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8c15b8c7 TJ |
1 | /* |
2 | The software in this package is distributed under the GNU General | |
3 | Public License version 2 (with a special exception described below). | |
4 | ||
5 | A copy of GNU General Public License (GPL) is included in this distribution, | |
6 | in the file COPYING.GPL. | |
7 | ||
8 | As a special exception, if other files instantiate templates or use macros | |
9 | or inline functions from this file, or you compile this file and link it | |
10 | with other works to produce a work based on this file, this file | |
11 | does not by itself cause the resulting work to be covered | |
12 | by the GNU General Public License. | |
13 | ||
14 | However the source code for this file must still be made available | |
15 | in accordance with section (3) of the GNU General Public License. | |
16 | ||
17 | This exception does not invalidate any other reasons why a work based | |
18 | on this file might be covered by the GNU General Public License. | |
19 | */ | |
20 | /** | |
5c8a3d40 RP |
21 | * @file |
22 | * @brief simple basic IO handling. | |
23 | * | |
24 | * @copyright © Copyright 2007-2008 by Intra2net AG | |
5c8a3d40 RP |
25 | * |
26 | * Deals with POSIX file descriptors; provides an additional abstraction | |
27 | * level above select() or poll() interface. | |
28 | * Also provides basic functionality for dealing with timer events. | |
29 | */ | |
30 | ||
42b7c46d RP |
31 | #ifndef __ASYNC_IO_HPP__ |
32 | #define __ASYNC_IO_HPP__ | |
5c8a3d40 RP |
33 | |
34 | #include <string> | |
35 | #include <list> | |
36 | #include <set> | |
37 | ||
fd6ea89e | 38 | #include <asyncio_config.hpp> |
aba4c34d | 39 | |
fd6ea89e | 40 | #include <asyncio_utils.hpp> |
5c8a3d40 RP |
41 | |
42 | #include <boost/signal.hpp> | |
43 | #include <boost/shared_ptr.hpp> | |
44 | ||
45 | ||
42b7c46d | 46 | namespace AsyncIo |
5c8a3d40 RP |
47 | { |
48 | ||
fd6ea89e | 49 | #ifdef HAVE_LIBI2NCOMMON |
42b7c46d | 50 | using namespace I2n; |
fd6ea89e | 51 | #endif |
aba4c34d | 52 | using Utils::MilliTime; |
5c8a3d40 RP |
53 | |
54 | /* | |
55 | * forward declarations | |
56 | */ | |
57 | class Backend; | |
58 | class IOImplementation; | |
59 | ||
60 | /* | |
61 | * end of forward declarations | |
62 | */ | |
63 | ||
64 | ||
65 | /** | |
66 | * direction for io operations. | |
67 | */ | |
68 | struct Direction | |
69 | { | |
70 | enum _Direction | |
71 | { | |
72 | unspecified= 0, | |
73 | in = 1, | |
74 | out = 2, | |
75 | both= 3 | |
76 | } m_direction; | |
77 | ||
78 | Direction( _Direction direction = unspecified) : m_direction(direction) {} | |
79 | ||
80 | operator _Direction () const { return m_direction; } | |
81 | }; // eo struct IODirection; | |
82 | ||
83 | ||
5c8a3d40 RP |
84 | |
85 | /** | |
86 | * base class for time based events (timer events). | |
87 | * | |
88 | * consists basically of a point in time (when the event should be executed) and a method | |
89 | * which will be called when the given time is reached (or passed). | |
90 | */ | |
91 | class TimerBase | |
92 | { | |
93 | friend class Backend; | |
94 | public: | |
95 | TimerBase(); | |
96 | virtual ~TimerBase(); | |
97 | ||
98 | bool active() const { return m_active; } | |
99 | ||
100 | MilliTime getWhenTime() const {return m_when;} | |
101 | MilliTime getRealWhenTime() const; | |
102 | ||
103 | protected: | |
104 | ||
105 | void setWhenTime(long sec, long msec=0); | |
106 | void setWhenTime(const MilliTime& mt); | |
107 | ||
108 | void setDeltaWhenTime(long sec, long msec=0); | |
109 | void setDeltaWhenTime(const MilliTime& mt); | |
110 | ||
111 | void activate(bool _active= true); | |
112 | void deactivate() { activate(false); } | |
113 | ||
114 | virtual void execute(); | |
115 | ||
116 | private: | |
