db_reclaim.c
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上传日期:2022-05-23
资源大小:18897k
文件大小:6k
- /*-
- * See the file LICENSE for redistribution information.
- *
- * Copyright (c) 1996-2002
- * Sleepycat Software. All rights reserved.
- */
- #include "db_config.h"
- #ifndef lint
- static const char revid[] = "$Id: db_reclaim.c,v 11.28 2002/08/06 06:11:17 bostic Exp $";
- #endif /* not lint */
- #ifndef NO_SYSTEM_INCLUDES
- #include <sys/types.h>
- #include <string.h>
- #endif
- #include "db_int.h"
- #include "dbinc/db_page.h"
- #include "dbinc/db_shash.h"
- #include "dbinc/btree.h"
- #include "dbinc/lock.h"
- /*
- * __db_traverse_big
- * Traverse a chain of overflow pages and call the callback routine
- * on each one. The calling convention for the callback is:
- * callback(dbp, page, cookie, did_put),
- * where did_put is a return value indicating if the page in question has
- * already been returned to the mpool.
- *
- * PUBLIC: int __db_traverse_big __P((DB *,
- * PUBLIC: db_pgno_t, int (*)(DB *, PAGE *, void *, int *), void *));
- */
- int
- __db_traverse_big(dbp, pgno, callback, cookie)
- DB *dbp;
- db_pgno_t pgno;
- int (*callback) __P((DB *, PAGE *, void *, int *));
- void *cookie;
- {
- DB_MPOOLFILE *mpf;
- PAGE *p;
- int did_put, ret;
- mpf = dbp->mpf;
- do {
- did_put = 0;
- if ((ret = mpf->get(mpf, &pgno, 0, &p)) != 0)
- return (ret);
- pgno = NEXT_PGNO(p);
- if ((ret = callback(dbp, p, cookie, &did_put)) == 0 &&
- !did_put)
- ret = mpf->put(mpf, p, 0);
- } while (ret == 0 && pgno != PGNO_INVALID);
- return (ret);
- }
- /*
- * __db_reclaim_callback
- * This is the callback routine used during a delete of a subdatabase.
- * we are traversing a btree or hash table and trying to free all the
- * pages. Since they share common code for duplicates and overflow
- * items, we traverse them identically and use this routine to do the
- * actual free. The reason that this is callback is because hash uses
- * the same traversal code for statistics gathering.
- *
- * PUBLIC: int __db_reclaim_callback __P((DB *, PAGE *, void *, int *));
- */
- int
- __db_reclaim_callback(dbp, p, cookie, putp)
- DB *dbp;
- PAGE *p;
- void *cookie;
- int *putp;
- {
- int ret;
- COMPQUIET(dbp, NULL);
- if ((ret = __db_free(cookie, p)) != 0)
- return (ret);
- *putp = 1;
- return (0);
- }
- /*
- * __db_truncate_callback
- * This is the callback routine used during a truncate.
- * we are traversing a btree or hash table and trying to free all the
- * pages.
