tdb2: rework hash.c functions to return enum TDB_ERROR.

This time we have to use our tri-value "tdb_bool_err" type to indicate
true, false, or error, which now allows us to correctly handle errors
in key matching (rather than treating it as a non-match).

ccan/tdb2/private.h

@@ -394,13 +394,13 @@ struct tdb_methods {
 /* hash.c: */
 void tdb_hash_init(struct tdb_context *tdb);
 
-int first_in_hash(struct tdb_context *tdb,
-		  struct traverse_info *tinfo,
-		  TDB_DATA *kbuf, size_t *dlen);
+tdb_bool_err first_in_hash(struct tdb_context *tdb,
+			   struct traverse_info *tinfo,
+			   TDB_DATA *kbuf, size_t *dlen);
 
-int next_in_hash(struct tdb_context *tdb,
-		 struct traverse_info *tinfo,
-		 TDB_DATA *kbuf, size_t *dlen);
+tdb_bool_err next_in_hash(struct tdb_context *tdb,
+			  struct traverse_info *tinfo,
+			  TDB_DATA *kbuf, size_t *dlen);
 
 /* Hash random memory. */
 uint64_t tdb_hash(struct tdb_context *tdb, const void *ptr, size_t len);
@@ -416,14 +416,14 @@ tdb_off_t find_and_lock(struct tdb_context *tdb,
 			struct tdb_used_record *rec,
 			struct traverse_info *tinfo);
 
-int replace_in_hash(struct tdb_context *tdb,
-		    struct hash_info *h,
-		    tdb_off_t new_off);
+enum TDB_ERROR replace_in_hash(struct tdb_context *tdb,
+			       struct hash_info *h,
+			       tdb_off_t new_off);
 
-int add_to_hash(struct tdb_context *tdb, struct hash_info *h,
-		tdb_off_t new_off);
+enum TDB_ERROR add_to_hash(struct tdb_context *tdb, struct hash_info *h,
+			   tdb_off_t new_off);
 
-int delete_from_hash(struct tdb_context *tdb, struct hash_info *h);
+enum TDB_ERROR delete_from_hash(struct tdb_context *tdb, struct hash_info *h);
 
 /* For tdb_check */
 bool is_subhash(tdb_off_t val);

ccan/tdb2/tdb.c

@@ -449,11 +449,13 @@ static int replace_data(struct tdb_context *tdb,
 		add_free_record(tdb, old_off,
 				sizeof(struct tdb_used_record)
 				+ key.dsize + old_room);
-		if (replace_in_hash(tdb, h, new_off) == -1)
-			return -1;
+		ecode = replace_in_hash(tdb, h, new_off);
 	} else {
-		if (add_to_hash(tdb, h, new_off) == -1)
-			return -1;
+		ecode = add_to_hash(tdb, h, new_off);
+	}
+	if (ecode != TDB_SUCCESS) {
+		tdb->ecode = ecode;
+		return -1;
 	}
 
 	new_off += sizeof(struct tdb_used_record);
@@ -485,8 +487,10 @@ int tdb_store(struct tdb_context *tdb,
 	enum TDB_ERROR ecode;
 
 	off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
-	if (unlikely(off == TDB_OFF_ERR))
+	if (TDB_OFF_IS_ERR(off)) {
+		tdb->ecode = off;
 		return -1;
+	}
 
 	/* Now we have lock on this hash bucket. */
 	if (flag == TDB_INSERT) {
@@ -551,8 +555,10 @@ int tdb_append(struct tdb_context *tdb,
 	int ret;
 
 	off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
-	if (unlikely(off == TDB_OFF_ERR))
+	if (TDB_OFF_IS_ERR(off)) {
+		tdb->ecode = off;
 		return -1;
+	}
 
 	if (off) {
 		old_dlen = rec_data_length(&rec);
@@ -621,8 +627,10 @@ struct tdb_data tdb_fetch(struct tdb_context *tdb, struct tdb_data key)
 	struct tdb_data ret;
 
 	off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
-	if (unlikely(off == TDB_OFF_ERR))
+	if (TDB_OFF_IS_ERR(off)) {
+		tdb->ecode = off;
 		return tdb_null;
+	}
 
 	if (!off) {
 		tdb->ecode = TDB_ERR_NOEXIST;
@@ -646,10 +654,13 @@ int tdb_delete(struct tdb_context *tdb, struct tdb_data key)
 	tdb_off_t off;
 	struct tdb_used_record rec;
 	struct hash_info h;
+	enum TDB_ERROR ecode;
 
 	off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
-	if (unlikely(off == TDB_OFF_ERR))
+	if (TDB_OFF_IS_ERR(off)) {
+		tdb->ecode = off;
 		return -1;
+	}
 
 	if (!off) {
 		tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
@@ -657,8 +668,11 @@ int tdb_delete(struct tdb_context *tdb, struct tdb_data key)
 		return -1;
 	}
 
