bt_rec.c

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

/*-
 * 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: bt_rec.c,v 11.57 2002/08/06 16:53:53 ubell 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"
#include "dbinc/log.h"

#define	IS_BTREE_PAGE(pagep)						\
	(TYPE(pagep) == P_IBTREE ||					\
	 TYPE(pagep) == P_LBTREE || TYPE(pagep) == P_LDUP)

/*
 * __bam_split_recover --
 *	Recovery function for split.
 *
 * PUBLIC: int __bam_split_recover
 * PUBLIC:   __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__bam_split_recover(dbenv, dbtp, lsnp, op, info)
	DB_ENV *dbenv;
	DBT *dbtp;
	DB_LSN *lsnp;
	db_recops op;
	void *info;
{
	__bam_split_args *argp;
	DB *file_dbp;
	DBC *dbc;
	DB_MPOOLFILE *mpf;
	PAGE *_lp, *lp, *np, *pp, *_rp, *rp, *sp;
	db_pgno_t pgno, root_pgno;
	u_int32_t ptype;
	int cmp, l_update, p_update, r_update, rc, ret, ret_l, rootsplit, t_ret;

	COMPQUIET(info, NULL);
	REC_PRINT(__bam_split_print);

	mpf = NULL;
	_lp = lp = np = pp = _rp = rp = NULL;
	sp = NULL;

	REC_INTRO(__bam_split_read, 1);

	/*
	 * There are two kinds of splits that we have to recover from.  The
	 * first is a root-page split, where the root page is split from a
	 * leaf page into an internal page and two new leaf pages are created.
	 * The second is where a page is split into two pages, and a new key
	 * is inserted into the parent page.
	 *
	 * DBTs are not aligned in log records, so we need to copy the page
	 * so that we can access fields within it throughout this routine.
	 * Although we could hardcode the unaligned copies in this routine,
	 * we will be calling into regular btree functions with this page,
	 * so it's got to be aligned.  Copying it into allocated memory is
	 * the only way to guarantee this.
	 */
	if ((ret = __os_malloc(dbenv, argp->pg.size, &sp)) != 0)
		goto out;
	memcpy(sp, argp->pg.data, argp->pg.size);

	pgno = PGNO(sp);
	root_pgno = argp->root_pgno;
	rootsplit = root_pgno != PGNO_INVALID;
	if ((ret_l = mpf->get(mpf, &argp->left, 0, &lp)) != 0)
		lp = NULL;
	if (mpf->get(mpf, &argp->right, 0, &rp) != 0)
		rp = NULL;

	if (DB_REDO(op)) {
		l_update = r_update = p_update = 0;
		/*
		 * Decide if we need to resplit the page.
		 *
		 * If this is a root split, then the root has to exist, it's
		 * the page we're splitting and it gets modified.  If this is
		 * not a root split, then the left page has to exist, for the
		 * same reason.
		 */
		if (rootsplit) {
			if ((ret = mpf->get(mpf, &pgno, 0, &pp)) != 0) {
				__db_pgerr(file_dbp, pgno, ret);
				pp = NULL;
				goto out;
			}
			cmp = log_compare(&LSN(pp), &LSN(argp->pg.data));
			CHECK_LSN(op, cmp, &LSN(pp), &LSN(argp->pg.data));
			p_update = cmp  == 0;
		} else if (lp == NULL) {
			__db_pgerr(file_dbp, argp->left, ret_l);
			goto out;
		}

		if (lp != NULL) {
			cmp = log_compare(&LSN(lp), &argp->llsn);
			CHECK_LSN(op, cmp, &LSN(lp), &argp->llsn);
			if (cmp == 0)
				l_update = 1;
		} else
			l_update = 1;

		if (rp != NULL) {
			cmp = log_compare(&LSN(rp), &argp->rlsn);
			CHECK_LSN(op, cmp, &LSN(rp), &argp->rlsn);
			if (cmp == 0)
				r_update = 1;
		} else
			r_update = 1;
		if (!p_update && !l_update && !r_update)
			goto check_next;

