1 # This file is part of NIT (http://www.nitlanguage.org).
3 # Copyright 2013 Jean-Philippe Caissy <jpcaissy@piji.ca>
4 # Copyright 2014 Alexis Laferrière <alexis.laf@xymus.net>
6 # Licensed under the Apache License, Version 2.0 (the "License");
7 # you may not use this file except in compliance with the License.
8 # You may obtain a copy of the License at
10 # http://www.apache.org/licenses/LICENSE-2.0
12 # Unless required by applicable law or agreed to in writing, software
13 # distributed under the License is distributed on an "AS IS" BASIS,
14 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 # See the License for the specific language governing permissions and
16 # limitations under the License.
18 # Low-level wrapper around the libevent library to manage events on file descriptors
20 # For mor information, refer to the libevent documentation at
21 # http://monkey.org/~provos/libevent/doxygen-2.0.1/
22 module libevent
is pkgconfig
("libevent")
25 #include <event2/listener.h>
26 #include <event2/bufferevent.h>
27 #include <event2/buffer.h>
32 #include <sys/types.h>
37 #include <sys/socket.h>
38 #include <arpa/inet.h>
39 #include <netinet/in.h>
40 #include <netinet/ip.h>
42 // Protect callbacks for compatibility with light FFI
43 #ifdef Connection_decr_ref
44 // Callback forwarded to 'Connection.write_callback'
45 static void c_write_cb(struct bufferevent *bev, Connection ctx) {
46 Connection_write_callback(ctx);
49 // Callback forwarded to 'Connection.read_callback_native'
50 static void c_read_cb(struct bufferevent *bev, Connection ctx)
52 Connection_read_callback_native(ctx, bev);
55 // Callback forwarded to 'Connection.event_callback'
56 static void c_event_cb(struct bufferevent *bev, short events, Connection ctx)
58 int release = Connection_event_callback(ctx, events);
59 if (release) Connection_decr_ref(ctx);
62 // Callback forwarded to 'ConnectionFactory.accept_connection'
63 static void accept_connection_cb(struct evconnlistener *listener, evutil_socket_t fd,
64 struct sockaddr *addrin, int socklen, ConnectionFactory ctx)
66 ConnectionFactory_accept_connection(ctx, listener, fd, addrin, socklen);
70 #ifdef EventCallback_incr_ref
71 // Callback forwarded to 'EventCallback.callback'
72 static void signal_cb(evutil_socket_t fd, short events, void *data)
74 EventCallback handler = data;
75 EventCallback_callback(handler, events);
80 # Structure to hold information and state for a Libevent dispatch loop.
82 # The event_base lies at the center of Libevent; every application will
83 # have one. It keeps track of all pending and active events, and
84 # notifies your application of the active ones.
85 extern class NativeEventBase `{ struct event_base * `}
87 # Create a new event_base to use with the rest of Libevent
88 new `{ return event_base_new(); `}
90 # Has `self` been correctly initialized?
91 fun is_valid
: Bool do return not address_is_null
93 # Reinitialize the event base after a fork
95 # Some event mechanisms do not survive across fork.
96 # The event base needs to be reinitialized with the `reinit` method.
98 # Returns `true` if some events could not be re-added.
99 fun reinit
: Bool `{ return event_reinit(self); `}
101 # Event dispatching loop
103 # This loop will run the event base until either there are no more added
104 # events, or until something calls `loopexit
`.