117 | /// @a true when the event is active. | |
118 | bool m_active; | |
119 | /// point in time when the event should be executed | |
120 | MilliTime m_when; | |
121 | /// mark from backend cycle that the event has to be executed. | |
122 | bool m_marked; | |
123 | }; // eo class TimerBase | |
124 | ||
125 | ||
126 | ||
127 | /** | |
128 | * base class for filter classes. | |
129 | * | |
130 | * filter objects can be "plugged" into IO objects for manipulating the data streams. | |
131 | * (for example: one could make a filter which handles the telnet protocol and plug it into a | |
132 | * socket io object.) | |
133 | * | |
134 | * @note filter object can be used only by one io object. | |
135 | */ | |
136 | class FilterBase | |
fd6ea89e | 137 | : virtual public Utils::SharedBase |
5c8a3d40 RP |
138 | { |
139 | friend class IOImplementation; | |
140 | public: | |
141 | typedef boost::shared_ptr< FilterBase > PtrType; | |
142 | public: | |
143 | FilterBase(); | |
9f5d794e | 144 | virtual ~FilterBase() { m_io = NULL; }; |
5c8a3d40 RP |
145 | |
146 | protected: | |
147 | ||
148 | virtual std::string filterIncomingData(const std::string& data)= 0; | |
149 | virtual std::string filterOutgoingData(const std::string& data)= 0; | |
150 | ||
151 | virtual void endOfIncomingData(); | |
152 | virtual void reset(); | |
153 | ||
154 | protected: | |
155 | ||
156 | void injectIncomingData(const std::string& data); | |
157 | void injectOutgoingData(const std::string& data); | |
158 | ||
159 | private: | |
160 | /// pointer to the io object which uses this filter: | |
161 | IOImplementation *m_io; | |
162 | }; // eo class FilterBase | |
163 | ||
164 | typedef FilterBase::PtrType FilterBasePtr; | |
165 | ||
166 | ||
167 | /** | |
168 | * identity filter; does nothing with the data (in other words: it's useless ;-) ). | |
169 | */ | |
170 | class FilterIdentity : public FilterBase | |
171 | { | |
172 | protected: | |
173 | virtual std::string filterIncomingData(const std::string& data) { return data; } | |
174 | virtual std::string filterOutgoingData(const std::string& data) { return data; } | |
175 | }; // eo class FilterIdentity | |
176 | ||
177 | ||
178 | /** | |
179 | * @brief null filter; deletes everything it receives. | |
180 | * | |
181 | * usefull when output from a subprocess (like stderr) should be ignored... | |
182 | */ | |
183 | class FilterNull : public FilterBase | |
184 | { | |
185 | protected: | |
186 | virtual std::string filterIncomingData(const std::string& data) { return std::string(); } | |
187 | virtual std::string filterOutgoingData(const std::string& data) { return std::string(); } | |
188 | }; // eo FilterNull | |
189 | ||
190 | ||
191 | /** | |
192 | * the base class of the IO classes. | |
193 | * | |
194 | * provides the functionality to read from a file desriptor and write to a file descriptor (which can be | |
195 | * identical (like for socket io), but also can be different (like pipes from/to a process)). | |
196 | * The data stream can be filtered through plugged filter objects which are building a filter chain. | |
197 | * Incoming data is filtered forward through the chain; outgoing data is filtered backward through the chain. | |
198 | * (So the first filter is the one which modifies the data closest to the connections). | |
199 | * | |
200 | * @note the functionality is provided in conjunction with the @a Backend class which handles parts of | |
201 | * the low level IO. | |
202 | * | |
203 | * @note this is a base class; it provides most "interesting" functionality in the protected section only. | |
204 | * This way, derived classes can decide which of that functionality they want to export in their own public | |
205 | * interfaces and which to keep hidden. | |
206 | */ | |
