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Date: Wed, 16 May 2012 07:44:52 +0200
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 <CAJNb-9qhQDBzFg0DbrvW8iw3gXEoCMxrp8PDUYUnVszcW8aO=g@mail.gmail.com>
Subject: Re: git commit: add Server-Sent Events protocol to db changes API.
 close #COUCHDB-986
From: Benoit Chesneau <bchesneau@gmail.com>
To: dev@couchdb.apache.org
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On Wed, May 16, 2012 at 7:42 AM, Paul Davis <paul.joseph.davis@gmail.com> w=
rote:
> That JS test looks broken for JS environments that don't support
> EventSource. Notably the CLI test suite but also browsers that don't
> implement it. I'd either move the entire test into the conditional or
> reimplement it by parsing the actual data sent across.
>


well there is an if() . Isn't it enough ?

- benoit
> On Wed, May 16, 2012 at 12:36 AM, =A0<benoitc@apache.org> wrote:
>> Updated Branches:
>> =A0refs/heads/master af7441d8d -> 093d2aa65
>>
>>
>> add Server-Sent Events protocol to db changes API. close #COUCHDB-986
>>
>> This patch add support for the new specification of w3c by adding a new
>> feed type named `eventsource`:
>>
>> http://www.w3.org/TR/2009/WD-eventsource-20090423/
>>
>> This patch is based on @indutny patch with edits.
>>
>>
>> Project: http://git-wip-us.apache.org/repos/asf/couchdb/repo
>> Commit: http://git-wip-us.apache.org/repos/asf/couchdb/commit/093d2aa6
>> Tree: http://git-wip-us.apache.org/repos/asf/couchdb/tree/093d2aa6
>> Diff: http://git-wip-us.apache.org/repos/asf/couchdb/diff/093d2aa6
>>
>> Branch: refs/heads/master
>> Commit: 093d2aa6544546a95f6133f1db3c4f4179793f3c
>> Parents: af7441d
>> Author: benoitc <benoitc@apache.org>
>> Authored: Wed May 16 07:30:19 2012 +0200
>> Committer: benoitc <benoitc@apache.org>
>> Committed: Wed May 16 07:30:19 2012 +0200
>>
>> ----------------------------------------------------------------------
>> =A0share/www/script/test/changes.js | =A0 28 +++++++++++++++++++++++++++=
+
>> =A0src/couchdb/couch_changes.erl =A0 =A0| =A0 15 ++++++++++-----
>> =A0src/couchdb/couch_httpd_db.erl =A0 | =A0 24 ++++++++++++++++++++++--
>> =A03 files changed, 60 insertions(+), 7 deletions(-)
>> ----------------------------------------------------------------------
>>
>>
>> http://git-wip-us.apache.org/repos/asf/couchdb/blob/093d2aa6/share/www/s=
cript/test/changes.js
>> ----------------------------------------------------------------------
>> diff --git a/share/www/script/test/changes.js b/share/www/script/test/ch=
anges.js
>> index 19e22fd..c529b21 100644
>> --- a/share/www/script/test/changes.js
>> +++ b/share/www/script/test/changes.js
>> @@ -139,6 +139,34 @@ couchTests.changes =3D function(debug) {
>> =A0 =A0 // otherwise we'll continue to receive heartbeats forever
>> =A0 =A0 xhr.abort();
>>
>> + =A0 =A0// test Server Sent Event (eventsource)
>> + =A0 =A0if (window.EventSource) {
>> + =A0 =A0 =A0var source =3D new EventSource(
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0"/test_suite_db/_changes?feed=3Deventsource=
");
>> + =A0 =A0 =A0var results =3D [];
>> + =A0 =A0 =A0var sourceListener =3D function(e) {
>> + =A0 =A0 =A0 =A0var data =3D JSON.parse(e.data);
>> + =A0 =A0 =A0 =A0results.push(data);
>> +
>> + =A0 =A0 =A0};
>> +
>> + =A0 =A0 =A0source.addEventListener('message', sourceListener , false);
>> +
>> + =A0 =A0 =A0waitForSuccess(function() {
>> + =A0 =A0 =A0 =A0if (results.length !=3D 3)