- *
- * PUBLIC: int __db_truncate_callback __P((DB *, PAGE *, void *, int *));
- */
- int
- __db_truncate_callback(dbp, p, cookie, putp)
- DB *dbp;
- PAGE *p;
- void *cookie;
- int *putp;
- {
- DBMETA *meta;
- DBT ldbt;
- DB_LOCK metalock;
- DB_MPOOLFILE *mpf;
- db_indx_t indx, len, off, tlen, top;
- db_pgno_t pgno;
- db_trunc_param *param;
- u_int8_t *hk, type;
- int ret;
- top = NUM_ENT(p);
- mpf = dbp->mpf;
- param = cookie;
- *putp = 1;
- switch (TYPE(p)) {
- case P_LBTREE:
- /* Skip for off-page duplicates and deleted items. */
- for (indx = 0; indx < top; indx += P_INDX) {
- type = GET_BKEYDATA(dbp, p, indx + O_INDX)->type;
- if (!B_DISSET(type) && B_TYPE(type) != B_DUPLICATE)
- ++param->count;
- }
- /* FALLTHROUGH */
- case P_IBTREE:
- case P_IRECNO:
- case P_INVALID:
- if (dbp->type != DB_HASH &&
- ((BTREE *)dbp->bt_internal)->bt_root == PGNO(p)) {
- type = dbp->type == DB_RECNO ? P_LRECNO : P_LBTREE;
- goto reinit;
- }
- break;
- case P_OVERFLOW:
- if (DBC_LOGGING(param->dbc)) {
- if ((ret = __db_ovref_log(dbp, param->dbc->txn,
- &LSN(p), 0, p->pgno, -1, &LSN(p))) != 0)
- return (ret);
- } else
- LSN_NOT_LOGGED(LSN(p));
- if (--OV_REF(p) != 0)
- *putp = 0;
- break;
- case P_LRECNO:
- param->count += top;
- if (((BTREE *)dbp->bt_internal)->bt_root == PGNO(p)) {
- type = P_LRECNO;
- goto reinit;
- }
- break;
- case P_LDUP:
- /* Correct for deleted items. */
- for (indx = 0; indx < top; indx += O_INDX)
- if (!B_DISSET(GET_BKEYDATA(dbp, p, indx)->type))
- ++param->count;
- break;
- case P_HASH:
- /* Correct for on-page duplicates and deleted items. */
- for (indx = 0; indx < top; indx += P_INDX) {
- switch (*H_PAIRDATA(dbp, p, indx)) {
- case H_OFFDUP:
- case H_OFFPAGE:
- break;
- case H_KEYDATA:
- ++param->count;
- break;
- case H_DUPLICATE:
- tlen = LEN_HDATA(dbp, p, 0, indx);
- hk = H_PAIRDATA(dbp, p, indx);
- for (off = 0; off < tlen;
- off += len + 2 * sizeof (db_indx_t)) {
- ++param->count;
- memcpy(&len,
- HKEYDATA_DATA(hk)
- + off, sizeof(db_indx_t));
- }
- }
- }
- /* Don't free the head of the bucket. */
- if (PREV_PGNO(p) == PGNO_INVALID) {
- type = P_HASH;
- reinit: *putp = 0;
- if (DBC_LOGGING(param->dbc)) {
- pgno = PGNO_BASE_MD;
- if ((ret = __db_lget(param->dbc, LCK_ALWAYS,
- pgno, DB_LOCK_WRITE, 0, &metalock)) != 0)
- return (ret);
- if ((ret = mpf->get(mpf,
- &pgno, 0, (PAGE **)&meta)) != 0) {
- goto err;
- }
- memset(&ldbt, 0, sizeof(ldbt));
- ldbt.data = p;
- ldbt.size = P_OVERHEAD(dbp);
- if ((ret = __db_pg_free_log(dbp,
- param->dbc->txn, &LSN(meta), 0,
- p->pgno, &LSN(meta),
- PGNO_BASE_MD, &ldbt, meta->free)) != 0)
- goto err;
- LSN(p) = LSN(meta);
- if ((ret =
- __db_pg_alloc_log(dbp,
- param->dbc->txn, &LSN(meta), 0,
- &LSN(meta), PGNO_BASE_MD,
- &p->lsn, p->pgno, type, meta->free)) != 0) {
- err: (void)mpf->put(mpf, (PAGE *)meta, 0);
- (void)__TLPUT(param->dbc, metalock);
- return (ret);
- }
- LSN(p) = LSN(meta);
- if ((ret = mpf->put(mpf,
- (PAGE *)meta, DB_MPOOL_DIRTY)) != 0) {
- (void)__TLPUT(param->dbc, metalock);
- return (ret);
- }
- if ((ret = __TLPUT(param->dbc, metalock)) != 0)
- return (ret);
- } else
- LSN_NOT_LOGGED(LSN(p));
- P_INIT(p, dbp->pgsize, PGNO(p), PGNO_INVALID,
- PGNO_INVALID, type == P_HASH ? 0 : 1, type);
- }
- break;
- default:
- return (__db_pgfmt(dbp->dbenv, p->pgno));
- }
- if (*putp == 1) {
- if ((ret = __db_free(param->dbc, p)) != 0)
- return (ret);
- } else {
- if ((ret = mpf->put(mpf, p, DB_MPOOL_DIRTY)) != 0)
- return (ret);
- *putp = 1;
- }
- return (0);
- }