105 fun dispatch `{ event_base_dispatch(self); `}
107 # Exit the event loop
110 fun loopexit
`{ event_base_loopexit(self, NULL); `}
112 redef fun free `{ event_base_free(self); `}
115 # Event, libevent's basic unit of operation
116 extern class NativeEvent `{ struct event * `}
118 # Add to the set of pending events
120 # TODO support timeout
121 fun add `{ event_add(self, NULL); `}
123 # Remove from the set of monitored events
124 fun del
`{ event_del(self); `}
126 redef fun free `{ event_free(self); `}
130 extern class NativeEvSignal
133 new (base
: NativeEventBase, signal
: Int, handler
: EventCallback)
134 import EventCallback.callback
`{
135 EventCallback_incr_ref(handler);
136 return evsignal_new(base, signal, signal_cb, handler);
140 # Receiver of event callbacks
141 interface EventCallback
143 # Callback on an event
144 fun callback
(events
: Int) do end
147 # Spawned to manage a specific connection
153 # Closing this connection has been requested, but may not yet be `closed`
154 var close_requested
= false
156 # This connection is closed
159 # The native libevent linked to `self`
160 var native_buffer_event
: NativeBufferEvent
162 # Close this connection if possible, otherwise mark it to be closed later
165 if closed
then return
167 var i
= native_buffer_event
.input_buffer
168 var o
= native_buffer_event
.output_buffer
169 if i
.length
> 0 or o
.length
> 0 then
170 close_requested
= true
176 # Force closing this connection and freeing `native_buffer_event`
179 if closed
then return
181 native_buffer_event
.free
185 # Callback method on a write event
188 if close_requested
then close
191 private fun read_callback_native
(bev
: NativeBufferEvent)
193 var evbuffer
= bev
.input_buffer
194 var len
= evbuffer
.length
195 var buf
= new CString(len
)
196 evbuffer
.remove
(buf
, len
)
197 var str
= buf
.to_s_with_length
(len
)
201 # Callback method when data is available to read
202 fun read_callback
(content
: String)
204 if close_requested
then close
207 # Callback method on events: EOF, user-defined timeout and unrecoverable errors
209 # Returns `true` if the native handles to `self` can be released.
210 fun event_callback
(events
: Int): Bool
212 if events
& bev_event_error
!= 0 or events
& bev_event_eof
!= 0 then
213 if events
& bev_event_error
!= 0 then
214 var sock_err
= evutil_socket_error
215 # Ignore some normal errors and print the others for debugging
216 if sock_err
== 110 then
217 # Connection timed out (ETIMEDOUT)
218 else if sock_err
== 104 then
219 # Connection reset by peer (ECONNRESET)
221 print_error
"libevent error event: {evutil_socket_error_to_string(sock_err)} ({sock_err})"
231 # Write a string to the connection
234 if close_requested
then return
235 native_buffer_event
.write
(str
.to_cstring
, str
.byte_length
)
238 redef fun write_byte
(byte
)
240 if close_requested
then return
241 native_buffer_event
.write_byte
(byte
)
244 redef fun write_bytes
(bytes
)
246 if close_requested
then return
247 native_buffer_event
.write
(bytes
.items
, bytes
.length
)
250 # Write a file to the connection
252 # If `not path.file_exists`, the method returns.
253 fun write_file
(path
: String)
255 if close_requested
then return
257 var file
= new FileReader.open
(path
)
258 if file
.last_error
!= null then
259 var error
= new IOError("Failed to open file at '{path}'")
260 error
.cause
= file
.last_error
261 self.last_error
= error
266 var stat
= file
.file_stat
268 last_error
= new IOError("Failed to stat file at '{path}'")
273 var err
= native_buffer_event
.output_buffer
.add_file
(file
.fd
, 0, stat
.size
)
275 last_error
= new IOError("Failed to add file at '{path}'")
282 # Error code for event callbacks
284 # error encountered while reading
285 fun bev_event_reading
: Int `{ return BEV_EVENT_READING; `}
287 # error encountered while writing
288 fun bev_event_writing: Int `{ return BEV_EVENT_WRITING; `}
291 fun bev_event_eof
: Int `{ return BEV_EVENT_EOF; `}
293 # unrecoverable error encountered
294 fun bev_event_error: Int `{ return BEV_EVENT_ERROR; `}
296 # user-specified timeout reached
297 fun bev_event_timeout
: Int `{ return BEV_EVENT_TIMEOUT; `}
299 # connect operation finished.
300 fun bev_event_connected: Int `{ return BEV_EVENT_CONNECTED; `}
302 # Global error code for the last socket operation on the calling thread
304 # Not idempotent on all platforms.
