openldap/servers/slapd/back-ldbm/dbcache.c
2001-01-17 17:01:19 +00:00

358 lines
8.9 KiB
C

/* ldbmcache.c - maintain a cache of open ldbm files */
/* $OpenLDAP$ */
/*
* Copyright 1998-2000 The OpenLDAP Foundation, All Rights Reserved.
* COPYING RESTRICTIONS APPLY, see COPYRIGHT file
*/
#include "portable.h"
#include <stdio.h>
#include <ac/errno.h>
#include <ac/socket.h>
#include <ac/string.h>
#include <ac/time.h>
#include <sys/stat.h>
#include "slap.h"
#include "back-ldbm.h"
DBCache *
ldbm_cache_open(
Backend *be,
const char *name,
const char *suffix,
int flags
)
{
struct ldbminfo *li = (struct ldbminfo *) be->be_private;
int i, lru, empty;
time_t oldtime, curtime;
char buf[MAXPATHLEN];
#ifdef HAVE_ST_BLKSIZE
struct stat st;
#endif
sprintf( buf, "%s" LDAP_DIRSEP "%s%s",
li->li_directory, name, suffix );
if( li->li_dblocking ) {
flags |= LDBM_LOCKING;
} else {
flags |= LDBM_NOLOCKING;
}
if( li->li_dbwritesync ) {
flags |= LDBM_SYNC;
} else {
flags |= LDBM_NOSYNC;
}
#ifdef NEW_LOGGING
LDAP_LOG(( "cache", LDAP_LEVEL_ENTRY,
"ldbm_cache_open: \"%s\", %d, %o\n", buf, flags, li->li_mode ));
#else
Debug( LDAP_DEBUG_TRACE, "=> ldbm_cache_open( \"%s\", %d, %o )\n", buf,
flags, li->li_mode );
#endif
curtime = slap_get_time();
empty = MAXDBCACHE;
ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
do {
lru = 0;
oldtime = curtime;
for ( i = 0; i < MAXDBCACHE; i++ ) {
/* see if this slot is free */
if ( li->li_dbcache[i].dbc_name == NULL) {
if (empty == MAXDBCACHE)
empty = i;
continue;
}
if ( strcmp( li->li_dbcache[i].dbc_name, buf ) == 0 ) {
/* already open - return it */
if (li->li_dbcache[i].dbc_flags != flags
&& li->li_dbcache[i].dbc_refcnt == 0)
{
/* we don't want to use an open cache with different
* permissions (esp. if we need write but the open
* cache is read-only). So close this one if
* possible, and re-open below.
*
* FIXME: what about the case where the refcount
* is > 0? right now, we're using it anyway and
* just praying. Can there be more than one open
* cache to the same db?
*
* Also, it's really only necessary to compare the
* read-only flag, instead of all of the flags,
* but for now I'm checking all of them.
*/
lru = i;
empty = MAXDBCACHE;
break;
}
li->li_dbcache[i].dbc_refcnt++;
#ifdef NEW_LOGGING
LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
"ldbm_cache_open: cache %d\n", i ));
#else
Debug( LDAP_DEBUG_TRACE,
"<= ldbm_cache_open (cache %d)\n", i, 0, 0 );
#endif
ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
return( &li->li_dbcache[i] );
}
/* keep track of lru db */
if ( li->li_dbcache[i].dbc_lastref < oldtime
&& li->li_dbcache[i].dbc_refcnt == 0 )
{
lru = i;
oldtime = li->li_dbcache[i].dbc_lastref;
}
}
i = empty;
if ( i == MAXDBCACHE ) {
/* no empty slots, not already open - close lru and use that slot */
if ( li->li_dbcache[lru].dbc_refcnt == 0 ) {
i = lru;
ldbm_close( li->li_dbcache[i].dbc_db );
free( li->li_dbcache[i].dbc_name );
li->li_dbcache[i].dbc_name = NULL;
} else {
#ifdef NEW_LOGGING
LDAP_LOG(( "cache", LDAP_LEVEL_INFO,
"ldbm_cache_open: no unused db to close - waiting\n" ));
#else
Debug( LDAP_DEBUG_ANY,
"ldbm_cache_open no unused db to close - waiting\n",
0, 0, 0 );
#endif
ldap_pvt_thread_cond_wait( &li->li_dbcache_cv,
&li->li_dbcache_mutex );
/* after waiting for a free slot, go back to square
* one: look for an open cache for this db, or an
* empty slot, or an unref'ed cache, or wait again.
