tdb: cleanup: find_nestlock() helper.

Factor out two loops which find locks; we are going to introduce a couple
more so a helper makes sense.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/ccan/tdb/lock.c b/ccan/tdb/lock.c
index 3013b06af6ec855477b0991422a2948bf7b69359..920ba95fe0515a7773ddefd61098510974c18f23 100644 (file)
--- a/ccan/tdb/lock.c
+++ b/ccan/tdb/lock.c
@@ -224,12 +224,24 @@ static tdb_off_t lock_offset(int list)
        return FREELIST_TOP + 4*list;
 }
 
+static struct tdb_lock_type *find_nestlock(struct tdb_context *tdb,
+                                          tdb_off_t offset)
+{
+       unsigned int i;
+
+       for (i=0; i<tdb->num_lockrecs; i++) {
+               if (tdb->lockrecs[i].off == offset) {
+                       return &tdb->lockrecs[i];
+               }
+       }
+       return NULL;
+}
+
 /* lock an offset in the database. */
 int tdb_nest_lock(struct tdb_context *tdb, uint32_t offset, int ltype,
                  enum tdb_lock_flags flags)
 {
        struct tdb_lock_type *new_lck;
-       int i;
 
        if (offset >= lock_offset(tdb->header.hash_size)) {
                tdb->ecode = TDB_ERR_LOCK;
@@ -240,24 +252,14 @@ int tdb_nest_lock(struct tdb_context *tdb, uint32_t offset, int ltype,
        if (tdb->flags & TDB_NOLOCK)
                return 0;
 
-       for (i=0; i<tdb->num_lockrecs; i++) {
-               if (tdb->lockrecs[i].off == offset) {
-                       if (tdb->lockrecs[i].count == 0) {
-                               /*
-                                * Can't happen, see tdb_unlock(). It should
-                                * be an assert.
-                                */
-                               TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_lock: "
-                                        "lck->count == 0 for offset %u",
-                                        offset));
-                       }
-                       /*
-                        * Just increment the in-memory struct, posix locks
-                        * don't stack.
-                        */
-                       tdb->lockrecs[i].count++;
-                       return 0;
-               }
+       new_lck = find_nestlock(tdb, offset);
+       if (new_lck) {
+               /*
+                * Just increment the in-memory struct, posix locks
+                * don't stack.
+                */
+               new_lck->count++;
+               return 0;
        }
 
        new_lck = (struct tdb_lock_type *)realloc(
@@ -332,8 +334,7 @@ int tdb_nest_unlock(struct tdb_context *tdb, uint32_t offset, int ltype,
                    bool mark_lock)
 {
        int ret = -1;
-       int i;
-       struct tdb_lock_type *lck = NULL;
+       struct tdb_lock_type *lck;
 
        if (tdb->flags & TDB_NOLOCK)
                return 0;
@@ -344,13 +345,7 @@ int tdb_nest_unlock(struct tdb_context *tdb, uint32_t offset, int ltype,
                return ret;
        }
 
-       for (i=0; i<tdb->num_lockrecs; i++) {
-               if (tdb->lockrecs[i].off == offset) {
-                       lck = &tdb->lockrecs[i];
-                       break;
-               }
-       }
-
+       lck = find_nestlock(tdb, offset);
        if ((lck == NULL) || (lck->count == 0)) {
                TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlock: count is 0\n"));
                return -1;