diff --git a/src/leveldb.nim b/src/leveldb.nim index e50eddd..c82618b 100644 --- a/src/leveldb.nim +++ b/src/leveldb.nim @@ -1,4 +1,4 @@ -import options, leveldb/raw +import options, strutils, leveldb/raw type LevelDb* = ref object @@ -122,6 +122,24 @@ iterator iter*(self: LevelDb, seek: string = "", reverse: bool = false): ( else: leveldb_iter_next(iterPtr) +iterator iterPrefix*(self: LevelDb, prefix: string): (string, string) = + for (key, value) in iter(self, prefix, reverse = false): + if key.startsWith(prefix): + yield (key, value) + else: + break + +iterator iterRange*(self: LevelDb, start, limit: string): (string, string) = + let reverse: bool = limit < start + for (key, value) in iter(self, start, reverse = reverse): + if reverse: + if key < limit: + break + else: + if key > limit: + break + yield (key, value) + proc removeDb*(name: string) = var err: cstring = nil let options = leveldb_options_create() diff --git a/tests/test.nim b/tests/test.nim index 8bb8f3d..6b614b1 100644 --- a/tests/test.nim +++ b/tests/test.nim @@ -52,3 +52,18 @@ suite "leveldb": initData(db) check(toSeq(db.iter(seek = "ab", reverse = true)) == @[("ba", "2"), ("aa", "1")]) + + test "iter prefix": + initData(db) + check(toSeq(db.iterPrefix(prefix = "b")) == + @[("ba", "2"), ("bb", "3")]) + + test "iter range": + initData(db) + check(toSeq(db.iterRange(start = "a", limit = "ba")) == + @[("aa", "1"), ("ba", "2")]) + + test "iter range reverse": + initData(db) + check(toSeq(db.iterRange(start = "bb", limit = "b")) == + @[("bb", "3"), ("ba", "2")])