Remove unused merger

src/lsm_btree_merger.erl

@@ -1,109 +0,0 @@
--module(lsm_btree_merger).
-
-%%
-%% Naive Merge of two b-trees.  A better implementation should iterate leafs, not KV's
-%%
-
--export([merge/4]).
-
--record(state, { out, a_pid, b_pid }).
-
-merge(A,B,C, Size) ->
-    {ok, Out} = lsm_btree_writer:open(C, Size),
-    Owner = self(),
-    PID1 = spawn_link(fun() -> scan(Owner, A) end),
-    PID2 = spawn_link(fun() -> scan(Owner, B) end),
-
-    %% "blocks" until both scans are done ...
-    {ok, Count} = receive_both(undefined, undefined, #state{ out=Out, a_pid=PID1, b_pid=PID2 }, 0),
-
-    %% finish stream tree
-    ok = lsm_btree_writer:close(Out),
-
-    {ok, Count}.
-
-
-scan(SendTo,FileName) ->
-    %% yes, we need a separate file to scan it, since pread doesn't do read-ahead
-    {ok, File} = lsm_btree_reader:open(FileName),
-    lsm_btree_reader:fold(fun(K,V,_) ->
-                              SendTo ! {ok, self(), K, V}
-                      end,
-                      ok,
-                      File),
-    lsm_btree_reader:close(File),
-    SendTo ! {eod, self()},
-    ok.
-
-
-receive_both(undefined, BVal, #state{a_pid=PID1}=State, Count) ->
-    receive
-        {ok, PID1, Key1, Value1} ->
-            receive_both({Key1,Value1}, BVal, State, Count);
-
-        {eod, PID1} ->
-            case BVal of
-                {Key2, Value2} ->
-                    lsm_btree_writer:add(State#state.out, Key2, Value2),
-                    receive_bonly(State, Count+1);
-
-                undefined ->
-                    receive_bonly(State, Count)
-            end
-    end;
-
-receive_both({Key1,Value1}=AValue, undefined, #state{ b_pid=PID2 }=State, Count) ->
-    receive
-        {ok, PID2, Key2, Value2} ->
-            receive_both(AValue, {Key2,Value2}, State, Count);
-
-        {eod, PID2} ->
-            ok = lsm_btree_writer:add(State#state.out, Key1, Value1),
-            receive_aonly(State, Count+1)
-    end;
-
-receive_both(AValue={Key1,Value1}, BValue={Key2,Value2}, State, Count) ->
-
-    if Key1 < Key2 ->
-            ok = lsm_btree_writer:add(State#state.out, Key1, Value1),
-            receive_both(undefined, BValue, State, Count+1);
-
-       Key2 < Key1 ->
-            ok = lsm_btree_writer:add(State#state.out, Key2, Value2),
-            receive_both(AValue, undefined, State, Count+1);
-
-       Key1 == Key2 ->
-            %% TODO: eliminate tombstones, right now they just bubble down
-            ok = lsm_btree_writer:add(State#state.out, Key2, Value2),
-            receive_both(undefined, undefined, State, Count+1)
-    end.
-
-%%
-%% Reached the end of the "B File" ... now just stream everything from A to OUT
-%%
-receive_aonly(#state{a_pid=PID1}=State, Count) ->
-    receive
-        {ok, PID1, Key1, Value1} ->
-            ok = lsm_btree_writer:add(State#state.out,
-                                         Key1,
-                                         Value1),
-            receive_aonly(State, Count+1);
-        {eod, PID1} ->
-            {ok, Count}
-    end.
-
-%%
-%% Reached the end of the "A File" ... now just stream everything from B to OUT
-%%
-receive_bonly(#state{b_pid=PID2}=State, Count) ->
-    receive
-        {ok, PID2, Key2, Value2} ->
-            ok = lsm_btree_writer:add(State#state.out,
-                                         Key2,
-                                         Value2),
-            receive_bonly(State, Count+1);
-        {eod, PID2} ->
-            {ok, Count}
-    end.
-
-