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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2000
* Sleepycat Software. All rights reserved.
*/
#include "htconfig.h"
#ifndef lint
static const char revid[] = "$Id: db_cam.c,v 1.2 2002/02/02 18:18:05 ghutchis Exp $";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#include <errno.h>
#endif
#include "db_int.h"
#include "db_page.h"
#include "db_shash.h"
#include "lock.h"
#include "btree.h"
#include "hash.h"
#include "qam.h"
#include "db_ext.h"
static int __db_c_cleanup __P((DBC *, DBC *, int));
static int __db_c_idup __P((DBC *, DBC **, u_int32_t));
static int __db_wrlock_err __P((DB_ENV *));
#define 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 (LOCKING((dbp)->dbenv)) { \
if (!F_ISSET(dbc, DBC_WRITECURSOR | DBC_WRITER)) \
return(__db_wrlock_err(dbp->dbenv)); \
\
if (F_ISSET(dbc, DBC_WRITECURSOR) && \
(ret = CDB_lock_get((dbp)->dbenv, (dbc)->locker, \
DB_LOCK_UPGRADE, &(dbc)->lock_dbt, DB_LOCK_WRITE, \
&(dbc)->mylock)) != 0) \
return (ret); \
}
#define LOCKING_DONE(dbp, dbc) \
/* Release the upgraded lock. */ \
if (F_ISSET(dbc, DBC_WRITECURSOR)) \
(void)CDB___lock_downgrade( \
(dbp)->dbenv, &(dbc)->mylock, DB_LOCK_IWRITE, 0);
#define IS_INITIALIZED(dbc) ((dbc)->internal->pgno != PGNO_INVALID)
/*
* CDB___db_c_close --
* Close the cursor.
*
* PUBLIC: int CDB___db_c_close __P((DBC *));
*/
int
CDB___db_c_close(dbc)
DBC *dbc;
{
DB *dbp;
DBC *opd;
DBC_INTERNAL *cp;
int ret, t_ret;
dbp = dbc->dbp;
ret = 0;
PANIC_CHECK(dbp->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 && dbp->dbenv)
CDB___db_err(dbp->dbenv, "Closing 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. It must also happen before any action that
* can fail and cause CDB___db_c_close to return an error, or else calls
* here from CDB___db_close may loop indefinitely.
*/
MUTEX_THREAD_LOCK(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(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 (LOCKING(dbc->dbp->dbenv)) {
/*
* If DBC_WRITEDUP is set, the cursor is an internally
* duplicated write cursor and the lock isn't ours to put.
*/
if (!F_ISSET(dbc, DBC_WRITEDUP) &&
dbc->mylock.off != LOCK_INVALID) {
if ((t_ret = CDB_lock_put(dbc->dbp->dbenv,
&dbc->mylock)) != 0 && ret == 0)
ret = t_ret;
dbc->mylock.off = LOCK_INVALID;
}
/* For safety's sake, since this is going on the free queue. */
memset(&dbc->mylock, 0, sizeof(dbc->mylock));
F_CLR(dbc, DBC_WRITEDUP);
}
/* Move the cursor(s) to the free queue. */
MUTEX_THREAD_LOCK(dbp->mutexp);
if (opd != NULL) {
TAILQ_INSERT_TAIL(&dbp->free_queue, opd, links);
opd = NULL;
}
TAILQ_INSERT_TAIL(&dbp->free_queue, dbc, links);
MUTEX_THREAD_UNLOCK(dbp->mutexp);
return (ret);
}
/*
* CDB___db_c_destroy --
* Destroy the cursor, called after DBC->c_close.
