Implement GDBM map backend.

* README: Document --with-gdbm
* configure.ac: Detect libgdbm.  New option --with-gdbm.
* lib/gdbmmap.c
* lib/Makefile.am (maps) [COND_GDBM]: Add new file.
* lib/libeclat.h (eclat_map_drv_gdbm): New extern.
* src/Makefile.am (LDADD): Add MAPLIBS.
* src/eclat.c (mail) [WITH_GDBM]: Register eclat_map_drv_gdbm.

1 files changed, 116 insertions, 0 deletions

diff --git a/lib/gdbmmap.c b/lib/gdbmmap.c
new file mode 100644
index 0000000..4fdaa33
--- /dev/null
+++ b/lib/gdbmmap.c
@@ -0,0 +1,116 @@
+/* This file is part of Eclat.
+   Copyright (C) 2012 Sergey Poznyakoff.
+ 
+   Eclat is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+ 
+   Eclat is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+ 
+   You should have received a copy of the GNU General Public License
+   along with Eclat.  If not, see <http://www.gnu.org/licenses/>. */
+
+#include "libeclat.h"
+#include <gdbm.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+
+struct gdbm_map {
+	char *name;
+	GDBM_FILE file;
+	struct grecs_locus locus;
+	int nullflag;
+};
+
+static int
+gdbm_map_config(int dbg, struct grecs_node *node, void *data)
+{
+	struct gdbm_map *gdbm_map, **return_gdbm_map = data;
+	const char *filename;
+	struct grecs_node *p;
+	
+	if (eclat_get_string_node(node, "file", 0, &p))
+		return eclat_map_failure;
+	gdbm_map = grecs_malloc(sizeof(*gdbm_map));
+	gdbm_map->name = grecs_strdup(p->v.value->v.string);
+	gdbm_map->locus = p->locus;
+	switch (eclat_get_string_node(node, "null", 1, &p)) {
+	case eclat_map_failure:
+		return eclat_map_failure;
+	case eclat_map_not_found:
+		break;
+	case eclat_map_ok:
+		if (grecs_string_convert(&gdbm_map->nullflag, grecs_type_bool,
+					 p->v.value->v.string,
+					 &p->locus))
+			return eclat_map_failure;
+	}
+		
+	*return_gdbm_map = gdbm_map;
+	return eclat_map_ok;
+}
+
+static void
+gdbm_map_free(int dbg, void *data)
+{
+	struct gdbm_map *gdbm_map = data;
+	free(gdbm_map->name);
+	free(gdbm_map);
+}
+
+static int
+gdbm_map_open(int dbg, void *data)
+{
+	struct gdbm_map *gdbm_map = data;
+
+	gdbm_map->file = gdbm_open(gdbm_map->name, 512, GDBM_READER, O_RDONLY,
+				   NULL);
+	if (gdbm_map->file == NULL)
+		return eclat_map_failure;
+	return eclat_map_ok;
+}
+
+static int
+gdbm_map_close(int dbg, void *data)
+{
+	struct gdbm_map *gdbm_map = data;
+	gdbm_close(gdbm_map->file);
+	return eclat_map_ok;
+}
+
+static int
+gdbm_map_get(int dbg, void *data, const char *key, char **return_value)
+{
+	struct gdbm_map *gdbm_map = data;
+	datum keydat, content;
+
+	keydat.dptr = (char*)key;
+	keydat.dsize = strlen(key) + (gdbm_map->nullflag ? 1 : 0);
+	gdbm_errno = 0;
+	content = gdbm_fetch(gdbm_map->file, keydat);
+	if (content.dptr == NULL) {
+		if (gdbm_errno == GDBM_ITEM_NOT_FOUND)
+			return eclat_map_not_found;
+		err("%s: %s", gdbm_map->name, gdbm_strerror(gdbm_errno));
+		return eclat_map_failure;
+	}
+	*return_value = grecs_malloc(content.dsize + 1);
+	memcpy(*return_value, content.dptr, content.dsize);
+	(*return_value)[content.dsize] = 0;
+	free (content.dptr);
+	return eclat_map_ok;
+}
+
+struct eclat_map_drv eclat_map_drv_gdbm = {
+	"gdbm",
+	gdbm_map_config,
+	gdbm_map_open,
+	gdbm_map_close,
+	gdbm_map_get,
+	gdbm_map_free
+};