>> + =A0 =A0 =A0 =A0 =A0throw "bad seq, try again";
>> + =A0 =A0 =A0});
>> +
>> + =A0 =A0 =A0source.removeEventListener('message', sourceListener, false=
);
>> +
>> + =A0 =A0 =A0T(results[0].seq =3D=3D 1);
>> + =A0 =A0 =A0T(results[0].id =3D=3D "foo");
>> +
>> + =A0 =A0 =A0T(results[1].seq =3D=3D 2);
>> + =A0 =A0 =A0T(results[1].id =3D=3D "bar");
>> + =A0 =A0 =A0T(results[1].changes[0].rev =3D=3D docBar._rev);
>> + =A0 =A0}
>> +
>> =A0 =A0 // test longpolling
>> =A0 =A0 xhr =3D CouchDB.newXhr();
>>
>>
>> http://git-wip-us.apache.org/repos/asf/couchdb/blob/093d2aa6/src/couchdb=
/couch_changes.erl
>> ----------------------------------------------------------------------
>> diff --git a/src/couchdb/couch_changes.erl b/src/couchdb/couch_changes.e=
rl
>> index aec7873..85c9e54 100644
>> --- a/src/couchdb/couch_changes.erl
>> +++ b/src/couchdb/couch_changes.erl
>> @@ -63,7 +63,8 @@ handle_changes(Args1, Req, Db0) ->
>> =A0 =A0 =A0 =A0 put(last_changes_heartbeat, now())
>> =A0 =A0 end,
>>
>> - =A0 =A0if Feed =3D=3D "continuous" orelse Feed =3D=3D "longpoll" ->
>> + =A0 =A0case lists:member(Feed, ["continuous", "longpoll", "eventsource=
"]) of
>> + =A0 =A0true ->
>> =A0 =A0 =A0 =A0 fun(CallbackAcc) ->
>> =A0 =A0 =A0 =A0 =A0 =A0 {Callback, UserAcc} =3D get_callback_acc(Callbac=
kAcc),
>> =A0 =A0 =A0 =A0 =A0 =A0 Self =3D self(),
>> @@ -89,7 +90,7 @@ handle_changes(Args1, Req, Db0) ->
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 get_rest_db_updated(ok) % clean out any =
remaining update messages
>> =A0 =A0 =A0 =A0 =A0 =A0 end
>> =A0 =A0 =A0 =A0 end;
>> - =A0 =A0true ->
>> + =A0 =A0false ->
>> =A0 =A0 =A0 =A0 fun(CallbackAcc) ->
>> =A0 =A0 =A0 =A0 =A0 =A0 {Callback, UserAcc} =3D get_callback_acc(Callbac=
kAcc),
>> =A0 =A0 =A0 =A0 =A0 =A0 UserAcc2 =3D start_sending_changes(Callback, Use=
rAcc, Feed),
>> @@ -261,7 +262,9 @@ get_changes_timeout(Args, Callback) ->
>> =A0 =A0 =A0 =A0 =A0 =A0 fun(UserAcc) -> {ok, Callback(timeout, ResponseT=
ype, UserAcc)} end}
>> =A0 =A0 end.
>>
>> -start_sending_changes(_Callback, UserAcc, "continuous") ->
>> +start_sending_changes(_Callback, UserAcc, ResponseType)
>> + =A0 =A0 =A0 =A0when ResponseType =3D:=3D "continuous"
>> + =A0 =A0 =A0 =A0orelse ResponseType =3D:=3D "eventsource" ->
>> =A0 =A0 UserAcc;
>> =A0start_sending_changes(Callback, UserAcc, ResponseType) ->
>> =A0 =A0 Callback(start, ResponseType, UserAcc).
>> @@ -434,7 +437,9 @@ keep_sending_changes(Args, Acc0, FirstRound) ->
>> =A0end_sending_changes(Callback, UserAcc, EndSeq, ResponseType) ->
>> =A0 =A0 Callback({stop, EndSeq}, ResponseType, UserAcc).
>>
>> -changes_enumerator(DocInfo, #changes_acc{resp_type =3D "continuous"} =
=3D Acc) ->
>> +changes_enumerator(DocInfo, #changes_acc{resp_type =3D ResponseType} =
=3D Acc)
>> + =A0 =A0 =A0 =A0when ResponseType =3D:=3D "continuous"
>> + =A0 =A0 =A0 =A0orelse ResponseType =3D:=3D "eventsource" ->
>> =A0 =A0 #changes_acc{
>> =A0 =A0 =A0 =A0 filter =3D FilterFun, callback =3D Callback,
>> =A0 =A0 =A0 =A0 user_acc =3D UserAcc, limit =3D Limit, db =3D Db,
>> @@ -456,7 +461,7 @@ changes_enumerator(DocInfo, #changes_acc{resp_type =
=3D "continuous"} =3D Acc) ->
>> =A0 =A0 =A0 =A0 end;
>> =A0 =A0 _ ->
>> =A0 =A0 =A0 =A0 ChangesRow =3D changes_row(Results, DocInfo, Acc),
>> - =A0 =A0 =A0 =A0UserAcc2 =3D Callback({change, ChangesRow, <<>>}, "cont=
inuous", UserAcc),
>> + =A0 =A0 =A0 =A0UserAcc2 =3D Callback({change, ChangesRow, <<>>}, Respo=
nseType, UserAcc),
>> =A0 =A0 =A0 =A0 reset_heartbeat(),