*
* PUBLIC: int CDB___db_c_destroy __P((DBC *));
*/
int
CDB___db_c_destroy(dbc)
DBC *dbc;
{
DB *dbp;
DBC_INTERNAL *cp;
int ret;
dbp = dbc->dbp;
cp = dbc->internal;
/* Remove the cursor from the free queue. */
MUTEX_THREAD_LOCK(dbp->mutexp);
TAILQ_REMOVE(&dbp->free_queue, dbc, links);
MUTEX_THREAD_UNLOCK(dbp->mutexp);
/* Free up allocated memory. */
if (dbc->rkey.data != NULL)
CDB___os_free(dbc->rkey.data, dbc->rkey.ulen);
if (dbc->rdata.data != NULL)
CDB___os_free(dbc->rdata.data, dbc->rdata.ulen);
/* Call the access specific cursor destroy routine. */
ret = dbc->c_am_destroy == NULL ? 0 : dbc->c_am_destroy(dbc);
CDB___os_free(dbc, sizeof(*dbc));
return (ret);
}
/*
* CDB___db_c_count --
* Return a count of duplicate data items.
*
* PUBLIC: int CDB___db_c_count __P((DBC *, db_recno_t *, u_int32_t));
*/
int
CDB___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 = CDB___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 = CDB___ham_c_count(dbc, recnop)) != 0)
return (ret);
break;
}
/* FALLTHROUGH */
case DB_BTREE:
if ((ret = CDB___bam_c_count(dbc, recnop)) != 0)
return (ret);
break;
default:
return (CDB___db_unknown_type(dbp->dbenv,
"CDB___db_c_count", dbp->type));
}
return (0);
}
/*
* CDB___db_c_del --
* Delete using a cursor.
*
* PUBLIC: int CDB___db_c_del __P((DBC *, u_int32_t));
*/
int
CDB___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 = CDB___db_cdelchk(dbp, flags,
F_ISSET(dbp, DB_AM_RDONLY), IS_INITIALIZED(dbc))) != 0)
return (ret);
DEBUG_LWRITE(dbc, dbc->txn, "db_c_del", NULL, NULL, flags);
LOCKING_INIT(dbp, dbc);
/*
* 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);
LOCKING_DONE(dbp, dbc);
return (ret);
}
/*
* CDB___db_c_dup --
* Duplicate a cursor
*
* PUBLIC: int CDB___db_c_dup __P((DBC *, DBC **, u_int32_t));
*/
int
CDB___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)) {
CDB___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 (LOCKING(dbenv) && flags != DB_POSITIONI) {
DB_ASSERT(!F_ISSET(dbc_orig, DBC_WRITER | DBC_WRITECURSOR));
if ((ret = CDB_lock_get(dbenv, dbc_n->locker, 0,
&dbc_n->lock_dbt, DB_LOCK_READ, &dbc_n->mylock)) != 0) {
(void)CDB___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;
}
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 CDB___db_c_dup.
*/
static 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 = CDB___db_icursor(dbp, dbc_orig->txn, dbc_orig->dbtype,
dbc_orig->internal->root, F_ISSET(dbc_orig, DBC_OPD), &dbc_n)) != 0)
return (ret);
dbc_n->locker = dbc_orig->locker;
/* 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;
dbc_n->flags = dbc_orig->flags;
int_n->indx = int_orig->indx;
int_n->pgno = int_orig->pgno;
int_n->root = int_orig->root;
switch (dbc_orig->dbtype) {
case DB_QUEUE:
if ((ret = CDB___qam_c_dup(dbc_orig, dbc_n)) != 0)
goto err;
break;
case DB_BTREE:
case DB_RECNO:
if ((ret = CDB___bam_c_dup(dbc_orig, dbc_n)) != 0)
goto err;
break;
case DB_HASH:
if ((ret = CDB___ham_c_dup(dbc_orig, dbc_n)) != 0)
goto err;
break;
default:
ret = CDB___db_unknown_type(dbp->dbenv,
"__db_c_idup", dbc_orig->dbtype);
goto err;
}
}
*dbcp = dbc_n;
return (0);
err: (void)dbc_n->c_close(dbc_n);
return (ret);
}
/*
* CDB___db_c_get --
* Get using a cursor.
