEK (f->shared->file_handle, addr)<0) {
+ /* low-level seek failure */
+ HRETURN_ERROR (H5E_IO, H5E_SEEKERROR, FAIL);
+ }
+ } /* end if */
+
if (H5F_WRITE (f->shared->file_handle, buf, size)<0) {
/* low-level write failure */
HRETURN_ERROR (H5E_IO, H5E_WRITEERROR, FAIL);
}
+ f->shared->f_cur_off=addr+size;
FUNC_LEAVE (SUCCEED);
}
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index 4165b1e..81f43ce 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -351,11 +351,25 @@ typedef struct H5F_search_t {
ino_t ino; /* Unique file number on device */
} H5F_search_t;
+/* For determining what the last file operation was */
+typedef enum
+ {
+ OP_UNKNOWN = 0, /* Don't know what the last operation was (after fopen frex) */
+ OP_SEEK, /* Last operation was a seek */
+ OP_WRITE, /* Last operation was a write */
+ OP_READ /* Last operation was a read */
+ }
+H5F_fileop_t;
+
/*
* Define the structure to store the file information for HDF5 files. One of
* these structures is allocated per file, not per H5Fopen().
*/
typedef struct H5F_file_t {
+ /* Seek caching info */
+ haddr_t f_cur_off; /* Current location in the file */
+ H5F_fileop_t last_op; /* the last file operation performed */
+
H5F_search_t key; /* The key for looking up files */
uintn flags; /* Access Permissions for file */
hdf_file_t file_handle; /* File handle for actual I/O */