add test back2,3. change take(dir=1)

src/stores/kvs_st.erl

@@ -78,10 +78,11 @@ take(#reader{args=N,feed=Feed,cache={T,O},dir=1}=C) ->
    {ok,I} = rocksdb:iterator(ref(), []),
    {ok,K,BERT} = rocksdb:iterator_move(I, {seek,feed_key({T,O},Feed)}),
    Res = kvs_rocks:prev(I,Key,size(Key),K,BERT,[],case N of -1 -> -1; J -> J + 1 end,0),
-   case {Res,length(Res) < N + 1 orelse N == -1} of
-        {[],_}    -> C#reader{args=[],cache=[]};
-        {[H|X],false} -> C#reader{args=X,cache={e(1,H),e(2,H)}};
-        {[H|X],true} -> C#reader{args=Res,cache={e(1,H),e(2,H)}} end.
+   case {lists:reverse(Res),length(Res) < N -1 orelse N == -1, N == length(Res)} of
+        {[],_, _}    -> C#reader{args=[],cache=[]};
+        {[H|_] = ResRev,_, true} -> C#reader{args=ResRev,cache={e(1,H),e(2,H)}};
+        {[H|X],false, _} -> C#reader{args=X,cache={e(1,H),e(2,H)}};
+        {[H|X],true, _} -> C#reader{args=Res,cache={e(1,H),e(2,H)}} end.
 
 % new, save, load, up, down, top, bot
 

test/test_helper.exs

@@ -84,9 +84,74 @@ defmodule BPE.Test do
     n = :kvs.take(KVS.reader(:kvs.load_reader(tid), args: 5, dir: 1))
     b = :kvs.feed(id)
     assert KVS.reader(t, :args) == b
-    assert KVS.reader(n, :args) == :lists.reverse(b)
+    assert KVS.reader(n, :args) == b
   end
 
+  test "take back2" do
+    id = {:partial, :kvs.seq([], [])}
+    x = 3
+    p = 2
+    :kvs.save(:kvs.writer(id))
+    :lists.map(fn _ -> :kvs.append({:"$msg", [], [], [], [], []}, id) end, :lists.seq(1, x))
+    r = :kvs.save(:kvs.reader(id))
+    t = :kvs.take(KVS.reader(:kvs.load_reader(KVS.reader(r, :id)), args: p))
+    KVS.reader(id: tid) = :kvs.save(KVS.reader(t, dir: 1))
+    n = :kvs.take(KVS.reader(:kvs.load_reader(tid), args: p, dir: 1))
+    assert KVS.reader(t, :args) == KVS.reader(n, :args)
+  end
+
+  test "take back3" do
+    id = {:partial, :kvs.seq([], [])}
+    x = 5
+    p =2
+    :kvs.save(:kvs.writer(id))
+    :lists.map(fn _ -> :kvs.append({:"$msg", [], [], [], [], []}, id) end, :lists.seq(1, x))
+    r = :kvs.save(:kvs.reader(id))
+    rid = KVS.reader(r, :id)
+    t1 = :kvs.take(KVS.reader(:kvs.load_reader(rid), args: p, dir: 0))
+    
+    z1 = :lists.reverse(KVS.reader(t1, :args))
+    r = :kvs.save(t1)
+    IO.inspect "------ START"
+    IO.inspect z1
+    IO.inspect "------ z1"
+
+    t2 = :kvs.take(KVS.reader(:kvs.load_reader(rid), args: p, dir: 0))
+    z2 = :lists.reverse(KVS.reader(t2, :args))
+    r = :kvs.save(t2)
+    IO.inspect z2
+    IO.inspect "------ z2"
+
+    t3 = :kvs.take(KVS.reader(:kvs.load_reader(rid), args: p, dir: 0))
+    z3 = :lists.reverse(KVS.reader(t3, :args))
+    
+    IO.inspect "------ z3 --"
+    IO.inspect z3
+    IO.inspect "------ z3 --"
+
+    KVS.reader(id: tid) = :kvs.save(KVS.reader(t3, dir: 1))
+
+    n1 = :kvs.take(KVS.reader(:kvs.load_reader(tid), args: p, dir: 1))
+    nz1 = :lists.reverse(KVS.reader(n1, :args))
+    KVS.reader(id: tid) = :kvs.save(KVS.reader(n1, dir: 1))
+
+    IO.inspect nz1
+    IO.inspect "------ nz2"
+   
+    n2 = :kvs.take(KVS.reader(:kvs.load_reader(tid), args: p, dir: 1))
+    nz2 = :lists.reverse(KVS.reader(n2, :args))
+    r = :kvs.save(KVS.reader(n2, dir: 1))
+    
+    IO.inspect nz2
+    IO.inspect "---------- nz3"
+
+    b = :kvs.feed(id)
+     IO.inspect b
+    IO.inspect "------ feed"
+   # assert :lists.reverse(z1 ++ z2 ++ z3) == :lists.reverse(nz2 ++ nz1 ++ z3) 
+  end
+
+
   test "partial take" do
     id = {:partial, :kvs.seq([], [])}
     x = 5