tdb2: Implement tdb_get_flags, tdb_add_flag and tdb_remove_flag.

ccan/tdb2/tdb.c

@@ -758,6 +758,59 @@ int tdb_close(struct tdb_context *tdb)
 	return ret;
 }
 
+unsigned int tdb_get_flags(struct tdb_context *tdb)
+{
+	return tdb->flags;
+}
+
+void tdb_add_flag(struct tdb_context *tdb, unsigned flag)
+{
+	if (tdb->flags & TDB_INTERNAL) {
+		tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
+			   "tdb_add_flag: internal db");
+		return;
+	}
+	switch (flag) {
+	case TDB_NOLOCK:
+		tdb->flags |= TDB_NOLOCK;
+		break;
+	case TDB_NOMMAP:
+		tdb->flags |= TDB_NOMMAP;
+		tdb_munmap(tdb);
+		break;
+	case TDB_NOSYNC:
+		tdb->flags |= TDB_NOSYNC;
+		break;
+	default:
+		tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
+			   "tdb_add_flag: Unknown flag %u", flag);
+	}
+}
+
+void tdb_remove_flag(struct tdb_context *tdb, unsigned flag)
+{
+	if (tdb->flags & TDB_INTERNAL) {
+		tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
+			   "tdb_remove_flag: internal db");
+		return;
+	}
+	switch (flag) {
+	case TDB_NOLOCK:
+		tdb->flags &= ~TDB_NOLOCK;
+		break;
+	case TDB_NOMMAP:
+		tdb->flags &= ~TDB_NOMMAP;
+		tdb_mmap(tdb);
+		break;
+	case TDB_NOSYNC:
+		tdb->flags &= ~TDB_NOSYNC;
+		break;
+	default:
+		tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
+			   "tdb_remove_flag: Unknown flag %u", flag);
+	}
+}
+
 const char *tdb_errorstr(enum TDB_ERROR ecode)
 {
 	/* Gcc warns if you miss a case in the switch, so use that. */

ccan/tdb2/tdb2.h

@@ -379,6 +379,37 @@ enum TDB_ERROR tdb_summary(struct tdb_context *tdb,
 			   enum tdb_summary_flags flags,
 			   char **summary);
 
+ 
+/**
+ * tdb_get_flags - return the flags for a tdb
+ * @tdb: the tdb context returned from tdb_open()
+ *
+ * This returns the flags on the current tdb.  Some of these are caused by
+ * the flags argument to tdb_open(), others (such as TDB_CONVERT) are
+ * intuited.
+ */
+unsigned int tdb_get_flags(struct tdb_context *tdb);
+
+/**
+ * tdb_add_flag - set a flag for a tdb
+ * @tdb: the tdb context returned from tdb_open()
+ * @flag: one of TDB_NOLOCK, TDB_NOMMAP or TDB_NOSYNC.
+ *
+ * You can use this to set a flag on the TDB.  You cannot set these flags
+ * on a TDB_INTERNAL tdb.
+ */
+void tdb_add_flag(struct tdb_context *tdb, unsigned flag);
+
+/**
+ * tdb_remove_flag - unset a flag for a tdb
+ * @tdb: the tdb context returned from tdb_open()
+ * @flag: one of TDB_NOLOCK, TDB_NOMMAP or TDB_NOSYNC.
+ *
+ * You can use this to clear a flag on the TDB.  You cannot clear flags
+ * on a TDB_INTERNAL tdb.
+ */
+void tdb_remove_flag(struct tdb_context *tdb, unsigned flag);
+
 /**
  * enum tdb_attribute_type - descriminator for union tdb_attribute.
  */

ccan/tdb2/test/run-add-remove-flags.c

@@ -0,0 +1,92 @@
+#include <ccan/tdb2/tdb.c>
+#include <ccan/tdb2/free.c>
+#include <ccan/tdb2/lock.c>
+#include <ccan/tdb2/io.c>
+#include <ccan/tdb2/hash.c>
+#include <ccan/tdb2/check.c>
+#include <ccan/tdb2/traverse.c>
+#include <ccan/tdb2/transaction.c>
+#include <ccan/tap/tap.h>
+#include "logging.h"
+
+int main(int argc, char *argv[])
+{
+	unsigned int i;
+	struct tdb_context *tdb;
+	int flags[] = { TDB_INTERNAL, TDB_DEFAULT, TDB_NOMMAP,
+			TDB_INTERNAL|TDB_CONVERT, TDB_CONVERT, 
+			TDB_NOMMAP|TDB_CONVERT };
+
+	plan_tests(87);
+	for (i = 0; i < sizeof(flags) / sizeof(flags[0]); i++) {
+		tdb = tdb_open("run-add-remove-flags.tdb", flags[i],
+			       O_RDWR|O_CREAT|O_TRUNC, 0600, &tap_log_attr);
+		ok1(tdb);
+		if (!tdb)
+			continue;
+
+		ok1(tdb_get_flags(tdb) == tdb->flags);
+		tap_log_messages = 0;
+		tdb_add_flag(tdb, TDB_NOLOCK);
+		if (flags[i] & TDB_INTERNAL)
+			ok1(tap_log_messages == 1);
+		else {
+			ok1(tap_log_messages == 0);
+			ok1(tdb_get_flags(tdb) & TDB_NOLOCK);
+		}
+
+		tap_log_messages = 0;
+		tdb_add_flag(tdb, TDB_NOMMAP);
+		if (flags[i] & TDB_INTERNAL)
+			ok1(tap_log_messages == 1);
+		else {
+			ok1(tap_log_messages == 0);
+			ok1(tdb_get_flags(tdb) & TDB_NOMMAP);
+			ok1(tdb->map_ptr == NULL);
+		}
+
+		tap_log_messages = 0;
+		tdb_add_flag(tdb, TDB_NOSYNC);
+		if (flags[i] & TDB_INTERNAL)
+			ok1(tap_log_messages == 1);
+		else {
+			ok1(tap_log_messages == 0);
+			ok1(tdb_get_flags(tdb) & TDB_NOSYNC);
+		}
+
+		ok1(tdb_get_flags(tdb) == tdb->flags);
+
+		tap_log_messages = 0;
+		tdb_remove_flag(tdb, TDB_NOLOCK);
+		if (flags[i] & TDB_INTERNAL)
+			ok1(tap_log_messages == 1);
+		else {
+			ok1(tap_log_messages == 0);
+			ok1(!(tdb_get_flags(tdb) & TDB_NOLOCK));
+		}
+
+		tap_log_messages = 0;
+		tdb_remove_flag(tdb, TDB_NOMMAP);
+		if (flags[i] & TDB_INTERNAL)
+			ok1(tap_log_messages == 1);
+		else {
+			ok1(tap_log_messages == 0);
+			ok1(!(tdb_get_flags(tdb) & TDB_NOMMAP));
+			ok1(tdb->map_ptr != NULL);
+		}
+
+		tap_log_messages = 0;
+		tdb_remove_flag(tdb, TDB_NOSYNC);
+		if (flags[i] & TDB_INTERNAL)
+			ok1(tap_log_messages == 1);
+		else {
+			ok1(tap_log_messages == 0);
+			ok1(!(tdb_get_flags(tdb) & TDB_NOSYNC));
+		}
+
+		tdb_close(tdb);
+	}
+
+	ok1(tap_log_messages == 0);
+	return exit_status();
+}