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: qam__open_8c-source.html,v 1.1 2008年06月08日 10:21:45 sebdiaz Exp $"; 00012 #endif /* not lint */ 00013 00014 #ifndef NO_SYSTEM_INCLUDES 00015 #include <sys/types.h> 00016 00017 #include <errno.h> 00018 #include <string.h> 00019 #endif 00020 00021 #include "db_int.h" 00022 #include "db_page.h" 00023 #include "db_shash.h" 00024 #include "db_swap.h" 00025 #include "db_am.h" 00026 #include "lock.h" 00027 #include "qam.h" 00028 00029 /* 00030 * CDB___qam_open 00031 * 00032 * PUBLIC: int CDB___qam_open __P((DB *, const char *, db_pgno_t, u_int32_t)); 00033 */ 00034 int 00035 CDB___qam_open(dbp, name, base_pgno, flags) 00036 DB *dbp; 00037 const char *name; 00038 db_pgno_t base_pgno; 00039 u_int32_t flags; 00040 { 00041 QUEUE *t; 00042 DBC *dbc; 00043 DB_LOCK metalock; 00044 DB_LSN orig_lsn; 00045 QMETA *qmeta; 00046 int locked; 00047 int ret, t_ret; 00048 00049 ret = 0; 00050 locked = 0; 00051 t = dbp->q_internal; 00052 00053 /* Initialize the remaining fields/methods of the DB. */ 00054 dbp->del = CDB___qam_delete; 00055 dbp->put = CDB___qam_put; 00056 dbp->stat = CDB___qam_stat; 00057 00058 metalock.off = LOCK_INVALID; 00059 00060 /* 00061 * Get a cursor. If DB_CREATE is specified, we may be creating 00062 * pages, and to do that safely in CDB we need a write cursor. 00063 * In STD_LOCKING mode, we'll synchronize using the meta page 00064 * lock instead. 00065 */ 00066 if ((ret = dbp->cursor(dbp, dbp->open_txn, 00067 &dbc, LF_ISSET(DB_CREATE) && LOCKING(dbp->dbenv) ? 00068 DB_WRITECURSOR : 0)) != 0) 00069 return (ret); 00070 00071 /* Get, and optionally create the metadata page. */ 00072 if ((ret = 00073 CDB___db_lget(dbc, 0, base_pgno, DB_LOCK_READ, 0, &metalock)) != 0) 00074 goto err; 00075 if ((ret = CDB_memp_fget( 00076 dbp->mpf, &base_pgno, DB_MPOOL_CREATE, (PAGE **)&qmeta)) != 0) 00077 goto err; 00078 00079 /* 00080 * If the magic number is correct, we're not creating the tree. 00081 * Correct any fields that may not be right. Note, all of the 00082 * local flags were set by DB->open. 00083 */ 00084 again: if (qmeta->dbmeta.magic == DB_QAMMAGIC) { 00085 t->re_pad = qmeta->re_pad; 00086 t->re_len = qmeta->re_len; 00087 t->rec_page = qmeta->rec_page; 00088 00089 (void)CDB_memp_fput(dbp->mpf, (PAGE *)qmeta, 0); 00090 goto done; 00091 } 00092 00093 /* If we're doing CDB; we now have to get the write lock. */ 00094 if (LOCKING(dbp->dbenv)) { 00095 DB_ASSERT(LF_ISSET(DB_CREATE)); 00096 if ((ret = CDB_lock_get(dbp->dbenv, dbc->locker, DB_LOCK_UPGRADE, 00097 &dbc->lock_dbt, DB_LOCK_WRITE, &dbc->mylock)) != 0) 00098 goto err; 00099 } 00100 00101 /* 00102 * If we are doing locking, relase the read lock 00103 * and get a write lock. We want to avoid deadlock. 00104 */ 00105 if (locked == 0 && STD_LOCKING(dbc)) { 00106 if ((ret = __LPUT(dbc, metalock)) != 0) 00107 goto err; 00108 if ((ret = CDB___db_lget(dbc, 00109 0, base_pgno, DB_LOCK_WRITE, 0, &metalock)) != 0) 00110 goto err; 00111 locked = 1; 00112 goto again; 00113 } 00114 /* Initialize the tree structure metadata information. */ 00115 orig_lsn = qmeta->dbmeta.lsn; 00116 memset(qmeta, 0, sizeof(QMETA)); 00117 ZERO_LSN(qmeta->dbmeta.lsn); 00118 qmeta->dbmeta.pgno = base_pgno; 00119 