From ace6dfe0107010b57c5da0596f69cfd10fc84a38 Mon Sep 17 00:00:00 2001 From: John Christopher Anderson Date: Thu, 29 Jan 2009 22:15:48 +0000 Subject: Replacement of inets with ibrowse. Fixes COUCHDB-179 and enhances replication. Thanks Jason Davies and Adam Kocoloski for the fix, Maximillian Dornseif for reporting. git-svn-id: https://svn.apache.org/repos/asf/couchdb/trunk@739047 13f79535-47bb-0310-9956-ffa450edef68 --- src/ibrowse/ibrowse.erl | 628 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 628 insertions(+) create mode 100644 src/ibrowse/ibrowse.erl (limited to 'src/ibrowse/ibrowse.erl') diff --git a/src/ibrowse/ibrowse.erl b/src/ibrowse/ibrowse.erl new file mode 100644 index 00000000..4e6404ad --- /dev/null +++ b/src/ibrowse/ibrowse.erl @@ -0,0 +1,628 @@ +%%%------------------------------------------------------------------- +%%% File : ibrowse.erl +%%% Author : Chandrashekhar Mullaparthi +%%% Description : Load balancer process for HTTP client connections. +%%% +%%% Created : 11 Oct 2003 by Chandrashekhar Mullaparthi +%%%------------------------------------------------------------------- +%% @author Chandrashekhar Mullaparthi +%% @copyright 2005-2008 Chandrashekhar Mullaparthi +%% @version 1.4 +%% @doc The ibrowse application implements an HTTP 1.1 client. This +%% module implements the API of the HTTP client. There is one named +%% process called 'ibrowse' which assists in load balancing and maintaining configuration. There is one load balancing process per unique webserver. There is +%% one process to handle one TCP connection to a webserver +%% (implemented in the module ibrowse_http_client). Multiple connections to a +%% webserver are setup based on the settings for each webserver. The +%% ibrowse process also determines which connection to pipeline a +%% certain request on. The functions to call are send_req/3, +%% send_req/4, send_req/5, send_req/6. +%% +%%

Here are a few sample invocations.

+%% +%% +%% ibrowse:send_req("http://intranet/messenger/", [], get). +%%

+%% +%% ibrowse:send_req("http://www.google.com/", [], get, [], +%% [{proxy_user, "XXXXX"}, +%% {proxy_password, "XXXXX"}, +%% {proxy_host, "proxy"}, +%% {proxy_port, 8080}], 1000). +%%

+%% +%%ibrowse:send_req("http://www.erlang.org/download/otp_src_R10B-3.tar.gz", [], get, [], +%% [{proxy_user, "XXXXX"}, +%% {proxy_password, "XXXXX"}, +%% {proxy_host, "proxy"}, +%% {proxy_port, 8080}, +%% {save_response_to_file, true}], 1000). +%%

+%% +%% ibrowse:send_req("http://www.erlang.org", [], head). +%% +%%

+%% ibrowse:send_req("http://www.sun.com", [], options). +%% +%%

+%% ibrowse:send_req("http://www.bbc.co.uk", [], trace). +%% +%%

+%% ibrowse:send_req("http://www.google.com", [], get, [], +%% [{stream_to, self()}]). +%% +%% +%%

A driver exists which implements URL encoding in C, but the +%% speed achieved using only erlang has been good enough, so the +%% driver isn't actually used.

