DBM Filters (via private mail)

	Message-Id: <199904182009.NAA19152@activestate.com>
	Subject: DBM Filters

p4raw-id: //depot/perl@3317

3 files changed, 136 insertions, 22 deletions

diff --git a/ext/NDBM_File/NDBM_File.pm b/ext/NDBM_File/NDBM_File.pm
index ed4fe2b36f..cad800adf4 100644
--- a/ext/NDBM_File/NDBM_File.pm
+++ b/ext/NDBM_File/NDBM_File.pm
@@ -12,7 +12,7 @@ require DynaLoader;
 
 @ISA = qw(Tie::Hash DynaLoader);
 
-$VERSION = "1.01";
+$VERSION = "1.02";
 
 bootstrap NDBM_File $VERSION;
 
@@ -35,6 +35,6 @@ NDBM_File - Tied access to ndbm files
 
 =head1 DESCRIPTION
 
-See L<perlfunc/tie>
+See L<perlfunc/tie>, L<perldbmfilter>
 
 =cut
diff --git a/ext/NDBM_File/NDBM_File.xs b/ext/NDBM_File/NDBM_File.xs
index d129a9c490..f5bc0f9a6a 100644
--- a/ext/NDBM_File/NDBM_File.xs
+++ b/ext/NDBM_File/NDBM_File.xs
@@ -3,13 +3,37 @@
 #include "XSUB.h"
 #include <ndbm.h>
 
-typedef DBM* NDBM_File;
-#define dbm_TIEHASH(dbtype,filename,flags,mode) dbm_open(filename,flags,mode)
-#define dbm_FETCH(db,key)			dbm_fetch(db,key)
-#define dbm_STORE(db,key,value,flags)		dbm_store(db,key,value,flags)
-#define dbm_DELETE(db,key)			dbm_delete(db,key)
-#define dbm_FIRSTKEY(db)			dbm_firstkey(db)
-#define dbm_NEXTKEY(db,key)			dbm_nextkey(db)
+typedef struct {
+	DBM * 	dbp ;
+	SV *    filter_fetch_key ;
+	SV *    filter_store_key ;
+	SV *    filter_fetch_value ;
+	SV *    filter_store_value ;
+	int     filtering ;
+	} NDBM_File_type;
+
+typedef NDBM_File_type * NDBM_File ;
+typedef datum datum_key ;
+typedef datum datum_value ;
+
+#define ckFilter(arg,type,name)					\
+	if (db->type) {						\
+	    SV * save_defsv ;					\
+            /* printf("filtering %s\n", name) ;*/		\
+	    if (db->filtering)					\
+	        croak("recursion detected in %s", name) ;	\
+	    db->filtering = TRUE ;				\
+	    save_defsv = newSVsv(DEFSV) ;			\
+	    sv_setsv(DEFSV, arg) ;				\
+	    PUSHMARK(sp) ;					\
+	    (void) perl_call_sv(db->type, G_DISCARD|G_NOARGS); 	\
+	    sv_setsv(arg, DEFSV) ;				\
+	    sv_setsv(DEFSV, save_defsv) ;			\
+	    SvREFCNT_dec(save_defsv) ;				\
+	    db->filtering = FALSE ;				\
+	    /*printf("end of filtering %s\n", name) ;*/		\
+	}
+
 
 MODULE = NDBM_File	PACKAGE = NDBM_File	PREFIX = dbm_
 
@@ -19,23 +43,39 @@ dbm_TIEHASH(dbtype, filename, flags, mode)
 	char *		filename
 	int		flags
 	int		mode
+	CODE:
+	{
+	    DBM * 	dbp ;
+
+	    RETVAL = NULL ;
+	    if (dbp =  dbm_open(filename, flags, mode)) {
+	        RETVAL = (NDBM_File)safemalloc(sizeof(NDBM_File_type)) ;
+    	        Zero(RETVAL, 1, NDBM_File_type) ;
+		RETVAL->dbp = dbp ;
+	    }
+	    
+	}
+	OUTPUT:
+	  RETVAL
 
 void
 dbm_DESTROY(db)
 	NDBM_File	db
 	CODE:
-	dbm_close(db);
+	dbm_close(db->dbp);
 
-datum
+#define dbm_FETCH(db,key)			dbm_fetch(db->dbp,key)
+datum_value
 dbm_FETCH(db, key)
 	NDBM_File	db
-	datum		key
+	datum_key	key
 
