qam_open.c
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上传日期:2022-05-23
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文件大小:8k
- /*-
- * See the file LICENSE for redistribution information.
- *
- * Copyright (c) 1999-2002
- * Sleepycat Software. All rights reserved.
- */
- #include "db_config.h"
- #ifndef lint
- static const char revid[] = "$Id: qam_open.c,v 11.55 2002/09/04 19:06:45 margo Exp $";
- #endif /* not lint */
- #ifndef NO_SYSTEM_INCLUDES
- #include <sys/types.h>
- #include <string.h>
- #endif
- #include "db_int.h"
- #include "dbinc/crypto.h"
- #include "dbinc/db_page.h"
- #include "dbinc/db_shash.h"
- #include "dbinc/db_swap.h"
- #include "dbinc/db_am.h"
- #include "dbinc/lock.h"
- #include "dbinc/qam.h"
- #include "dbinc/fop.h"
- static int __qam_init_meta __P((DB *, QMETA *));
- /*
- * __qam_open
- *
- * PUBLIC: int __qam_open __P((DB *,
- * PUBLIC: DB_TXN *, const char *, db_pgno_t, int, u_int32_t));
- */
- int
- __qam_open(dbp, txn, name, base_pgno, mode, flags)
- DB *dbp;
- DB_TXN *txn;
- const char *name;
- db_pgno_t base_pgno;
- int mode;
- u_int32_t flags;
- {
- DBC *dbc;
- DB_ENV *dbenv;
- DB_LOCK metalock;
- DB_MPOOLFILE *mpf;
- QMETA *qmeta;
- QUEUE *t;
- int ret, t_ret;
- dbenv = dbp->dbenv;
- mpf = dbp->mpf;
- t = dbp->q_internal;
- ret = 0;
- qmeta = NULL;
- /* Initialize the remaining fields/methods of the DB. */
- dbp->stat = __qam_stat;
- dbp->sync = __qam_sync;
- dbp->db_am_remove = __qam_remove;
- dbp->db_am_rename = __qam_rename;
- /*
- * Get a cursor. If DB_CREATE is specified, we may be creating
- * pages, and to do that safely in CDB we need a write cursor.
- * In STD_LOCKING mode, we'll synchronize using the meta page
- * lock instead.
- */
- if ((ret = dbp->cursor(dbp, txn, &dbc,
- LF_ISSET(DB_CREATE) && CDB_LOCKING(dbenv) ? DB_WRITECURSOR : 0))
- != 0)
- return (ret);
- /*
- * Get the meta data page. It must exist, because creates of
- * files/databases come in through the __qam_new_file interface
- * and queue doesn't support subdatabases.
- */
- if ((ret =
- __db_lget(dbc, 0, base_pgno, DB_LOCK_READ, 0, &metalock)) != 0)
- goto err;
- if ((ret =
- mpf->get(mpf, &base_pgno, 0, (PAGE **)&qmeta)) != 0)
- goto err;
- /* If the magic number is incorrect, that's a fatal error. */
- if (qmeta->dbmeta.magic != DB_QAMMAGIC) {
- __db_err(dbenv, "%s: unexpected file type or format", name);
- ret = EINVAL;
- goto err;
- }
- /* Setup information needed to open extents. */
- t->page_ext = qmeta->page_ext;
- if (t->page_ext != 0) {
- t->pginfo.db_pagesize = dbp->pgsize;
- t->pginfo.flags =
- F_ISSET(dbp, (DB_AM_CHKSUM | DB_AM_ENCRYPT | DB_AM_SWAP));
- t->pginfo.type = dbp->type;
- t->pgcookie.data = &t->pginfo;
- t->pgcookie.size = sizeof(DB_PGINFO);
- if ((ret = __os_strdup(dbp->dbenv, name, &t->path)) != 0)
- return (ret);
- t->dir = t->path;
- if ((t->name = __db_rpath(t->path)) == NULL) {
- t->name = t->path;
- t->dir = PATH_DOT;
- } else
- *t->name++ = ' ';
- if (mode == 0)
- mode = __db_omode("rwrw--");
- t->mode = mode;
- }
- if (name == NULL && t->page_ext != 0) {
- __db_err(dbenv,
- "Extent size may not be specified for in-memory queue database");
- return (EINVAL);
- }
- t->re_pad = qmeta->re_pad;
- t->re_len = qmeta->re_len;
- t->rec_page = qmeta->rec_page;
- t->q_meta = base_pgno;
- t->q_root = base_pgno + 1;
- err: if (qmeta != NULL && (t_ret = mpf->put(mpf, qmeta, 0)) != 0 && ret == 0)
- ret = t_ret;
- /* Don't hold the meta page long term. */
- (void)__LPUT(dbc, metalock);
- if ((t_ret = dbc->c_close(dbc)) != 0 && ret == 0)
- ret = t_ret;
- return (ret);
- }
- /*
- * __qam_metachk --
- *
- * PUBLIC: int __qam_metachk __P((DB *, const char *, QMETA *));
- */
- int
- __qam_metachk(dbp, name, qmeta)
- DB *dbp;
- const char *name;
- QMETA *qmeta;
- {
- DB_ENV *dbenv;
- u_int32_t vers;
- int ret;
- dbenv = dbp->dbenv;
- ret = 0;
- /*
- * At this point, all we know is that the magic number is for a Queue.
- * Check the version, the database may be out of date.
