Add thrift_http_transport for alterl.


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@666478 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/alterl/src/thrift_http_transport.erl b/lib/alterl/src/thrift_http_transport.erl
new file mode 100644
index 0000000..3b9565c
--- /dev/null
+++ b/lib/alterl/src/thrift_http_transport.erl
@@ -0,0 +1,163 @@
+%%%-------------------------------------------------------------------
+%%% File    : thrift_http_transport.erl
+%%% Author  : <dreiss@facebook.com>
+%%% Description : Client-only HTTP-based transport for thrift
+%%%
+%%% Created : 24 May 2008 by <dreiss@facebook.com>
+%%%-------------------------------------------------------------------
+-module(thrift_http_transport).
+
+-behaviour(gen_server).
+-behaviour(thrift_transport).
+
+%% API
+-export([new/2, set_http_options/2]).
+
+%% gen_server callbacks
+-export([init/1,
+         handle_call/3,
+         handle_cast/2,
+         handle_info/2,
+         terminate/2,
+         code_change/3]).
+
+%% thrift_transport callbacks
+-export([write/2, read/2, flush/1, close/1]).
+
+-record(http_transport, {host, % string()
+                         path, % string()
+                         read_buffer, % iolist()
+                         write_buffer, % iolist()
+                         http_options
+                        }).
+
+%%====================================================================
+%% API
+%%====================================================================
+%%--------------------------------------------------------------------
+%% Function: new() -> {ok,Pid} | ignore | {error,Error}
+%% Description: Starts the server
+%%--------------------------------------------------------------------
+new(Host, Path) ->
+    case gen_server:start_link(?MODULE, {Host, Path}, []) of
+        {ok, Pid} ->
+            thrift_transport:new(?MODULE, Pid);
+        Else ->
+            Else
+    end.
+
+%%--------------------------------------------------------------------
+%% Function: set_http_options() -> ok | {error,Error}
+%% Description: Set HTTP options
+%%--------------------------------------------------------------------
+set_http_options(Transport, HTTPOptions) ->
+    gen_server:call(Transport, {set_http_options, HTTPOptions}).
+
+%%--------------------------------------------------------------------
+%% Function: write(Transport, Data) -> ok
+%%
+%% Data = iolist()
+%%
+%% Description: Writes data into the buffer
+%%--------------------------------------------------------------------
+write(Transport, Data) ->
+    gen_server:call(Transport, {write, Data}).
+
+%%--------------------------------------------------------------------
+%% Function: flush(Transport) -> ok
+%%
+%% Description: Flushes the buffer, making a request
+%%--------------------------------------------------------------------
+flush(Transport) ->
+    gen_server:call(Transport, flush).
+
+%%--------------------------------------------------------------------
+%% Function: close(Transport) -> ok
+%%
+%% Description: Closes the transport
+%%--------------------------------------------------------------------
+close(Transport) ->
+    gen_server:cast(Transport, close).
+
+%%--------------------------------------------------------------------
+%% Function: Read(Transport, Len) -> {ok, Data}
+%%
+%% Data = binary()
+%%
+%% Description: Reads data through from the wrapped transoprt
+%%--------------------------------------------------------------------
+read(Transport, Len) when is_integer(Len) ->
+    gen_server:call(Transport, {read, Len}).
+
+%%====================================================================
+%% gen_server callbacks
+%%====================================================================
+
+init({Host, Path}) ->
+    {ok, #http_transport{host = Host,
+                         path = Path,
+                         read_buffer = [],
+                         write_buffer = [],
+                         http_options = []}}.
+
+handle_call({write, Data}, _From, State = #http_transport{write_buffer = WBuf}) ->
+    {reply, ok, State#http_transport{write_buffer = [WBuf, Data]}};
+
+handle_call({read, Len}, _From, State = #http_transport{read_buffer = RBuf}) ->
+    %% Pull off Give bytes, return them to the user, leave the rest in the buffer.
+    Give = min(iolist_size(RBuf), Len),
+    case iolist_to_binary(RBuf) of
+        <<Data:Give/binary, RBuf1/binary>> ->
+            Response = {ok, Data},
+            State1 = State#http_transport{read_buffer=RBuf1},
+            {reply, Response, State1};
+        _ ->
+            {reply, {error, 'EOF'}, State}
+    end;
+
+handle_call({set_http_options, HTTPOptions}, _From, State) ->
+    {reply, ok, State#http_transport{http_options = HTTPOptions}};
+
+handle_call(flush, _From, State) ->
+    {Response, State1} = do_flush(State),
+    {reply, Response, State1}.
+
+handle_cast(close, State) ->
+    {_, State1} = do_flush(State),
+    {stop, normal, State1};
+
+handle_cast(_Msg, State=#http_transport{}) ->
+    {noreply, State}.
+
+handle_info(_Info, State) ->
+    {noreply, State}.
+
+terminate(_Reason, _State) ->
+    ok.
+
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.
+
+%%--------------------------------------------------------------------
+%%% Internal functions
+%%--------------------------------------------------------------------
+do_flush(State = #http_transport{host = Host,
+                                 path = Path,
+                                 read_buffer = Rbuf,
+                                 write_buffer = Wbuf,
+                                 http_options = HttpOptions}) ->
+    {ok, {{_Version, 200, _ReasonPhrase}, _Headers, Body}} =
+      http:request(post,
+                   {"http://" ++ Host ++ Path,
+                    [{"User-Agent", "Erlang/thrift_http_transport"}],
+                    "application/x-thrift",
+                    iolist_to_binary(Wbuf)},
+                   HttpOptions,
+                   [{body_format, binary}]),
+
+    State1 = State#http_transport{read_buffer = [Rbuf, Body],
+                                  write_buffer = []},
+    {ok, State1}.
+
+min(A,B) when A<B -> A;
+min(_,B)          -> B.