# Module ibrowse

- Description
- Function Index
- Function Details

The ibrowse application implements an HTTP 1.1 client in erlang.

Copyright © 2005-2014 Chandrashekhar Mullaparthi

Behaviours: `gen_server`.

Authors: Chandrashekhar Mullaparthi (`chandrashekhar dot mullaparthi at gmail dot com`).

## Description

The ibrowse application implements an HTTP 1.1 client in erlang. 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()}]).`

## Function Index

add_config/1 | Add additional configuration elements at runtime.
all_trace_off/0 | Turn Off ALL tracing.
code_change/3 |
get_config_value/1 | Internal export.
get_config_value/2 | Internal export.
get_metrics/0 |
get_metrics/2 |
handle_call/3 |
handle_cast/2 |
handle_info/2 |
init/1 |
rescan_config/0 | Clear current configuration for ibrowse and load from the file ibrowse.conf in the IBROWSE_EBIN/../priv directory.
rescan_config/1 |
send_req/3 | This is the basic function to send a HTTP request.
send_req/4 | Same as send_req/3.
send_req/5 | Same as send_req/4.
send_req/6 | Same as send_req/5.
send_req_direct/4 | 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/5 | 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/6 | 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/7 | 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.
set_dest/3 | Deprecated.
set_max_attempts/3 | Set the maximum attempts for each connection to a specific Host:Port.
set_max_pipeline_size/3 | Set the maximum pipeline size for each connection to a specific Host:Port.
set_max_sessions/3 | Set the maximum number of connections allowed to a specific Host:Port.
show_dest_status/0 | Shows some internal information about load balancing.
show_dest_status/1 |
show_dest_status/2 | Shows some internal information about load balancing to a specified Host:Port.
spawn_link_worker_process/1 | Same as spawn_worker_process/1 except the the calling process is linked to the worker process which is spawned.
spawn_link_worker_process/2 | Same as spawn_link_worker_process/1 except with Erlang process options.
spawn_worker_process/1 | Creates a HTTP client process to the specified Host:Port which is not part of the load balancing pool.
spawn_worker_process/2 | Same as spawn_worker_process/1 except with Erlang process options.
start/0 | Starts the ibrowse process without linking.
start_link/0 | Starts the ibrowse process linked to the calling process.
stop/0 | Stop the ibrowse process.
stop_worker_process/1 | Terminate a worker process spawned using spawn_worker_process/2 or spawn_link_worker_process/2.
stream_close/1 | Tell ibrowse to close the connection associated with the specified stream.
stream_next/1 | Tell ibrowse to stream the next chunk of data to the caller.
terminate/2 |
trace_off/0 | Turn tracing off for the ibrowse process.
trace_off/2 | Turn tracing OFF for all connections to the specified HTTP server.
trace_on/0 | Turn tracing on for the ibrowse process.
trace_on/2 | Turn tracing on for all connections to the specified HTTP server.

## Function Details

### add_config/1

`add_config(Terms) -> any()`

Add additional configuration elements at runtime.

### all_trace_off/0

`all_trace_off() -> ok`

Turn Off ALL tracing

### code_change/3

`code_change(OldVsn, State, Extra) -> any()`

### get_config_value/1

`get_config_value(Key) -> any()`

Internal export

### get_config_value/2

`get_config_value(Key, DefVal) -> any()`

Internal export

### get_metrics/0

`get_metrics() -> any()`

### get_metrics/2

`get_metrics(Host, Port) -> any()`

### handle_call/3

`handle_call(Request, From, State) -> any()`

### handle_cast/2

`handle_cast(Msg, State) -> any()`

### handle_info/2

`handle_info(Info, State) -> any()`

### init/1

`init(X1) -> any()`

### rescan_config/0

`rescan_config() -> any()`

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/1

`rescan_config(Terms) -> any()`

### send_req/3

`send_req(Url::string(), Headers::headerList(), Method::method()) -> response()`

- `headerList() = [{header(), value()}]`
- `header() = atom() | string() | binary()`
- `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} | {ibrowse_req_id, req_id()} | {error, Reason}`
- `req_id() = term()`
- `ResponseBody = string() | {file, Filename}`
- `Reason = term()`

This is the basic function to send a HTTP request. The Status return value indicates the HTTP status code returned by the webserver

### send_req/4

`send_req(Url, Headers, Method::method(), Body::body()) -> response()`

- `body() = [] | string() | binary() | fun_arity_0() | {fun_arity_1(), initial_state()}`
- `initial_state() = term()`

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

### send_req/5

`send_req(Url::string(), Headers::headerList(), Method::method(), Body::body(), Options::optionList()) -> response()`

