1 files changed, 118 insertions, 0 deletions
diff --git a/apps/couch/src/couch_rep_att.erl b/apps/couch/src/couch_rep_att.erl
new file mode 100644
index 00000000..9988c5db
--- /dev/null
+++ b/apps/couch/src/couch_rep_att.erl
@@ -0,0 +1,118 @@
+% Licensed under the Apache License, Version 2.0 (the "License"); you may not
+% use this file except in compliance with the License. You may obtain a copy of
+% the License at
+%
+%   http://www.apache.org/licenses/LICENSE-2.0
+%
+% Unless required by applicable law or agreed to in writing, software
+% distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+% WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+% License for the specific language governing permissions and limitations under
+% the License.
+
+-module(couch_rep_att).
+
+-export([convert_stub/2, cleanup/0]).
+
+-include("couch_db.hrl").
+
+convert_stub(#att{data=stub, name=Name} = Attachment,
+	     {#http_db{} = Db, Id, Rev}) ->
+    {Pos, [RevId|_]} = Rev,
+    Request = Db#http_db{
+        resource = lists:flatten([couch_util:url_encode(Id), "/",
+            couch_util:url_encode(Name)]),
+        qs = [{rev, couch_doc:rev_to_str({Pos,RevId})}]
+    },
+    Ref = make_ref(),
+    RcvFun = fun() -> attachment_receiver(Ref, Request) end,
+    Attachment#att{data=RcvFun}.
+
+cleanup() ->
+    receive
+    {ibrowse_async_response, _, _} ->
+        %% TODO maybe log, didn't expect to have data here
+        cleanup();
+    {ibrowse_async_response_end, _} ->
+        cleanup();
+    {ibrowse_async_headers, _, _, _} ->
+        cleanup()
+    after 0 ->
+        erase(),
+        ok
+    end.
+        
+% internal funs
+
+attachment_receiver(Ref, Request) ->
+    try case get(Ref) of
+    undefined ->
+        {ReqId, ContentEncoding} = start_http_request(Request),
+        put(Ref, {ReqId, ContentEncoding}),
+        receive_data(Ref, ReqId, ContentEncoding);
+    {ReqId, ContentEncoding} ->
+        receive_data(Ref, ReqId, ContentEncoding)
+    end
+    catch
+    throw:{attachment_request_failed, _} ->
+        case {Request#http_db.retries, Request#http_db.pause} of
+        {0, _} ->
+             ?LOG_INFO("request for ~p failed", [Request#http_db.resource]),
+             throw({attachment_request_failed, max_retries_reached});
+        {N, Pause} when N > 0 ->
+            ?LOG_INFO("request for ~p timed out, retrying in ~p seconds",
+                [Request#http_db.resource, Pause/1000]),
+            timer:sleep(Pause),
+            cleanup(),
+            attachment_receiver(Ref, Request#http_db{retries = N-1})
+        end
+    end.
+
+receive_data(Ref, ReqId, ContentEncoding) ->
+    receive
+    {ibrowse_async_response, ReqId, {chunk_start,_}} ->
+        receive_data(Ref, ReqId, ContentEncoding);
+    {ibrowse_async_response, ReqId, chunk_end} ->
+        receive_data(Ref, ReqId, ContentEncoding);
+    {ibrowse_async_response, ReqId, {error, Err}} ->
+        ?LOG_ERROR("streaming attachment ~p failed with ~p", [ReqId, Err]),
+        throw({attachment_request_failed, Err});
+    {ibrowse_async_response, ReqId, Data} ->
+        Data;
+    {ibrowse_async_response_end, ReqId} ->
+        ?LOG_ERROR("streaming att. ended but more data requested ~p", [ReqId]),
+        throw({attachment_request_failed, premature_end})
+    after 31000 ->
+        throw({attachment_request_failed, timeout})
+    end.
+
+start_http_request(Req) ->
+    %% set stream_to here because self() has changed
+    Req2 = Req#http_db{options = [{stream_to,self()} | Req#http_db.options]},
+    {ibrowse_req_id, ReqId} = couch_rep_httpc:request(Req2),
+    receive {ibrowse_async_headers, ReqId, Code, Headers} ->
+        case validate_headers(Req2, list_to_integer(Code), Headers) of
+        {ok, ContentEncoding} ->
+            {ReqId, ContentEncoding};
+        {ok, ContentEncoding, NewReqId} ->
+            {NewReqId, ContentEncoding}
+        end
+    after 10000 ->
+        throw({attachment_request_failed, timeout})
+    end.
+
+validate_headers(_Req, 200, Headers) ->
+    MochiHeaders = mochiweb_headers:make(Headers),
+    {ok, mochiweb_headers:get_value("Content-Encoding", MochiHeaders)};
+validate_headers(Req, Code, Headers) when Code > 299, Code < 400 ->
+    NewReq = couch_rep_httpc:redirected_request(Code, Headers, Req),
+    {ibrowse_req_id, ReqId} = couch_rep_httpc:request(NewReq),
+    receive {ibrowse_async_headers, ReqId, NewCode, NewHeaders} ->
+        {ok, Encoding} = validate_headers(NewReq, list_to_integer(NewCode),
+            NewHeaders)
+    end,
+    {ok, Encoding, ReqId};
+validate_headers(Req, Code, _Headers) ->
+    #http_db{url=Url, resource=Resource} = Req,
+    ?LOG_ERROR("got ~p for ~s~s", [Code, Url, Resource]),
+    throw({attachment_request_failed, {bad_code, Code}}).