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

skip_s_update:
	/*
	 * If we have an off-page duplicates cursor, and the operation applies
	 * to it, perform the operation.  Duplicate the cursor and call the
	 * underlying function.
	 *
	 * 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 put operation is done in an off-page
	 * duplicate tree, call the primary cursor's upgrade routine first.
	 */
	if (dbc_arg->internal->opd != NULL &&
	    (flags == DB_AFTER || flags == DB_BEFORE || flags == DB_CURRENT)) {
		/*
		 * A special case for hash off-page duplicates.  Hash doesn't
		 * support (and is documented not to support) put operations
		 * relative to a cursor which references an already deleted
		 * item.  For consistency, apply the same criteria to off-page
		 * duplicates as well.
		 */
		if (dbc_arg->dbtype == DB_HASH && F_ISSET(
		    ((BTREE_CURSOR *)(dbc_arg->internal->opd->internal)),
		    C_DELETED)) {
			ret = DB_NOTFOUND;
			goto err;
		}

		if ((ret = dbc_arg->c_am_writelock(dbc_arg)) != 0)
			return (ret);
		if ((ret = __db_c_dup(dbc_arg, &dbc_n, DB_POSITIONI)) != 0)
			goto err;
		opd = dbc_n->internal->opd;
		if ((ret = opd->c_am_put(
		    opd, key, data, flags, NULL)) != 0)
			goto err;
		goto done;
	}

	/*
	 * Perform an operation on the main cursor.  Duplicate the cursor,
	 * and call the underlying function.
	 *
	 * XXX: MARGO
	 *
	tmp_flags = flags == DB_AFTER ||
	    flags == DB_BEFORE || flags == DB_CURRENT ? DB_POSITIONI : 0;
	 */
	tmp_flags = DB_POSITIONI;

	/*
	 * If this cursor is going to be closed immediately, we don't
	 * need to take precautions to clean it up on error.
	 */
	if (F_ISSET(dbc_arg, DBC_TRANSIENT))
		dbc_n = dbc_arg;
	else if ((ret = __db_c_idup(dbc_arg, &dbc_n, tmp_flags)) != 0)
		goto err;

	pgno = PGNO_INVALID;
	if ((ret = dbc_n->c_am_put(dbc_n, key, data, flags, &pgno)) != 0)
		goto err;

	/*
	 * We may be referencing a new off-page duplicates tree.  Acquire
	 * a new cursor and call the underlying function.
	 */
	if (pgno != PGNO_INVALID) {
		oldopd = dbc_n->internal->opd;
		if ((ret = __db_c_newopd(dbc_arg, pgno, oldopd, &opd)) != 0) {
			dbc_n->internal->opd = opd;
			goto err;
		}

		dbc_n->internal->opd = opd;

		if ((ret = opd->c_am_put(
		    opd, key, data, flags, NULL)) != 0)
			goto err;
	}

done:
err:	/* Cleanup and cursor resolution. */
	if ((t_ret = __db_c_cleanup(dbc_arg, dbc_n, ret)) != 0 && ret == 0)
		ret = t_ret;

	/* If newdata was used, free its buffer. */
	if (newdata.data != NULL)
		__os_free(dbp->dbenv, newdata.data);

	CDB_LOCKING_DONE(dbp, dbc_arg);

	if (sdbp != NULL && (t_ret = __db_s_done(sdbp)) != 0)
		return (t_ret);

	return (ret);
}

/*
 * __db_duperr()
 *	Error message: we don't currently support sorted duplicate duplicates.
 * PUBLIC: int __db_duperr __P((DB *, u_int32_t));
 */
int
__db_duperr(dbp, flags)
	DB *dbp;
	u_int32_t flags;
{

	/*
	 * If we run into this error while updating a secondary index,
	 * don't yell--there's no clean way to pass DB_NODUPDATA in along
	 * with DB_UPDATE_SECONDARY, but we may run into this problem
	 * in a normal, non-error course of events.
	 *
	 * !!!
	 * If and when we ever permit duplicate duplicates in sorted-dup
	 * databases, we need to either change the secondary index code
	 * to check for dup dups, or we need to maintain the implicit
	 * "DB_NODUPDATA" behavior for databases with DB_AM_SECONDARY set.
	 */
	if (flags != DB_NODUPDATA && !F_ISSET(dbp, DB_AM_SECONDARY))
		__db_err(dbp->dbenv,
		    "Duplicate data items are not supported with sorted data");
	return (DB_KEYEXIST);
}