305 fun evutil_socket_error
: Int `{
306 return EVUTIL_SOCKET_ERROR();
309 # Convert an error code from `evutil_socket_error` to a string
310 fun evutil_socket_error_to_string
(error_code
: Int): CString `{
311 return evutil_socket_error_to_string(error_code);
315 # Options that can be specified when creating a `NativeBufferEvent`
317 # Close the underlying file descriptor/bufferevent/whatever when this bufferevent is freed.
318 fun bev_opt_close_on_free
: Int `{ return BEV_OPT_CLOSE_ON_FREE; `}
320 # If threading is enabled, protect the operations on this bufferevent with a lock.
321 fun bev_opt_threadsafe: Int `{ return BEV_OPT_THREADSAFE; `}
323 # Run callbacks deferred in the event loop.
324 fun bev_opt_defer_callbacks
: Int `{ return BEV_OPT_DEFER_CALLBACKS; `}
326 # If set, callbacks are executed without locks being held on the bufferevent.
327 fun bev_opt_unlock_callbacks: Int `{ return BEV_OPT_UNLOCK_CALLBACKS; `}
330 # Options for `NativeBufferEvent::enable`
333 fun ev_read
: Int `{ return EV_READ; `}
336 fun ev_write: Int `{ return EV_WRITE; `}
340 # A buffer event structure, strongly associated to a connection, an input buffer and an output_buffer
341 extern class NativeBufferEvent `{ struct bufferevent * `}
343 # Socket-based `NativeBufferEvent` that reads and writes data onto a network
344 new socket(base: NativeEventBase, fd, options: Int) `{
345 return bufferevent_socket_new
(base
, fd
, options
);
348 # Enable a bufferevent.
349 fun enable(operation: Int) `{
350 bufferevent_enable
(self, operation
);
353 # Set callbacks to `read_callback_native
`, `write_callback
` and `event_callback
` of `conn
`
354 fun setcb(conn: Connection) import Connection.read_callback_native,
355 Connection.write_callback, Connection.event_callback, CString `{
356 Connection_incr_ref(conn
);
357 bufferevent_setcb
(self,
358 (bufferevent_data_cb
)c_read_cb
,
359 (bufferevent_data_cb
)c_write_cb
,
360 (bufferevent_event_cb
)c_event_cb
, conn
);
363 # Write `length
` bytes of `line
`
364 fun write(line: CString, length: Int): Int `{
365 return bufferevent_write
(self, line
, length
);
368 # Write the byte `value
`
369 fun write_byte(value: Byte): Int `{
370 unsigned char byt
= (unsigned char
)value
;
371 return bufferevent_write
(self, &byt
, 1);
374 redef fun free `{ bufferevent_free(self); `}
376 # The output buffer associated to `self`
377 fun output_buffer
: OutputNativeEvBuffer `{ return bufferevent_get_output(self); `}
379 # The input buffer associated to `self`
380 fun input_buffer: InputNativeEvBuffer `{ return bufferevent_get_input(self); `}
382 # Read data from this buffer
383 fun read_buffer
(buf
: NativeEvBuffer): Int `{ return bufferevent_read_buffer(self, buf); `}
385 # Write data to this buffer
386 fun write_buffer(buf: NativeEvBuffer): Int `{ return bufferevent_write_buffer(self, buf); `}
390 extern class NativeEvBuffer `{ struct evbuffer * `}
391 # Length of data in this buffer
392 fun length: Int `{ return evbuffer_get_length(self); `}
394 # Read data from an evbuffer and drain the bytes read
395 fun remove
(buffer
: CString, len
: Int) `{
396 evbuffer_remove(self, buffer, len);
401 extern class InputNativeEvBuffer
404 # Empty/clear `length` data from buffer
405 fun drain
(length
: Int) `{ evbuffer_drain(self, length); `}
409 extern class OutputNativeEvBuffer
413 fun add_file(fd, offset, length: Int): Bool `{
414 return evbuffer_add_file
(self, fd
, offset
, length
);
418 # A listener acting on an interface and port, spawns `Connection` on new connections
419 extern class ConnectionListener `{ struct evconnlistener * `}
421 private new bind_to
(base
