ldbm.c

来自「OpenLdap是LDAP的开源项目」· C语言 代码 · 共 1,212 行 · 第 1/2 页

#if DB_VERSION_MAJOR >= 2
	ldbm_datum_init( data );

	ldbm_datum_free( ldbm, key );
	key.flags = data.flags = DB_DBT_MALLOC;

	rc = dbcp->c_get( dbcp, &key, &data, DB_NEXT );
	if ( rc == 0 ) {
		ldbm_datum_free( ldbm, data );
	} else
#else
	rc = ldbm->seq( ldbm, &key, &data, R_NEXT );

	if ( rc == 0 ) {
		key = ldbm_datum_dup( ldbm, key );
	} else
#endif
	{
		key.dptr = NULL;
		key.dsize = 0;
	}

	LDBM_RUNLOCK;
	return( key );
}

int
ldbm_errno( LDBM ldbm )
{
	return( errno );
}

/******************************************************************
 *                                                                *
 *         END Berkeley section                                   *
 *                                                                *
 ******************************************************************/

#elif defined( HAVE_GDBM )

#ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
#include <sys/stat.h>
#endif

/*****************************************************************
 *                                                               *
 * use gdbm                                                      *
 *                                                               *
 *****************************************************************/

LDBM
ldbm_open( DB_ENV *env, char *name, int rw, int mode, int dbcachesize )
{
	LDBM		db;
#ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
		struct stat	st;
#endif
#ifdef HAVE_EBCDIC
	char n2[2048];

	strncpy(n2, name, sizeof(n2)-1);
	n2[sizeof(n2)-1] = '\0';
	__atoe(n2);
	name = n2;
#endif

	LDBM_WLOCK;

	if ( (db = gdbm_open( name, 0, rw | GDBM_FAST, mode, 0 )) == NULL ) {
		LDBM_WUNLOCK;
		return( NULL );
	}

#ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
	if ( dbcachesize > 0 && stat( name, &st ) == 0 ) {
		dbcachesize /= st.st_blksize;
		if( dbcachesize == 0 ) dbcachesize = 1;
		gdbm_setopt( db, GDBM_CACHESIZE, &dbcachesize, sizeof(int) );
	}
#else
	if ( dbcachesize > 0 ) {
		dbcachesize /= 4096;
		if( dbcachesize == 0 ) dbcachesize = 1;
		gdbm_setopt( db, GDBM_CACHESIZE, &dbcachesize, sizeof(int) );
	}
#endif

	LDBM_WUNLOCK;

	return( db );
}

void
ldbm_close( LDBM ldbm )
{
	LDBM_WLOCK;
	gdbm_close( ldbm );
	LDBM_WUNLOCK;
}

void
ldbm_sync( LDBM ldbm )
{
	LDBM_WLOCK;
	gdbm_sync( ldbm );
	LDBM_WUNLOCK;
}

Datum
ldbm_fetch( LDBM ldbm, Datum key )
{
	Datum d;

	LDBM_RLOCK;
	d = gdbm_fetch( ldbm, key );
	LDBM_RUNLOCK;

	return d;
}

int
ldbm_store( LDBM ldbm, Datum key, Datum data, int flags )
{
	int	rc;

	LDBM_WLOCK;
	rc = gdbm_store( ldbm, key, data, flags & ~LDBM_SYNC );
	if ( flags & LDBM_SYNC )
		gdbm_sync( ldbm );
	LDBM_WUNLOCK;

	return( rc );
}

int
ldbm_delete( LDBM ldbm, Datum key )
{
	int	rc;

	LDBM_WLOCK;
	rc = gdbm_delete( ldbm, key );
	gdbm_sync( ldbm );
	LDBM_WUNLOCK;

	return( rc );
}

Datum
ldbm_firstkey( LDBM ldbm, LDBMCursor **dbcp )
{
	Datum d;

	LDBM_RLOCK;
	d = gdbm_firstkey( ldbm );
	LDBM_RUNLOCK;

	if ( d.dptr != NULL ) {
		*dbcp = (Datum *) malloc( sizeof( Datum ) );
		**dbcp = ldbm_datum_dup( ldbm, d );
	}

	return d;
}

Datum
ldbm_nextkey( LDBM ldbm, Datum key, LDBMCursor *dbcp )
{
	Datum d;

	LDBM_RLOCK;
	d = gdbm_nextkey( ldbm, *dbcp );
	LDBM_RUNLOCK;

	ldbm_datum_free( ldbm, *dbcp );

	if ( d.dptr != NULL ) {
		*dbcp = ldbm_datum_dup( ldbm, d );
	} else {
		free( dbcp );
	}

	return d;
}

int
ldbm_errno( LDBM ldbm )
{
	int err;

	LDBM_WLOCK;
	err = gdbm_errno;
	LDBM_WUNLOCK;

	return( err );
}

#elif HAVE_MDBM

/* MMAPED DBM HASHING DATABASE */

#include <ac/string.h>

/* #define MDBM_DEBUG */

#ifdef MDBM_DEBUG
#include <stdio.h>
#endif

#define NO_NULL_KEY
/* #define MDBM_CHAIN */

#ifdef MDBM_CHAIN

/* Use chaining */

#define mdbm_store	mdbm_chain_store
#define mdbm_fetch	mdbm_chain_fetch
#define mdbm_delete	mdbm_chain_delete
#define mdbm_first	mdbm_chain_first
#define mdbm_next	mdbm_chain_next