>> =A0 =A0 =A0 =A0 {Go, Acc#changes_acc{seq =3D Seq, user_acc =3D UserAcc2,=
 limit =3D Limit - 1}}
>> =A0 =A0 end;
>>
>> http://git-wip-us.apache.org/repos/asf/couchdb/blob/093d2aa6/src/couchdb=
/couch_httpd_db.erl
>> ----------------------------------------------------------------------
>> diff --git a/src/couchdb/couch_httpd_db.erl b/src/couchdb/couch_httpd_db=
.erl
>> index de39b9e..0920014 100644
>> --- a/src/couchdb/couch_httpd_db.erl
>> +++ b/src/couchdb/couch_httpd_db.erl
>> @@ -76,14 +76,23 @@ handle_changes_req1(Req, #db{name=3DDbName}=3DDb) ->
>>
>> =A0handle_changes_req2(Req, Db) ->
>> =A0 =A0 MakeCallback =3D fun(Resp) ->
>> - =A0 =A0 =A0 =A0fun({change, Change, _}, "continuous") ->
>> + =A0 =A0 =A0 =A0fun({change, {ChangeProp}=3DChange, _}, "eventsource") =
->
>> + =A0 =A0 =A0 =A0 =A0 =A0Seq =3D proplists:get_value(<<"seq">>, ChangePr=
op),
>> + =A0 =A0 =A0 =A0 =A0 =A0send_chunk(Resp, ["data: ", ?JSON_ENCODE(Change=
),
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0"\n", "id: =
", ?JSON_ENCODE(Seq),
>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0"\n\n"]);
>> + =A0 =A0 =A0 =A0({change, Change, _}, "continuous") ->
>> =A0 =A0 =A0 =A0 =A0 =A0 send_chunk(Resp, [?JSON_ENCODE(Change) | "\n"]);
>> =A0 =A0 =A0 =A0 ({change, Change, Prepend}, _) ->
>> =A0 =A0 =A0 =A0 =A0 =A0 send_chunk(Resp, [Prepend, ?JSON_ENCODE(Change)]=
);
>> + =A0 =A0 =A0 =A0(start, "eventsource") ->
>> + =A0 =A0 =A0 =A0 =A0 =A0ok;
>> =A0 =A0 =A0 =A0 (start, "continuous") ->
>> =A0 =A0 =A0 =A0 =A0 =A0 ok;
>> =A0 =A0 =A0 =A0 (start, _) ->
>> =A0 =A0 =A0 =A0 =A0 =A0 send_chunk(Resp, "{\"results\":[\n");
>> + =A0 =A0 =A0 =A0({stop, _EndSeq}, "eventsource") ->
>> + =A0 =A0 =A0 =A0 =A0 =A0end_json_response(Resp);
>> =A0 =A0 =A0 =A0 ({stop, EndSeq}, "continuous") ->
>> =A0 =A0 =A0 =A0 =A0 =A0 send_chunk(
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 Resp,
>> @@ -118,6 +127,15 @@ handle_changes_req2(Req, Db) ->
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 end
>> =A0 =A0 =A0 =A0 =A0 =A0 )
>> =A0 =A0 =A0 =A0 end;
>> + =A0 =A0"eventsource" ->
>> + =A0 =A0 =A0 =A0Headers =3D [
>> + =A0 =A0 =A0 =A0 =A0 =A0{"Content-Type", "text/event-stream"},
>> + =A0 =A0 =A0 =A0 =A0 =A0{"Cache-Control", "no-cache"}
>> + =A0 =A0 =A0 =A0],
>> + =A0 =A0 =A0 =A0{ok, Resp} =3D couch_httpd:start_json_response(Req, 200=
, Headers),
>> + =A0 =A0 =A0 =A0fun(FeedChangesFun) ->
>> + =A0 =A0 =A0 =A0 =A0 =A0FeedChangesFun(MakeCallback(Resp))
>> + =A0 =A0 =A0 =A0end;
>> =A0 =A0 _ ->
>> =A0 =A0 =A0 =A0 % "longpoll" or "continuous"
>> =A0 =A0 =A0 =A0 {ok, Resp} =3D couch_httpd:start_json_response(Req, 200)=
,
>> @@ -1097,13 +1115,15 @@ parse_doc_query(Req) ->
>>
>> =A0parse_changes_query(Req) ->
>> =A0 =A0 lists:foldl(fun({Key, Value}, Args) ->
>> - =A0 =A0 =A0 =A0case {Key, Value} of
>> + =A0 =A0 =A0 =A0case {string:to_lower(Key), Value} of
>> =A0 =A0 =A0 =A0 {"feed", _} ->
>> =A0 =A0 =A0 =A0 =A0 =A0 Args#changes_args{feed=3DValue};
>> =A0 =A0 =A0 =A0 {"descending", "true"} ->
>> =A0 =A0 =A0 =A0 =A0 =A0 Args#changes_args{dir=3Drev};
>> =A0 =A0 =A0 =A0 {"since", _} ->
>> =A0 =A0 =A0 =A0 =A0 =A0 Args#changes_args{since=3Dlist_to_integer(Value)=
};
>> + =A0 =A0 =A0 =A0{"last-event-id", _} ->
>> + =A0 =A0 =A0 =A0 =A0 =A0Args#changes_args{since=3Dlist_to_integer(Value=
)};
>> =A0 =A0 =A0 =A0 {"limit", _} ->
>> =A0 =A0 =A0 =A0 =A0 =A0 Args#changes_args{limit=3Dlist_to_integer(Value)=
};
>> =A0 =A0 =A0 =A0 {"style", _} ->
>>