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Diffstat (limited to 'db2/mp/mp_fget.c')
-rw-r--r--db2/mp/mp_fget.c114
1 files changed, 39 insertions, 75 deletions
diff --git a/db2/mp/mp_fget.c b/db2/mp/mp_fget.c
index 3f99e60505..1010751c92 100644
--- a/db2/mp/mp_fget.c
+++ b/db2/mp/mp_fget.c
@@ -7,7 +7,7 @@
#include "config.h"
#ifndef lint
-static const char sccsid[] = "@(#)mp_fget.c 10.30 (Sleepycat) 10/25/97";
+static const char sccsid[] = "@(#)mp_fget.c 10.32 (Sleepycat) 11/26/97";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
@@ -38,13 +38,11 @@ memp_fget(dbmfp, pgnoaddr, flags, addrp)
int flags;
void *addrp;
{
- BH *bhp, *tbhp;
+ BH *bhp;
DB_MPOOL *dbmp;
MPOOL *mp;
MPOOLFILE *mfp;
- db_pgno_t lastpgno;
size_t bucket, mf_offset;
- off_t size;
u_long cnt;
int b_incr, b_inserted, readonly_alloc, ret;
void *addr;
@@ -97,7 +95,7 @@ memp_fget(dbmfp, pgnoaddr, flags, addrp)
mf_offset = R_OFFSET(dbmp, mfp);
addr = NULL;
bhp = NULL;
- b_incr = b_inserted = readonly_alloc = ret = 0;
+ b_incr = b_inserted = ret = 0;
LOCKREGION(dbmp);
@@ -114,11 +112,10 @@ memp_fget(dbmfp, pgnoaddr, flags, addrp)
* It would be possible to do so by reference counting the open
* pages from the mmap, but it's unclear to me that it's worth it.
*/
- if (dbmfp->addr != NULL && dbmfp->mfp->can_mmap) {
- lastpgno = dbmfp->len == 0 ?
- 0 : (dbmfp->len - 1) / mfp->stat.st_pagesize;
+ if (dbmfp->addr != NULL && F_ISSET(dbmfp->mfp, MP_CAN_MMAP)) {
+ readonly_alloc = 0;
if (LF_ISSET(DB_MPOOL_LAST))
- *pgnoaddr = lastpgno;
+ *pgnoaddr = mfp->last_pgno;
else {
/*
* !!!
@@ -128,10 +125,10 @@ memp_fget(dbmfp, pgnoaddr, flags, addrp)
*/
if (LF_ISSET(DB_MPOOL_CREATE | DB_MPOOL_NEW))
readonly_alloc = 1;
- else if (*pgnoaddr > lastpgno) {
+ else if (*pgnoaddr > mfp->last_pgno) {
__db_err(dbmp->dbenv,
"%s: page %lu doesn't exist",
- dbmfp->path, (u_long)*pgnoaddr);
+ __memp_fn(dbmfp), (u_long)*pgnoaddr);
ret = EINVAL;
goto err;
}
@@ -146,79 +143,38 @@ memp_fget(dbmfp, pgnoaddr, flags, addrp)
}
}
- /*
- * If requesting the last page or a new page, find the last page. The
- * tricky thing is that the user may have created a page already that's
- * after any page that exists in the file.
- */
- if (LF_ISSET(DB_MPOOL_LAST | DB_MPOOL_NEW)) {
- /*
- * Temporary files may not yet have been created.
- *
- * Don't lock -- there are no atomicity issues for stat(2).
- */
- if (dbmfp->fd == -1)
- size = 0;
- else if ((ret =
- __db_ioinfo(dbmfp->path, dbmfp->fd, &size, NULL)) != 0) {
- __db_err(dbmp->dbenv,
- "%s: %s", dbmfp->path, strerror(ret));
- goto err;
- }
-
- *pgnoaddr = size == 0 ? 0 : (size - 1) / mfp->stat.st_pagesize;
+ /* Check if requesting the last page or a new page. */
+ if (LF_ISSET(DB_MPOOL_LAST))
+ *pgnoaddr = mfp->last_pgno;
- /*
- * Walk the list of BH's, looking for later pages. Save the
- * pointer if a later page is found so that we don't have to
- * search the list twice.