*/
}
}
} while (i == MAXDBCACHE);
if ( (li->li_dbcache[i].dbc_db = ldbm_open( buf, flags, li->li_mode,
li->li_dbcachesize )) == NULL )
{
int err = errno;
#ifdef NEW_LOGGING
LDAP_LOG(( "cache", LDAP_LEVEL_ERR,
"ldbm_cache_open: \"%s\" failed, errono=%d, reason=%s\n",
buf, err, err > -1 && err < sys_nerr ? sys_errlist[err] :
"unknown" ));
#else
Debug( LDAP_DEBUG_TRACE,
"<= ldbm_cache_open NULL \"%s\" errno=%d reason=\"%s\")\n",
buf, err, err > -1 && err < sys_nerr ?
sys_errlist[err] : "unknown" );
#endif
ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
return( NULL );
}
li->li_dbcache[i].dbc_name = ch_strdup( buf );
li->li_dbcache[i].dbc_refcnt = 1;
li->li_dbcache[i].dbc_lastref = curtime;
li->li_dbcache[i].dbc_flags = flags;
li->li_dbcache[i].dbc_dirty = 0;
#ifdef HAVE_ST_BLKSIZE
if ( stat( buf, &st ) == 0 ) {
li->li_dbcache[i].dbc_blksize = st.st_blksize;
} else
#endif
{
li->li_dbcache[i].dbc_blksize = DEFAULT_BLOCKSIZE;
}
li->li_dbcache[i].dbc_maxids = (li->li_dbcache[i].dbc_blksize /
sizeof(ID)) - ID_BLOCK_IDS_OFFSET;
li->li_dbcache[i].dbc_maxindirect = ( SLAPD_LDBM_MIN_MAXIDS /
li->li_dbcache[i].dbc_maxids ) + 1;
assert( li->li_dbcache[i].dbc_maxindirect < 256 );
#ifdef NEW_LOGGING
LDAP_LOG(( "cache", LDAP_LEVEL_ARGS,
"ldbm_cache_open: blksize:%ld maxids:%d maxindirect:%d\n",
li->li_dbcache[i].dbc_blksize, li->li_dbcache[i].dbc_maxids,
li->li_dbcache[i].dbc_maxindirect ));
#else
Debug( LDAP_DEBUG_ARGS,
"ldbm_cache_open (blksize %ld) (maxids %d) (maxindirect %d)\n",
li->li_dbcache[i].dbc_blksize, li->li_dbcache[i].dbc_maxids,
li->li_dbcache[i].dbc_maxindirect );
#endif
#ifdef NEW_LOGGING
LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
"ldbm_cache_open: opened %d\n", i ));
#else
Debug( LDAP_DEBUG_TRACE, "<= ldbm_cache_open (opened %d)\n", i, 0, 0 );
#endif
ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
return( &li->li_dbcache[i] );
}
void
ldbm_cache_close( Backend *be, DBCache *db )
{
struct ldbminfo *li = (struct ldbminfo *) be->be_private;
if( li->li_dbwritesync && db->dbc_dirty ) {
ldbm_sync( db->dbc_db );
db->dbc_dirty = 0;
}
ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
if ( --db->dbc_refcnt <= 0 ) {
db->dbc_refcnt = 0;
ldap_pvt_thread_cond_signal( &li->li_dbcache_cv );
}
ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
}
void
ldbm_cache_really_close( Backend *be, DBCache *db )
{
struct ldbminfo *li = (struct ldbminfo *) be->be_private;
ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
if ( --db->dbc_refcnt <= 0 ) {