- */
- vers = qmeta->dbmeta.version;
- if (F_ISSET(dbp, DB_AM_SWAP))
- M_32_SWAP(vers);
- switch (vers) {
- case 1:
- case 2:
- __db_err(dbenv,
- "%s: queue version %lu requires a version upgrade",
- name, (u_long)vers);
- return (DB_OLD_VERSION);
- case 3:
- case 4:
- break;
- default:
- __db_err(dbenv,
- "%s: unsupported qam version: %lu", name, (u_long)vers);
- return (EINVAL);
- }
- /* Swap the page if we need to. */
- if (F_ISSET(dbp, DB_AM_SWAP) && (ret = __qam_mswap((PAGE *)qmeta)) != 0)
- return (ret);
- /* Check the type. */
- if (dbp->type != DB_QUEUE && dbp->type != DB_UNKNOWN)
- return (EINVAL);
- dbp->type = DB_QUEUE;
- DB_ILLEGAL_METHOD(dbp, DB_OK_QUEUE);
- /* Set the page size. */
- dbp->pgsize = qmeta->dbmeta.pagesize;
- /* Copy the file's ID. */
- memcpy(dbp->fileid, qmeta->dbmeta.uid, DB_FILE_ID_LEN);
- /* Set up AM-specific methods that do not require an open. */
- dbp->db_am_rename = __qam_rename;
- dbp->db_am_remove = __qam_remove;
- return (ret);
- }
- /*
- * __qam_init_meta --
- * Initialize the meta-data for a Queue database.
- */
- static int
- __qam_init_meta(dbp, meta)
- DB *dbp;
- QMETA *meta;
- {
- QUEUE *t;
- t = dbp->q_internal;
- memset(meta, 0, sizeof(QMETA));
- LSN_NOT_LOGGED(meta->dbmeta.lsn);
- meta->dbmeta.pgno = PGNO_BASE_MD;
- meta->dbmeta.last_pgno = 0;
- meta->dbmeta.magic = DB_QAMMAGIC;
- meta->dbmeta.version = DB_QAMVERSION;
- meta->dbmeta.pagesize = dbp->pgsize;
- if (F_ISSET(dbp, DB_AM_CHKSUM))
- FLD_SET(meta->dbmeta.metaflags, DBMETA_CHKSUM);
- if (F_ISSET(dbp, DB_AM_ENCRYPT)) {
- meta->dbmeta.encrypt_alg =
- ((DB_CIPHER *)dbp->dbenv->crypto_handle)->alg;
- DB_ASSERT(meta->dbmeta.encrypt_alg != 0);
- meta->crypto_magic = meta->dbmeta.magic;
- }
- meta->dbmeta.type = P_QAMMETA;
- meta->re_pad = t->re_pad;
- meta->re_len = t->re_len;
- meta->rec_page = CALC_QAM_RECNO_PER_PAGE(dbp);
- meta->cur_recno = 1;
- meta->first_recno = 1;
- meta->page_ext = t->page_ext;
- t->rec_page = meta->rec_page;
- memcpy(meta->dbmeta.uid, dbp->fileid, DB_FILE_ID_LEN);
- /* Verify that we can fit at least one record per page. */
- if (QAM_RECNO_PER_PAGE(dbp) < 1) {
- __db_err(dbp->dbenv,
- "Record size of %lu too large for page size of %lu",
- (u_long)t->re_len, (u_long)dbp->pgsize);
- return (EINVAL);
- }
- return (0);
- }
- /*
- * __qam_new_file --
- * Create the necessary pages to begin a new queue database file.
- *
- * This code appears more complex than it is because of the two cases (named
- * and unnamed). The way to read the code is that for each page being created,
- * there are three parts: 1) a "get page" chunk (which either uses malloc'd
- * memory or calls mpf->get), 2) the initialization, and 3) the "put page"
- * chunk which either does a fop write or an mpf->put.
- *
- * PUBLIC: int __qam_new_file __P((DB *, DB_TXN *, DB_FH *, const char *));
- */
- int
- __qam_new_file(dbp, txn, fhp, name)
- DB *dbp;
- DB_TXN *txn;
- DB_FH *fhp;
- const char *name;
- {
- QMETA *meta;
- DB_ENV *dbenv;
- DB_MPOOLFILE *mpf;
- DB_PGINFO pginfo;
- DBT pdbt;
- db_pgno_t pgno;
- int ret;
- void *buf;
- dbenv = dbp->dbenv;
- mpf = dbp->mpf;
- buf = NULL;
- meta = NULL;
- /* Build meta-data page. */
- if (name == NULL) {
- pgno = PGNO_BASE_MD;
- ret = mpf->get(mpf, &pgno, DB_MPOOL_CREATE, &meta);
- } else {
- ret = __os_calloc(dbp->dbenv, 1, dbp->pgsize, &buf);
- meta = (QMETA *)buf;
- }
- if (ret != 0)
- return (ret);
- if ((ret = __qam_init_meta(dbp, meta)) != 0)
- goto err;
- if (name == NULL)
- ret = mpf->put(mpf, meta, DB_MPOOL_DIRTY);
- else {
- pginfo.db_pagesize = dbp->pgsize;
- pginfo.flags =
- F_ISSET(dbp, (DB_AM_CHKSUM | DB_AM_ENCRYPT | DB_AM_SWAP));
- pginfo.type = DB_QUEUE;
- pdbt.data = &pginfo;
- pdbt.size = sizeof(pginfo);
- if ((ret = __db_pgout(dbenv, PGNO_BASE_MD, meta, &pdbt)) != 0)
- goto err;
- ret = __fop_write(dbenv,
- txn, name, DB_APP_DATA, fhp, 0, buf, dbp->pgsize, 1);
- }
- if (ret != 0)
- goto err;
- meta = NULL;
- err: if (name != NULL)
- __os_free(dbenv, buf);
- else if (meta != NULL)
- (void)mpf->put(mpf, meta, 0);
- return (ret);
- }