- *
- * If requesting a new page, return the page one after the last
- * page -- which we'll have to create.
- */
- for (tbhp = SH_TAILQ_FIRST(&mp->bhq, __bh);
- tbhp != NULL; tbhp = SH_TAILQ_NEXT(tbhp, q, __bh))
- if (tbhp->pgno >= *pgnoaddr &&
- tbhp->mf_offset == mf_offset) {
- bhp = tbhp;
- *pgnoaddr = bhp->pgno;
- }
- if (LF_ISSET(DB_MPOOL_NEW))
- ++*pgnoaddr;
- }
-
- /* If we already found the right buffer, return it. */
- if (LF_ISSET(DB_MPOOL_LAST) && bhp != NULL) {
- addr = bhp->buf;
- goto found;
+ if (LF_ISSET(DB_MPOOL_NEW)) {
+ *pgnoaddr = mfp->last_pgno + 1;
+ goto alloc;
}
- /* If we haven't checked the BH hash bucket queue, do the search. */
- if (!LF_ISSET(DB_MPOOL_LAST | DB_MPOOL_NEW)) {
- bucket = BUCKET(mp, mf_offset, *pgnoaddr);
- for (cnt = 0,
- bhp = SH_TAILQ_FIRST(&dbmp->htab[bucket], __bh);
- bhp != NULL; bhp = SH_TAILQ_NEXT(bhp, hq, __bh)) {
- ++cnt;
- if (bhp->pgno == *pgnoaddr &&
- bhp->mf_offset == mf_offset) {
- addr = bhp->buf;
- ++mp->stat.st_hash_searches;
- if (cnt > mp->stat.st_hash_longest)
- mp->stat.st_hash_longest = cnt;
- mp->stat.st_hash_examined += cnt;
- goto found;
- }
- }
- if (cnt != 0) {
+ /* Check the BH hash bucket queue. */
+ bucket = BUCKET(mp, mf_offset, *pgnoaddr);
+ for (cnt = 0,
+ bhp = SH_TAILQ_FIRST(&dbmp->htab[bucket], __bh);
+ bhp != NULL; bhp = SH_TAILQ_NEXT(bhp, hq, __bh)) {
+ ++cnt;
+ if (bhp->pgno == *pgnoaddr && bhp->mf_offset == mf_offset) {
+ addr = bhp->buf;
++mp->stat.st_hash_searches;
if (cnt > mp->stat.st_hash_longest)
mp->stat.st_hash_longest = cnt;
mp->stat.st_hash_examined += cnt;
+ goto found;
}
}
+ if (cnt != 0) {
+ ++mp->stat.st_hash_searches;
+ if (cnt > mp->stat.st_hash_longest)
+ mp->stat.st_hash_longest = cnt;
+ mp->stat.st_hash_examined += cnt;
+ }
- /*
+alloc: /*
* Allocate a new buffer header and data space, and mark the contents
* as useless.
*/
@@ -300,7 +256,7 @@ found: /* Increment the reference count. */
if (bhp->ref == UINT16_T_MAX) {
__db_err(dbmp->dbenv,
"%s: too many references to page %lu",
- dbmfp->path, bhp->pgno);
+ __memp_fn(dbmfp), bhp->pgno);
ret = EINVAL;
goto err;
}
@@ -346,6 +302,14 @@ found: /* Increment the reference count. */
++mfp->stat.st_cache_hit;
}
+ /*
+ * If we're returning a page after our current notion of the last-page,
+ * update our information. Note, there's no way to un-instantiate this
+ * page, it's going to exist whether it's returned to us dirty or not.
+ */
+ if (bhp->pgno > mfp->last_pgno)
+ mfp->last_pgno = bhp->pgno;
+
mapret: LOCKHANDLE(dbmp, dbmfp->mutexp);
++dbmfp->pinref;
UNLOCKHANDLE(dbmp, dbmfp->mutexp);
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-28 09:24:17 +0000