/*
 * __db_c_cleanup --
 *	Clean up duplicate cursors.
 */
static int
__db_c_cleanup(dbc, dbc_n, failed)
	DBC *dbc, *dbc_n;
	int failed;
{
	DB *dbp;
	DBC *opd;
	DBC_INTERNAL *internal;
	DB_MPOOLFILE *mpf;
	int ret, t_ret;

	dbp = dbc->dbp;
	mpf = dbp->mpf;
	internal = dbc->internal;
	ret = 0;

	/* Discard any pages we're holding. */
	if (internal->page != NULL) {
		if ((t_ret = mpf->put(mpf, internal->page, 0)) != 0 && ret == 0)
			ret = t_ret;
		internal->page = NULL;
	}
	opd = internal->opd;
	if (opd != NULL && opd->internal->page != NULL) {
		if ((t_ret =
		    mpf->put(mpf, opd->internal->page, 0)) != 0 && ret == 0)
			ret = t_ret;
		 opd->internal->page = NULL;
	}

	/*
	 * If dbc_n is NULL, there's no internal cursor swapping to be done
	 * and no dbc_n to close--we probably did the entire operation on an
	 * offpage duplicate cursor.  Just return.
	 *
	 * If dbc and dbc_n are the same, we're either inside a DB->{put/get}
	 * operation, and as an optimization we performed the operation on
	 * the main cursor rather than on a duplicated one, or we're in a
	 * bulk get that can't have moved the cursor (DB_MULTIPLE with the
	 * initial c_get operation on an off-page dup cursor).  Just
	 * return--either we know we didn't move the cursor, or we're going
	 * to close it before we return to application code, so we're sure
	 * not to visibly violate the "cursor stays put on error" rule.
	 */
	if (dbc_n == NULL || dbc == dbc_n)
		return (ret);

	if (dbc_n->internal->page != NULL) {
		if ((t_ret =
		    mpf->put(mpf, dbc_n->internal->page, 0)) != 0 && ret == 0)
			ret = t_ret;
		dbc_n->internal->page = NULL;
	}
	opd = dbc_n->internal->opd;
	if (opd != NULL && opd->internal->page != NULL) {
		if ((t_ret =
		    mpf->put(mpf, opd->internal->page, 0)) != 0 && ret == 0)
			ret = t_ret;
		opd->internal->page = NULL;
	}

	/*
	 * If we didn't fail before entering this routine or just now when
	 * freeing pages, swap the interesting contents of the old and new
	 * cursors.
	 */
	if (!failed && ret == 0) {
		dbc->internal = dbc_n->internal;
		dbc_n->internal = internal;
	}

	/*
	 * Close the cursor we don't care about anymore.  The close can fail,
	 * but we only expect DB_LOCK_DEADLOCK failures.  This violates our
	 * "the cursor is unchanged on error" semantics, but since all you can
	 * do with a DB_LOCK_DEADLOCK failure is close the cursor, I believe
	 * that's OK.
	 *
	 * XXX
	 * There's no way to recover from failure to close the old cursor.
	 * All we can do is move to the new position and return an error.
	 *
	 * XXX
	 * We might want to consider adding a flag to the cursor, so that any
	 * subsequent operations other than close just return an error?
	 */
	if ((t_ret = dbc_n->c_close(dbc_n)) != 0 && ret == 0)
		ret = t_ret;

	return (ret);
}

/*
 * __db_c_secondary_get --
 *	This wrapper function for DBC->c_pget() is the DBC->c_get() function
 *	for a secondary index cursor.
 *
 * PUBLIC: int __db_c_secondary_get __P((DBC *, DBT *, DBT *, u_int32_t));
 */
int
__db_c_secondary_get(dbc, skey, data, flags)
	DBC *dbc;
	DBT *skey, *data;
	u_int32_t flags;
{

	DB_ASSERT(F_ISSET(dbc->dbp, DB_AM_SECONDARY));
	return (dbc->c_pget(dbc, skey, NULL, data, flags));
}