207 | class IOImplementation | |
208 | : public boost::signals::trackable | |
fd6ea89e | 209 | , virtual public Utils::SharedBase |
5c8a3d40 RP |
210 | { |
211 | friend class Backend; | |
212 | friend class FilterBase; | |
213 | ||
214 | public: | |
215 | ||
216 | typedef std::list< FilterBasePtr > FilterChain; | |
217 | ||
218 | typedef boost::signal< void() > SignalType; | |
219 | ||
220 | typedef boost::shared_ptr< IOImplementation > PtrType; | |
221 | ||
222 | public: | |
223 | IOImplementation(int read_fd=-1, int write_fd=-1); | |
224 | virtual ~IOImplementation(); | |
225 | ||
226 | virtual void close(Direction direction = Direction::both); | |
227 | ||
228 | virtual bool wantRead(); | |
229 | virtual bool wantWrite(); | |
230 | ||
231 | virtual bool opened() const; | |
232 | virtual bool eof() const; | |
233 | virtual bool writable() const; | |
234 | virtual bool empty() const; | |
235 | ||
236 | protected: | |
237 | ||
238 | void addFilter(FilterBasePtr filter); | |
239 | void removeFilter(FilterBasePtr); | |
240 | ||
241 | ||
242 | void lowSend(const std::string& data); | |
243 | ||
244 | std::string::size_type getOutputBufferSize() const { return m_output_buffer.size(); } | |
245 | ||
246 | void setWriteFd(int fd); | |
247 | void setReadFd(int fd); | |
248 | ||
249 | inline int readFd() const | |
250 | { | |
251 | return m_read_fd; | |
252 | } | |
253 | ||
254 | inline int writeFd() const | |
255 | { | |
256 | return m_write_fd; | |
257 | } | |
258 | ||
259 | inline bool isMarkedForReading() const { return m_marked_for_reading; } | |
260 | inline bool isMarkedForWriting() const { return m_marked_for_writing; } | |
261 | ||
262 | ||
263 | protected: | |
264 | virtual void doRead(); | |
265 | virtual void doWrite(); | |
266 | ||
267 | void resetReadMark() { m_marked_for_reading= false; } | |
268 | void resetWriteMark() { m_marked_for_writing= false; } | |
269 | ||
270 | void injectIncomingData(FilterBasePtr from_filter, const std::string& _data); | |
271 | void injectOutgoingData(FilterBasePtr from_filter, const std::string& _data); | |
272 | ||
273 | protected: | |
274 | /// last error number | |
275 | int m_errno; | |
276 | /// the input buffer (i.e. the data read from @a m_read_fd) | |
277 | std::string m_input_buffer; | |
278 | ||
279 | /// the chain of filter which are applied to the data received are the data which should be send. | |
280 | FilterChain m_filter_chain; | |
281 | ||
282 | /// signal which is fired when end of file is detected | |
283 | SignalType m_signal_eof; | |
284 | /// signal which is fired when write is no longer possible | |
285 | SignalType m_signal_not_writable; | |
286 | /// signal which is fired when new data was read | |
287 | SignalType m_signal_read; | |
288 | /// signal which is fired when data was written | |
289 | SignalType m_signal_write; | |
290 | ||
291 | /// end of file (on @a m_read_fd) detected (used additionally when m_read_fd is valid) | |
292 | bool m_eof; | |
293 | ||
294 | /// unable-to-write (on @a m_write_fd) detected (used additionally when m_write_fd is valid) | |
295 | bool m_not_writable; | |
296 | ||
297 | private: | |
298 | /// the file descriptor to read from (-1 if none is given) | |
299 | int m_read_fd; | |
300 | /// the file descriptor to write to (-1 if none is given) | |
301 | int m_write_fd; | |
302 | /// output buffer; contains the data which needs to be written. | |
303 | std::string m_output_buffer; | |
304 | ||
305 | private: | |
306 | /// @a true when data is available to be read | |
307 | bool m_marked_for_reading; | |
308 | /// @a true when data can be written | |
309 | bool m_marked_for_writing; | |
310 | ||
311 | }; // eo class IOImplementation | |
312 | ||
313 | ||
314 | ||
315 | /** | |
316 | * same as IOImplementation, but makes fd access functions public. | |