+ +-module(ibrowse). +-vsn('$Id: ibrowse.erl,v 1.7 2008/05/21 15:28:11 chandrusf Exp $ '). + +-behaviour(gen_server). +%%-------------------------------------------------------------------- +%% Include files +%%-------------------------------------------------------------------- + +%%-------------------------------------------------------------------- +%% External exports +-export([start_link/0, start/0, stop/0]). + +%% gen_server callbacks +-export([init/1, handle_call/3, handle_cast/2, handle_info/2, + terminate/2, code_change/3]). + +%% API interface +-export([ + rescan_config/0, + rescan_config/1, + get_config_value/1, + get_config_value/2, + spawn_worker_process/2, + spawn_link_worker_process/2, + stop_worker_process/1, + send_req/3, + send_req/4, + send_req/5, + send_req/6, + send_req_direct/4, + send_req_direct/5, + send_req_direct/6, + send_req_direct/7, + set_max_sessions/3, + set_max_pipeline_size/3, + set_dest/3, + trace_on/0, + trace_off/0, + trace_on/2, + trace_off/2, + show_dest_status/2 + ]). + +-ifdef(debug). +-compile(export_all). +-endif. + +-import(ibrowse_lib, [ + parse_url/1, + printable_date/0, + get_value/2, + get_value/3, + do_trace/2 + ]). + +-record(state, {trace = false}). + +-include("ibrowse.hrl"). + +-define(DEF_MAX_SESSIONS,10). +-define(DEF_MAX_PIPELINE_SIZE,10). + +%%==================================================================== +%% External functions +%%==================================================================== +%%-------------------------------------------------------------------- +%% Function: start_link/0 +%% Description: Starts the server +%%-------------------------------------------------------------------- +%% @doc Starts the ibrowse process linked to the calling process. Usually invoked by the supervisor ibrowse_sup +%% @spec start_link() -> {ok, pid()} +start_link() -> + gen_server:start_link({local, ?MODULE}, ?MODULE, [], []). + +%% @doc Starts the ibrowse process without linking. Useful when testing using the shell +start() -> + gen_server:start({local, ?MODULE}, ?MODULE, [], [{debug, []}]). + +%% @doc Stop the ibrowse process. Useful when testing using the shell. +stop() -> + catch gen_server:call(ibrowse, stop). + +%% @doc This is the basic function to send a HTTP request. +%% The Status return value indicates the HTTP status code returned by the webserver +%% @spec send_req(Url::string(), Headers::headerList(), Method::method()) -> response() +%% headerList() = [{header(), value()}] +%% header() = atom() | string() +%% value() = term() +%% method() = get | post | head | options | put | delete | trace | mkcol | propfind | proppatch | lock | unlock | move | copy +%% Status = string() +%% ResponseHeaders = [respHeader()] +%% respHeader() = {headerName(), headerValue()} +%% headerName() = string() +%% headerValue() = string() +%% response() = {ok, Status, ResponseHeaders, ResponseBody} | {error, Reason} +%% ResponseBody = string() | {file, Filename} +%% Reason = term() +send_req(Url, Headers, Method) -> + send_req(Url, Headers, Method, [], []). + +%% @doc Same as send_req/3. +%% If a list is specified for the body it has to be a flat list. The body can also be a fun/0 or a fun/1.
+%% If fun/0, the connection handling process will repeatdely call the fun until it returns an error or eof. 
Fun() = {ok, Data} | eof

+%% If fun/1, the connection handling process will repeatedly call the fun with the supplied state until it returns an error or eof. 
Fun(State) = {ok, Data} | {ok, Data, NewState} | eof
+%% @spec send_req(Url, Headers, Method::method(), Body::body()) -> response() +%% body() = [] | string() | binary() | fun_arity_0() | {fun_arity_1(), initial_state()} +%% initial_state() = term() +send_req(Url, Headers, Method, Body) -> + send_req(Url, Headers, Method, Body, []). + +%% @doc Same as send_req/4. +%% For a description of SSL Options, look in the ssl manpage. If the +%% HTTP Version to use is not specified, the default is 1.1. +%%
+%%

The host_header is useful in the case where ibrowse is +%% connecting to a component such as stunnel which then sets up a +%% secure connection to a webserver. In this case, the URL supplied to +%% ibrowse must have the stunnel host/port details, but that won't +%% make sense to the destination webserver. This option can then be +%% used to specify what should go in the Host header in +%% the request.

