HACK: enable parallel readers

1 files changed, 13 insertions, 1 deletions

diff --git a/src/couch/src/couch_file.erl b/src/couch/src/couch_file.erl
index e63b58353..0cfc91ec8 100644
--- a/src/couch/src/couch_file.erl
+++ b/src/couch/src/couch_file.erl
@@ -82,7 +82,8 @@ open(Filepath, Options, IOQPid0) ->
                 IOQPid0
         end,
         Tab = gen_server:call(Fd, get_cache_ref),
-        {ok, #ioq_file{fd=Fd, ioq=IOQPid, tab=Tab}};
+        ParallelReads = config:get_boolean("couchdb", "couch_file_parallel", false),
+        {ok, #ioq_file{fd=Fd, ioq=IOQPid, tab=Tab, parallel=ParallelReads}};
     ignore ->
         % get the error
         receive
@@ -198,6 +199,17 @@ pread_binary(Fd, Pos) ->
     {ok, iolist_to_binary(L)}.
 
 
+pread_iolist(#ioq_file{parallel=true, fd=File}, Pos) ->
+    {LenIolist, NextPos} = read_raw_iolist_int(File, Pos, 4),
+    case iolist_to_binary(LenIolist) of
+        <<1:1/integer,Len:31/integer>> -> % an MD5-prefixed term
+            {Md5AndIoList, _} = read_raw_iolist_int(File, NextPos, Len+16),
+            {Md5, IoList} = extract_md5(Md5AndIoList),
+            {ok, verify_md5(File, Pos, IoList, Md5)};
+        <<0:1/integer,Len:31/integer>> ->
+            {Iolist, _} = read_raw_iolist_int(File, NextPos, Len),
+            {ok, Iolist}
+    end;
 pread_iolist(Fd, Pos) ->
     case load_from_cache(Fd, Pos) of
         {ok, IoList, Md5} ->