- `optionList() = [option()]`
- `option() = {max_sessions, integer()} | {response_format, response_format()} | {stream_chunk_size, 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, stream_to()} | {http_vsn, {MajorVsn, MinorVsn}} | {host_header, string()} | {inactivity_timeout, integer()} | {connect_timeout, integer()} | {socket_options, Sock_opts} | {transfer_encoding, {chunked, ChunkSize}} | {headers_as_is, boolean()} | {give_raw_headers, boolean()} | {preserve_chunked_encoding, boolean()} | {workaround, head_response_with_body} | {worker_process_options, list()} | {return_raw_request, true} | {max_attempts, integer()}`
- `stream_to() = process() | {process(), once}`
- `process() = pid() | atom()`
- `username() = string()`
- `password() = string()`
- `SSLOpt = term()`
- `Sock_opts = [Sock_opt]`
- `Sock_opt = term()`
- `ChunkSize = integer()`
- `srtf() = boolean() | filename() | {append, filename()}`
- `filename() = string()`
- `response_format() = list | binary`

Same as send_req/4.

### send_req/6

`send_req(Url, Headers::headerList(), Method::method(), Body::body(), Options::optionList(), Timeout) -> response()`

- `Timeout = integer() | infinity`

Same as send_req/5. All timeout values are in milliseconds.

### send_req_direct/4

`send_req_direct(Conn_pid, Url, Headers, Method) -> any()`

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/5

`send_req_direct(Conn_pid, Url, Headers, Method, Body) -> any()`

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/6

`send_req_direct(Conn_pid, Url, Headers, Method, Body, Options) -> any()`

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/7

`send_req_direct(Conn_pid, Url, Headers, Method, Body, Options, Timeout) -> any()`

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

### set_dest/3

`set_dest(Host, Port, T) -> any()`

Deprecated. Use set_max_sessions/3 and set_max_pipeline_size/3 for achieving the same effect.

### set_max_attempts/3

`set_max_attempts(Host::string(), Port::integer(), Max::integer()) -> ok`

Set the maximum attempts for each connection to a specific Host:Port.

### set_max_pipeline_size/3

`set_max_pipeline_size(Host::string(), Port::integer(), Max::integer()) -> ok`

Set the maximum pipeline size for each connection to a specific Host:Port.

### set_max_sessions/3

`set_max_sessions(Host::string(), Port::integer(), Max::integer()) -> ok`

Set the maximum number of connections allowed to a specific Host:Port.

### show_dest_status/0

`show_dest_status() -> any()`

Shows some internal information about load balancing. Info about workers spawned using spawn_worker_process/2 or spawn_link_worker_process/2 is not included.

### show_dest_status/1

`show_dest_status(Url) -> any()`

### show_dest_status/2

`show_dest_status(Host, Port) -> any()`

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.

### spawn_link_worker_process/1

`spawn_link_worker_process(Url::string() | {Host::string(), Port::integer()}) -> {ok, pid()}`

Same as spawn_worker_process/1 except the the calling process is linked to the worker process which is spawned.

### spawn_link_worker_process/2

`spawn_link_worker_process(Host::string(), Port::integer()) -> {ok, pid()}`

Same as spawn_link_worker_process/1 except with Erlang process options.

### spawn_worker_process/1

`spawn_worker_process(Url::string() | {Host::string(), Port::integer()}) -> {ok, pid()}`

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.

### spawn_worker_process/2

`spawn_worker_process(Host::string(), Port::integer()) -> {ok, pid()}`

Same as spawn_worker_process/1 except with Erlang process options.

### start/0

`start() -> any()`

Starts the ibrowse process without linking. Useful when testing using the shell

### start_link/0

`start_link() -> {ok, pid()}`

Starts the ibrowse process linked to the calling process. Usually invoked by the supervisor ibrowse_sup

### stop/0

`stop() -> any()`

Stop the ibrowse process. Useful when testing using the shell.

### stop_worker_process/1

`stop_worker_process(Conn_pid::pid()) -> ok`

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}

### stream_close/1

`stream_close(Req_id::req_id()) -> ok | {error, unknown_req_id}`

Tell ibrowse to close the connection associated with the specified stream. Should be used in conjunction with the `stream_to` option. Note that all requests in progress on the connection which is serving this Req_id will be aborted, and an error returned.

### stream_next/1

`stream_next(Req_id::req_id()) -> ok | {error, unknown_req_id}`

Tell ibrowse to stream the next chunk of data to the caller. Should be used in conjunction with the `stream_to` option

### terminate/2

`terminate(Reason, State) -> any()`

### trace_off/0

`trace_off() -> any()`

Turn tracing off for the ibrowse process

### trace_off/2

`trace_off(Host, Port) -> ok`

Turn tracing OFF for all connections to the specified HTTP server.

### trace_on/0

`trace_on() -> any()`

Turn tracing on for the ibrowse process

### trace_on/2

`trace_on(Host, Port) -> ok`

- `Host = string()`
- `Port = integer()`

Turn tracing on for all connections to the specified HTTP server. Host is whatever is specified as the domain name in the URL

Generated by EDoc, Nov 6 2015, 11:40:24.