diff options
Diffstat (limited to 'db2/db/db_am.c')
| -rw-r--r-- | db2/db/db_am.c | 430 |
1 files changed, 430 insertions, 0 deletions
diff --git a/db2/db/db_am.c b/db2/db/db_am.c new file mode 100644 index 0000000000..e02ad57f53 --- /dev/null +++ b/db2/db/db_am.c @@ -0,0 +1,430 @@ +/*- + * See the file LICENSE for redistribution information. + * + * Copyright (c) 1998 + * Sleepycat Software. All rights reserved. + */ + +#include "config.h" + +#ifndef lint +static const char sccsid[] = "@(#)db_am.c 10.15 (Sleepycat) 12/30/98"; +#endif /* not lint */ + +#ifndef NO_SYSTEM_INCLUDES +#include <sys/types.h> + +#include <errno.h> +#include <stdlib.h> +#include <string.h> +#endif + +#include "db_int.h" +#include "shqueue.h" +#include "db_page.h" +#include "db_shash.h" +#include "mp.h" +#include "btree.h" +#include "hash.h" +#include "db_am.h" +#include "db_ext.h" + +static int __db_c_close __P((DBC *)); +static int __db_cursor __P((DB *, DB_TXN *, DBC **, u_int32_t)); +static int __db_fd __P((DB *, int *)); +static int __db_get __P((DB *, DB_TXN *, DBT *, DBT *, u_int32_t)); +static int __db_put __P((DB *, DB_TXN *, DBT *, DBT *, u_int32_t)); + +/* + * __db_init_wrapper -- + * Wrapper layer to implement generic DB functions. + * + * PUBLIC: int __db_init_wrapper __P((DB *)); + */ +int +__db_init_wrapper(dbp) + DB *dbp; +{ + dbp->close = __db_close; + dbp->cursor = __db_cursor; + dbp->del = NULL; /* !!! Must be set by access method. */ + dbp->fd = __db_fd; + dbp->get = __db_get; + dbp->join = __db_join; + dbp->put = __db_put; + dbp->stat = NULL; /* !!! Must be set by access method. */ + dbp->sync = __db_sync; + + return (0); +} + +/* + * __db_cursor -- + * Allocate and return a cursor. + */ +static int +__db_cursor(dbp, txn, dbcp, flags) + DB *dbp; + DB_TXN *txn; + DBC **dbcp; + u_int32_t flags; +{ + DBC *dbc, *adbc; + int ret; + db_lockmode_t mode; + u_int32_t op; + + DB_PANIC_CHECK(dbp); + + /* Take one from the free list if it's available. */ + DB_THREAD_LOCK(dbp); + if ((dbc = TAILQ_FIRST(&dbp->free_queue)) != NULL) + TAILQ_REMOVE(&dbp->free_queue, dbc, links); + else { + DB_THREAD_UNLOCK(dbp); + + if ((ret = __os_calloc(1, sizeof(DBC), &dbc)) != 0) + return (ret); + + dbc->dbp = dbp; + dbc->c_close = __db_c_close; + + /* Set up locking information. */ + if (F_ISSET(dbp, DB_AM_LOCKING | DB_AM_CDB)) { + /* + * If we are not threaded, then there is no need to + * create new locker ids. We know that no one else + * is running concurrently using this DB, so we can + * take a peek at any cursors on the active queue. + */ + if (!F_ISSET(dbp, DB_AM_THREAD) && + (adbc = TAILQ_FIRST(&dbp->active_queue)) != NULL) + dbc->lid = adbc->lid; + else + if ((ret = lock_id(dbp->dbenv->lk_info, + &dbc->lid)) != 0) + goto err; + + memcpy(dbc->lock.fileid, dbp->fileid, DB_FILE_ID_LEN); + if (F_ISSET(dbp, DB_AM_CDB)) { + dbc->lock_dbt.size = DB_FILE_ID_LEN; + dbc->lock_dbt.data = dbc->lock.fileid; + } else { + dbc->lock_dbt.size = sizeof(dbc->lock); + dbc->lock_dbt.data = &dbc->lock; + } + } + + switch (dbp->type) { + case DB_BTREE: + case DB_RECNO: + if ((ret = __bam_c_init(dbc)) != 0) + goto err; + break; + case DB_HASH: + if ((ret = __ham_c_init(dbc)) != 