db->dbc_refcnt = 0;
ldap_pvt_thread_cond_signal( &li->li_dbcache_cv );
ldbm_close( db->dbc_db );
free( db->dbc_name );
db->dbc_name = NULL;
}
ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
}
void
ldbm_cache_flush_all( Backend *be )
{
struct ldbminfo *li = (struct ldbminfo *) be->be_private;
int i;
ldap_pvt_thread_mutex_lock( &li->li_dbcache_mutex );
for ( i = 0; i < MAXDBCACHE; i++ ) {
if ( li->li_dbcache[i].dbc_name != NULL ) {
#ifdef NEW_LOGGING
LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
"ldbm_cache_flush_all: flushing db (%s)\n",
li->li_dbcache[i].dbc_name ));
#else
Debug( LDAP_DEBUG_TRACE, "ldbm flushing db (%s)\n",
li->li_dbcache[i].dbc_name, 0, 0 );
#endif
ldbm_sync( li->li_dbcache[i].dbc_db );
li->li_dbcache[i].dbc_dirty = 0;
if ( li->li_dbcache[i].dbc_refcnt != 0 ) {
#ifdef NEW_LOGGING
LDAP_LOG(( "cache", LDAP_LEVEL_INFO,
"ldbm_cache_flush_all: couldn't close db (%s), refcnt=%d\n",
li->li_dbcache[i].dbc_name, li->li_dbcache[i].dbc_refcnt ));
#else
Debug( LDAP_DEBUG_TRACE,
"refcnt = %d, couldn't close db (%s)\n",
li->li_dbcache[i].dbc_refcnt,
li->li_dbcache[i].dbc_name, 0 );
#endif
} else {
#ifdef NEW_LOGGING
LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
"ldbm_cache_flush_all: ldbm closing db (%s)\n",
li->li_dbcache[i].dbc_name ));
#else
Debug( LDAP_DEBUG_TRACE,
"ldbm closing db (%s)\n",
li->li_dbcache[i].dbc_name, 0, 0 );
#endif
ldap_pvt_thread_cond_signal( &li->li_dbcache_cv );
ldbm_close( li->li_dbcache[i].dbc_db );
free( li->li_dbcache[i].dbc_name );
li->li_dbcache[i].dbc_name = NULL;
}
}
}
ldap_pvt_thread_mutex_unlock( &li->li_dbcache_mutex );
}
Datum
ldbm_cache_fetch(
DBCache *db,
Datum key
)
{
Datum data;
return ldbm_fetch( db->dbc_db, key );
return( data );
}
int
ldbm_cache_store(
DBCache *db,
Datum key,
Datum data,
int flags
)
{
int rc;
#ifdef LDBM_DEBUG
Statslog( LDAP_DEBUG_STATS,
"=> ldbm_cache_store(): key.dptr=%s, key.dsize=%d\n",
key.dptr, key.dsize, 0, 0, 0 );
Statslog( LDAP_DEBUG_STATS,
"=> ldbm_cache_store(): key.dptr=0x%08x, data.dptr=0x%0 8x\n",
key.dptr, data.dptr, 0, 0, 0 );
Statslog( LDAP_DEBUG_STATS,
"=> ldbm_cache_store(): data.dptr=%s, data.dsize=%d\n",
data.dptr, data.dsize, 0, 0, 0 );
Statslog( LDAP_DEBUG_STATS,
"=> ldbm_cache_store(): flags=0x%08x\n",
flags, 0, 0, 0, 0 );
#endif /* LDBM_DEBUG */
db->dbc_dirty = 1;
rc = ldbm_store( db->dbc_db, key, data, flags );
return( rc );
}
int
ldbm_cache_delete(
DBCache *db,
Datum key
)
{
int rc;
db->dbc_dirty = 1;
rc = ldbm_delete( db->dbc_db, key );
return( rc );
}