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authorQuincey Koziol <koziol@hdfgroup.org>2006-10-16 04:30:07 (GMT)
committerQuincey Koziol <koziol@hdfgroup.org>2006-10-16 04:30:07 (GMT)
commit10e8a68a0c380cc58d831e95271ccc8ce658ad20 (patch)
tree646ed8390da9065d97ac91891bddc180facc67a4
parent2374bb1012dd1d1233a3d1f5b807460cece72b0f (diff)
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[svn-r12760] Description:
Speculatively attempt to read in the entire first chunk in object header with the object header prefix. If successful (which it is most of the time), this reduces by 1 the # of I/Os required to read in the object header. Since the object header typically was taking 2 I/Os, this should cut the number of I/O operations when opening an object's header in half. Tested on: FreeBSD/32 4.11 (sleipnir) w/threadsafe Linux/32 2.4 (heping) w/C++ & FORTRAN
-rw-r--r--src/H5Ocache.c256
1 files changed, 253 insertions, 3 deletions
diff --git a/src/H5Ocache.c b/src/H5Ocache.c
index 7970e70..ceb6b5a 100644
--- a/src/H5Ocache.c
+++ b/src/H5Ocache.c
@@ -23,17 +23,42 @@
*-------------------------------------------------------------------------
*/
-#define H5O_PACKAGE /*suppress error about including H5Opkg */
+/****************/
+/* Module Setup */
+/****************/
+#define H5O_PACKAGE /*suppress error about including H5Opkg */
+/***********/
+/* Headers */
+/***********/
#include "H5private.h" /* Generic Functions */
#include "H5Eprivate.h" /* Error handling */
#include "H5FLprivate.h" /* Free lists */
#include "H5Opkg.h" /* Object headers */
-/* Private typedefs */
+/****************/
+/* Local Macros */
+/****************/
+
+/* Set the object header size to speculatively read in */
+/* (needs to be more than the default dataset header size) */
+#define H5O_SPEC_READ_SIZE 512
+
+
+/******************/
+/* Local Typedefs */
+/******************/
+
-/* PRIVATE PROTOTYPES */
+/********************/
+/* Package Typedefs */
+/********************/
+
+
+/********************/
+/* Local Prototypes */
+/********************/
/* Metadata cache callbacks */
static H5O_t *H5O_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_udata1,
@@ -42,6 +67,21 @@ static herr_t H5O_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr,
static herr_t H5O_clear(H5F_t *f, H5O_t *oh, hbool_t destroy);
static herr_t H5O_size(const H5F_t *f, const H5O_t *oh, size_t *size_ptr);
+
+/*********************/
+/* Package Variables */
+/*********************/
+
+
+/*****************************/
+/* Library Private Variables */
+/*****************************/
+
+
+/*******************/
+/* Local Variables */
+/*******************/
+
/* H5O inherits cache-like properties from H5AC */
const H5AC_class_t H5AC_OHDR[1] = {{
H5AC_OHDR_ID,
@@ -136,6 +176,7 @@ done:
FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O_flush_msgs() */
+#ifdef OLD_WAY
/*-------------------------------------------------------------------------
* Function: H5O_load
@@ -314,6 +355,215 @@ done:
FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O_load() */
+#else /* OLD_WAY */
+
+/*-------------------------------------------------------------------------
+ * Function: H5O_load
+ *
+ * Purpose: Loads an object header from disk.
+ *
+ * Return: Success: Pointer to the new object header.