: NativeEventBase, address
: CString, port
: Int, factory
: ConnectionFactory)
422 import ConnectionFactory.accept_connection
, error_callback
`{
424 struct sockaddr_in sin;
425 struct evconnlistener *listener;
426 ConnectionFactory_incr_ref(factory);
428 struct hostent *hostent = gethostbyname(address);
434 memset(&sin, 0, sizeof(sin));
435 sin.sin_family = hostent->h_addrtype;
436 sin.sin_port = htons(port);
437 memcpy( &(sin.sin_addr.s_addr), (const void*)hostent->h_addr, hostent->h_length );
439 listener = evconnlistener_new_bind(base,
440 (evconnlistener_cb)accept_connection_cb, factory,
441 LEV_OPT_CLOSE_ON_FREE | LEV_OPT_REUSEABLE, -1,
442 (struct sockaddr*)&sin, sizeof(sin));
444 if (listener != NULL) {
445 evconnlistener_set_error_cb(listener, (evconnlistener_errorcb)ConnectionListener_error_callback);
451 # Get the `NativeEventBase` associated to `self`
452 fun base
: NativeEventBase `{ return evconnlistener_get_base(self); `}
454 # Callback method on listening error
455 fun error_callback do
456 var cstr = evutil_socket_error_to_string(evutil_socket_error)
457 print_error "libevent error: '{cstr}'"
461 # Factory to listen on sockets and create new `Connection`
462 class ConnectionFactory
463 # The `NativeEventBase` for the dispatch loop of this factory
464 var event_base: NativeEventBase
466 # Accept a connection on `listener
`
468 # By default, it creates a new NativeBufferEvent and calls `spawn_connection
`.
469 fun accept_connection(listener: ConnectionListener, fd: Int, addrin: Pointer, socklen: Int)
471 var base = listener.base
472 var bev = new NativeBufferEvent.socket(base, fd, bev_opt_close_on_free)
474 # Human representation of remote client address
475 var addr_len = 46 # Longest possible IPv6 address + null byte
476 var addr_buf = new CString(addr_len)
477 addr_buf = addrin_to_address(addrin, addr_buf, addr_len)
478 var addr = if addr_buf.address_is_null then
482 var conn = spawn_connection(bev, addr)
483 bev.enable ev_read|ev_write
487 # Create a new `Connection` object for `buffer_event
`
488 fun spawn_connection(buffer_event: NativeBufferEvent, address: String): Connection
490 return new Connection(buffer_event)
493 # Listen on `address
`:`port
` for new connection, which will callback `spawn_connection
`
494 fun bind_to(address: String, port: Int): nullable ConnectionListener
496 var listener = new ConnectionListener.bind_to(event_base, address.to_cstring, port, self)
497 if listener.address_is_null then
498 sys.stderr.write "libevent warning: Opening {address}:{port} failed\n"
503 # Put string representation of source `address
` into `buf
`
504 private fun addrin_to_address(address: Pointer, buf: CString, buf_len: Int): CString `{
505 struct sockaddr
*addrin
= (struct sockaddr
*)address
;
507 if (addrin-
>sa_family
== AF_INET) {
508 struct in_addr
*src
= &((struct sockaddr_in
*)addrin
)->sin_addr
;
509 return (char
*)inet_ntop
(addrin-
>sa_family
, src
, buf
, buf_len
);
511 else if (addrin-
>sa_family
== AF_INET6) {
512 struct in6_addr
*src
= &((struct sockaddr_in6
*)addrin
)->sin6_addr
;
513 return (char
*)inet_ntop
(addrin-
>sa_family
, src
, buf
, buf_len
);
519 # Enable some relatively expensive debugging checks that would normally be turned off
520 fun enable_debug_mode `{ event_enable_debug_mode(); `}
522 # Use Windows builtin locking and thread ID functions
523 fun use_windows_threads
: Bool `{
524 #ifdef EVTHREAD_USE_WINDOWS_THREADS_IMPLEMENTED
525 return evthread_use_windows_threads();
531 # Use Pthreads locking and thread ID functions
532 fun use_pthreads
: Bool `{
533 #ifdef EVTHREAD_USE_PTHREADS_IMPLEMENTED
534 return evthread_use_pthreads();