xref: /haiku/src/kits/debug/DebugEventStream.cpp (revision a1163de83ea633463a79de234b8742ee106531b2)
1 /*
2  * Copyright 2009, Ingo Weinhold, ingo_weinhold@gmx.de.
3  * Distributed under the terms of the MIT License.
4  */
5 
6 #include <DebugEventStream.h>
7 
8 #include <stdlib.h>
9 #include <string.h>
10 
11 #include <DataIO.h>
12 
13 #include <system_profiler_defs.h>
14 
15 
16 #define INPUT_BUFFER_SIZE	(128 * 1024)
17 
18 
19 BDebugEventInputStream::BDebugEventInputStream()
20 	:
21 	fStream(NULL),
22 	fFlags(0),
23 	fEventMask(0),
24 	fBuffer(NULL),
25 	fBufferCapacity(0),
26 	fBufferSize(0),
27 	fBufferPosition(0),
28 	fStreamPosition(0),
29 	fOwnsBuffer(false)
30 {
31 }
32 
33 
34 BDebugEventInputStream::~BDebugEventInputStream()
35 {
36 	Unset();
37 
38 	if (fOwnsBuffer)
39 		free(fBuffer);
40 }
41 
42 
43 status_t
44 BDebugEventInputStream::SetTo(BDataIO* stream)
45 {
46 	Unset();
47 
48 	// set the new values
49 	if (stream == NULL)
50 		return B_BAD_VALUE;
51 
52 	fStream = stream;
53 
54 	// allocate a buffer
55 	if (fBuffer == NULL) {
56 		fBuffer = (uint8*)malloc(INPUT_BUFFER_SIZE);
57 		if (fBuffer == NULL) {
58 			Unset();
59 			return B_NO_MEMORY;
60 		}
61 
62 		fOwnsBuffer = true;
63 		fBufferCapacity = INPUT_BUFFER_SIZE;
64 		fBufferSize = 0;
65 	}
66 
67 	return _Init();
68 }
69 
70 
71 status_t
72 BDebugEventInputStream::SetTo(const void* data, size_t size,
73 	bool takeOverOwnership)
74 {
75 	Unset();
76 
77 	if (data == NULL || size == 0)
78 		return B_BAD_VALUE;
79 
80 	if (fBuffer != NULL) {
81 		if (fOwnsBuffer)
82 			free(fBuffer);
83 		fBuffer = NULL;
84 		fBufferCapacity = 0;
85 		fBufferSize = 0;
86 	}
87 
88 	fBuffer = (uint8*)data;
89 	fBufferCapacity = fBufferSize = size;
90 	fOwnsBuffer = takeOverOwnership;
91 
92 	return _Init();
93 }
94 
95 
96 void
97 BDebugEventInputStream::Unset()
98 {
99 	fStream = NULL;
100 	fFlags = 0;
101 	fEventMask = 0;
102 
103 	// If we have a buffer that we own and has the right size, we keep it.
104 	if (fOwnsBuffer) {
105 		if (fBuffer != NULL && fBufferSize != INPUT_BUFFER_SIZE) {
106 			free(fBuffer);
107 			fBuffer = NULL;
108 			fBufferCapacity = 0;
109 			fBufferSize = 0;
110 		}
111 	} else {
112 		fBuffer = NULL;
113 		fBufferCapacity = 0;
114 		fBufferSize = 0;
115 	}
116 }
117 
118 
119 /*!	\brief Returns the next event in the stream.
120 
121 	At the end of the stream \c 0 is returned and \c *_buffer is set to \c NULL.
122 	For events that don't have data associated with them, \c *_buffer will still
123 	be non-NULL, even if dereferencing that address is not allowed.
124 
125 	\param _event Pointer to a pre-allocated location where the event ID shall
126 		be stored.
127 	\param _cpu Pointer to a pre-allocated location where the CPU index shall
128 		be stored.
129 	\param _buffer Pointer to a pre-allocated location where the pointer to the
130 		event data shall be stored.
131 	\param _streamOffset Pointer to a pre-allocated location where the event
132 		header's offset relative to the beginning of the stream shall be stored.
133 		May be \c NULL.
134 	\return A negative error code in case an error occurred while trying to read
135 		the info, the size of the data associated with the event otherwise.
136 */
137 ssize_t
138 BDebugEventInputStream::ReadNextEvent(uint32* _event, uint32* _cpu,
139 	const void** _buffer, off_t* _streamOffset)
140 {
141 	// get the next header
142 	status_t error = _GetData(sizeof(system_profiler_event_header));
143 	if (error != B_OK) {
144 		if (error == B_BAD_DATA && fBufferSize == 0) {
145 			*_buffer = NULL;
146 			return 0;
147 		}
148 		return error;
149 	}
150 
151 	system_profiler_event_header header
152 		= *(system_profiler_event_header*)(fBuffer + fBufferPosition);
153 
154 	off_t streamOffset = fStreamPosition + fBufferPosition;
155 
156 	// skip the header in the buffer
157 	fBufferSize -= sizeof(system_profiler_event_header);
158 	fBufferPosition += sizeof(system_profiler_event_header);
159 
160 	// get the data
161 	if (header.size > 0) {
162 		error = _GetData(header.size);
163 		if (error != B_OK)
164 			return error;
165 	}
166 
167 	*_event = header.event;
168 	*_cpu = header.cpu;
169 	*_buffer = fBuffer + fBufferPosition;
170 	if (_streamOffset)
171 		*_streamOffset = streamOffset;
172 
173 	// skip the event in the buffer
174 	fBufferSize -= header.size;
175 	fBufferPosition += header.size;
176 
177 	return header.size;
178 }
179 
180 
181 status_t
182 BDebugEventInputStream::_Init()
183 {
184 	fStreamPosition = 0;
185 	fBufferPosition = 0;
186 
187 	// get the header
188 	status_t error = _GetData(sizeof(debug_event_stream_header));
189 	if (error != B_OK) {
190 		Unset();
191 		return error;
192 	}
193 	const debug_event_stream_header& header
194 		= *(const debug_event_stream_header*)(fBuffer + fBufferPosition);
195 
196 	fBufferPosition += sizeof(debug_event_stream_header);
197 	fBufferSize -= sizeof(debug_event_stream_header);
198 
199 	// check the header
200 	if (strncmp(header.signature, B_DEBUG_EVENT_STREAM_SIGNATURE,
201 			sizeof(header.signature)) != 0
202 		|| header.version != B_DEBUG_EVENT_STREAM_VERSION
203 		|| (header.flags & B_DEBUG_EVENT_STREAM_FLAG_HOST_ENDIAN) == 0) {
204 		// TODO: Support non-host endianess!