+ *
+ * Failure: NULL
+ *
+ * Programmer: Robb Matzke
+ * matzke@llnl.gov
+ * Aug 5 1997
+ *
+ *-------------------------------------------------------------------------
+ */
+static H5O_t *
+H5O_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void UNUSED * _udata1,
+ void UNUSED * _udata2)
+{
+ H5O_t *oh = NULL; /* Object header read in */
+ uint8_t read_buf[H5O_SPEC_READ_SIZE]; /* Buffer for speculative read */
+ uint8_t *p; /* Pointer into buffer to decode */
+ size_t spec_read_size; /* Size of buffer to speculatively read in */
+ size_t prefix_size; /* Size of object header prefix */
+ unsigned nmesgs; /* Total # of messages in this object header */
+ unsigned curmesg = 0; /* Current message being decoded in object header */
+ unsigned skipped_msgs = 0; /* Number of unknown messages skipped */
+ unsigned merged_null_msgs = 0; /* Number of null messages merged together */
+ haddr_t chunk_addr; /* Address of first chunk */
+ size_t chunk_size; /* Size of first chunk */
+ haddr_t abs_eoa; /* Absolute end of file address */
+ haddr_t rel_eoa; /* Relative end of file address */
+ H5O_t *ret_value; /* Return value */
+
+ FUNC_ENTER_NOAPI(H5O_load, NULL)
+
+ /* check args */
+ HDassert(f);
+ HDassert(H5F_addr_defined(addr));
+ HDassert(!_udata1);
+ HDassert(!_udata2);
+
+ /* Make certain we don't speculatively read off the end of the file */
+ if(HADDR_UNDEF == (abs_eoa = H5F_get_eoa(f)))
+ HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, NULL, "unable to determine file size")
+
+ /* Adjust absolute EOA address to relative EOA address */
+ rel_eoa = abs_eoa - H5F_get_base_addr(f);
+
+ /* Compute the size of the speculative object header buffer */
+ H5_ASSIGN_OVERFLOW(spec_read_size, MIN(rel_eoa - addr, H5O_SPEC_READ_SIZE), /* From: */ hsize_t, /* To: */ size_t);
+
+ /* Attempt to speculatively read both object header prefix and first chunk */
+ if(H5F_block_read(f, H5FD_MEM_OHDR, addr, spec_read_size, dxpl_id, read_buf) < 0)
+ HGOTO_ERROR(H5E_OHDR, H5E_READERROR, NULL, "unable to read object header")
+ p = read_buf;
+
+ /* allocate ohdr and init chunk list */
+ if(NULL == (oh = H5FL_CALLOC(H5O_t)))
+ HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
+
+ /* decode version */
+ oh->version = *p++;
+ if(H5O_VERSION != oh->version)
+ HGOTO_ERROR(H5E_OHDR, H5E_VERSION, NULL, "bad object header version number")
+
+ /* reserved */
+ p++;
+
+ /* decode number of messages */
+ UINT16DECODE(p, nmesgs);
+
+ /* decode link count */
+ UINT32DECODE(p, oh->nlink);
+
+ /* decode first chunk size */
+ UINT32DECODE(p, chunk_size);
+
+ /* reserved */
+ p += 4;
+
+ /* Compute first chunk address */
+ prefix_size = (size_t)(p - read_buf);
+ chunk_addr = addr + (hsize_t)prefix_size;
+
+ /* build the message array */
+ oh->alloc_nmesgs = nmesgs;
+ if(NULL == (oh->mesg = H5FL_SEQ_MALLOC(H5O_mesg_t, oh->alloc_nmesgs)))
+ HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
+
+ /* read each chunk from disk */
+ while(H5F_addr_defined(chunk_addr)) {
+ unsigned chunkno; /* Current chunk's index */
+ size_t mesg_size; /* Size of message read in */
+
+ /* increase chunk array size */
+ if(oh->nchunks >= oh->alloc_nchunks) {
+ unsigned na = oh->alloc_nchunks + H5O_NCHUNKS;
+ H5O_chunk_t *x = H5FL_SEQ_REALLOC(H5O_chunk_t, oh->chunk, (size_t)na);
+
+ if(!x)
+ HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
+ oh->alloc_nchunks = na;
+ oh->chunk = x;
+ } /* end if */
+
+ /* Init the chunk raw data info */
+ chunkno = oh->nchunks++;
+ oh->chunk[chunkno].dirty = FALSE;
+ oh->chunk[chunkno].addr = chunk_addr;
+ oh->chunk[chunkno].size = chunk_size;