/*
 * __db_c_pget --
 *	Get a primary key/data pair through a secondary index.
 *
 * PUBLIC: int __db_c_pget __P((DBC *, DBT *, DBT *, DBT *, u_int32_t));
 */
int
__db_c_pget(dbc, skey, pkey, data, flags)
	DBC *dbc;
	DBT *skey, *pkey, *data;
	u_int32_t flags;
{
	DB *pdbp, *sdbp;
	DBC *pdbc;
	DBT *save_rdata, nullpkey;
	int pkeymalloc, ret, save_pkey_flags, t_ret;

	sdbp = dbc->dbp;
	pdbp = sdbp->s_primary;
	pkeymalloc = t_ret = 0;

	PANIC_CHECK(sdbp->dbenv);
	if ((ret = __db_cpgetchk(sdbp,
	    skey, pkey, data, flags, IS_INITIALIZED(dbc))) != 0)
		return (ret);

	/*
	 * The challenging part of this function is getting the behavior
	 * right for all the various permutations of DBT flags.  The
	 * next several blocks handle the various cases we need to
	 * deal with specially.
	 */

	/*
	 * We may be called with a NULL pkey argument, if we've been
	 * wrapped by a 2-DBT get call.  If so, we need to use our
	 * own DBT.
	 */
	if (pkey == NULL) {
		memset(&nullpkey, 0, sizeof(DBT));
		pkey = &nullpkey;
	}

	/*
	 * DB_GET_RECNO is a special case, because we're interested not in
	 * the primary key/data pair, but rather in the primary's record
	 * number.
	 */
	if ((flags & DB_OPFLAGS_MASK) == DB_GET_RECNO)
		return (__db_c_pget_recno(dbc, pkey, data, flags));

	/*
	 * If the DBTs we've been passed don't have any of the
	 * user-specified memory management flags set, we want to make sure
	 * we return values using the DBTs dbc->rskey, dbc->rkey, and
	 * dbc->rdata, respectively.
	 *
	 * There are two tricky aspects to this:  first, we need to pass
	 * skey and pkey *in* to the initial c_get on the secondary key,
	 * since either or both may be looked at by it (depending on the
	 * get flag).  Second, we must not use a normal DB->get call
	 * on the secondary, even though that's what we want to accomplish,
	 * because the DB handle may be free-threaded.  Instead,
	 * we open a cursor, then take steps to ensure that we actually use
	 * the rkey/rdata from the *secondary* cursor.
	 *
	 * We accomplish all this by passing in the DBTs we started out
	 * with to the c_get, but having swapped the contents of rskey and
	 * rkey, respectively, into rkey and rdata;  __db_ret will treat
	 * them like the normal key/data pair in a c_get call, and will
	 * realloc them as need be (this is "step 1").  Then, for "step 2",
	 * we swap back rskey/rkey/rdata to normal, and do a get on the primary
	 * with the secondary dbc appointed as the owner of the returned-data
	 * memory.
	 *
	 * Note that in step 2, we copy the flags field in case we need to
	 * pass down a DB_DBT_PARTIAL or other flag that is compatible with
	 * letting DB do the memory management.
	 */
	/* Step 1. */
	save_rdata = dbc->rdata;
	dbc->rdata = dbc->rkey;
	dbc->rkey = dbc->rskey;

	/*
	 * It is correct, though slightly sick, to attempt a partial get
	 * of a primary key.  However, if we do so here, we'll never find the
	 * primary record;  clear the DB_DBT_PARTIAL field of pkey just
	 * for the duration of the next call.
	 */
	save_pkey_flags = pkey->flags;
	F_CLR(pkey, DB_DBT_PARTIAL);

	/*
	 * Now we can go ahead with the meat of this call.  First, get the
	 * primary key from the secondary index.  (What exactly we get depends
	 * on the flags, but the underlying cursor get will take care of the
	 * dirty work.)
	 */
	if ((ret = dbc->c_real_get(dbc, skey, pkey, flags)) != 0) {
		/* Restore rskey/rkey/rdata and return. */
		pkey->flags = save_pkey_flags;
		dbc->rskey = dbc->rkey;
		dbc->rkey = dbc->rdata;
		dbc->rdata = save_rdata;
		goto err;
	}

