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-rw-r--r--apps/couch/src/couch_rep_att.erl118
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
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+% 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}}).