+ if(NULL == (oh->chunk[chunkno].image = H5FL_BLK_MALLOC(chunk_image, chunk_size)))
+ HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
+
+ /* Check for speculative read of first chunk containing all the data needed */
+ if(chunkno == 0 && (spec_read_size - prefix_size) >= chunk_size)
+ HDmemcpy(oh->chunk[chunkno].image, p, chunk_size);
+ else {
+ /* Read the chunk raw data */
+ if(H5F_block_read(f, H5FD_MEM_OHDR, chunk_addr, chunk_size, dxpl_id, oh->chunk[chunkno].image) < 0)
+ HGOTO_ERROR(H5E_OHDR, H5E_READERROR, NULL, "unable to read object header data")
+ } /* end else */
+
+ /* load messages from this chunk */
+ for(p = oh->chunk[chunkno].image; p < oh->chunk[chunkno].image + chunk_size; p += mesg_size) {
+ unsigned mesgno; /* Current message to operate on */
+ unsigned id; /* ID (type) of current message */
+ uint8_t flags; /* Flags for current message */
+
+ UINT16DECODE(p, id);
+ UINT16DECODE(p, mesg_size);
+ HDassert(mesg_size==H5O_ALIGN (mesg_size));
+ flags = *p++;
+ p += 3; /*reserved*/
+
+ /* Try to detect invalidly formatted object header messages */
+ if(p + mesg_size > oh->chunk[chunkno].image + chunk_size)
+ HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, NULL, "corrupt object header")
+
+ /* Skip header messages we don't know about */
+ /* (Usually from future versions of the library */
+ if(id >= NELMTS(H5O_msg_class_g) || NULL == H5O_msg_class_g[id]) {
+ skipped_msgs++;
+ continue;
+ } /* end if */
+
+ if((H5F_get_intent(f) & H5F_ACC_RDWR) &&
+ H5O_NULL_ID == id && oh->nmesgs > 0 &&
+ H5O_NULL_ID == oh->mesg[oh->nmesgs - 1].type->id &&
+ oh->mesg[oh->nmesgs - 1].chunkno == chunkno) {
+ /* combine adjacent null messages */
+ mesgno = oh->nmesgs - 1;
+ oh->mesg[mesgno].raw_size += H5O_SIZEOF_MSGHDR(f) + mesg_size;
+ oh->mesg[mesgno].dirty = TRUE;
+ merged_null_msgs++;
+ } else {
+ /* new message */
+ if (oh->nmesgs >= nmesgs)
+ HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "corrupt object header - too many messages")
+ mesgno = oh->nmesgs++;
+ oh->mesg[mesgno].type = H5O_msg_class_g[id];
+ oh->mesg[mesgno].dirty = FALSE;
+ oh->mesg[mesgno].flags = flags;
+ oh->mesg[mesgno].native = NULL;
+ oh->mesg[mesgno].raw = p;
+ oh->mesg[mesgno].raw_size = mesg_size;
+ oh->mesg[mesgno].chunkno = chunkno;
+ } /* end else */
+ } /* end for */
+
+ HDassert(p == oh->chunk[chunkno].image + chunk_size);
+
+ /* decode next object header continuation message */
+ for(chunk_addr = HADDR_UNDEF; !H5F_addr_defined(chunk_addr) && curmesg < oh->nmesgs; ++curmesg) {
+ if(H5O_CONT_ID == oh->mesg[curmesg].type->id) {
+ H5O_cont_t *cont;
+
+ cont = (H5O_MSG_CONT->decode) (f, dxpl_id, oh->mesg[curmesg].raw);
+ oh->mesg[curmesg].native = cont;
+ chunk_addr = cont->addr;
+ chunk_size = cont->size;
+ cont->chunkno = oh->nchunks; /*the next chunk to allocate */
+ } /* end if */
+ } /* end for */
+ } /* end while */
+
+ /* Mark the object header dirty if we've merged a message */
+ if(merged_null_msgs)
+ oh->cache_info.is_dirty = TRUE;
+
+ /* Sanity check for the correct # of messages in object header */
+ if((oh->nmesgs + skipped_msgs + merged_null_msgs) != nmesgs)
+ HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "corrupt object header - too few messages")
+
+ /* Set return value */
+ ret_value = oh;
+
+done:
+ /* Release the [possibly partially initialized] object header on errors */
+ if(!ret_value && oh) {
+ if(H5O_dest(f,oh) < 0)
+ HDONE_ERROR(H5E_OHDR, H5E_CANTFREE, NULL, "unable to destroy object header data")
+ } /* end if */
+
+ FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_load() */
+#endif /* OLD_WAY */
/*-------------------------------------------------------------------------