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")
26 #include <sys/types.h>
29 #include <sys/socket.h>
31 #include <event2/listener.h>
32 #include <event2/bufferevent.h>
33 #include <event2/buffer.h>
37 // Callback forwarded to 'Connection.write_callback'
38 static void c_write_cb(struct bufferevent *bev, Connection ctx) {
39 Connection_write_callback(ctx);
42 // Callback forwarded to 'Connection.read_callback_native'
43 static void c_read_cb(struct bufferevent *bev, Connection ctx)
45 Connection_read_callback_native(ctx, bev);
48 // Callback forwarded to 'Connection.event_callback'
49 static void c_event_cb(struct bufferevent *bev, short events, Connection ctx)
51 int release = Connection_event_callback(ctx, events);
52 if (release) Connection_decr_ref(ctx);
55 // Callback forwarded to 'ConnectionFactory.accept_connection'
56 static void accept_connection_cb(struct evconnlistener *listener, evutil_socket_t fd,
57 struct sockaddr *address, int socklen, ConnectionFactory ctx)
59 ConnectionFactory_accept_connection(ctx, listener, fd, address, socklen);
63 # Structure to hold information and state for a Libevent dispatch loop.
65 # The event_base lies at the center of Libevent; every application will
66 # have one. It keeps track of all pending and active events, and
67 # notifies your application of the active ones.
68 extern class NativeEventBase `{ struct event_base * `}
70 # Create a new event_base to use with the rest of Libevent
71 new `{ return event_base_new(); `}
73 # Has `self` been correctly initialized?
74 fun is_valid
: Bool do return not address_is_null
76 # Event dispatching loop
78 # This loop will run the event base until either there are no more added
79 # events, or until something calls `exit_loop`.
80 fun dispatch
`{ event_base_dispatch(self); `}
85 fun exit_loop `{ event_base_loopexit(self, NULL); `}
87 # Destroy this instance
88 fun destroy
`{ event_base_free(self); `}
91 # Spawned to manage a specific connection
97 # Closing this connection has been requested, but may not yet be `closed
`
98 var close_requested = false
100 # This connection is closed
103 # The native libevent linked to `self`
104 var native_buffer_event: NativeBufferEvent
106 # Close this connection if possible, otherwise mark it to be closed later
109 if closed then return
110 var success = native_buffer_event.destroy
111 close_requested = true
115 # Callback method on a write event
118 if close_requested then close
121 private fun read_callback_native(bev: NativeBufferEvent)
123 var evbuffer = bev.input_buffer
124 var len = evbuffer.length
125 var buf = new NativeString(len)
126 evbuffer.remove(buf, len)
127 var str = buf.to_s_with_length(len)
131 # Callback method when data is available to read
132 fun read_callback(content: String)
134 if close_requested then close
137 # Callback method on events: EOF, user-defined timeout and unrecoverable errors
139 # Returns `true` if the native handles to `self` can be released.
140 fun event_callback(events: Int): Bool
142 if events & bev_event_error != 0 or events & bev_event_eof != 0 then
143 if events & bev_event_error != 0 then print_error "Error from bufferevent"
151 # Write a string to the connection
154 if close_requested then return
155 native_buffer_event.write(str.to_cstring, str.bytelen)
158 redef fun write_byte(byte)
160 if close_requested then return
161 native_buffer_event.write_byte(byte)
164 redef fun write_bytes(bytes)
166 if close_requested then return
167 native_buffer_event.write(bytes.items, bytes.length)
170 # Write a file to the connection
172 # If `not path
.file_exists
`, the method returns.
