3 #ifndef ALIHLTDATABUFFER_H
4 #define ALIHLTDATABUFFER_H
5 /* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
6 * See cxx source for full Copyright notice */
8 /** @file AliHLTDataBuffer.h
9 @author Matthias Richter
11 @brief Handling of Data Buffers for HLT components.
12 @note The class is used in Offline (AliRoot) context
15 // see below for class documentation
17 // refer to README to build package
19 // visit http://web.ift.uib.no/~kjeks/doc/alice-hlt
22 #include "AliHLTLogging.h"
23 #include "AliHLTDataTypes.h"
26 class AliHLTComponent;
27 class AliHLTConsumerDescriptor;
30 * @class AliHLTDataBuffer
31 * @brief Handling of data buffers for the HLT.
33 * The class provides handling of data buffers for HLT tasks. Each task gets
34 * its own Data Buffer instance. The buffer is grouped into different data
35 * segments according to the output of the component.<br>
36 * The Data Buffer keeps control over the data requests of the 'child'
37 * components. Each component can subscribe to a certain segment of the data
38 * buffer. It's state is then changed from 'reserved' to 'active'. After the
39 * data processing, the component has to release the segment and it's state is
40 * set to 'processed'. If all components have requested and released their data,
41 * the Raw Buffer is released and pushed back in the list of available buffers.
43 * @note This class is only used for the @ref alihlt_system.
45 * @ingroup alihlt_system
47 class AliHLTDataBuffer : public TObject, public AliHLTLogging
50 //////////////////////////////////////////////////////////////////////////////
51 // constructors and destructors
53 /* standard constructor
57 virtual ~AliHLTDataBuffer();
59 //////////////////////////////////////////////////////////////////////////////
63 * Add component to the list of consumers
64 * @param pConsumer - a consumer of type AliHLTComponent
66 int SetConsumer(AliHLTComponent* pConsumer);
68 //////////////////////////////////////////////////////////////////////////////
69 // component to component communication
72 * Determine the number of matching data blocks for the component and a
73 * consumer component. <br>
74 * The first approach will support only one output data type for processing
76 * @param pConsumer the component which subscribes to the buffer
77 * @param tgtList (optional) the list to receive the data types
78 * @return: number of data blocks which match the input data types
79 * of the consumer, neg. error code if failed <br>
80 * -EINVAL invalid parameter <br>
82 int FindMatchingDataBlocks(const AliHLTComponent* pConsumer,
83 vector<AliHLTComponentDataType>* tgtList=NULL);
86 * Subscribe to a segment of the data buffer.
87 * The function prepares the block descriptor for subsequent use with the
88 * AliHLTComponent::ProcessEvent method, the method can prepare several block
89 * descriptors up to the array size specified by iArraySize. The return value
90 * is independent from the array size the number of block descriptors which
91 * would have been prepared if there was enough space in the array<br>
92 * The method is used by the consumer component.
93 * @param pConsumer the component which subscribes to the buffer
94 * @param arrayBlockDesc pointer to block descriptor to be filled
95 * @param iArraySize size of the block descriptor array
96 * @return: number of matching data blocks, neg. error code if failed<br>
97 * -EACCESS the consumer state can't be changed (activated)
98 * -EBADF unresolved data segments <br>
99 * -ENOENT consumer component not found <br>
100 * -ENODATA data buffer does not have raw data <br>
101 * -EINVAL invalid parameter <br>
103 int Subscribe(const AliHLTComponent* pConsumer,
104 AliHLTComponentBlockData* arrayBlockDesc,
108 * Release an instance of the data buffer.
109 * Resets the variables of the block descriptor.
110 * If all buffer segments are released, the Data Buffer is reseted
111 * and the Raw Buffer released.<br>
112 * The method is used by the consumer component.
113 * @param pBlockDesc descriptor of the data segment
114 * @param pConsumer the component which subscribes to the buffer
115 * @return: >0 if success, negative error code if failed <br>
116 * -EACCESS the consumer state can not be changed (de-activated)
117 * -ENOENT consumer has not subscribed to the buffer <br>
118 * -EINVAL invalid parameter <br>
120 int Release(AliHLTComponentBlockData* pBlockDesc, const AliHLTComponent* pConsumer);
123 * Get a target buffer of minimum size iMinSize.
124 * The method is used by the component which owns the Data Buffer to
125 * allocate a buffer for the data it is going to produce.
126 * @param iMinSize minumum size of the requested buffer
127 * @return: pointer to target buffer if
129 AliHLTUInt8_t* GetTargetBuffer(int iMinSize);
132 * Set the segments for the data buffer.
133 * This is usually done after the component has written the data to the buffer,
134 * which was requested by the @ref GetTargetBuffer method. The component might
135 * produce different types of data, for each type a segment has to be defined
136 * which describes the data inside the buffer.<br>
137 * The @ref AliHLTComponentBlockData segment descriptor comes directly from
138 * the @ref AliHLTComponent::ProcessEvent method.
139 * @param pTgt the target buffer which the segments refer to
140 * @param arraySegments the output block descriptors of the component
141 * @param iSize size of the array
143 int SetSegments(AliHLTUInt8_t* pTgt, AliHLTComponentBlockData* arraySegments, int iSize);
146 * Check if the data buffer is empty.
147 * @return 1 if empty, 0 if not
152 * Get the total and maximum size of the buffer.
153 * Lets see if this is needed later
155 //int GetTotalSize();
158 * Get the number of segments
159 * @return number of segments
161 int GetNofSegments();
164 * Get the total number of consumers.
165 * This gives the number of consumers regardless of their state.
166 * @return number of consumers
168 int GetNofConsumers();
171 * Get the number of consumers which still need to be processed during
173 * @return number of consumers
175 int GetNofPendingConsumers();
178 * Get the number of consumers currently under processing.
179 * @return number of active consumers
181 int GetNofActiveConsumers();
184 * Check if a consumer is already in the list
185 * @param pConsumer pointer to consumer component
186 * @param bAllLists search in all lists if 1
187 * search only in fConsumer list if 0
188 * @return 1 if found, 0 if not
190 int FindConsumer(AliHLTComponent* pConsumer, int bAllLists=1);
193 * Public method to reset the buffer.
194 * Eventually with some additional checks. In normal operation,
195 * an external reset should not be necessary.
200 * @class AliHLTDataSegment
201 * @brief Descriptor of a data segment within the buffer.
203 class AliHLTDataSegment {
204 friend class AliHLTDataBuffer;
205 friend class AliHLTConsumerDescriptor;
214 memset(&fDataType, 0, sizeof(AliHLTComponentDataType));
216 AliHLTDataSegment(AliHLTUInt32_t offset, AliHLTUInt32_t size)
219 fSegmentOffset(offset),
223 memset(&fDataType, 0, sizeof(AliHLTComponentDataType));
226 /** the data type of this segment */
227 AliHLTComponentDataType fDataType; // see above
228 /** offset in byte within the data buffer */
229 AliHLTUInt32_t fSegmentOffset; // see above
230 /** size of the actual content */
231 AliHLTUInt32_t fSegmentSize; // see above
232 /** data specification */
233 AliHLTUInt32_t fSpecification; // see above
237 * @class AliHLTRawBuffer
238 * @brief Descriptor of the raw data buffer which can host several segments.
240 class AliHLTRawBuffer {
242 /** standard constructor */
243 AliHLTRawBuffer() : fSize(0), fTotalSize(0), fPtr(NULL) {}
245 AliHLTRawBuffer(AliHLTUInt32_t size);
247 virtual ~AliHLTRawBuffer();
250 * