db_cam.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) 2000-2002
 *	Sleepycat Software.  All rights reserved.
 */

#include "db_config.h"

#ifndef lint
static const char revid[] = "$Id: db_cam.c,v 11.114 2002/09/03 15:44:46 krinsky 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/hash.h"
#include "dbinc/lock.h"
#include "dbinc/log.h"
#include "dbinc/qam.h"

static int __db_buildpartial __P((DB *, DBT *, DBT *, DBT *));
static int __db_c_cleanup __P((DBC *, DBC *, int));
static int __db_c_del_secondary __P((DBC *));
static int __db_c_pget_recno __P((DBC *, DBT *, DBT *, u_int32_t));
static int __db_wrlock_err __P((DB_ENV *));

#define	CDB_LOCKING_INIT(dbp, dbc)					\
	/*								\
	 * If we are running CDB, this had better be either a write	\
	 * cursor or an immediate writer.  If it's a regular writer,	\
	 * that means we have an IWRITE lock and we need to upgrade	\
	 * it to a write lock.						\
	 */								\
	if (CDB_LOCKING((dbp)->dbenv)) {				\
		if (!F_ISSET(dbc, DBC_WRITECURSOR | DBC_WRITER))	\
			return (__db_wrlock_err(dbp->dbenv));		\
									\
		if (F_ISSET(dbc, DBC_WRITECURSOR) &&			\
		    (ret = (dbp)->dbenv->lock_get((dbp)->dbenv,		\
		    (dbc)->locker, DB_LOCK_UPGRADE, &(dbc)->lock_dbt,	\
		    DB_LOCK_WRITE, &(dbc)->mylock)) != 0)		\
			return (ret);					\
	}
#define	CDB_LOCKING_DONE(dbp, dbc)					\
	/* Release the upgraded lock. */				\
	if (F_ISSET(dbc, DBC_WRITECURSOR))				\
		(void)__lock_downgrade(					\
		    (dbp)->dbenv, &(dbc)->mylock, DB_LOCK_IWRITE, 0);
/*
 * Copy the lock info from one cursor to another, so that locking
 * in CDB can be done in the context of an internally-duplicated
 * or off-page-duplicate cursor.
 */
#define	CDB_LOCKING_COPY(dbp, dbc_o, dbc_n)				\
	if (CDB_LOCKING((dbp)->dbenv) &&				\
	    F_ISSET((dbc_o), DBC_WRITECURSOR | DBC_WRITEDUP)) { \
		memcpy(&(dbc_n)->mylock, &(dbc_o)->mylock,		\
		    sizeof((dbc_o)->mylock));				\
		/* This lock isn't ours to put--just discard it on close. */ \
		F_SET((dbc_n), DBC_WRITEDUP);				\
	}

/*
 * __db_c_close --
 *	Close the cursor.
 *
 * PUBLIC: int __db_c_close __P((DBC *));
 */
int
__db_c_close(dbc)
	DBC *dbc;
{
	DB *dbp;
	DBC *opd;
	DBC_INTERNAL *cp;
	DB_ENV *dbenv;
	int ret, t_ret;

	dbp = dbc->dbp;
	dbenv = dbp->dbenv;
	ret = 0;

	PANIC_CHECK(dbenv);

	/*
	 * If the cursor is already closed we have a serious problem, and we
	 * assume that the cursor isn't on the active queue.  Don't do any of
	 * the remaining cursor close processing.
	 */
	if (!F_ISSET(dbc, DBC_ACTIVE)) {
		if (dbp != NULL)
			__db_err(dbenv, "Closing already-closed cursor");

		DB_ASSERT(0);
		return (EINVAL);
	}

	cp = dbc->internal;
	opd = cp->opd;

	/*
	 * Remove the cursor(s) from the active queue.  We may be closing two
	 * cursors at once here, a top-level one and a lower-level, off-page
	 * duplicate one.  The acess-method specific cursor close routine must
	 * close both of them in a single call.
	 *
	 * !!!
	 * Cursors must be removed from the active queue before calling the
	 * access specific cursor close routine, btree depends on having that
	 * order of operations.
	 */
	MUTEX_THREAD_LOCK(dbenv, dbp->mutexp);

	if (opd != NULL) {
		F_CLR(opd, DBC_ACTIVE);
		TAILQ_REMOVE(&dbp->active_queue, opd, links);
	}
	F_CLR(dbc, DBC_ACTIVE);
	TAILQ_REMOVE(&dbp->active_queue, dbc, links);

	MUTEX_THREAD_UNLOCK(dbenv, dbp->mutexp);

	/* Call the access specific cursor close routine. */
	if ((t_ret =
	    dbc->c_am_close(dbc, PGNO_INVALID, NULL)) != 0 && ret == 0)
		ret = t_ret;

	/*
	 * Release the lock after calling the access method specific close
	 * routine, a Btree cursor may have had pending deletes.
	 */
	if (CDB_LOCKING(dbenv)) {
		/*
		 * If DBC_WRITEDUP is set, the cursor is an internally
		 * duplicated write cursor and the lock isn't ours to put.
		 *
		 * Also, be sure not to free anything if mylock.off is
		 * INVALID;  in some cases, such as idup'ed read cursors
		 * and secondary update cursors, a cursor in a CDB
		 * environment may not have a lock at all.
		 */
		if (!F_ISSET(dbc, DBC_WRITEDUP) && LOCK_ISSET(dbc->mylock)) {
			if ((t_ret = dbenv->lock_put(
			    dbenv, &dbc->mylock)) != 0 && ret == 0)
				ret = t_ret;
		}

		/* For safety's sake, since this is going on the free queue. */
		memset(&dbc->mylock, 0, sizeof(dbc->mylock));
		F_CLR(dbc, DBC_WRITEDUP);
	}

	if (dbc->txn != NULL)
		dbc->txn->cursors--;

	/* Move the cursor(s) to the free queue. */
	MUTEX_THREAD_LOCK(dbenv, dbp->mutexp);
	if (opd != NULL) {
		if (dbc->txn != NULL)
			dbc->txn->cursors--;
		TAILQ_INSERT_TAIL(&dbp->free_queue, opd, links);
		opd = NULL;
	}
	TAILQ_INSERT_TAIL(&dbp->free_queue, dbc, links);
	MUTEX_THREAD_UNLOCK(dbenv, dbp->mutexp);

	return (ret);
}

/*
 * __db_c_destroy --
 *	Destroy the cursor, called after DBC->c_close.
 *
 * PUBLIC: int __db_c_destroy __P((DBC *));
 */
int
__db_c_destroy(dbc)
	DBC *dbc;
{
	DB *dbp;
	DB_ENV *dbenv;
	int ret, t_ret;

	dbp = dbc->dbp;
	dbenv = dbp->dbenv;

	/* Remove the cursor from the free queue. */
	MUTEX_THREAD_LOCK(dbenv, dbp->mutexp);
	TAILQ_REMOVE(&dbp->free_queue, dbc, links);
	MUTEX_THREAD_UNLOCK(dbenv, dbp->mutexp);

	/* Free up allocated memory. */
	if (dbc->my_rskey.data != NULL)
		__os_free(dbenv, dbc->my_rskey.data);
	if (dbc->my_rkey.data != NULL)
		__os_free(dbenv, dbc->my_rkey.data);
	if (dbc->my_rdata.data != NULL)
		__os_free(dbenv, dbc->my_rdata.data);

	/* Call the access specific cursor destroy routine. */
	ret = dbc->c_am_destroy == NULL ? 0 : dbc->c_am_destroy(dbc);

	/*
	 * Release the lock id for this cursor.
	 */
	if (LOCKING_ON(dbenv) &&
	    F_ISSET(dbc, DBC_OWN_LID) &&
	    (t_ret = dbenv->lock_id_free(dbenv, dbc->lid)) != 0 && ret == 0)
		ret = t_ret;

	__os_free(dbenv, dbc);

	return (ret);
}

/*
 * __db_c_count --
 *	Return a count of duplicate data items.
 *
 * PUBLIC: int __db_c_count __P((DBC *, db_recno_t *, u_int32_t));
 */
int
__db_c_count(dbc, recnop, flags)
	DBC *dbc;
	db_recno_t *recnop;
	u_int32_t flags;
{
	DB *dbp;
	int ret;

	/*
	 * Cursor Cleanup Note:
	 * All of the cursors passed to the underlying access methods by this
	 * routine are not duplicated and will not be cleaned up on return.
	 * So, pages/locks that the cursor references must be resolved by the
	 * underlying functions.
	 */
	dbp = dbc->dbp;

	PANIC_CHECK(dbp->dbenv);

	/* Check for invalid flags. */
	if ((ret = __db_ccountchk(dbp, flags, IS_INITIALIZED(dbc))) != 0)
		return (ret);

	switch (dbc->dbtype) {
	case DB_QUEUE:
	case DB_RECNO:
		*recnop = 1;
		break;
	case DB_HASH:
		if (dbc->internal->opd == NULL) {
			if ((ret = __ham_c_count(dbc, recnop)) != 0)
				return (ret);
			break;
		}
		/* FALLTHROUGH */
	case DB_BTREE:
		if ((ret = __bam_c_count(dbc, recnop)) != 0)
			return (ret);
		break;
	default:
		return (__db_unknown_type(dbp->dbenv,
		    "__db_c_count", dbp->type));
	}
	return (0);
}

/*
 * __db_c_del --
 *	Delete using a cursor.
 *
 * PUBLIC: int __db_c_del __P((DBC *, u_int32_t));
 */
int
__db_c_del(dbc, flags)
	DBC *dbc;
	u_int32_t flags;
{
	DB *dbp;
	DBC *opd;
	int ret;

	/*
	 * Cursor Cleanup Note:
	 * All of the cursors passed to the underlying access methods by this
	 * routine are not duplicated and will not be cleaned up on return.
	 * So, pages/locks that the cursor references must be resolved by the
	 * underlying functions.
	 */
	dbp = dbc->dbp;

	PANIC_CHECK(dbp->dbenv);

	/* Check for invalid flags. */
	if ((ret = __db_cdelchk(dbp, flags, IS_INITIALIZED(dbc))) != 0)
		return (ret);

	/* Check for consistent transaction usage. */
	if ((ret = __db_check_txn(dbp, dbc->txn, dbc->locker, 0)) != 0)
		return (ret);

	DEBUG_LWRITE(dbc, dbc->txn, "db_c_del", NULL, NULL, flags);

	CDB_LOCKING_INIT(dbp, dbc);

	/*
	 * If we're a secondary index, and DB_UPDATE_SECONDARY isn't set
	 * (which it only is if we're being called from a primary update),
	 * then we need to call through to the primary and delete the item.
	 *
	 * Note that this will delete the current item;  we don't need to
	 * delete it ourselves as well, so we can just goto done.
	 */
	if (flags != DB_UPDATE_SECONDARY && F_ISSET(dbp, DB_AM_SECONDARY)) {
		ret = __db_c_del_secondary(dbc);
		goto done;
	}

	/*
	 * If we are a primary and have secondary indices, go through
	 * and delete any secondary keys that point at the current record.
	 */
	if (LIST_FIRST(&dbp->s_secondaries) != NULL &&
	    (ret = __db_c_del_primary(dbc)) != 0)
		goto done;

	/*
	 * Off-page duplicate trees are locked in the primary tree, that is,
	 * we acquire a write lock in the primary tree and no locks in the
	 * off-page dup tree.  If the del operation is done in an off-page
	 * duplicate tree, call the primary cursor's upgrade routine first.
	 */
	opd = dbc->internal->opd;
	if (opd == NULL)
		ret = dbc->c_am_del(dbc);
	else
		if ((ret = dbc->c_am_writelock(dbc)) == 0)
			ret = opd->c_am_del(opd);

done:	CDB_LOCKING_DONE(dbp, dbc);

	return (ret);
}

/*
 * __db_c_dup --
 *	Duplicate a cursor
 *
 * PUBLIC: int __db_c_dup __P((DBC *, DBC **, u_int32_t));
 */
int
__db_c_dup(dbc_orig, dbcp, flags)
	DBC *dbc_orig;
	DBC **dbcp;
	u_int32_t flags;
{
	DB_ENV *dbenv;
	DB *dbp;
	DBC *dbc_n, *dbc_nopd;
	int ret;

	dbp = dbc_orig->dbp;
	dbenv = dbp->dbenv;
	dbc_n = dbc_nopd = NULL;

	PANIC_CHECK(dbp->dbenv);

	/*
	 * We can never have two write cursors open in CDB, so do not
	 * allow duplication of a write cursor.
	 */
	if (flags != DB_POSITIONI &&
	    F_ISSET(dbc_orig, DBC_WRITER | DBC_WRITECURSOR)) {
		__db_err(dbenv, "Cannot duplicate writeable cursor");
		return (EINVAL);
	}

	/* Allocate a new cursor and initialize it. */
	if ((ret = __db_c_idup(dbc_orig, &dbc_n, flags)) != 0)
		goto err;
	*dbcp = dbc_n;

	/*
	 * If we're in CDB, and this isn't an internal duplication (in which
	 * case we're explicitly overriding CDB locking), the duplicated
	 * cursor needs its own read lock.  (We know it's not a write cursor
	 * because we wouldn't have made it this far;  you can't dup them.)
	 */
	if (CDB_LOCKING(dbenv) && flags != DB_POSITIONI) {
		DB_ASSERT(!F_ISSET(dbc_orig, DBC_WRITER | DBC_WRITECURSOR));

		if ((ret = dbenv->lock_get(dbenv, dbc_n->locker, 0,
		    &dbc_n->lock_dbt, DB_LOCK_READ, &dbc_n->mylock)) != 0) {
			(void)__db_c_close(dbc_n);
			return (ret);
		}
	}

	/*
	 * If the cursor references an off-page duplicate tree, allocate a
	 * new cursor for that tree and initialize it.
	 */
	if (dbc_orig->internal->opd != NULL) {
		if ((ret =
		   __db_c_idup(dbc_orig->internal->opd, &dbc_nopd, flags)) != 0)
			goto err;
		dbc_n->internal->opd = dbc_nopd;
	}

	/* Copy the dirty read flag to the new cursor. */
	F_SET(dbc_n, F_ISSET(dbc_orig, DBC_DIRTY_READ));
	return (0);

err:	if (dbc_n != NULL)
		(void)dbc_n->c_close(dbc_n);
	if (dbc_nopd != NULL)
		(void)dbc_nopd->c_close(dbc_nopd);

	return (ret);
}

/*
 * __db_c_idup --
 *	Internal version of __db_c_dup.
 *
 * PUBLIC: int __db_c_idup __P((DBC *, DBC **, u_int32_t));
 */
int
__db_c_idup(dbc_orig, dbcp, flags)
	DBC *dbc_orig, **dbcp;
	u_int32_t flags;
{
	DB *dbp;
	DBC *dbc_n;
	DBC_INTERNAL *int_n, *int_orig;
	int ret;

	dbp = dbc_orig->dbp;
	dbc_n = *dbcp;

	if ((ret = __db_icursor(dbp, dbc_orig->txn, dbc_orig->dbtype,
	    dbc_orig->internal->root, F_ISSET(dbc_orig, DBC_OPD),
	    dbc_orig->locker, &dbc_n)) != 0)
		return (ret);

	/* If the user wants the cursor positioned, do it here.  */
	if (flags == DB_POSITION || flags == DB_POSITIONI) {
		int_n = dbc_n->internal;
		int_orig = dbc_orig->internal;