0) + goto err; + break; + default: + ret = EINVAL; + goto err; + } + + DB_THREAD_LOCK(dbp); + } + + if ((dbc->txn = txn) == NULL) + dbc->locker = dbc->lid; + else + dbc->locker = txn->txnid; + + TAILQ_INSERT_TAIL(&dbp->active_queue, dbc, links); + DB_THREAD_UNLOCK(dbp); + + /* + * If this is the concurrent DB product, then we do all locking + * in the interface, which is right here. + */ + if (F_ISSET(dbp, DB_AM_CDB)) { + op = LF_ISSET(DB_OPFLAGS_MASK); + mode = (op == DB_WRITELOCK) ? DB_LOCK_WRITE : + (LF_ISSET(DB_RMW) ? DB_LOCK_IWRITE : DB_LOCK_READ); + if ((ret = lock_get(dbp->dbenv->lk_info, dbc->locker, 0, + &dbc->lock_dbt, mode, &dbc->mylock)) != 0) { + (void)__db_c_close(dbc); + return (EAGAIN); + } + if (LF_ISSET(DB_RMW)) + F_SET(dbc, DBC_RMW); + if (op == DB_WRITELOCK) + F_SET(dbc, DBC_WRITER); + } + + *dbcp = dbc; + return (0); + +err: __os_free(dbc, sizeof(*dbc)); + return (ret); +} + +/* + * __db_c_close -- + * Close the cursor (recycle for later use). + */ +static int +__db_c_close(dbc) + DBC *dbc; +{ + DB *dbp; + int ret, t_ret; + + dbp = dbc->dbp; + + DB_PANIC_CHECK(dbp); + + ret = 0; + + /* + * We cannot release the lock until after we've called the + * access method specific routine, since btrees may have pending + * deletes. + */ + + /* Remove the cursor from the active queue. */ + DB_THREAD_LOCK(dbp); + TAILQ_REMOVE(&dbp->active_queue, dbc, links); + DB_THREAD_UNLOCK(dbp); + + /* Call the access specific cursor close routine. */ + if ((t_ret = dbc->c_am_close(dbc)) != 0 && ret == 0) + t_ret = ret; + + /* Release the lock. */ + if (F_ISSET(dbc->dbp, DB_AM_CDB) && dbc->mylock != LOCK_INVALID) { + ret = lock_put(dbc->dbp->dbenv->lk_info, dbc->mylock); + dbc->mylock = LOCK_INVALID; + } + + /* Clean up the cursor. */ + dbc->flags = 0; + +#ifdef DEBUG + /* + * Check for leftover locks, unless we're running with transactions. + * + * If we're running tests, display any locks currently held. It's + * possible that some applications may hold locks for long periods, + * e.g., conference room locks, but the DB tests should never close + * holding locks. + */ + if (F_ISSET(dbp, DB_AM_LOCKING) && dbc->lid == dbc->locker) { + DB_LOCKREQ request; + + request.op = DB_LOCK_DUMP; + if ((t_ret = lock_vec(dbp->dbenv->lk_info, + dbc->locker, 0, &request, 1, NULL)) != 0 && ret == 0) + ret = EAGAIN; + } +#endif + /* Move the cursor to the free queue. */ + DB_THREAD_LOCK(dbp); + TAILQ_INSERT_TAIL(&dbp->free_queue, dbc, links); + DB_THREAD_UNLOCK(dbp); + + return (ret); +} + +#ifdef DEBUG +/* + * __db_cprint -- + * Display the current cursor list. + * + * PUBLIC: int __db_cprint __P((DB *)); + */ +int +__db_cprint(dbp) + DB *dbp; +{ + static const FN fn[] = { + { DBC_RECOVER, "recover" }, + { DBC_RMW, "read-modify-write" }, + { 0 }, + }; + DBC *dbc; + + DB_THREAD_LOCK(dbp); + for (dbc = TAILQ_FIRST(&dbp->active_queue); + dbc != NULL; dbc = TAILQ_NEXT(dbc, links)) { + fprintf(stderr, + "%#0x: dbp: %#0x txn: %#0x lid: %lu locker: %lu", + (u_int)dbc, (u_int)dbc->dbp, (u_int)dbc->txn, + (u_long)dbc->lid, (u_long)dbc->locker); + __db_prflags(dbc->flags, fn, stderr); + fprintf(stderr, "\n"); + } + DB_THREAD_UNLOCK(dbp); + + return (0); +} +#endif /* DEBUG */ + +/* + * __db_c_destroy -- + * Destroy the cursor. + * + * PUBLIC: int __db_c_destroy __P((DBC *)); + */ +int +__db_c_destroy(dbc) + DBC *dbc; +{ + DB *dbp; + int ret; + + dbp = dbc->dbp; + + /* Remove the cursor from the free queue. */ + DB_THREAD_LOCK(dbp); + TAILQ_REMOVE(&dbp->free_queue, dbc, links); + DB_THREAD_UNLOCK(dbp); + + /* Call the access specific cursor destroy routine. */ + ret = dbc->c_am_destroy == NULL ? 