+#define dbm_STORE(db,key,value,flags)		dbm_store(db->dbp,key,value,flags)
 int
 dbm_STORE(db, key, value, flags = DBM_REPLACE)
 	NDBM_File	db
-	datum		key
-	datum		value
+	datum_key	key
+	datum_value	value
 	int		flags
     CLEANUP:
 	if (RETVAL) {
@@ -43,28 +83,92 @@ dbm_STORE(db, key, value, flags = DBM_REPLACE)
 		croak("No write permission to ndbm file");
 	    croak("ndbm store returned %d, errno %d, key \"%s\"",
 			RETVAL,errno,key.dptr);
-	    dbm_clearerr(db);
+	    dbm_clearerr(db->dbp);
 	}
 
+#define dbm_DELETE(db,key)			dbm_delete(db->dbp,key)
 int
 dbm_DELETE(db, key)
 	NDBM_File	db
-	datum		key
+	datum_key	key
 
-datum
+#define dbm_FIRSTKEY(db)			dbm_firstkey(db->dbp)
+datum_key
 dbm_FIRSTKEY(db)
 	NDBM_File	db
 
-datum
+#define dbm_NEXTKEY(db,key)			dbm_nextkey(db->dbp)
+datum_key
 dbm_NEXTKEY(db, key)
 	NDBM_File	db
-	datum		key
+	datum_key	key
 
+#define dbm_error(db)				dbm_error(db->dbp)
 int
 dbm_error(db)
 	NDBM_File	db
 
+#define dbm_clearerr(db)			dbm_clearerr(db->dbp)
 void
 dbm_clearerr(db)
 	NDBM_File	db
 
+
+#define setFilter(type)					\
+	{						\
+	    if (db->type)				\
+	        RETVAL = newSVsv(db->type) ; 		\
+	    if (db->type && (code == &PL_sv_undef)) {	\
+                SvREFCNT_dec(db->type) ;		\
+	        db->type = NULL ;			\
+	    }						\
+	    else if (code) {				\
+	        if (db->type)				\
+	            sv_setsv(db->type, code) ;		\
+	        else					\
+	            db->type = newSVsv(code) ;		\
+	    }	    					\
+	}
+
+
+
+SV *
+filter_fetch_key(db, code)
+	NDBM_File	db
+	SV *		code
+	SV *		RETVAL = &PL_sv_undef ;
+	CODE:
+	    setFilter(filter_fetch_key) ;
+	OUTPUT:
+	    RETVAL
+
+SV *
+filter_store_key(db, code)
+	NDBM_File	db
+	SV *		code
+	SV *		RETVAL =  &PL_sv_undef ;
+	CODE:
+	    setFilter(filter_store_key) ;
+	OUTPUT:
+	    RETVAL
+
+SV *
+filter_fetch_value(db, code)
+	NDBM_File	db
+	SV *		code
+	SV *		RETVAL =  &PL_sv_undef ;
+	CODE:
+	    setFilter(filter_fetch_value) ;
+	OUTPUT:
+	    RETVAL
+
+SV *
+filter_store_value(db, code)
+	NDBM_File	db
+	SV *		code
+	SV *		RETVAL =  &PL_sv_undef ;
+	CODE:
+	    setFilter(filter_store_value) ;
+	OUTPUT:
+	    RETVAL
+
diff --git a/ext/NDBM_File/typemap b/ext/NDBM_File/typemap
index 317a8f3886..eeb5d59027 100644
--- a/ext/NDBM_File/typemap
+++ b/ext/NDBM_File/typemap
@@ -2,7 +2,8 @@
 #################################### DBM SECTION
 #
 
-datum			T_DATUM
+datum_key		T_DATUM_K
+datum_value		T_DATUM_V
 gdatum			T_GDATUM
 NDBM_File		T_PTROBJ
 GDBM_File		T_PTROBJ
@@ -13,14 +14,23 @@ DBZ_File		T_PTROBJ
 FATALFUNC		T_OPAQUEPTR
 
 INPUT
-T_DATUM
+T_DATUM_K
+	ckFilter($arg, filter_store_key, \"filter_store_key\");
+	$var.dptr = SvPV($arg, PL_na);
+	$var.dsize = (int)PL_na;
+T_DATUM_V
+        ckFilter($arg, filter_store_value, \"filter_store_value\");
 	$var.dptr = SvPV($arg, PL_na);
 	$var.dsize = (int)PL_na;
 T_GDATUM
 	UNIMPLEMENTED
 OUTPUT
-T_DATUM
+T_DATUM_K
+	sv_setpvn($arg, $var.dptr, $var.dsize);
+	ckFilter($arg, filter_fetch_key,\"filter_fetch_key\");
+T_DATUM_V
 	sv_setpvn($arg, $var.dptr, $var.dsize);
+	ckFilter($arg, filter_fetch_value,\"filter_fetch_value\");
 T_GDATUM
 	sv_usepvn($arg, $var.dptr, $var.dsize);
 T_PTROBJ