+%%
    +%%
  • When both the options save_response_to_file and stream_to +%% are specified, the former takes precedence.
    • +%% +%%
  • For the save_response_to_file option, the response body is saved to +%% file only if the status code is in the 200-299 range. If not, the response body is returned +%% as a string.
    • +%%
  • Whenever an error occurs in the processing of a request, ibrowse will return as much +%% information as it has, such as HTTP Status Code and HTTP Headers. When this happens, the response +%% is of the form {error, {Reason, {stat_code, StatusCode}, HTTP_headers}}
    • +%%
+%% @spec send_req(Url::string(), Headers::headerList(), Method::method(), Body::body(), Options::optionList()) -> response() +%% optionList() = [option()] +%% option() = {max_sessions, integer()} | +%% {max_pipeline_size, integer()} | +%% {trace, boolean()} | +%% {is_ssl, boolean()} | +%% {ssl_options, [SSLOpt]} | +%% {pool_name, atom()} | +%% {proxy_host, string()} | +%% {proxy_port, integer()} | +%% {proxy_user, string()} | +%% {proxy_password, string()} | +%% {use_absolute_uri, boolean()} | +%% {basic_auth, {username(), password()}} | +%% {cookie, string()} | +%% {content_length, integer()} | +%% {content_type, string()} | +%% {save_response_to_file, srtf()} | +%% {stream_to, process()} | +%% {http_vsn, {MajorVsn, MinorVsn}} | +%% {host_header, string()} | +%% {transfer_encoding, {chunked, ChunkSize}} +%% +%% process() = pid() | atom() +%% username() = string() +%% password() = string() +%% SSLOpt = term() +%% ChunkSize = integer() +%% srtf() = boolean() | filename() +%% filename() = string() +%% +send_req(Url, Headers, Method, Body, Options) -> + send_req(Url, Headers, Method, Body, Options, 30000). + +%% @doc Same as send_req/5. +%% All timeout values are in milliseconds. +%% @spec send_req(Url, Headers::headerList(), Method::method(), Body::body(), Options::optionList(), Timeout) -> response() +%% Timeout = integer() | infinity +send_req(Url, Headers, Method, Body, Options, Timeout) -> + case catch parse_url(Url) of + #url{host = Host, + port = Port} = Parsed_url -> + Lb_pid = case ets:lookup(ibrowse_lb, {Host, Port}) of + [] -> + get_lb_pid(Parsed_url); + [#lb_pid{pid = Lb_pid_1}] -> + Lb_pid_1 + end, + Max_sessions = get_max_sessions(Host, Port, Options), + Max_pipeline_size = get_max_pipeline_size(Host, Port, Options), + Options_1 = merge_options(Host, Port, Options), + {SSLOptions, IsSSL} = + case get_value(is_ssl, Options_1, false) of + false -> {[], false}; + true -> {get_value(ssl_options, Options_1), true} + end, + case ibrowse_lb:spawn_connection(Lb_pid, Parsed_url, + Max_sessions, + Max_pipeline_size, + {SSLOptions, IsSSL}) of + {ok, Conn_Pid} -> + do_send_req(Conn_Pid, Parsed_url, Headers, + Method, Body, Options_1, Timeout); + Err -> + Err + end; + Err -> + {error, {url_parsing_failed, Err}} + end. + +merge_options(Host, Port, Options) -> + Config_options = get_config_value({options, Host, Port}, []), + lists:foldl( + fun({Key, Val}, Acc) -> + case lists:keysearch(Key, 1, Options) of + false -> + [{Key, Val} | Acc]; + _ -> + Acc + end + end, Options, Config_options). + +get_lb_pid(Url) -> + gen_server:call(?MODULE, {get_lb_pid, Url}). + +get_max_sessions(Host, Port, Options) -> + get_value(max_sessions, Options, + get_config_value({max_sessions, Host, Port}, ?DEF_MAX_SESSIONS)). + +get_max_pipeline_size(Host, Port, Options) -> + get_value(max_pipeline_size, Options, + get_config_value({max_pipeline_size, Host, Port}, ?DEF_MAX_PIPELINE_SIZE)). + +%% @doc Deprecated. Use set_max_sessions/3 and set_max_pipeline_size/3 +%% for achieving the same effect. +set_dest(Host, Port, [{max_sessions, Max} | T]) -> + set_max_sessions(Host, Port, Max), + set_dest(Host, Port, T); +set_dest(Host, Port, [{max_pipeline_size, Max} | T]) -> + set_max_pipeline_size(Host, Port, Max), + set_dest(Host, Port, T); +set_dest(Host, Port, [{trace, Bool} | T]) when Bool == true; Bool == false -> + ibrowse ! {trace, true, Host, Port}, + set_dest(Host, Port, T); +set_dest(_Host, _Port, [H | _]) -> + exit({invalid_option, H}); +set_dest(_, _, []) -> + ok. + +%% @doc Set the maximum number of connections allowed to a specific Host:Port. +%% @spec set_max_sessions(Host::string(), Port::integer(), Max::integer()) -> ok +set_max_sessions(Host, Port, Max) when is_integer(Max), Max > 0 -> + gen_server:call(?MODULE, {set_config_value, {max_sessions, Host, Port}, Max}). + +%% @doc Set the maximum pipeline size for each connection to a specific Host:Port. +%% @spec set_max_pipeline_size(Host::string(), Port::integer(), Max::integer()) -> ok +set_max_pipeline_size(Host, Port, Max) when is_integer(Max), Max > 0 -> + gen_server:call(?MODULE, {set_config_value, {max_pipeline_size, Host, Port}, Max}). + +do_send_req(Conn_Pid, Parsed_url, Headers, Method, Body, Options, Timeout) -> + case catch ibrowse_http_client:send_req(Conn_Pid, Parsed_url, + Headers, Method, Body, + Options, Timeout) of + {'EXIT', {timeout, _}} -> + {error, req_timedout}; + {'EXIT', Reason} -> + {error, {'EXIT', Reason}}; + Ret -> + Ret + end. + +%% @doc Creates a HTTP client process to the specified Host:Port which +%% is not part of the load balancing pool. This is useful in cases +%% where some requests to a webserver might take a long time whereas +%% some might take a very short time. To avoid getting these quick +%% requests stuck in the pipeline behind time consuming requests, use +%% this function to get a handle to a connection process.
+%% Note: Calling this function only creates a worker process. No connection +%% is setup. The connection attempt is made only when the first +%% request is sent via any of the send_req_direct/4,5,6,7 functions.
+%% Note: It is the responsibility of the calling process to control +%% pipeline size on such connections. +%% +%% @spec spawn_worker_process(Host::string(), Port::integer()) -> {ok, pid()} +spawn_worker_process(Host, Port) -> + ibrowse_http_client:start({Host, Port}). + +%% @doc Same as spawn_worker_process/2 except the the calling process +%% is linked to the worker process which is spawned. +spawn_link_worker_process(Host, Port) -> + ibrowse_http_client:start_link({Host, Port}). + +%% @doc Terminate a worker process spawned using +%% spawn_worker_process/2 or spawn_link_worker_process/2. Requests in +%% progress will get the error response 
{error, closing_on_request}
+%% @spec stop_worker_process(Conn_pid::pid()) -> ok +stop_worker_process(Conn_pid) -> + ibrowse_http_client:stop(Conn_pid). + +%% @doc Same as send_req/3 except that the first argument is the PID +%% returned by spawn_worker_process/2 or spawn_link_worker_process/2 +send_req_direct(Conn_pid, Url, Headers, Method) -> + send_req_direct(Conn_pid, Url, Headers, Method, [], []). + +%% @doc Same as send_req/4 except that the first argument is the PID +%% returned by spawn_worker_process/2 or spawn_link_worker_process/2 +send_req_direct(Conn_pid, Url, Headers, Method, Body) -> + send_req_direct(Conn_pid, Url, Headers, Method, Body, []). + +%% @doc Same as send_req/5 except that the first argument is the PID +%% returned by spawn_worker_process/2 or spawn_link_worker_process/2 +send_req_direct(Conn_pid, Url, Headers, Method, Body, Options) -> + send_req_direct(Conn_pid, Url, Headers, Method, Body, Options, 30000). + +%% @doc Same as send_req/6 except that the first argument is the PID +%% returned by spawn_worker_process/2 or spawn_link_worker_process/2 +send_req_direct(Conn_pid, Url, Headers, Method, Body, Options, Timeout) -> + case catch parse_url(Url) of + #url{host = Host, + port = Port} = Parsed_url -> + Options_1 = merge_options(Host, Port, Options), + case do_send_req(Conn_pid, Parsed_url, Headers, Method, Body, Options_1, Timeout) of + {error, {'EXIT', {noproc, _}}} -> + {error, worker_is_dead}; + Ret -> + Ret + end; + Err -> + {error, {url_parsing_failed, Err}} + end. + +%% @doc