make concurrent (but don't need anymore)

datastore/memoryds.nim

@@ -1,8 +1,12 @@
 import std/tables
 import std/sharedtables
+import std/sharedlist
 import std/sequtils
 import std/strutils
 import std/algorithm
+import std/locks
+
+import std/atomics
 
 import pkg/chronos
 import pkg/questionable
@@ -20,21 +24,36 @@ push: {.upraises: [].}
 type
   MemoryDatastore* = ref object of Datastore
     store*: SharedTable[Key, seq[byte]]
+    keys*: SharedList[Key]
+    lock: Lock # yes, we need the lock since we need to update both the table and the list :facepalm:
+
+template withLock(lock: Lock, body: untyped) =
+  try:
+    lock.acquire()
+    body
+  finally:
+    lock.release()
 
 method has*(
   self: MemoryDatastore,
   key: Key): Future[?!bool] {.async.} =
+  let
+    keys = toSeq(self.keys)
 
-  self.store.withValue(key, value):
-    return success true
-  do:
-    return success(false)
+  for k in keys:
+    if k == key:
+      return success true
+
+  return success false
 
 method delete*(
   self: MemoryDatastore,
   key: Key): Future[?!void] {.async.} =
 
-  self.store.del(key)
+  withLock(self.lock):
+    self.keys.iterAndMutate(proc(k: Key): bool = k == key)
+    self.store.del(key)
+
   return success()
 
 method delete*(
@@ -51,18 +70,25 @@ method get*(
   self: MemoryDatastore,
   key: Key): Future[?!seq[byte]] {.async.} =
 
-  self.store.withValue(key, value):
-    return success value[]
-  do:
-    return failure (ref DatastoreError)(msg: "no such key")
+  withLock(self.lock):
+    let
+      has = (await self.has(key))
+
+    if has.isOk and has.get:
+      return self.store.mget(key).catch()
+
+  return failure (ref DatastoreError)(msg: "not found")
 
 method put*(
   self: MemoryDatastore,
   key: Key,
   data: seq[byte]): Future[?!void] {.async.} =
 
-  self.store[key] = data
-  return success()
+  withLock(self.lock):
+    if not self.store.hasKeyOrPut(key, data):
+      self.keys.add(key)
+    else:
+      self.store[key] = data
 
 method put*(
   self: MemoryDatastore,
@@ -74,50 +100,50 @@ method put*(
 
   return success()
 
-# proc keyIterator(self: MemoryDatastore, queryKey: string): iterator: KeyBuffer {.gcsafe.} =
-#   return iterator(): KeyBuffer {.closure.} =
-#     var keys = self.store.keys().toSeq()
-#     keys.sort(proc (x, y: KeyBuffer): int = cmp(x.toString, y.toString))
-#     for key in keys:
-#       if key.toString().startsWith(queryKey):
-#         yield key
+method query*(
+  self: MemoryDatastore,
+  query: Query,
+): Future[?!QueryIter] {.async.} =
 
-# method query*(
-#   self: MemoryDatastore,
-#   query: Query,
-# ): Future[?!QueryIter] {.async.} =
+  let
+    queryKey = query.key.id()
+    keys = toSeq(self.keys)
 
-#   let
-#     queryKey = query.key.id()
-#     walker = keyIterator(self, queryKey)
-#   var
-#     iter = QueryIter.new()
+  var
+    iter = QueryIter.new()
+    pos = 0
 
-#   proc next(): Future[?!QueryResponse] {.async.} =
-#     let kb = walker()
+  proc next(): Future[?!QueryResponse] {.async.} =
+    defer:
+      pos.inc
 
-#     if finished(walker):
-#       iter.finished = true
-#       return success (Key.none, EmptyBytes)
+    if iter.finished:
+      return failure (ref QueryEndedError)(msg: "Calling next on a finished query!")
 
-#     let key = kb.toKey().expect("should not fail")
-#     var ds: ValueBuffer
-#     if query.value:
-#       ds = self.store[kb]
-#     let data = if ds.isNil: EmptyBytes else: ds.toSeq(byte)
+    if pos > keys.len - 1:
+      iter.finished = true
+      return success (Key.none, EmptyBytes)
 
-#     return success (key.some, data)
+    return success (
+      Key.init(keys[pos]).expect("Should not fail!").some,
+      if query.value: self.store.mget(keys[pos]) else: EmptyBytes)
 
-#   iter.next = next
-#   return success iter
+  iter.next = next
+  return success iter
 
 method close*(self: MemoryDatastore): Future[?!void] {.async.} =
   self.store.deinitSharedTable()
+  self.keys.deinitSharedList()
+  self.lock.deinitLock()
   return success()
 
 proc new*(tp: type MemoryDatastore): MemoryDatastore =
   var
     table: SharedTable[Key, seq[byte]]
+    keys: SharedList[Key]
+    lock: Lock
 
   table.init()
-  MemoryDatastore(store: table)
+  keys.init()
+  lock.initLock()
+  MemoryDatastore(store: table, keys: keys, lock: lock)