*
* PUBLIC: int CDB___db_c_get __P((DBC *, DBT *, DBT *, u_int32_t));
*/
int
CDB___db_c_get(dbc_arg, key, data, flags)
DBC *dbc_arg;
DBT *key, *data;
u_int32_t flags;
{
DB *dbp;
DBC *dbc, *dbc_n, *opd;
DBC_INTERNAL *cp, *cp_n;
db_pgno_t pgno;
u_int32_t tmp_flags, tmp_rmw;
u_int8_t type;
int ret, t_ret;
/*
* Cursor Cleanup Note:
* All of the cursors passed to the underlying access methods by this
* routine are duplicated cursors. On return, any referenced pages
* will be discarded, and, if the cursor is not intended to be used
* again, the close function will be called. So, pages/locks that
* the cursor references do not need to be resolved by the underlying
* functions.
*/
dbp = dbc_arg->dbp;
dbc_n = NULL;
opd = NULL;
PANIC_CHECK(dbp->dbenv);
/* Check for invalid flags. */
if ((ret =
CDB___db_cgetchk(dbp, key, data, flags, IS_INITIALIZED(dbc_arg))) != 0)
return (ret);
/* Clear OR'd in additional bits so we can check for flag equality. */
tmp_rmw = LF_ISSET(DB_RMW);
LF_CLR(DB_RMW);
DEBUG_LREAD(dbc_arg, dbc_arg->txn, "db_c_get",
flags == DB_SET || flags == DB_SET_RANGE ? key : NULL, NULL, flags);
/*
* Return a cursor's record number. It has nothing to do with the
* cursor get code except that it was put into the interface.
*/
if (flags == DB_GET_RECNO)
return (CDB___bam_c_rget(dbc_arg, data, flags | tmp_rmw));
/*
* 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 DB_RMW flag was specified and the get
* operation is done in an off-page duplicate tree, call the primary
* cursor's upgrade routine first.
*/
cp = dbc_arg->internal;
if (cp->opd != NULL &&
(flags == DB_CURRENT || flags == DB_GET_BOTHC ||
flags == DB_NEXT || flags == DB_NEXT_DUP || flags == DB_PREV)) {
if (tmp_rmw && (ret = dbc_arg->c_am_writelock(dbc_arg)) != 0)
return (ret);
if ((ret = __db_c_idup(cp->opd, &opd, DB_POSITIONI)) != 0)
return (ret);
/*
* If we're in CDB, the newly dup'ed off-page dup cursor
* may need the original outer cursor's locking info.
*/
if (LOCKING(dbp->dbenv))
(void)CDB___db_cdb_cdup(dbc_arg, opd);
switch (ret = opd->c_am_get(
opd, key, data, flags, NULL)) {
case 0:
goto done;
case DB_NOTFOUND:
/*
* Translate DB_NOTFOUND failures for the DB_NEXT and
* DB_PREV operations into a subsequent operation on
* the parent cursor.
*/
if (flags == DB_NEXT || flags == DB_PREV) {
if ((ret = opd->c_close(opd)) != 0)
goto err;
opd = NULL;
break;
}
goto err;
default:
goto err;
}
}
/*
* Perform an operation on the CDB_main cursor. Duplicate the cursor,
* upgrade the lock as required, and call the underlying function.
*/
switch (flags) {
case DB_CURRENT:
case DB_GET_BOTHC:
case DB_NEXT:
case DB_NEXT_DUP:
case DB_NEXT_NODUP:
case DB_PREV:
case DB_PREV_NODUP:
tmp_flags = DB_POSITIONI;
break;
default:
tmp_flags = 0;
break;
}
if ((ret = __db_c_idup(dbc_arg, &dbc_n, tmp_flags)) != 0)
goto err;
/*
* If we're in CDB, the new cursor may need the old cursor's locking
* info.
*/
if (LOCKING(dbp->dbenv))
(void)CDB___db_cdb_cdup(dbc_arg, dbc_n);
if (tmp_rmw)
F_SET(dbc_n, DBC_RMW);
pgno = PGNO_INVALID;
ret = dbc_n->c_am_get(dbc_n, key, data, flags, &pgno);
if (tmp_rmw)
F_CLR(dbc_n, DBC_RMW);
if (ret != 0)
goto err;
cp_n = dbc_n->internal;
/*
* We may be referencing a new off-page duplicates tree. Acquire
* a new cursor and call the underlying function.
