hash_meta.c

00001 /*-
00002  * See the file LICENSE for redistribution information.
00003  *
00004  * Copyright (c) 1999, 2000
00005  * Sleepycat Software. All rights reserved.
00006  */
00007 
00008 #include "config.h"
00009 
00010 #ifndef lint
00011 static const char revid[] = "$Id: hash__meta_8c-source.html,v 1.1 2008年06月08日 10:19:32 sebdiaz Exp $";
00012 #endif /* not lint */
00013 
00014 #ifndef NO_SYSTEM_INCLUDES
00015 #include <sys/types.h>
00016 #include <errno.h>
00017 #endif
00018 
00019 #include "db_int.h"
00020 #include "db_page.h"
00021 #include "hash.h"
00022 #include "db_shash.h"
00023 #include "lock.h"
00024 #include "txn.h"
00025 
00026 /*
00027  * Acquire the meta-data page.
00028  *
00029  * PUBLIC: int CDB___ham_get_meta __P((DBC *));
00030  */
00031 int
00032 CDB___ham_get_meta(dbc)
00033 DBC *dbc;
00034 {
00035 HASH_CURSOR *hcp;
00036 HASH *hashp;
00037 DB *dbp;
00038 int ret;
00039 
00040 hcp = (HASH_CURSOR *)dbc->internal;
00041 dbp = dbc->dbp;
00042 hashp = dbp->h_internal;
00043 
00044 if (dbp->dbenv != NULL &&
00045 STD_LOCKING(dbc) && !F_ISSET(dbc, DBC_RECOVER)) {
00046 dbc->lock.pgno = hashp->meta_pgno;
00047 if ((ret = CDB_lock_get(dbp->dbenv, dbc->locker,
00048 DB_NONBLOCK(dbc) ? DB_LOCK_NOWAIT : 0,
00049 &dbc->lock_dbt, DB_LOCK_READ, &hcp->hlock)) != 0)
00050 return (ret);
00051 }
00052 
00053 if ((ret = CDB___ham_get_page(dbc->dbp,
00054 hashp->meta_pgno, (PAGE **)&(hcp->hdr))) != 0 &&
00055 hcp->hlock.off != LOCK_INVALID) {
00056 (void)CDB_lock_put(dbc->dbp->dbenv, &hcp->hlock);
00057 hcp->hlock.off = LOCK_INVALID;
00058 }
00059 
00060 return (ret);
00061 }
00062 
00063 /*
00064  * Release the meta-data page.
00065  *
00066  * PUBLIC: int CDB___ham_release_meta __P((DBC *));
00067  */
00068 int
00069 CDB___ham_release_meta(dbc)
00070 DBC *dbc;
00071 {
00072 HASH_CURSOR *hcp;
00073 
00074 hcp = (HASH_CURSOR *)dbc->internal;
00075 
00076 if (hcp->hdr)
00077 (void)CDB___ham_put_page(dbc->dbp, (PAGE *)hcp->hdr,
00078 F_ISSET(hcp, H_DIRTY) ? 1 : 0);
00079 hcp->hdr = NULL;
00080 if (!F_ISSET(dbc, DBC_RECOVER) &&
00081 dbc->txn == NULL && hcp->hlock.off != LOCK_INVALID)
00082 (void)CDB_lock_put(dbc->dbp->dbenv, &hcp->hlock);
00083 hcp->hlock.off = LOCK_INVALID;
00084 F_CLR(hcp, H_DIRTY);
00085 
00086 return (0);
00087 }
00088 
00089 /*
00090  * Mark the meta-data page dirty.
00091  *
00092  * PUBLIC: int CDB___ham_dirty_meta __P((DBC *));
00093  */
00094 int
00095 CDB___ham_dirty_meta(dbc)
00096 DBC *dbc;
00097 {
00098 DB *dbp;
00099 DB_LOCK _tmp;
00100 HASH *hashp;
00101 HASH_CURSOR *hcp;
00102 int ret;
00103 
00104 dbp = dbc->dbp;
00105 hashp = dbp->h_internal;
00106 hcp = (HASH_CURSOR *)dbc->internal;
00107 
00108 ret = 0;
00109 if (STD_LOCKING(dbc) && !F_ISSET(dbc, DBC_RECOVER)) {
00110 dbc->lock.pgno = hashp->meta_pgno;
00111 if ((ret = CDB_lock_get(dbp->dbenv, dbc->locker,
00112 DB_NONBLOCK(dbc) ? DB_LOCK_NOWAIT : 0,
00113 &dbc->lock_dbt, DB_LOCK_WRITE, &_tmp)) == 0) {
00114 ret = CDB_lock_put(dbp->dbenv, &hcp->hlock);
00115 hcp->hlock = _tmp;
00116 }
00117 }
00118 
00119 if (ret == 0)
00120 F_SET(hcp, H_DIRTY);
00121 return (ret);
00122 }