		/* Allocate and initialize new left/right child pages. */
		if ((ret = __os_malloc(dbenv, file_dbp->pgsize, &_lp)) != 0 ||
		    (ret = __os_malloc(dbenv, file_dbp->pgsize, &_rp)) != 0)
			goto out;
		if (rootsplit) {
			P_INIT(_lp, file_dbp->pgsize, argp->left,
			    PGNO_INVALID,
			    ISINTERNAL(sp) ? PGNO_INVALID : argp->right,
			    LEVEL(sp), TYPE(sp));
			P_INIT(_rp, file_dbp->pgsize, argp->right,
			    ISINTERNAL(sp) ?  PGNO_INVALID : argp->left,
			    PGNO_INVALID, LEVEL(sp), TYPE(sp));
		} else {
			P_INIT(_lp, file_dbp->pgsize, PGNO(sp),
			    ISINTERNAL(sp) ? PGNO_INVALID : PREV_PGNO(sp),
			    ISINTERNAL(sp) ? PGNO_INVALID : argp->right,
			    LEVEL(sp), TYPE(sp));
			P_INIT(_rp, file_dbp->pgsize, argp->right,
			    ISINTERNAL(sp) ? PGNO_INVALID : sp->pgno,
			    ISINTERNAL(sp) ? PGNO_INVALID : NEXT_PGNO(sp),
			    LEVEL(sp), TYPE(sp));
		}

		/* Split the page. */
		if ((ret = __bam_copy(file_dbp, sp, _lp, 0, argp->indx)) != 0 ||
		    (ret = __bam_copy(file_dbp, sp, _rp, argp->indx,
		    NUM_ENT(sp))) != 0)
			goto out;

		/* If the left child is wrong, update it. */
		if (lp == NULL && (ret = mpf->get(
		    mpf, &argp->left, DB_MPOOL_CREATE, &lp)) != 0) {
			__db_pgerr(file_dbp, argp->left, ret);
			lp = NULL;
			goto out;
		}
		if (l_update) {
			memcpy(lp, _lp, file_dbp->pgsize);
			lp->lsn = *lsnp;
			if ((ret = mpf->put(mpf, lp, DB_MPOOL_DIRTY)) != 0)
				goto out;
			lp = NULL;
		}

		/* If the right child is wrong, update it. */
		if (rp == NULL && (ret = mpf->get(
		    mpf, &argp->right, DB_MPOOL_CREATE, &rp)) != 0) {
			__db_pgerr(file_dbp, argp->right, ret);
			rp = NULL;
			goto out;
		}
		if (r_update) {
			memcpy(rp, _rp, file_dbp->pgsize);
			rp->lsn = *lsnp;
			if ((ret = mpf->put(mpf, rp, DB_MPOOL_DIRTY)) != 0)
				goto out;
			rp = NULL;
		}

		/*
		 * If the parent page is wrong, update it.  This is of interest
		 * only if it was a root split, since root splits create parent
		 * pages.  All other splits modify a parent page, but those are
		 * separately logged and recovered.
		 */
		if (rootsplit && p_update) {
			if (IS_BTREE_PAGE(sp)) {
				ptype = P_IBTREE;
				rc = argp->opflags & SPL_NRECS ? 1 : 0;
			} else {
				ptype = P_IRECNO;
				rc = 1;
			}

			P_INIT(pp, file_dbp->pgsize, root_pgno,
			    PGNO_INVALID, PGNO_INVALID, _lp->level + 1, ptype);
			RE_NREC_SET(pp, rc ?  __bam_total(file_dbp, _lp) +
			    __bam_total(file_dbp, _rp) : 0);

			pp->lsn = *lsnp;
			if ((ret = mpf->put(mpf, pp, DB_MPOOL_DIRTY)) != 0)
				goto out;
			pp = NULL;
		}

check_next:	/*
		 * Finally, redo the next-page link if necessary.  This is of
		 * interest only if it wasn't a root split -- inserting a new
		 * page in the tree requires that any following page have its
		 * previous-page pointer updated to our new page.  The next
		 * page must exist because we're redoing the operation.
		 */
		if (!rootsplit && !IS_ZERO_LSN(argp->nlsn)) {
			if ((ret = mpf->get(mpf, &argp->npgno, 0, &np)) != 0) {
				__db_pgerr(file_dbp, argp->npgno, ret);
				np = NULL;
				goto out;
			}
			cmp = log_compare(&LSN(np), &argp->nlsn);
			CHECK_LSN(op, cmp, &LSN(np), &argp->nlsn);
			if (cmp == 0) {
				PREV_PGNO(np) = argp->right;
				np->lsn = *lsnp;
				if ((ret =
				    mpf->put(mpf, np, DB_MPOOL_DIRTY)) != 0)
					goto out;
				np = NULL;
			}
		}
	} else {
		/*
		 * If the split page is wrong, replace its contents with the
		 * logged page contents.  If the page doesn't exist, it means
		 * that the create of the page never happened, nor did any of
		 * the adds onto the page that caused the split, and there's
		 * really no undo-ing to be done.
		 */
		if ((ret = mpf->get(mpf, &pgno, 0, &pp)) != 0) {
			pp = NULL;
			goto lrundo;
		}
		if (log_compare(lsnp, &LSN(pp)) == 0) {
			memcpy(pp, argp->pg.data, argp->pg.size);
			if ((ret = mpf->put(mpf, pp, DB_MPOOL_DIRTY)) != 0)
				goto out;
			pp = NULL;
		}

		/*
		 * If it's a root split and the left child ever existed, update
		 * its LSN.  (If it's not a root split, we've updated the left
		 * page already -- it's the same as the split page.) If the
		 * right child ever existed, root split or not, update its LSN.
		 * The undo of the page allocation(s) will restore them to the
		 * free list.
		 */
lrundo:		if ((rootsplit && lp != NULL) || rp != NULL) {
			if (rootsplit && lp != NULL &&
			    log_compare(lsnp, &LSN(lp)) == 0) {
				lp->lsn = argp->llsn;
				if ((ret =
				    mpf->put(mpf, lp, DB_MPOOL_DIRTY)) != 0)
					goto out;
				lp = NULL;
			}
			if (rp != NULL &&
			    log_compare(lsnp, &LSN(rp)) == 0) {
				rp->lsn = argp->rlsn;
				if ((ret =
				    mpf->put(mpf, rp, DB_MPOOL_DIRTY)) != 0)
					goto out;
				rp = NULL;
			}
		}

		/*
		 * Finally, undo the next-page link if necessary.  This is of
		 * interest only if it wasn't a root split -- inserting a new
		 * page in the tree requires that any following page have its
		 * previous-page pointer updated to our new page.  Since it's
		 * possible that the next-page never existed, we ignore it as
		 * if there's nothing to undo.
		 */
		if (!rootsplit && !IS_ZERO_LSN(argp->nlsn)) {
			if ((ret = mpf->get(mpf, &argp->npgno, 0, &np)) != 0) {
				np = NULL;
				goto done;
			}
			if (log_compare(lsnp, &LSN(np)) == 0) {
				PREV_PGNO(np) = argp->left;
				np->lsn = argp->nlsn;
				if (mpf->put(mpf, np, DB_MPOOL_DIRTY))
					goto out;
				np = NULL;
			}
		}
	}

done:	*lsnp = argp->prev_lsn;
	ret = 0;

out:	/* Free any pages that weren't dirtied. */
	if (pp != NULL && (t_ret = mpf->put(mpf, pp, 0)) != 0 && ret == 0)
		ret = t_ret;
	if (lp != NULL && (t_ret = mpf->put(mpf, lp, 0)) != 0 && ret == 0)
		ret = t_ret;
	if (np != NULL && (t_ret = mpf->put(mpf, np, 0)) != 0 && ret == 0)
		ret = t_ret;
	if (rp != NULL && (t_ret = mpf->put(mpf, rp, 0)) != 0 && ret == 0)
		ret = t_ret;

	/* Free any allocated space. */
	if (_lp != NULL)
		__os_free(dbenv, _lp);
	if (_rp != NULL)
		__os_free(dbenv, _rp);
	if (sp != NULL)
		__os_free(dbenv, sp);

	REC_CLOSE;
}

/*
 * __bam_rsplit_recover --
 *	Recovery function for a reverse split.
 *
 * PUBLIC: int __bam_rsplit_recover
 * PUBLIC:   __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__bam_rsplit_recover(dbenv, dbtp, lsnp, op, info)
	DB_ENV *dbenv;
	DBT *dbtp;
	DB_LSN *lsnp;
	db_recops op;
	void *info;
{
	__bam_rsplit_args *argp;
	DB *file_dbp;
	DBC *dbc;
	DB_LSN copy_lsn;
	DB_MPOOLFILE *mpf;
	PAGE *pagep;
	db_pgno_t pgno, root_pgno;
	int cmp_n, cmp_p, modified, ret;

	pagep = NULL;
	COMPQUIET(info, NULL);
	REC_PRINT(__bam_rsplit_print);
	REC_INTRO(__bam_rsplit_read, 1);

	/* Fix the root page. */
	pgno = root_pgno = argp->root_pgno;
	if ((ret = mpf->get(mpf, &pgno, 0, &pagep)) != 0) {
		/* The root page must always exist if we are going forward. */
		if (DB_REDO(op)) {
			__db_pgerr(file_dbp, pgno, ret);
			goto out;
		}
		/* This must be the root of an OPD tree. */
		DB_ASSERT(root_pgno !=
		    ((BTREE *)file_dbp->bt_internal)->bt_root);
		ret = 0;
		goto do_page;
	}
	modified = 0;
	cmp_n = log_compare(lsnp, &LSN(pagep));
	cmp_p = log_compare(&LSN(pagep), &argp->rootlsn);
	CHECK_LSN(op, cmp_p, &LSN(pagep), &argp->rootlsn);
	if (cmp_p == 0 && DB_REDO(op)) {
		/* Need to redo update described. */
		memcpy(pagep, argp->pgdbt.data, argp->pgdbt.size);
		pagep->pgno = root_pgno;
		pagep->lsn = *lsnp;
		modified = 1;
	} else if (cmp_n == 0 && DB_UNDO(op)) {
		/* Need to undo update described. */
		P_INIT(pagep, file_dbp->pgsize, root_pgno,
		    argp->nrec, PGNO_INVALID, pagep->level + 1,
		    IS_BTREE_PAGE(pagep) ? P_IBTREE : P_IRECNO);
		if ((ret = __db_pitem(dbc, pagep, 0,
		    argp->rootent.size, &argp->rootent, NULL)) != 0)
			goto out;
		pagep->lsn = argp->rootlsn;
		modified = 1;
	}
	if ((ret = mpf->put(mpf, pagep, modified ? DB_MPOOL_DIRTY : 0)) != 0)
		goto out;

do_page:
	/*
	 * Fix the page copied over the root page.  It's possible that the
	 * page never made it to disk, so if we're undo-ing and the page
	 * doesn't exist, it's okay and there's nothing further to do.
	 */
	if ((ret = mpf->get(mpf, &argp->pgno, 0, &pagep)) != 0) {
		if (DB_UNDO(op))
			goto done;
		__db_pgerr(file_dbp, argp->pgno, ret);
		goto out;
	}
	modified = 0;
	(void)__ua_memcpy(&copy_lsn, &LSN(argp->pgdbt.data), sizeof(DB_LSN));
	cmp_n = log_compare(lsnp, &LSN(pagep));
	cmp_p = log_compare(&LSN(pagep), &copy_lsn);
	CHECK_LSN(op, cmp_p, &LSN(pagep), &copy_lsn);
	if (cmp_p == 0 && DB_REDO(op)) {
		/* Need to redo update described. */
		pagep->lsn = *lsnp;
		modified = 1;
	} else if (cmp_n == 0 && DB_UNDO(op)) {
		/* Need to undo update described. */
		memcpy(pagep, argp->pgdbt.data, argp->pgdbt.size);
		modified = 1;
	}
	if ((ret = mpf->put(mpf, pagep, modified ? DB_MPOOL_DIRTY : 0)) != 0)
		goto out;
	pagep = NULL;

done:	*lsnp = argp->prev_lsn;
	ret = 0;

out:	if (pagep != NULL)
		(void)mpf->put(mpf, pagep, 0);
	REC_CLOSE;
}

/*
 * __bam_adj_recover --
 *	Recovery function for adj.
 *
 * PUBLIC: int __bam_adj_recover
 * PUBLIC:   __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__bam_adj_recover(dbenv, dbtp, lsnp, op, info)
	DB_ENV *dbenv;
	DBT *dbtp;
	DB_LSN *lsnp;
	db_recops op;
	void *info;
{
	__bam_adj_args *argp;
	DB *file_dbp;
	DBC *dbc;
	DB_MPOOLFILE *mpf;
	PAGE *pagep;
	int cmp_n, cmp_p, modified, ret;

	pagep = NULL;
	COMPQUIET(info, NULL);
	REC_PRINT(__bam_adj_print);
	REC_INTRO(__bam_adj_read, 1);

	/* Get the page; if it never existed and we're undoing, we're done. */
	if ((ret = mpf->get(mpf, &argp->pgno, 0, &pagep)) != 0) {
		if (DB_UNDO(op))
			goto done;
		__db_pgerr(file_dbp, argp->pgno, ret);
		goto out;
	}

	modified = 0;
	cmp_n = log_compare(lsnp, &LSN(pagep));
	cmp_p = log_compare(&LSN(pagep), &argp->lsn);
	CHECK_LSN(op, cmp_p, &LSN(pagep), &argp->lsn);
	if (cmp_p == 0 && DB_REDO(op)) {
		/* Need to redo update described. */
		if ((ret = __bam_adjindx(dbc,
		    pagep, argp->indx, argp->indx_copy, argp->is_insert)) != 0)
			goto out;

		LSN(pagep) = *lsnp;
		modified = 1;
	} else if (cmp_n == 0 && DB_UNDO(op)) {