205 		Unset();
206 		return B_BAD_DATA;
207 	}
208 
209 	fFlags = header.flags;
210 	fEventMask = header.event_mask;
211 
212 	return B_OK;
213 }
214 
215 
216 ssize_t
217 BDebugEventInputStream::_Read(void* _buffer, size_t size)
218 {
219 	uint8* buffer = (uint8*)_buffer;
220 	size_t totalBytesRead = 0;
221 	ssize_t bytesRead = 0;
222 
223 	while (size > 0 && (bytesRead = fStream->Read(buffer, size)) > 0) {
224 		totalBytesRead += bytesRead;
225 		buffer += bytesRead;
226 		size -= bytesRead;
227 	}
228 
229 	if (bytesRead < 0)
230 		return bytesRead;
231 
232 	return totalBytesRead;
233 }
234 
235 
236 status_t
237 BDebugEventInputStream::_GetData(size_t size)
238 {
239 	if (fBufferSize >= size)
240 		return B_OK;
241 
242 	if (size > fBufferCapacity)
243 		return B_BUFFER_OVERFLOW;
244 
245 	// move remaining data to the start of the buffer
246 	if (fBufferSize > 0 && fBufferPosition > 0)
247 		memmove(fBuffer, fBuffer + fBufferPosition, fBufferSize);
248 	fStreamPosition += fBufferPosition;
249 	fBufferPosition = 0;
250 
251 	// read more data
252 	if (fStream != NULL) {
253 		ssize_t bytesRead = _Read(fBuffer + fBufferSize,
254 			fBufferCapacity - fBufferSize);
255 		if (bytesRead < 0)
256 			return bytesRead;
257 
258 		fBufferSize += bytesRead;
259 	}
260 
261 	return fBufferSize >= size ? B_OK : B_BAD_DATA;
262 }
263 
264 
265 // #pragma mark - BDebugEventOutputStream
266 
267 
268 BDebugEventOutputStream::BDebugEventOutputStream()
269 	:
270 	fStream(NULL),
271 	fFlags(0)
272 {
273 }
274 
275 
276 BDebugEventOutputStream::~BDebugEventOutputStream()
277 {
278 	Unset();
279 }
280 
281 
282 status_t
283 BDebugEventOutputStream::SetTo(BDataIO* stream, uint32 flags, uint32 eventMask)
284 {
285 	Unset();
286 
287 	// set the new values
288 	if (stream == NULL)
289 		return B_BAD_VALUE;
290 
291 	fStream = stream;
292 	fFlags = /*(flags & B_DEBUG_EVENT_STREAM_FLAG_ZIPPED)
293 		|*/ B_DEBUG_EVENT_STREAM_FLAG_HOST_ENDIAN;
294 		// TODO: Support zipped data!
295 
296 	// init and write the header
297 	debug_event_stream_header header;
298 	memset(header.signature, 0, sizeof(header.signature));
299 	strlcpy(header.signature, B_DEBUG_EVENT_STREAM_SIGNATURE,
300 		sizeof(header.signature));
301 	header.version = B_DEBUG_EVENT_STREAM_VERSION;
302 	header.flags = fFlags;
303 	header.event_mask = eventMask;
304 
305 	ssize_t written = fStream->Write(&header, sizeof(header));
306 	if (written < 0) {
307 		Unset();
308 		return written;
309 	}
310 	if ((size_t)written != sizeof(header)) {
311 		Unset();
312 		return B_FILE_ERROR;
313 	}
314 
315 	return B_OK;
316 }
317 
318 
319 void
320 BDebugEventOutputStream::Unset()
321 {
322 	Flush();
323 	fStream = NULL;
324 	fFlags = 0;
325 }
326 
327 
328 status_t
329 BDebugEventOutputStream::Write(const void* buffer, size_t size)
330 {
331 	if (size == 0)
332 		return B_OK;
333 	if (buffer == NULL)
334 		return B_BAD_VALUE;
335 
336 	ssize_t written = fStream->Write(buffer, size);
337 	if (written < 0)
338 		return written;
339 	if ((size_t)written != size)
340 		return B_FILE_ERROR;
341 
342 	return B_OK;
343 }
344 
345 
346 status_t
347 BDebugEventOutputStream::Flush()
348 {
349 	return B_OK;
350 }
351