173 fun write_file(path: String)
175 if close_requested then return
177 var file = new FileReader.open(path)
178 if file.last_error != null then
179 var error = new IOError("Failed to open file at '{path}'")
180 error.cause = file.last_error
181 self.last_error = error
186 var stat = file.file_stat
188 last_error = new IOError("Failed to stat file at '{path}'")
193 var err = native_buffer_event.output_buffer.add_file(file.fd, 0, stat.size)
195 last_error = new IOError("Failed to add file at '{path}'")
202 # Error code for event callbacks
204 # error encountered while reading
205 fun bev_event_reading: Int `{ return BEV_EVENT_READING; `}
207 # error encountered while writing
208 fun bev_event_writing
: Int `{ return BEV_EVENT_WRITING; `}
211 fun bev_event_eof: Int `{ return BEV_EVENT_EOF; `}
213 # unrecoverable error encountered
214 fun bev_event_error
: Int `{ return BEV_EVENT_ERROR; `}
216 # user-specified timeout reached
217 fun bev_event_timeout: Int `{ return BEV_EVENT_TIMEOUT; `}
219 # connect operation finished.
220 fun bev_event_connected
: Int `{ return BEV_EVENT_CONNECTED; `}
223 # Options that can be specified when creating a `NativeBufferEvent`
225 # Close the underlying file descriptor/bufferevent/whatever when this bufferevent is freed.
226 fun bev_opt_close_on_free: Int `{ return BEV_OPT_CLOSE_ON_FREE; `}
228 # If threading is enabled, protect the operations on this bufferevent with a lock.
229 fun bev_opt_threadsafe
: Int `{ return BEV_OPT_THREADSAFE; `}
231 # Run callbacks deferred in the event loop.
232 fun bev_opt_defer_callbacks: Int `{ return BEV_OPT_DEFER_CALLBACKS; `}
234 # If set, callbacks are executed without locks being held on the bufferevent.
235 fun bev_opt_unlock_callbacks
: Int `{ return BEV_OPT_UNLOCK_CALLBACKS; `}
238 # Options for `NativeBufferEvent::enable
`
241 fun ev_read: Int `{ return EV_READ; `}
244 fun ev_write
: Int `{ return EV_WRITE; `}
248 # A buffer event structure, strongly associated to a connection, an input buffer and an output_buffer
249 extern class NativeBufferEvent `{ struct bufferevent * `}
251 # Socket-based `NativeBufferEvent` that reads and writes data onto a network
252 new socket
(base
: NativeEventBase, fd
, options
: Int) `{
253 return bufferevent_socket_new(base, fd, options);
256 # Enable a bufferevent.
257 fun enable
(operation
: Int) `{
258 bufferevent_enable(self, operation);
261 # Set callbacks to `read_callback_native`, `write_callback` and `event_callback` of `conn`
262 fun setcb
(conn
: Connection) import Connection.read_callback_native
,
263 Connection.write_callback
, Connection.event_callback
, NativeString `{
264 Connection_incr_ref(conn);
265 bufferevent_setcb(self,
266 (bufferevent_data_cb)c_read_cb,
267 (bufferevent_data_cb)c_write_cb,
268 (bufferevent_event_cb)c_event_cb, conn);
271 # Write `length` bytes of `line`
272 fun write
(line
: NativeString, length
: Int): Int `{
273 return bufferevent_write(self, line, length);
276 # Write the byte `value`
277 fun write_byte
(value
: Byte): Int `{
278 unsigned char byt = (unsigned char)value;
279 return bufferevent_write(self, &byt, 1);
282 # Check if we have anything left in our buffers. If so, we set our connection to be closed
283 # on a callback. Otherwise we close it and free it right away.
