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Diffstat (limited to 'db2/db/db_dispatch.c')
| -rw-r--r-- | db2/db/db_dispatch.c | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/db2/db/db_dispatch.c b/db2/db/db_dispatch.c new file mode 100644 index 0000000000..3d7b162d75 --- /dev/null +++ b/db2/db/db_dispatch.c @@ -0,0 +1,270 @@ +/*- + * See the file LICENSE for redistribution information. + * + * Copyright (c) 1996, 1997 + * Sleepycat Software. All rights reserved. + */ +/* + * Copyright (c) 1995, 1996 + * The President and Fellows of Harvard University. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Margo Seltzer. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include "config.h" + +#ifndef lint +static const char sccsid[] = "@(#)db_dispatch.c 10.5 (Sleepycat) 7/2/97"; +#endif /* not lint */ + +#ifndef NO_SYSTEM_INCLUDES +#include <sys/types.h> + +#include <errno.h> +#include <fcntl.h> +#include <stddef.h> +#include <stdlib.h> +#include <string.h> +#endif + +#include "db_int.h" +#include "db_page.h" +#include "db_dispatch.h" +#include "db_am.h" +#include "common_ext.h" + +/* + * Data structures to manage the DB dispatch table. The dispatch table + * is a dynamically allocated array of pointers to dispatch functions. + * The dispatch_size is the number of entries possible in the current + * dispatch table and the dispatch_valid is the number of valid entries + * in the dispatch table. + */ +static int (**dispatch_table) __P((DB_LOG *, DBT *, DB_LSN *, int, void *)); +static u_int32_t dispatch_size = 0; + +/* + * __db_dispatch -- + * + * This is the transaction dispatch function used by the db access methods. + * It is designed to handle the record format used by all the access + * methods (the one automatically generated by the db_{h,log,read}.sh + * scripts in the tools directory). An application using a different + * recovery paradigm will supply a different dispatch function to txn_open. + * + * PUBLIC: int __db_dispatch __P((DB_LOG *, DBT *, DB_LSN *, int, void *)); + */ +int +__db_dispatch(logp, db, lsnp, redo, info) + DB_LOG *logp; /* The log file. */ + DBT *db; /* The log record upon which to dispatch. */ + DB_LSN *lsnp; /* The lsn of the record being dispatched. */ + int redo; /* Redo this op (or undo it). */ + void *info; +{ + u_int32_t rectype, txnid; + + memcpy(&rectype, db->data, sizeof(rectype)); + memcpy(&txnid, (u_int8_t *)db->data + sizeof(rectype), sizeof(txnid)); + + switch (redo) { + case TXN_REDO: + case TXN_UNDO: + return ((dispatch_table[rectype])(logp, db, lsnp, redo, info)); + case TXN_OPENFILES: + if (rectype < DB_txn_BEGIN ) + return ((dispatch_table[rectype])(logp, + db, lsnp, redo, info)); + break; + case TXN_BACKWARD_ROLL: + /* + * Running full recovery in the backward pass. If we've + * seen this txnid before and added to it our commit list, + * then we do nothing during this pass. If we've never + * seen it, then we call the appropriate recovery routine + * in "abort mode". + */ + if (__db_txnlist_find(info, txnid) == DB_NOTFOUND) + return ((dispatch_table[rectype])(logp, + db, lsnp, TXN_UNDO, info)); + break; + case TXN_FORWARD_ROLL: + /* + * In the forward pass, if we haven't seen the transaction, + * do nothing, else recovery it. + */ + if (__db_txnlist_find(info, txnid) != DB_NOTFOUND) + return ((dispatch_table[rectype])(logp, + db, lsnp, TXN_REDO, info)); + break; + default: + abort(); + } + return (0); +} + +/* + * __db_add_recovery -- + * + * PUBLIC: int __db_add_recovery __P((DB_ENV *, + * PUBLIC: int (*)(DB_LOG *, DBT *, DB_LSN *, int, void *), u_int32_t)); + */ +int +__db_add_recovery(dbenv, func, ndx) + DB_ENV *dbenv; + int (*func) __P((DB_LOG *, DBT *, DB_LSN *, int, void *)); + u_int32_t ndx; +{ + u_int32_t i; + + /* Check if function is already registered. */ + if (dispatch_table && ndx < dispatch_size && + dispatch_table[ndx] != 0 && dispatch_table[ndx] != func) + return (DB_REGISTERED); + + /* Check if we have to grow the table. */ + if (ndx >= dispatch_size) { + if (dispatch_table == NULL) + dispatch_table = (int (**) + __P((DB_LOG *, DBT *, DB_LSN *, int, void *))) + malloc(DB_user_BEGIN * sizeof(dispatch_table[0])); + else + dispatch_table = (int (**) + __P((DB_LOG *, DBT *, DB_LSN *, int, void *))) + realloc(dispatch_table, (DB_user_BEGIN + + dispatch_size) * sizeof(dispatch_table[0])); + if (dispatch_table == NULL) { + __db_err(dbenv, "%s", strerror(ENOMEM)); + return (ENOMEM); + } + for (i = dispatch_size, + dispatch_size += DB_user_BEGIN; i < dispatch_size; ++i) + dispatch_table[i] = NULL; + } + + dispatch_table[ndx] = func; + return (0); +} + +/* + * __db_txnlist_init -- + * Initialize transaction linked list. + * + * PUBLIC: int __db_txnlist_init __P((void *)); + */ +int +__db_txnlist_init(retp) + void *retp; +{ + __db_txnhead *headp; + + if ((headp = + (struct __db_txnhead *)malloc(sizeof(struct __db_txnhead))) == NULL) + return (ENOMEM); + + LIST_INIT(&headp->head); + headp->maxid = 0; + + *(void **)retp = headp; + return (0); +} + +/* + * __db_txnlist_add -- + * Add an element to our transaction linked list. + * + * PUBLIC: int __db_txnlist_add __P((void *, u_int32_t)); + */ +int +__db_txnlist_add(listp, txnid) + void *listp; + u_int32_t txnid; +{ + __db_txnhead *hp; + __db_txnlist *elp; + + if ((elp = (__db_txnlist *)malloc(sizeof(__db_txnlist))) == NULL) + return (ENOMEM); + + elp->txnid = txnid; + hp = (struct __db_txnhead *)listp; + LIST_INSERT_HEAD(&hp->head, elp, links); + if (txnid > hp->maxid) + hp->maxid = txnid; + + return (0); +} + +/* + * __db_txnlist_find -- + * Checks to see if txnid is in the txnid list, returns 1 if found, + * 0 if not found. + * + * PUBLIC: int __db_txnlist_find __P((void *, u_int32_t)); + */ +int +__db_txnlist_find(listp, txnid) + void *listp; + u_int32_t txnid; +{ + __db_txnlist *p; + __db_txnhead *hp; + + if ((hp = (struct __db_txnhead *)listp) == NULL) + return (DB_NOTFOUND); + + if (hp->maxid < txnid) { + hp->maxid = txnid; + return (DB_NOTFOUND); + } + + for (p = hp->head.lh_first; p != NULL; p = p->links.le_next) + if (p->txnid == txnid) + return (0); + + return (DB_NOTFOUND); +} + +#ifdef DEBUG +void +__db_txnlist_print(listp) + void *listp; +{ + __db_txnlist *p; + __db_txnhead *hp; + + hp = (struct __db_txnhead *)listp; + printf("Maxid: %lu\n", (u_long)hp->maxid); + for (p = hp->head.lh_first; p != NULL; p = p->links.le_next) + printf("TXNID: %lu\n", (u_long)p->txnid); +} +#endif |