#endif

#define MDBM_PG_SZ	(4*1024)

/*****************************************************************
 *                                                               *
 * use mdbm                                                      *
 *                                                               *
 *****************************************************************/

LDBM
ldbm_open( DB_ENV *env, char *name, int rw, int mode, int dbcachesize )
{
	LDBM		db;

#ifdef MDBM_DEBUG
	fprintf( stdout,
		 "==>(mdbm)ldbm_open(name=%s,rw=%x,mode=%x,cachesize=%d)\n",
		 name ? name : "NULL", rw, mode, dbcachesize );
	fflush( stdout );
#endif

	LDBM_WLOCK;	/* We need locking here, this is the only non-thread
		* safe function we have.  */

	if ( (db =  mdbm_open( name, rw, mode, MDBM_PG_SZ )) == NULL ) {
		LDBM_WUNLOCK;
#ifdef MDBM_DEBUG
		fprintf( stdout, "<==(mdbm)ldbm_open(db=NULL)\n" );
		fflush( stdout );
#endif
		return( NULL );
	}

#ifdef MDBM_CHAIN
	(void)mdbm_set_chain(db);
#endif

	LDBM_WUNLOCK;

#ifdef MDBM_DEBUG
	fprintf( stdout, "<==(mdbm)ldbm_open(db=%p)\n", db );
	fflush( stdout );
#endif

	return( db );
}

void
ldbm_close( LDBM ldbm )
{
	/* Open and close are not reentrant so we need to use locks here */

#ifdef MDBM_DEBUG
	fprintf( stdout,
		 "==>(mdbm)ldbm_close(db=%p)\n", ldbm );
	fflush( stdout );
#endif

	LDBM_WLOCK;
	mdbm_close( ldbm );
	LDBM_WUNLOCK;

#ifdef MDBM_DEBUG
	fprintf( stdout, "<==(mdbm)ldbm_close()\n" );
	fflush( stdout );
#endif
}

void
ldbm_sync( LDBM ldbm )
{
	/* XXX: Not sure if this is re-entrant need to check code, if so
	 * you can leave LOCKS out.
	 */

	LDBM_WLOCK;
	mdbm_sync( ldbm );
	LDBM_WUNLOCK;
}

#define MAX_MDBM_RETRY	5

Datum
ldbm_fetch( LDBM ldbm, Datum key )
{
	Datum	d;
	kvpair	k;
	int	retry = 0;

	/* This hack is needed because MDBM does not take keys
	 * which begin with NULL when working in the chaining
	 * mode.
	 */

#ifdef NO_NULL_KEY
	k.key.dsize = key.dsize + 1;			
	k.key.dptr = malloc(k.key.dsize);
	*(k.key.dptr) = 'l';
	AC_MEMCPY( (void *)(k.key.dptr + 1), key.dptr, key.dsize );	
#else
	k.key = key;
#endif	

	k.val.dptr = NULL;
	k.val.dsize = 0;

	/* LDBM_RLOCK; */
	do {
		d = mdbm_fetch( ldbm, k );

		if ( d.dsize > 0 ) {
			if ( k.val.dptr != NULL ) {
				free( k.val.dptr );
			}

			if ( (k.val.dptr = malloc( d.dsize )) != NULL ) {
				k.val.dsize = d.dsize;
				d = mdbm_fetch( ldbm, k );

			} else { 
				d.dsize = 0;
				break;
			}
		}/* if ( d.dsize > 0 ) */
	} while ((d.dsize > k.val.dsize) && (++retry < MAX_MDBM_RETRY));
	/* LDBM_RUNLOCK; */

#ifdef NO_NULL_KEY
	free(k.key.dptr);
#endif

	return d;
}

int
ldbm_store( LDBM ldbm, Datum key, Datum data, int flags )
{
	int	rc;
	Datum	int_key;	/* Internal key */

#ifdef MDBM_DEBUG
	fprintf( stdout,
		 "==>(mdbm)ldbm_store(db=%p, key(dptr=%p,sz=%d), data(dptr=%p,sz=%d), flags=%x)\n",
		 ldbm, key.dptr, key.dsize, data.dptr, data.dsize, flags );
	fflush( stdout );
#endif

	/* LDBM_WLOCK; */

#ifdef NO_NULL_KEY
	int_key.dsize = key.dsize + 1;
	int_key.dptr = malloc( int_key.dsize );
	*(int_key.dptr) = 'l';	/* Must not be NULL !*/
	AC_MEMCPY( (void *)(int_key.dptr + 1), key.dptr, key.dsize );
#else
	int_key = key;
#endif

	rc = mdbm_store( ldbm, int_key, data, flags );
	if ( flags & LDBM_SYNC ) {
		mdbm_sync( ldbm );
	}