*/
if (pgno != PGNO_INVALID) {
if ((ret = CDB___db_icursor(dbp, dbc_arg->txn,
dbp->dup_compare == NULL ? DB_RECNO : DB_BTREE,
pgno, 1, &cp_n->opd)) != 0)
goto err;
switch (flags) {
case DB_FIRST:
case DB_NEXT:
case DB_NEXT_NODUP:
case DB_SET:
case DB_SET_RECNO:
case DB_SET_RANGE:
tmp_flags = DB_FIRST;
break;
case DB_LAST:
case DB_PREV:
case DB_PREV_NODUP:
tmp_flags = DB_LAST;
break;
case DB_GET_BOTH:
tmp_flags = DB_GET_BOTH;
break;
case DB_GET_BOTHC:
tmp_flags = DB_GET_BOTHC;
break;
default:
ret =
CDB___db_unknown_flag(dbp->dbenv, "CDB___db_c_get", flags);
goto err;
}
if ((ret = cp_n->opd->c_am_get(
cp_n->opd, key, data, tmp_flags, NULL)) != 0)
goto err;
}
done: /*
* Return a key/data item. The only exception is that we don't return
* a key if the user already gave us one, that is, if the DB_SET flag
* was set. The DB_SET flag is necessary. In a Btree, the user's key
* doesn't have to be the same as the key stored the tree, depending on
* the magic performed by the comparison function. As we may not have
* done any key-oriented operation here, the page reference may not be
* valid. Fill it in as necessary. We don't have to worry about any
* locks, the cursor must already be holding appropriate locks.
*
* XXX
* If not a Btree and DB_SET_RANGE is set, we shouldn't return a key
* either, should we?
*/
cp_n = dbc_n == NULL ? dbc_arg->internal : dbc_n->internal;
if (!F_ISSET(key, DB_DBT_ISSET)) {
if (cp_n->page == NULL && (ret =
CDB_memp_fget(dbp->mpf, &cp_n->pgno, 0, &cp_n->page)) != 0)
goto err;
if ((ret = CDB___db_ret(dbp, cp_n->page, cp_n->indx,
key, &dbc_arg->rkey.data, &dbc_arg->rkey.ulen)) != 0)
goto err;
}
dbc = opd != NULL ? opd : cp_n->opd != NULL ? cp_n->opd : dbc_n;
if (!F_ISSET(data, DB_DBT_ISSET)) {
type = TYPE(dbc->internal->page);
ret = CDB___db_ret(dbp, dbc->internal->page, dbc->internal->indx +
(type == P_LBTREE || type == P_HASH ? O_INDX : 0),
data, &dbc_arg->rdata.data, &dbc_arg->rdata.ulen);
}
err: /* Don't pass DB_DBT_ISSET back to application level, error or no. */
F_CLR(key, DB_DBT_ISSET);
F_CLR(data, DB_DBT_ISSET);
/* Cleanup and cursor resolution. */
if (opd != NULL) {
if ((t_ret =
__db_c_cleanup(dbc_arg->internal->opd,
opd, ret)) != 0 && ret == 0)
ret = t_ret;
}
if ((t_ret = __db_c_cleanup(dbc_arg, dbc_n, ret)) != 0 && ret == 0)
ret = t_ret;
return (ret);
}
/*
* CDB___db_c_put --
* Put using a cursor.
*
* PUBLIC: int CDB___db_c_put __P((DBC *, DBT *, DBT *, u_int32_t));
*/
int
CDB___db_c_put(dbc_arg, key, data, flags)
DBC *dbc_arg;
DBT *key, *data;
u_int32_t flags;
{
DB *dbp;
DBC *dbc_n, *opd;
db_pgno_t pgno;
u_int32_t tmp_flags;
int ret, t_ret;
/*
* Cursor Cleanup Note:
* All of the cursors passed to the underlying access methods by this
* routine are duplicated cursors. On return, any referenced pages
* will be discarded, and, if the cursor is not intended to be used
* again, the close function will be called. So, pages/locks that
* the cursor references do not need to be resolved by the underlying
* functions.