-	if (delete_from_hash(tdb, &h) == -1)
+	ecode = delete_from_hash(tdb, &h);
+	if (ecode != TDB_SUCCESS) {
+		tdb->ecode = ecode;
 		goto unlock_err;
+	}
 
 	/* Free the deleted entry. */
 	add_stat(tdb, frees, 1);

ccan/tdb2/test/run-15-append.c

@@ -19,7 +19,7 @@ static tdb_off_t tdb_offset(struct tdb_context *tdb, struct tdb_data key)
 	struct hash_info h;
 
 	off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
-	if (unlikely(off == TDB_OFF_ERR))
+	if (TDB_OFF_IS_ERR(off))
 		return 0;
 	tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
 	return off;

ccan/tdb2/traverse.c

@@ -20,15 +20,15 @@
 
 int64_t tdb_traverse(struct tdb_context *tdb, tdb_traverse_func fn, void *p)
 {
-	int ret;
+	enum TDB_ERROR ecode;
 	struct traverse_info tinfo;
 	struct tdb_data k, d;
 	int64_t count = 0;
 
 	k.dptr = NULL;
-	for (ret = first_in_hash(tdb, &tinfo, &k, &d.dsize);
-	     ret == 1;
-	     ret = next_in_hash(tdb, &tinfo, &k, &d.dsize)) {
+	for (ecode = first_in_hash(tdb, &tinfo, &k, &d.dsize);
+	     ecode == TDB_SUCCESS;
+	     ecode = next_in_hash(tdb, &tinfo, &k, &d.dsize)) {
 		d.dptr = k.dptr + k.dsize;
 		
 		count++;
@@ -39,8 +39,10 @@ int64_t tdb_traverse(struct tdb_context *tdb, tdb_traverse_func fn, void *p)
 		free(k.dptr);
 	}
 
-	if (ret < 0)
+	if (ecode != TDB_ERR_NOEXIST) {
+		tdb->ecode = ecode;
 		return -1;
+	}
 	return count;
 }
 	
@@ -48,15 +50,16 @@ TDB_DATA tdb_firstkey(struct tdb_context *tdb)
 {
 	struct traverse_info tinfo;
 	struct tdb_data k;
-	switch (first_in_hash(tdb, &tinfo, &k, NULL)) {
-	case 1:
+	enum TDB_ERROR ecode;
+
+	ecode = first_in_hash(tdb, &tinfo, &k, NULL);
+	if (ecode == TDB_SUCCESS) {
 		return k;
-	case 0:
-		tdb->ecode = TDB_SUCCESS;
-		/* Fall thru... */
-	default:
-		return tdb_null;
 	}
+	if (ecode == TDB_ERR_NOEXIST)
+		ecode = TDB_SUCCESS;
+	tdb->ecode = ecode;
+	return tdb_null;
 }
 
 /* We lock twice, not very efficient.  We could keep last key & tinfo cached. */
@@ -65,19 +68,21 @@ TDB_DATA tdb_nextkey(struct tdb_context *tdb, TDB_DATA key)
 	struct traverse_info tinfo;
 	struct hash_info h;
 	struct tdb_used_record rec;
+	enum TDB_ERROR ecode;
 
 	tinfo.prev = find_and_lock(tdb, key, F_RDLCK, &h, &rec, &tinfo);
-	if (unlikely(tinfo.prev == TDB_OFF_ERR))
+	if (TDB_OFF_IS_ERR(tinfo.prev)) {
+		tdb->ecode = tinfo.prev;
 		return tdb_null;
+	}
 	tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
 
-	switch (next_in_hash(tdb, &tinfo, &key, NULL)) {
-	case 1:
+	ecode = next_in_hash(tdb, &tinfo, &key, NULL);
+	if (ecode == TDB_SUCCESS) {
 		return key;
-	case 0:
-		tdb->ecode = TDB_SUCCESS;
-		/* Fall thru... */
-	default:
-		return tdb_null;
 	}
+	if (ecode == TDB_ERR_NOEXIST)
+		ecode = TDB_SUCCESS;
+	tdb->ecode = ecode;
+	return tdb_null;
 }