From 6ce903ad2b278daefb5dc1da21c29b621f618e3b Mon Sep 17 00:00:00 2001
From: Martin Sumner <martin.sumner@adaptip.co.uk>
Date: Thu, 22 Mar 2018 17:12:58 +0000
Subject: [PATCH] Change segment_hahs for HEAD

Needs toaling with ?RIAK tag, and so that AAE key-ordered and segment-ordered stores also agree on definition of Segment ID
---
 src/leveled_codec.erl | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/leveled_codec.erl b/src/leveled_codec.erl
index 844aa71..0eb8fec 100644
--- a/src/leveled_codec.erl
+++ b/src/leveled_codec.erl
@@ -98,9 +98,12 @@ segment_hash(Key) when is_binary(Key) ->
 segment_hash({?RIAK_TAG, Bucket, Key, null}) 
                                     when is_binary(Bucket), is_binary(Key) ->
     segment_hash(<<Bucket/binary, Key/binary>>);
-segment_hash({?HEAD_TAG, Bucket, Key, SubKey})
-                when is_binary(Bucket), is_binary(Key), is_binary(SubKey) ->
-    segment_hash(<<Bucket/binary, Key/binary, SubKey/binary>>);
+segment_hash({?HEAD_TAG, Bucket, Key, null})
+                                    when is_binary(Bucket), is_binary(Key) ->
+    segment_hash(<<Bucket/binary, Key/binary>>);
+segment_hash({?HEAD_TAG, Bucket, Key, SubK})
+                    when is_binary(Bucket), is_binary(Key), is_binary(SubK) ->
+    segment_hash(<<Bucket/binary, Key/binary, SubK/binary>>);
 segment_hash(Key) ->
     segment_hash(term_to_binary(Key)).
 
@@ -960,5 +963,13 @@ delayedupdate_aaeidx_test() ->
     AAESpecs = aae_indexspecs(AAE, Bucket, Key, SQN, H, LastMods),
     ?assertMatch(0, length(AAESpecs)).
 
+head_segment_compare_test() ->
+    % Reminder to align native and parallel(leveled_ko) key stores for 
+    % kv_index_tictactree
+    H1 = segment_hash({?HEAD_TAG, <<"B1">>, <<"K1">>, null}),
+    H2 = segment_hash({?RIAK_TAG, <<"B1">>, <<"K1">>, null}),
+    H3 = segment_hash({?HEAD_TAG, <<"B1">>, <<"K1">>, <<>>}),
+    ?assertMatch(H1, H2),
+    ?assertMatch(H1, H3).
 
 -endif.