X-Git-Url: http://git.bytex64.net/?a=blobdiff_plain;f=database%2Fdatabase.c;h=e6e87075e43cbeb896728ad32f8cfe8fa101bad3;hb=c65ce42fec106b10019bae07456f651bb175bbaa;hp=a45c92bc3dbdaa7f1cb8f9fc902215aa26f5703a;hpb=ec8746b44dc85fd3e3b42835f779890684a9e90a;p=blerg.git

diff --git a/database/database.c b/database/database.c
index a45c92b..e6e8707 100644
--- a/database/database.c
+++ b/database/database.c
@@ -164,10 +164,17 @@ struct blerg *blerg_open(const char *name) {
 		goto open_failed_meta_open;
 	}
 	fstat(blerg->meta_fd, &st);
-	if (st.st_size == 0) {
-		char *buf = (char *) malloc(sizeof(struct meta));
-		memset(buf, 0, sizeof(struct meta));
-		write(blerg->meta_fd, buf, sizeof(struct meta));
+	if (st.st_size < sizeof(struct meta)) {
+		// Fill the difference in size between sizeof(struct meta) and
+		// the file size with nulls.  This allows seamless upgrades as
+		// long as struct meta only adds members.
+		int len = sizeof(struct meta) - st.st_size;
+		char *buf = (char *) malloc(len);
+		memset(buf, 0, len);
+		int tmpfd = dup(blerg->meta_fd);
+		FILE* tmp = fdopen(tmpfd, "a");
+		fwrite(buf, len, 1, tmp);
+		fclose(tmp);
 		free(buf);
 	}
 	blerg->meta = (struct meta *) mmap(NULL, sizeof(struct meta), PROT_READ | PROT_WRITE, MAP_SHARED, blerg->meta_fd, 0);
@@ -324,3 +331,11 @@ time_t blerg_get_timestamp(struct blerg *blerg, int record) {
 
 	return blerg->index[seg_rec].timestamp;
 }
+
+int blerg_set_subscription_mark(struct blerg *blerg) {
+	blerg->meta->subscription_mark = subscription_count_items(blerg->name);
+}
+
+uint64_t blerg_get_subscription_mark(struct blerg *blerg) {
+	return blerg->meta->subscription_mark;
+}