0 : dbc->c_am_destroy(dbc); + + /* Free up allocated memory. */ + if (dbc->rkey.data != NULL) + __os_free(dbc->rkey.data, dbc->rkey.ulen); + if (dbc->rdata.data != NULL) + __os_free(dbc->rdata.data, dbc->rdata.ulen); + __os_free(dbc, sizeof(*dbc)); + + return (0); +} + +/* + * db_fd -- + * Return a file descriptor for flock'ing. + */ +static int +__db_fd(dbp, fdp) + DB *dbp; + int *fdp; +{ + DB_PANIC_CHECK(dbp); + + /* + * XXX + * Truly spectacular layering violation. + */ + return (__mp_xxx_fd(dbp->mpf, fdp)); +} + +/* + * __db_get -- + * Return a key/data pair. + */ +static int +__db_get(dbp, txn, key, data, flags) + DB *dbp; + DB_TXN *txn; + DBT *key, *data; + u_int32_t flags; +{ + DBC *dbc; + int ret, t_ret; + + DB_PANIC_CHECK(dbp); + + if ((ret = __db_getchk(dbp, key, data, flags)) != 0) + return (ret); + + if ((ret = dbp->cursor(dbp, txn, &dbc, 0)) != 0) + return (ret); + + DEBUG_LREAD(dbc, txn, "__db_get", key, NULL, flags); + + ret = dbc->c_get(dbc, key, data, + flags == 0 || flags == DB_RMW ? flags | DB_SET : flags); + + if ((t_ret = __db_c_close(dbc)) != 0 && ret == 0) + ret = t_ret; + + return (ret); +} + +/* + * __db_put -- + * Store a key/data pair. + */ +static int +__db_put(dbp, txn, key, data, flags) + DB *dbp; + DB_TXN *txn; + DBT *key, *data; + u_int32_t flags; +{ + DBC *dbc; + DBT tdata; + int ret, t_ret; + + DB_PANIC_CHECK(dbp); + + if ((ret = __db_putchk(dbp, key, data, + flags, F_ISSET(dbp, DB_AM_RDONLY), F_ISSET(dbp, DB_AM_DUP))) != 0) + return (ret); + + if ((ret = dbp->cursor(dbp, txn, &dbc, DB_WRITELOCK)) != 0) + return (ret); + + DEBUG_LWRITE(dbc, txn, "__db_put", key, data, flags); + + if (flags == DB_NOOVERWRITE) { + /* + * Set DB_DBT_USERMEM, this might be a threaded application and + * the flags checking will catch us. We don't want the actual + * data, so request a partial of length 0. + */ + memset(&tdata, 0, sizeof(tdata)); + F_SET(&tdata, DB_DBT_USERMEM | DB_DBT_PARTIAL); + if ((ret = dbc->c_get(dbc, key, &tdata, DB_SET | DB_RMW)) == 0) + ret = DB_KEYEXIST; + else + ret = 0; + } + if (ret == 0) + ret = dbc->c_put(dbc, key, data, DB_KEYLAST); + + if ((t_ret = __db_c_close(dbc)) != 0 && ret == 0) + ret = t_ret; + + return (ret); +} + +/* + * __db_sync -- + * Flush the database cache. + * + * PUBLIC: int __db_sync __P((DB *, u_int32_t)); + */ +int +__db_sync(dbp, flags) + DB *dbp; + u_int32_t flags; +{ + int ret; + + DB_PANIC_CHECK(dbp); + + if ((ret = __db_syncchk(dbp, flags)) != 0) + return (ret); + + /* If it wasn't possible to modify the file, we're done. */ + if (F_ISSET(dbp, DB_AM_INMEM | DB_AM_RDONLY)) + return (0); + + /* Flush any dirty pages from the cache to the backing file. */ + if ((ret = memp_fsync(dbp->mpf)) == DB_INCOMPLETE) + ret = 0; + + return (ret); +} |