From d5b4cb844fb6d6bfe4727aa5792e0ee47c9d932c Mon Sep 17 00:00:00 2001
From: martinsumner <martin.sumner@adaptip.co.uk>
Date: Mon, 19 Jun 2017 18:38:55 +0100
Subject: [PATCH] Finding keys

Progresses from a segment list to scanning for the keys in that segment
---
 src/leveled_tictac.erl           | 10 ++++++----
 test/end_to_end/tictac_SUITE.erl | 28 +++++++++++++++++++++++++++-
 2 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/src/leveled_tictac.erl b/src/leveled_tictac.erl
index 3463a81..b1e5846 100644
--- a/src/leveled_tictac.erl
+++ b/src/leveled_tictac.erl
@@ -61,7 +61,8 @@
             find_dirtysegments/2,
             fetch_root/1,
             fetch_leaves/2,
-            merge_trees/2
+            merge_trees/2,
+            get_segment/1
         ]).
 
 
@@ -200,6 +201,10 @@ merge_trees(TreeA, TreeB) ->
                                 
     MergedTree#tictactree{level1 = NewLevel1, level2 = NewLevel2}.
 
+get_segment(Key) ->
+    erlang:phash2(Key) band (?SEGMENT_COUNT - 1).
+
+
 %%%============================================================================
 %%% Internal functions
 %%%============================================================================
@@ -219,9 +224,6 @@ segmentcompare(SrcBin, SnkBin, Acc, Counter) ->
             segmentcompare(SrcTail, SnkTail, [Counter|Acc], Counter + 1)
     end.
 
-get_segment(Key) ->
-    erlang:phash2(Key) band (?SEGMENT_COUNT - 1).
-
 merge_binaries(BinA, BinB) ->
     BitSize = bit_size(BinA),
     BitSize = bit_size(BinB),
diff --git a/test/end_to_end/tictac_SUITE.erl b/test/end_to_end/tictac_SUITE.erl
index 819c8b1..6230dc9 100644
--- a/test/end_to_end/tictac_SUITE.erl
+++ b/test/end_to_end/tictac_SUITE.erl
@@ -92,7 +92,33 @@ many_put_compare(_Config) ->
     true = length(SegList0) == 1, 
     % only the test object should be different
     true = length(AltList) > 100000, 
-    % check there are a significant number fo differences from empty
+    % check there are a significant number of differences from empty
+    
+    FoldKeysFun =
+        fun(SegListToFind) ->
+            fun(_B, K, Acc) ->
+                Seg = leveled_tictac:get_segment(K),
+                case lists:member(Seg, SegListToFind) of
+                    true ->
+                        [K|Acc];
+                    false ->
+                        Acc
+                end
+            end
+        end,
+    SegQuery = {keylist, o_rkv, "Bucket", {FoldKeysFun(SegList0), []}},
+    {async, SegKeyFinder} =
+        leveled_bookie:book_returnfolder(Bookie2, SegQuery),
+    SWSKL0 = os:timestamp(),
+    SegKeyList = SegKeyFinder(),
+    io:format("Finding ~w keys in ~w dirty segments in ~w~n",
+                [length(SegKeyList),
+                    length(SegList0),
+                    timer:now_diff(os:timestamp(), SWSKL0)]),
+    
+    true = length(SegKeyList) >= 1,
+    true = length(SegKeyList) < 10,
+    true = lists:member("Key1.1.4567.4321", SegKeyList),
     
     % Now remove the object which represents the difference between these
     % stores and confirm that the tictac trees will now match