fix the block_at method luwak_tree

beerriot · May 27, 2010 · 9fd968d · 9fd968d
1 parent 1ae5a1e
commit 9fd968d
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Showing 2 changed files with 23 additions and 11 deletions.
diff --git a/apps/luwak/src/luwak_tree.erl b/apps/luwak/src/luwak_tree.erl
@@ -191,21 +191,23 @@ block_at_retr(Riak, NodeName, NodeOffset, Pos) ->
 
 block_at_node(Riak, NodeObj, node, Links, NodeOffset, Pos) ->
   case which_child(Links, NodeOffset, Pos, []) of
-    {_, {ChildName,_}, _} -> block_at_retr(Riak, ChildName, NodeOffset, Pos);
+    {Head, {ChildName,_}, _} -> block_at_retr(Riak, ChildName, NodeOffset+luwak_tree_utils:blocklist_length(Head), Pos);
     {_, undefined, _} -> {ok, undefined}
   end;
 block_at_node(Riak, NodeObj, block, _, NodeOffset, _) ->
   {ok, NodeObj}.
 
 which_child([E={ChildName,Length}], NodeOffset, Pos, Acc) when Pos > Length+NodeOffset ->
+  % error_logger:info_msg("A which_child(~p, ~p, ~p)~n", [E, NodeOffset, Pos]),
   {lists:reverse([E|Acc]), undefined, []};
-which_child([{ChildName,Length}], _, _, Acc) ->
-  {lists:reverse(Acc), {ChildName,Length}, []};
-which_child([E={ChildName,Length}|Tail], NodeOffset, Pos, Acc) when Pos > NodeOffset + Length ->
-%  error_logger:info_msg("which_child(~p, ~p, ~p)~n", [[{ChildName,Length}|Tail], NodeOffset, Pos]),
+which_child([E={ChildName,Length}], NodeOffset, Pos, Acc) ->
+  % error_logger:info_msg("B which_child(~p, ~p, ~p)~n", [E, NodeOffset, Pos]),
+  {lists:reverse(Acc), E, []};
+which_child([E={ChildName,Length}|Tail], NodeOffset, Pos, Acc) when Pos >= NodeOffset + Length ->
+  % error_logger:info_msg("C which_child(~p, ~p, ~p)~n", [[{ChildName,Length}|Tail], NodeOffset, Pos]),
   which_child(Tail, NodeOffset+Length, Pos, [E|Acc]);
-which_child([E={ChildName,Length}|Tail], NodeOffset, Pos, Acc) when Pos =< NodeOffset + Length ->
-%  error_logger:info_msg("which_child(~p, ~p, ~p)~n", [[{ChildName,Length}|Tail], NodeOffset, Pos]),
+which_child([E={ChildName,Length}|Tail], NodeOffset, Pos, Acc) when Pos < NodeOffset + Length ->
+  % error_logger:info_msg("D which_child(~p, ~p, ~p)~n", [[{ChildName,Length}|Tail], NodeOffset, Pos]),
   {lists:reverse(Acc), {ChildName,Length}, Tail}.
 
 map_sublist(Fun, N, List) ->

diff --git a/apps/luwak/test/luwak_tree_tests.erl b/apps/luwak/test/luwak_tree_tests.erl
@@ -17,7 +17,7 @@ create_simple_tree_test() ->
       Children = RootNode#n.children,
       ?assertEqual([{BHash1,5},{BHash2,5},{BHash3,3}], Children)
     end).
-    
+
 create_and_overwrite_middle_tree_test() ->
   test_helper:riak_test(fun(Riak) ->
       {ok, File} = luwak_file:create(Riak, <<"file1">>, [{tree_order,4},{block_size,5}], dict:new()),
@@ -58,7 +58,7 @@ create_multilevel_tree_test() ->
       ?assertEqual(SecondNodeChildren, Node2Node#n.children),
       ?assertEqual(ThirdNodeChildren, Node3Node#n.children)
     end).
-    
+
 create_and_overwrite_multilevel_tree_test() ->
   test_helper:riak_test(fun(Riak) ->
       {ok, File} = luwak_file:create(Riak, <<"file1">>, [{tree_order,5},{block_size,1}], dict:new()),
@@ -84,12 +84,22 @@ create_and_overwrite_multilevel_tree_test() ->
       ?assertEqual(SecondNodeChildren, Node2Node#n.children),
       ?assertEqual(ThirdNodeChildren, Node3Node#n.children)
     end).
-    
+
 create_and_append_test() ->
   test_helper:riak_test(fun(Riak) ->
       {ok, File} = luwak_file:create(Riak, <<"file1">>, [{tree_order,3},{block_size,2}], dict:new()),
       {ok, Written1, File2} = luwak_io:put_range(Riak, File, 0, <<"wontyouplease">>),
       {ok, Written2, File3} = luwak_io:put_range(Riak, File2, 13, <<"touchmymonkey">>),
       Blocks = [ {skerl:hexhash(512, X), 2} || <<X:2/binary>> <= <<"wontyoupleasetouchmymonkey">> ],
       ok = file:write_file("/Users/cliff/tree3.dot", luwak_tree:visualize_tree(Riak, luwak_file:get_property(File3, root)))
-    end).
+    end).
+
+block_at_test() ->
+  test_helper:riak_test(fun(Riak) ->
+      {ok, File} = luwak_file:create(Riak, <<"file1">>, [{tree_order,3},{block_size,3}], dict:new()),
+      {ok, Written1, File1} = luwak_io:put_range(Riak, File, 0, <<"heywhyareyoudrp">>),
+      {ok, Block} = luwak_tree:block_at(Riak, File1, 9),
+      Data = luwak_block:data(Block),
+      timer:sleep(1000),
+      ?assertEqual(<<"you">>, Data)
+    end).