Turn tracing on for the ibrowse process +trace_on() -> + ibrowse ! {trace, true}. +%% @doc Turn tracing off for the ibrowse process +trace_off() -> + ibrowse ! {trace, false}. + +%% @doc Turn tracing on for all connections to the specified HTTP +%% server. Host is whatever is specified as the domain name in the URL +%% @spec trace_on(Host, Port) -> term() +%% Host = string() +%% Port = integer() +trace_on(Host, Port) -> + ibrowse ! {trace, true, Host, Port}. + +%% @doc Turn tracing OFF for all connections to the specified HTTP +%% server. +%% @spec trace_off(Host, Port) -> term() +trace_off(Host, Port) -> + ibrowse ! {trace, false, Host, Port}. + +%% @doc Shows some internal information about load balancing to a +%% specified Host:Port. Info about workers spawned using +%% spawn_worker_process/2 or spawn_link_worker_process/2 is not +%% included. +show_dest_status(Host, Port) -> + case ets:lookup(ibrowse_lb, {Host, Port}) of + [] -> + no_active_processes; + [#lb_pid{pid = Lb_pid}] -> + io:format("Load Balancer Pid : ~p~n", [Lb_pid]), + io:format("LB process msg q size : ~p~n", [(catch process_info(Lb_pid, message_queue_len))]), + case lists:dropwhile( + fun(Tid) -> + ets:info(Tid, owner) /= Lb_pid + end, ets:all()) of + [] -> + io:format("Couldn't locate ETS table for ~p~n", [Lb_pid]); + [Tid | _] -> + First = ets:first(Tid), + Last = ets:last(Tid), + Size = ets:info(Tid, size), + io:format("LB ETS table id : ~p~n", [Tid]), + io:format("Num Connections : ~p~n", [Size]), + case Size of + 0 -> + ok; + _ -> + {First_p_sz, _} = First, + {Last_p_sz, _} = Last, + io:format("Smallest pipeline : ~1000.p~n", [First_p_sz]), + io:format("Largest pipeline : ~1000.p~n", [Last_p_sz]) + end + end + end. + +%% @doc Clear current configuration for ibrowse and load from the file +%% ibrowse.conf in the IBROWSE_EBIN/../priv directory. Current +%% configuration is cleared only if the ibrowse.conf file is readable +%% using file:consult/1 +rescan_config() -> + gen_server:call(?MODULE, rescan_config). + +%% Clear current configuration for ibrowse and load from the specified +%% file. Current configuration is cleared only if the specified +%% file is readable using file:consult/1 +rescan_config(File) when is_list(File) -> + gen_server:call(?MODULE, {rescan_config, File}). + +%%==================================================================== +%% Server functions +%%==================================================================== + +%%-------------------------------------------------------------------- +%% Function: init/1 +%% Description: Initiates the server +%% Returns: {ok, State} | +%% {ok, State, Timeout} | +%% ignore | +%% {stop, Reason} +%%-------------------------------------------------------------------- +init(_) -> + process_flag(trap_exit, true), + State = #state{}, + put(my_trace_flag, State#state.trace), + put(ibrowse_trace_token, "ibrowse"), + ets:new(ibrowse_lb, [named_table, public, {keypos, 2}]), + ets:new(ibrowse_conf, [named_table, protected, {keypos, 2}]), + import_config(), + {ok, #state{}}. + +import_config() -> + case code:priv_dir(ibrowse) of + {error, _} = Err -> + Err; + PrivDir -> + Filename = filename:join(PrivDir, "ibrowse.conf"), + import_config(Filename) + end. + +import_config(Filename) -> + case file:consult(Filename) of + {ok, Terms} -> + ets:delete_all_objects(ibrowse_conf), + Fun = fun({dest, Host, Port, MaxSess, MaxPipe, Options}) + when list(Host), integer(Port), + integer(MaxSess), MaxSess > 0, + integer(MaxPipe), MaxPipe > 0, list(Options) -> + I = [{{max_sessions, Host, Port}, MaxSess}, + {{max_pipeline_size, Host, Port}, MaxPipe}, + {{options, Host, Port}, Options}], + lists:foreach( + fun({X, Y}) -> + ets:insert(ibrowse_conf, + #ibrowse_conf{key = X, + value = Y}) + end, I); + ({K, V}) -> + ets:insert(ibrowse_conf, + #ibrowse_conf{key = K, + value = V}); + (X) -> + io:format("Skipping unrecognised term: ~p~n", [X]) + end, + lists:foreach(Fun, Terms); + Err -> + Err + end. + +%% @doc Internal export +get_config_value(Key) -> + [#ibrowse_conf{value = V}] = ets:lookup(ibrowse_conf, Key), + V. + +%% @doc Internal export +get_config_value(Key, DefVal) -> + case ets:lookup(ibrowse_conf, Key) of + [] -> + DefVal; + [#ibrowse_conf{value = V}] -> + V + end. + +set_config_value(Key, Val) -> + ets:insert(ibrowse_conf, #ibrowse_conf{key = Key, value = Val}). +%%-------------------------------------------------------------------- +%% Function: handle_call/3 +%% Description: Handling call messages +%% Returns: {reply, Reply, State} | +%% {reply, Reply, State, Timeout} | +%% {noreply, State} | +%% {noreply, State, Timeout} | +%% {stop, Reason, Reply, State} | (terminate/2 is called) +%% {stop, Reason, State} (terminate/2 is called) +%%-------------------------------------------------------------------- +handle_call({get_lb_pid, #url{host = Host, port = Port} = Url}, _From, State) -> + Pid = do_get_connection(Url, ets:lookup(ibrowse_lb, {Host, Port})), + {reply, Pid, State}; + +handle_call(stop, _From, State) -> + do_trace("IBROWSE shutting down~n", []), + {stop, normal, ok, State}; + +handle_call({set_config_value, Key, Val}, _From, State) -> + set_config_value(Key, Val), + {reply, ok, State}; + +handle_call(rescan_config, _From, State) -> + Ret = (catch import_config()), + {reply, Ret, State}; + +handle_call({rescan_config, File}, _From, State) -> + Ret = (catch import_config(File)), + {reply, Ret, State}; + +handle_call(Request, _From, State) -> + Reply = {unknown_request, Request}, + {reply, Reply, State}. + +%%-------------------------------------------------------------------- +%% Function: handle_cast/2 +%% Description: Handling cast messages +%% Returns: {noreply, State} | +%% {noreply, State, Timeout} | +%% {stop, Reason, State} (terminate/2 is called) +%%-------------------------------------------------------------------- + +handle_cast(_Msg, State) -> + {noreply, State}. + +%%-------------------------------------------------------------------- +%% Function: handle_info/2 +%% Description: Handling all non call/cast messages +%% Returns: {noreply, State} | +%% {noreply, State, Timeout} | +%% {stop, Reason, State} (terminate/2 is called) +%%-------------------------------------------------------------------- +handle_info({trace, Bool}, State) -> + put(my_trace_flag, Bool), + {noreply, State}; + +handle_info({trace, Bool, Host, Port}, State) -> + Fun = fun(#lb_pid{host_port = {H, P}, pid = Pid}, _) + when H == Host, + P == Port -> + catch Pid ! {trace, Bool}; + (#client_conn{key = {H, P, Pid}}, _) + when H == Host, + P == Port -> + catch Pid ! {trace, Bool}; + (_, Acc) -> + Acc + end, + ets:foldl(Fun, undefined, ibrowse_lb), + ets:insert(ibrowse_conf, #ibrowse_conf{key = {trace, Host, Port}, + value = Bool}), + {noreply, State}; + +handle_info(_Info, State) -> + {noreply, State}. + +%%-------------------------------------------------------------------- +%% Function: terminate/2 +%% Description: Shutdown the server +%% Returns: any (ignored by gen_server) +%%-------------------------------------------------------------------- +terminate(_Reason, _State) -> + ok. + +%%-------------------------------------------------------------------- +%% Func: code_change/3 +%% Purpose: Convert process state when code is changed +%% Returns: {ok, NewState} +%%-------------------------------------------------------------------- +code_change(_OldVsn, State, _Extra) -> + {ok, State}. + +%%-------------------------------------------------------------------- +%%% Internal functions +%%-------------------------------------------------------------------- +do_get_connection(#url{host = Host, port = Port}, []) -> + {ok, Pid} = ibrowse_lb:start_link([Host, Port]), + ets:insert(ibrowse_lb, #lb_pid{host_port = {Host, Port}, pid = Pid}), + Pid; +do_get_connection(_Url, [#lb_pid{pid = Pid}]) -> + Pid. -- cgit v1.2.3