317 | */ | |
318 | class IOImplementation2 : public IOImplementation | |
319 | { | |
320 | typedef IOImplementation inherited; | |
321 | public: | |
322 | IOImplementation2(int read_fd=-1, int write_fd=-1) : inherited(read_fd, write_fd) {} | |
323 | ||
324 | void setWriteFd(int fd) { inherited::setWriteFd(fd); } | |
325 | void setReadFd(int fd) { inherited::setReadFd(fd); } | |
326 | ||
327 | int readFd() const { return inherited::readFd(); } | |
328 | int writeFd() const { return inherited::writeFd(); } | |
329 | ||
330 | }; // eo class IOImplementation2 | |
331 | ||
332 | ||
333 | /** | |
334 | * provides sending data and receiving data via a signal. | |
335 | * | |
336 | * @note the received data is passed as parameter to the signal and no longer stored in the received buffer. | |
337 | */ | |
338 | class SimpleIO : public IOImplementation | |
339 | { | |
340 | typedef IOImplementation inherited; | |
341 | public: | |
342 | SimpleIO(int read_fd=-1, int write_fd=-1); | |
343 | virtual ~SimpleIO(); | |
344 | ||
345 | void sendString(const std::string& data); | |
346 | ||
347 | boost::signal<void(const std::string&)> signal_received_string; | |
348 | ||
349 | private: | |
350 | ||
351 | void slotReceived(); | |
352 | }; // eo class SimpleIO | |
353 | ||
354 | ||
355 | /** | |
356 | * provides sending data and receiving data via a signal. | |
357 | * | |
358 | * @note the received data is passed as parameter to the signal and no longer stored in the received buffer. | |
359 | */ | |
360 | class SimpleIO2 : public IOImplementation2 | |
361 | { | |
362 | typedef IOImplementation2 inherited; | |
363 | public: | |
364 | SimpleIO2(int read_fd=-1, int write_fd=-1); | |
365 | virtual ~SimpleIO2(); | |
366 | ||
367 | void sendString(const std::string& data); | |
368 | ||
369 | boost::signal<void(const std::string&)> signal_received_string; | |
370 | ||
371 | private: | |
372 | ||
373 | void slotReceived(); | |
374 | }; // eo class SimpleIO2 | |
375 | ||
376 | ||
377 | /** | |
378 | * provides the backend for io handling. | |
379 | * | |
380 | * This (singleton) object provides the management of io events. It collects all wishes for reading/writing | |
381 | * from the io objects and information from the timer events. | |
382 | * It poll()s for the events and distributes them to the objects, | |
383 | * | |
384 | * The class provides the possibility for executing one io cycle (/step) or to run a backend loop. | |
385 | * | |
386 | * @note the Backend class needs to be a friend of IOImplementation since it accesses private members | |
387 | * of IOImplementation while performing the io cycles. | |
388 | */ | |
389 | class Backend | |
390 | { | |
391 | public: | |
392 | typedef std::set< int > FdSetType; | |
393 | ||
394 | public: | |
395 | ||
396 | bool doOneStep(int ms_timeout= -1); | |
397 | void run(); | |
398 | void stop(); | |
399 | ||
400 | protected: | |
401 | Backend(); | |
402 | Backend(const Backend& other); | |
403 | ~Backend(); | |
404 | ||
405 | protected: | |
406 | ||
407 | /// the number of currently active backend loops | |
408 | int m_count_active_loops; | |
409 | /// the number of pending stop requests (where each one should exit one active backend loop) | |
410 | int m_count_stop_requests; | |
411 | ||
412 | /// the number of currently active backend cycles(/ steps) | |
413 | static int m_count_active_steps; | |
414 | ||
415 | public: | |
416 | static Backend* getBackend(); | |
417 | ||
418 | protected: | |
419 | /// pointer to the active backend (which is delivered by Backend::getBackend) | |
420 | static Backend* g_backend; | |
421 | }; // eo class Backend | |
422 | ||
423 | ||
424 | ||
42b7c46d | 425 | } // eo namespace AsyncIo |
5c8a3d40 RP |
426 | |
427 | #endif |