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Replace init_stream/5 with stream_body/2

This allows us to change the max chunk length on a per chunk basis
instead of for the whole stream. It's also much easier to use this
way even if we don't want to change the chunk size.
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1 parent 66f7c15 commit ce1d8862c093b31a2e3ba0a072b58b697a6b55de @essen essen committed Apr 2, 2013
Showing with 39 additions and 34 deletions.
  1. +3 −3 guide/req.md
  2. +36 −31 src/cowboy_req.erl
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@@ -104,9 +104,9 @@ and `body_qs/2` will return `{error, badlength}`. If the request
contains chunked body, `body/1`, `body/2`, `body_qs/1`
and `body_qs/2` will return `{error, chunked}`.
If you get either of the above two errors, you will want to
-handle the body of the request using `stream_body/1` and
-`skip_body/1`, with the streaming process optionally
-initialized using `init_stream/4` or `init_stream/5`.
+handle the body of the request using `stream_body/1`,
+`stream_body/2` and `skip_body/1`, with the streaming process
+optionally initialized using `init_stream/4`.
Multipart request body
----------------------
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@@ -78,8 +78,8 @@
-export([has_body/1]).
-export([body_length/1]).
-export([init_stream/4]).
--export([init_stream/5]).
-export([stream_body/1]).
+-export([stream_body/2]).
-export([skip_body/1]).
-export([body/1]).
-export([body/2]).
@@ -155,8 +155,8 @@
meta = [] :: [{atom(), any()}],
%% Request body.
- body_state = waiting :: waiting | done | {stream,
- non_neg_integer(), non_neg_integer(), fun(), any(), fun()},
+ body_state = waiting :: waiting | done
+ | {stream, non_neg_integer(), fun(), any(), fun()},
multipart = undefined :: undefined | {non_neg_integer(), fun()},
buffer = <<>> :: binary(),
@@ -591,17 +591,11 @@ body_length(Req) ->
{undefined, Req2}
end.
-%% @equiv init_stream(1000000, TransferDecode, TransferState, ContentDecode, Req)
--spec init_stream(fun(), any(), fun(), Req)
- -> {ok, Req} when Req::req().
-init_stream(TransferDecode, TransferState, ContentDecode, Req) ->
- init_stream(1000000, TransferDecode, TransferState, ContentDecode, Req).
-
%% @doc Initialize body streaming and set custom decoding functions.
%%
%% Calling this function is optional. It should only be used if you
%% need to override the default behavior of Cowboy. Otherwise you
-%% should call stream_body/1 directly.
+%% should call stream_body/{1,2} directly.
%%
%% Two decodings happen. First a decoding function is applied to the
%% transferred data, and then another is applied to the actual content.
@@ -613,27 +607,36 @@ init_stream(TransferDecode, TransferState, ContentDecode, Req) ->
%% Content encoding is generally used for compression.
%%
%% Standard encodings can be found in cowboy_http.
--spec init_stream(non_neg_integer(), fun(), any(), fun(), Req)
+-spec init_stream(fun(), any(), fun(), Req)
-> {ok, Req} when Req::req().
-init_stream(MaxLength, TransferDecode, TransferState, ContentDecode, Req) ->
+init_stream(TransferDecode, TransferState, ContentDecode, Req) ->
{ok, Req#http_req{body_state=
- {stream, 0, MaxLength, TransferDecode, TransferState, ContentDecode}}}.
+ {stream, 0, TransferDecode, TransferState, ContentDecode}}}.
+
+%% @equiv stream_body(Req, 1000000)
+-spec stream_body(Req) -> {ok, binary(), Req}
+ | {done, Req} | {error, atom()} when Req::req().
+stream_body(Req) ->
+ stream_body(Req, 1000000).
%% @doc Stream the request's body.
%%
%% This is the most low level function to read the request body.
%%
-%% In most cases, if they weren't defined before using stream_body/4,
+%% In most cases, if they weren't defined before using init_stream/4,
%% this function will guess which transfer and content encodings were
%% used for building the request body, and configure the decoding
%% functions that will be used when streaming.
%%
%% It then starts streaming the body, returning {ok, Data, Req}
%% for each streamed part, and {done, Req} when it's finished streaming.