*/
dbp = dbc_arg->dbp;
dbc_n = NULL;
PANIC_CHECK(dbp->dbenv);
/* Check for invalid flags. */
if ((ret = CDB___db_cputchk(dbp, key, data, flags,
F_ISSET(dbp, DB_AM_RDONLY), IS_INITIALIZED(dbc_arg))) != 0)
return (ret);
DEBUG_LWRITE(dbc_arg, dbc_arg->txn, "db_c_put",
flags == DB_KEYFIRST || flags == DB_KEYLAST ||
flags == DB_NODUPDATA ? key : NULL, data, flags);
LOCKING_INIT(dbp, dbc_arg);
/*
* 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)) {
if ((ret = dbc_arg->c_am_writelock(dbc_arg)) != 0)
return (ret);
if ((ret = CDB___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 CDB_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 ((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) {
if ((ret = CDB___db_icursor(dbp, dbc_arg->txn,
dbp->dup_compare == NULL ? DB_RECNO : DB_BTREE,
pgno, 1, &dbc_n->internal->opd)) != 0)
goto err;
opd = dbc_n->internal->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;
LOCKING_DONE(dbp, dbc_arg);
return (ret);
}
/*
* CDB___db_duperr()
* Error message: we don't currently support sorted duplicate duplicates.
* PUBLIC: int CDB___db_duperr __P((DB *, u_int32_t));
*/
int
CDB___db_duperr(dbp, flags)
DB *dbp;
u_int32_t flags;
{
if (flags != DB_NODUPDATA)
CDB___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;
int ret, t_ret;
dbp = dbc->dbp;
internal = dbc->internal;
ret = 0;
/* Discard any pages we're holding. */
if (internal->page != NULL) {
if ((t_ret =
CDB_memp_fput(dbp->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 = CDB_memp_fput(dbp->mpf,
opd->internal->page, 0)) != 0 && ret == 0)
ret = t_ret;
opd->internal->page = NULL;
}
if (dbc_n == NULL)
return (ret);
if (dbc_n->internal->page != NULL) {
if ((t_ret = CDB_memp_fput(dbp->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 = CDB_memp_fput(dbp->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);
}
/*
* CDB___db_cdb_cdup --
* Duplicate the internal lock of a CDB write cursor. The method-
* independent cursor get and put code duplicate the cursor before
* performing operations on it, using the internal cursor interface, which
* does no CDB locking. Under normal circumstances this is desirable;
* there's no need for an additional lock, as the original cursor
* is extant--and its lock is held--throughout, and there's never a
* need to perform locking operations on the new cursor.
*
* The sole exception to this is in the case of a DBC->c_get with a
* write cursor. Here, the cursor holds only an IWRITE lock when it
* is duplicated; in the common case, there's never a need to
* perform a write. If, however, the cursor moves away from a
* deleted item in a btree, the btree close method will attempt to
* upgrade the lock to a WRITE. This close happens on the _duplicated_
* cursor, so we use this function to provide it with a copy of the
* lock. (The lock structure itself doesn't change on an
* upgrade/downgrade, so simply copying and later discarding is
* sufficient.)
*
* PUBLIC: int CDB___db_cdb_cdup __P((DBC *, DBC *));
*/
int
CDB___db_cdb_cdup(dbc_orig, dbc_n)
DBC *dbc_orig, *dbc_n;
{
if (F_ISSET(dbc_orig, DBC_WRITECURSOR | DBC_WRITEDUP)) {
memcpy(&dbc_n->mylock, &dbc_orig->mylock,
sizeof(dbc_orig->mylock));
/*
* dbc_n's locker may be different, since if it's an off-page
* duplicate it may not be an idup'ed copy of dbc_orig. It's
* not meaningful, though, so overwrite it with dbc_orig's so
* we don't self-deadlock.
*/
dbc_n->locker = dbc_orig->locker;
/*
* Flag that this lock isn't ours to put; just discard it
* in c_close.
*/
F_SET(dbc_n, DBC_WRITEDUP);
}
return (0);
}
/*
* __db_wrlock_err -- do not have a write lock.
*/
static int
__db_wrlock_err(dbenv)
DB_ENV *dbenv;
{
CDB___db_err(dbenv, "Write attempted on read-only cursor");
return (EPERM);
}