285 struct evbuffer* out = bufferevent_get_output(self);
286 struct evbuffer* in = bufferevent_get_input(self);
287 if(evbuffer_get_length(in) > 0 || evbuffer_get_length(out) > 0) {
290 bufferevent_free(self);
295 # The output buffer associated to `self`
296 fun output_buffer
: OutputNativeEvBuffer `{ return bufferevent_get_output(self); `}
298 # The input buffer associated to `self`
299 fun input_buffer: InputNativeEvBuffer `{ return bufferevent_get_input(self); `}
301 # Read data from this buffer
302 fun read_buffer
(buf
: NativeEvBuffer): Int `{ return bufferevent_read_buffer(self, buf); `}
304 # Write data to this buffer
305 fun write_buffer(buf: NativeEvBuffer): Int `{ return bufferevent_write_buffer(self, buf); `}
309 extern class NativeEvBuffer `{ struct evbuffer * `}
310 # Length of data in this buffer
311 fun length: Int `{ return evbuffer_get_length(self); `}
313 # Read data from an evbuffer and drain the bytes read
314 fun remove
(buffer
: NativeString, len
: Int) `{
315 evbuffer_remove(self, buffer, len);
320 extern class InputNativeEvBuffer
323 # Empty/clear `length` data from buffer
324 fun drain
(length
: Int) `{ evbuffer_drain(self, length); `}
328 extern class OutputNativeEvBuffer
332 fun add_file(fd, offset, length: Int): Bool `{
333 return evbuffer_add_file
(self, fd
, offset
, length
);
337 # A listener acting on an interface and port, spawns `Connection` on new connections
338 extern class ConnectionListener `{ struct evconnlistener * `}
340 private new bind_to
(base
: NativeEventBase, address
: NativeString, port
: Int, factory
: ConnectionFactory)
341 import ConnectionFactory.accept_connection
, error_callback
`{
343 struct sockaddr_in sin;
344 struct evconnlistener *listener;
345 ConnectionFactory_incr_ref(factory);
347 struct hostent *hostent = gethostbyname(address);
353 memset(&sin, 0, sizeof(sin));
354 sin.sin_family = hostent->h_addrtype;
355 sin.sin_port = htons(port);
356 memcpy( &(sin.sin_addr.s_addr), (const void*)hostent->h_addr, hostent->h_length );
358 listener = evconnlistener_new_bind(base,
359 (evconnlistener_cb)accept_connection_cb, factory,
360 LEV_OPT_CLOSE_ON_FREE | LEV_OPT_REUSEABLE, -1,
361 (struct sockaddr*)&sin, sizeof(sin));
363 if (listener != NULL) {
364 evconnlistener_set_error_cb(listener, (evconnlistener_errorcb)ConnectionListener_error_callback);
370 # Get the `NativeEventBase` associated to `self`
371 fun base
: NativeEventBase `{ return evconnlistener_get_base(self); `}
373 # Callback method on listening error
374 fun error_callback do
375 var cstr = socket_error
376 sys.stderr.write "libevent error: '{cstr}'"
380 fun socket_error: NativeString `{
381 // TODO move to
Nit and maybe
NativeEventBase
382 int err
= EVUTIL_SOCKET_ERROR();
383 return evutil_socket_error_to_string
(err
);
387 # Factory to listen on sockets and create new `Connection`
388 class ConnectionFactory
389 # The `NativeEventBase` for the dispatch loop of this factory
390 var event_base: NativeEventBase
392 # Accept a connection on `listener
`
394 # By default, it creates a new NativeBufferEvent and calls `spawn_connection
`.
395 fun accept_connection(listener: ConnectionListener, fd: Int, address: Pointer, socklen: Int)
397 var base = listener.base
398 var bev = new NativeBufferEvent.socket(base, fd, bev_opt_close_on_free)
399 var conn = spawn_connection(bev)
400 bev.enable ev_read|ev_write
404 # Create a new `Connection` object for `buffer_event
`
405 fun spawn_connection(buffer_event: NativeBufferEvent): Connection
407 return new Connection(buffer_event)
410 # Listen on `address
`:`port
` for new connection, which will callback `spawn_connection
`
411 fun bind_to(address: String, port: Int): nullable ConnectionListener
413 var listener = new ConnectionListener.bind_to(event_base, address.to_cstring, port, self)
414 if listener.address_is_null then
415 sys.stderr.write "libevent warning: Opening {address}:{port} failed\n"