	/* Restore pkey's flags in case we stomped the PARTIAL flag. */
	pkey->flags = save_pkey_flags;

	/*
	 * Restore the cursor's rskey, rkey, and rdata DBTs.  If DB
	 * is handling the memory management, we now have newly
	 * reallocated buffers and ulens in rkey and rdata which we want
	 * to put in rskey and rkey.  save_rdata contains the old value
	 * of dbc->rdata.
	 */
	dbc->rskey = dbc->rkey;
	dbc->rkey = dbc->rdata;
	dbc->rdata = save_rdata;

	/*
	 * Now we're ready for "step 2".  If either or both of pkey and
	 * data do not have memory management flags set--that is, if DB is
	 * managing their memory--we need to swap around the rkey/rdata
	 * structures so that we don't wind up trying to use memory managed
	 * by the primary database cursor, which we'll close before we return.
	 *
	 * !!!
	 * If you're carefully following the bouncing ball, you'll note
	 * that in the DB-managed case, the buffer hanging off of pkey is
	 * the same as dbc->rkey->data.  This is just fine;  we may well
	 * realloc and stomp on it when we return, if we're going a
	 * DB_GET_BOTH and need to return a different partial or key
	 * (depending on the comparison function), but this is safe.
	 *
	 * !!!
	 * We need to use __db_icursor here rather than simply calling
	 * pdbp->cursor, because otherwise, if we're in CDB, we'll
	 * allocate a new locker ID and leave ourselves open to deadlocks.
	 * (Even though we're only acquiring read locks, we'll still block
	 * if there are any waiters.)
	 */
	if ((ret = __db_icursor(pdbp,
	    dbc->txn, pdbp->type, PGNO_INVALID, 0, dbc->locker, &pdbc)) != 0)
		goto err;

	/*
	 * We're about to use pkey a second time.  If DB_DBT_MALLOC
	 * is set on it, we'll leak the memory we allocated the first time.
	 * Thus, set DB_DBT_REALLOC instead so that we reuse that memory
	 * instead of leaking it.
	 *
	 * !!!
	 * This assumes that the user must always specify a compatible
	 * realloc function if a malloc function is specified.  I think
	 * this is a reasonable requirement.
	 */
	if (F_ISSET(pkey, DB_DBT_MALLOC)) {
		F_CLR(pkey, DB_DBT_MALLOC);
		F_SET(pkey, DB_DBT_REALLOC);
		pkeymalloc = 1;
	}

	/*
	 * Do the actual get.  Set DBC_TRANSIENT since we don't care
	 * about preserving the position on error, and it's faster.
	 * SET_RET_MEM so that the secondary DBC owns any returned-data
	 * memory.
	 */
	F_SET(pdbc, DBC_TRANSIENT);
	SET_RET_MEM(pdbc, dbc);
	ret = pdbc->c_get(pdbc, pkey, data, DB_SET);

	/*
	 * If the item wasn't found in the primary, this is a bug;
	 * our secondary has somehow gotten corrupted, and contains
	 * elements that don't correspond to anything in the primary.
	 * Complain.
	 */
	if (ret == DB_NOTFOUND)
		ret = __db_secondary_corrupt(pdbp);

	/* Now close the primary cursor. */
	t_ret = pdbc->c_close(pdbc);

err:	if (pkeymalloc) {
		/*
		 * If pkey had a MALLOC flag, we need to restore it;
		 * otherwise, if the user frees the buffer but reuses
		 * the DBT without NULL'ing its data field or changing
		 * the flags, we may drop core.
		 */
		F_CLR(pkey, DB_DBT_REALLOC);
		F_SET(pkey, DB_DBT_MALLOC);
	}
	return (t_ret == 0 ? ret : t_ret);
}

/*
 * __db_c_pget_recno --
 *	Perform a DB_GET_RECNO c_pget on a secondary index.  Returns
 * the secondary's record number in the pkey field and the primary's
 * in the data field.
 */
static int
__db_c_pget_recno(sdbc, pkey, data, flags)
	DBC *sdbc;
	DBT *pkey, *data;
	u_int32_t flags;
{
	DB *pdbp, *sdbp;
	DB_ENV *dbenv;
	DBC *pdbc;
	DBT discardme, primary_key;
	db_recno_t oob;
	u_int32_t rmw;