fix: fixed length string with terminating character

src/leveldb.nim

@@ -60,6 +60,10 @@ proc put*(self: LevelDb, key: string, value: string, sync = true) =
               key, key.len.csize, value, value.len.csize, addr errPtr)
   checkError(errPtr)
 
+proc newString(cstr: cstring, length: csize): string =
+  result = newString(length)
+  copyMem(unsafeAddr result[0], cstr, length)
+
 proc get*(self: LevelDb, key: string): Option[string] =
   var size: csize
   var errPtr: cstring = nil
@@ -69,7 +73,7 @@ proc get*(self: LevelDb, key: string): Option[string] =
   if s == nil:
     result = none(string)
   else:
-    result = some ($s)[0..<size]
+    result = some (newString(s, size))
     free(s)
 
 proc delete*(self: LevelDb, key: string, sync = true) =
@@ -84,13 +88,13 @@ proc getIterData(iterPtr: ptr leveldb_iterator_t): (Option[string], Option[strin
 
   str = leveldb_iter_key(iterPtr, addr len)
   if len > 0:
-    result[0] = some ($str)[0..<len]
+    result[0] = some (newString(str, len))
   else:
     result[0] = none string
 
   str = leveldb_iter_value(iterPtr, addr len)
   if len > 0:
-    result[1] = some ($str)[0..<len]
+    result[1] = some (newString(str, len))
   else:
     result[1] = none string
 

tests/test.nim

@@ -29,6 +29,10 @@ suite "leveldb":
     db.delete("hello")
     check(db.get("hello") == none(string))
 
+  test "get value with 0x00":
+    db.put("\0key", "\0ff")
+    check(db.get("\0key") == some("\0ff"))
+
   proc initData(db: LevelDb) =
     db.put("aa", "1")
     db.put("ba", "2")
@@ -67,3 +71,8 @@ suite "leveldb":
     initData(db)
     check(toSeq(db.iterRange(start = "bb", limit = "b")) ==
           @[("bb", "3"), ("ba", "2")])
+
+  test "iter with 0x00":
+    db.put("\0z1", "\0ff")
+    db.put("z2\0", "ff\0")
+    check(toSeq(db.iter()) == @[("\0z1", "\0ff"), ("z2\0", "ff\0")])