qmeta->dbmeta.magic = DB_QAMMAGIC; 00120 qmeta->dbmeta.version = DB_QAMVERSION; 00121 qmeta->dbmeta.pagesize = dbp->pgsize; 00122 qmeta->dbmeta.type = P_QAMMETA; 00123 qmeta->re_pad = t->re_pad; 00124 qmeta->start = 1; 00125 qmeta->re_len = t->re_len; 00126 qmeta->rec_page = CALC_QAM_RECNO_PER_PAGE(dbp); 00127 t->rec_page = qmeta->rec_page; 00128 memcpy(qmeta->dbmeta.uid, dbp->fileid, DB_FILE_ID_LEN); 00129 00130 /* Verify that we can fit at least one record per page. */ 00131 if (QAM_RECNO_PER_PAGE(dbp) < 1) { 00132 CDB___db_err(dbp->dbenv, 00133 "Record size of %lu too large for page size of %lu", 00134 (u_long)t->re_len, (u_long)dbp->pgsize); 00135 (void)CDB_memp_fput(dbp->mpf, (PAGE *)qmeta, 0); 00136 ret = EINVAL; 00137 goto err; 00138 } 00139 00140 if ((ret = CDB___db_log_page(dbp, 00141 name, &orig_lsn, base_pgno, (PAGE *)qmeta)) != 0) 00142 goto err; 00143 00144 /* Release the metadata page. */ 00145 if ((ret = CDB_memp_fput(dbp->mpf, (PAGE *)qmeta, DB_MPOOL_DIRTY)) != 0) 00146 goto err; 00147 DB_TEST_RECOVERY(dbp, DB_TEST_POSTLOG, ret, name); 00148 00149 /* 00150 * Flush the metadata page to disk. 00151 * 00152 * !!! 00153 * It's not useful to return not-yet-flushed here -- convert it to 00154 * an error. 00155 */ 00156 if ((ret = CDB_memp_fsync(dbp->mpf)) == DB_INCOMPLETE) { 00157 CDB___db_err(dbp->dbenv, "Flush of metapage failed"); 00158 ret = EINVAL; 00159 } 00160 DB_TEST_RECOVERY(dbp, DB_TEST_POSTSYNC, ret, name); 00161 00162 done: t->q_meta = base_pgno; 00163 t->q_root = base_pgno + 1; 00164 00165 err: 00166 DB_TEST_RECOVERY_LABEL 00167 /* Don't hold the meta page long term. */ 00168 (void)__LPUT(dbc, metalock); 00169 00170 if ((t_ret = dbc->c_close(dbc)) != 0 && ret == 0) 00171 ret = t_ret; 00172 00173 return (ret); 00174 } 00175 00176 /* 00177 * CDB___qam_metachk -- 00178 * 00179 * PUBLIC: int CDB___qam_metachk __P((DB *, const char *, QMETA *)); 00180 */ 00181 int 00182 CDB___qam_metachk(dbp, name, qmeta) 00183 DB *dbp; 00184 const char *name; 00185 QMETA *qmeta; 00186 { 00187 DB_ENV *dbenv; 00188 u_int32_t vers; 00189 int ret; 00190 00191 dbenv = dbp->dbenv; 00192 00193 /* 00194 * At this point, all we know is that the magic number is for a Queue. 00195 * Check the version, the database may be out of date. 00196 */ 00197 vers = qmeta->dbmeta.version; 00198 if (F_ISSET(dbp, DB_AM_SWAP)) 00199 M_32_SWAP(vers); 00200 switch (vers) { 00201 case 1: 00202 CDB___db_err(dbenv, 00203 "%s: queue version %lu requires a version upgrade", 00204 name, (u_long)vers); 00205 return (DB_OLD_VERSION); 00206 case 2: 00207 break; 00208 default: 00209 CDB___db_err(dbenv, 00210 "%s: unsupported qam version: %lu", name, (u_long)vers); 00211 return (EINVAL); 00212 } 00213 00214 /* Swap the page if we need to. */ 00215 if (F_ISSET(dbp, DB_AM_SWAP) && (ret = CDB___qam_mswap((PAGE *)qmeta)) != 0) 00216 return (ret); 00217 00218 /* Check the type. */ 00219 if (dbp->type != DB_QUEUE && dbp->type != DB_UNKNOWN) 00220 return (EINVAL); 00221 dbp->type = DB_QUEUE; 00222 DB_ILLEGAL_METHOD(dbp, DB_OK_QUEUE); 00223 00224 /* Set the page size. */ 00225 dbp->pgsize = qmeta->dbmeta.pagesize; 00226 00227 /* Copy the file's ID. */ 00228 memcpy(dbp->fileid, qmeta->dbmeta.uid, DB_FILE_ID_LEN); 00229 00230 return (0); 00231 }