--spec stream_body(Req) -> {ok, binary(), Req}
+%%
+%% You can limit the size of the chunks being returned by using the
+%% second argument which is the size in bytes. It defaults to 1000000 bytes.
+-spec stream_body(Req, non_neg_integer()) -> {ok, binary(), Req}
| {done, Req} | {error, atom()} when Req::req().
-stream_body(Req=#http_req{body_state=waiting,
- version=Version, transport=Transport, socket=Socket}) ->
+stream_body(Req=#http_req{body_state=waiting, version=Version,
+ transport=Transport, socket=Socket}, MaxLength) ->
{ok, ExpectHeader, Req1} = parse_header(<<"expect">>, Req),
case ExpectHeader of
[<<"100-continue">>] ->
@@ -646,34 +649,36 @@ stream_body(Req=#http_req{body_state=waiting,
case parse_header(<<"transfer-encoding">>, Req1) of
{ok, [<<"chunked">>], Req2} ->
stream_body(Req2#http_req{body_state=
- {stream, 0, 1000000,
+ {stream, 0,
fun cowboy_http:te_chunked/2, {0, 0},
- fun cowboy_http:ce_identity/1}});
+ fun cowboy_http:ce_identity/1}},
+ MaxLength);
{ok, [<<"identity">>], Req2} ->
{Length, Req3} = body_length(Req2),
case Length of
0 ->
{done, Req3#http_req{body_state=done}};
Length ->
stream_body(Req3#http_req{body_state=
- {stream, Length, 1000000,
+ {stream, Length,
fun cowboy_http:te_identity/2, {0, Length},
- fun cowboy_http:ce_identity/1}})
+ fun cowboy_http:ce_identity/1}},
+ MaxLength)
end
end;
-stream_body(Req=#http_req{body_state=done}) ->
+stream_body(Req=#http_req{body_state=done}, _) ->
{done, Req};
-stream_body(Req=#http_req{buffer=Buffer})
+stream_body(Req=#http_req{buffer=Buffer}, _)
when Buffer =/= <<>> ->
transfer_decode(Buffer, Req#http_req{buffer= <<>>});
-stream_body(Req) ->
- stream_body_recv(Req).
+stream_body(Req, MaxLength) ->
+ stream_body_recv(Req, MaxLength).
--spec stream_body_recv(Req)
+-spec stream_body_recv(Req, non_neg_integer())
-> {ok, binary(), Req} | {error, atom()} when Req::req().
stream_body_recv(Req=#http_req{
transport=Transport, socket=Socket, buffer=Buffer,
- body_state={stream, Length, MaxLength, _, _, _}}) ->
+ body_state={stream, Length, _, _, _}}, MaxLength) ->
%% @todo Allow configuring the timeout.
case Transport:recv(Socket, min(Length, MaxLength), 5000) of
{ok, Data} -> transfer_decode(<< Buffer/binary, Data/binary >>,
@@ -683,20 +688,20 @@ stream_body_recv(Req=#http_req{
-spec transfer_decode(binary(), Req)
-> {ok, binary(), Req} | {error, atom()} when Req::req().
-transfer_decode(Data, Req=#http_req{body_state={stream, _, MaxLength,
+transfer_decode(Data, Req=#http_req{body_state={stream, _,
TransferDecode, TransferState, ContentDecode}}) ->
case TransferDecode(Data, TransferState) of
{ok, Data2, Rest, TransferState2} ->
content_decode(ContentDecode, Data2,
- Req#http_req{buffer=Rest, body_state={stream, 0, MaxLength,
+ Req#http_req{buffer=Rest, body_state={stream, 0,
TransferDecode, TransferState2, ContentDecode}});
%% @todo {header(s) for chunked
more ->
stream_body_recv(Req#http_req{buffer=Data, body_state={stream,
- 0, MaxLength, TransferDecode, TransferState, ContentDecode}});
+ 0, TransferDecode, TransferState, ContentDecode}}, 0);
{more, Length, Data2, TransferState2} ->
content_decode(ContentDecode, Data2,
- Req#http_req{body_state={stream, Length, MaxLength,
+ Req#http_req{body_state={stream, Length,
TransferDecode, TransferState2, ContentDecode}});
{done, Length, Rest} ->
Req2 = transfer_decode_done(Length, Rest, Req),

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