	/* LDBM_WUNLOCK; */

#ifdef MDBM_DEBUG
	fprintf( stdout, "<==(mdbm)ldbm_store(rc=%d)\n", rc );
	fflush( stdout );
#endif

#ifdef NO_NULL_KEY
	free(int_key.dptr);
#endif

	return( rc );
}

int
ldbm_delete( LDBM ldbm, Datum key )
{
	int	rc;
	Datum	int_key;

	/* LDBM_WLOCK; */

#ifdef NO_NULL_KEY
	int_key.dsize = key.dsize + 1;
	int_key.dptr = malloc(int_key.dsize);
	*(int_key.dptr) = 'l';
	AC_MEMCPY( (void *)(int_key.dptr + 1), key.dptr, key.dsize );	
#else
	int_key = key;
#endif
	
	rc = mdbm_delete( ldbm, int_key );

	/* LDBM_WUNLOCK; */
#ifdef NO_NULL_KEY
	free(int_key.dptr);
#endif

	return( rc );
}

static Datum
ldbm_get_next( LDBM ldbm, kvpair (*fptr)(MDBM *, kvpair) ) 
{
	kvpair	out;
	kvpair	in;
	Datum	ret;
	size_t	sz = MDBM_PAGE_SIZE(ldbm);
#ifdef NO_NULL_KEY
	int	delta = 1;
#else
	int	delta = 0;
#endif

	/* LDBM_RLOCK; */

	in.key.dsize = sz;	/* Assume first key in one pg */
	in.key.dptr = malloc(sz);
	
	in.val.dptr = NULL;	/* Don't need data just key */ 
	in.val.dsize = 0;

	ret.dptr = NULL;
	ret.dsize = NULL;

	out = fptr( ldbm, in );

	if (out.key.dsize > 0) {
		ret.dsize = out.key.dsize - delta;

		if ((ret.dptr = (char *)malloc(ret.dsize)) == NULL) { 
			ret.dsize = 0;
			ret.dptr = NULL;

		} else {
			AC_MEMCPY(ret.dptr, (void *)(out.key.dptr + delta),
				ret.dsize );
	    }
	}

	/* LDBM_RUNLOCK; */
	
	free(in.key.dptr);
	return ret;
}

Datum
ldbm_firstkey( LDBM ldbm, LDBMCursor **dbcp )
{
	return ldbm_get_next( ldbm, mdbm_first );
}

Datum
ldbm_nextkey( LDBM ldbm, Datum key, LDBMCursor *dbcp )
{
	/* XXX:
	 * don't know if this will affect the LDAP server operation 
	 * but mdbm cannot take and input key.
	 */

	return ldbm_get_next( ldbm, mdbm_next );
}

int
ldbm_errno( LDBM ldbm )
{
	/* XXX: best we can do with current  mdbm interface */
	return( errno );
}

#elif defined( HAVE_NDBM )

/*****************************************************************
 *                                                               *
 * if no gdbm or mdbm, fall back to using ndbm, the standard unix thing  *
 *                                                               *
 *****************************************************************/

/* ARGSUSED */
LDBM
ldbm_open( DB_ENV *env, char *name, int rw, int mode, int dbcachesize )
{
	LDBM ldbm;

	LDBM_WLOCK;
	ldbm = dbm_open( name, rw, mode );
	LDBM_WUNLOCK;

	return( ldbm );
}

void
ldbm_close( LDBM ldbm )
{
	LDBM_WLOCK;
	dbm_close( ldbm );
	LDBM_WUNLOCK;
}

/* ARGSUSED */
void
ldbm_sync( LDBM ldbm )
{
	return;
}

Datum
ldbm_fetch( LDBM ldbm, Datum key )
{
	Datum d;

	LDBM_RLOCK;
	d = ldbm_datum_dup( ldbm, dbm_fetch( ldbm, key ) );
	LDBM_RUNLOCK;

	return d;
}

int
ldbm_store( LDBM ldbm, Datum key, Datum data, int flags )
{
	int rc;

	LDBM_WLOCK;
	rc = dbm_store( ldbm, key, data, flags );
	LDBM_WUNLOCK;

	return rc;
}

int
ldbm_delete( LDBM ldbm, Datum key )
{
	int rc;

	LDBM_WLOCK;
	rc = dbm_delete( ldbm, key );
	LDBM_WUNLOCK;

	return rc;
}

Datum
ldbm_firstkey( LDBM ldbm, LDBMCursor **dbcp )
{
	Datum d;

	LDBM_RLOCK;
	d = dbm_firstkey( ldbm );
	LDBM_RUNLOCK;

	return d;
}

Datum
ldbm_nextkey( LDBM ldbm, Datum key, LDBMCursor *dbcp )
{
	Datum d;

	LDBM_RLOCK;
	d = dbm_nextkey( ldbm );
	LDBM_RUNLOCK;

	return d;
}

int
ldbm_errno( LDBM ldbm )
{
	int err;

	LDBM_WLOCK;
	err = dbm_error( ldbm );
	LDBM_WUNLOCK;

	return err;
}

#endif /* ndbm */
#endif /* ldbm */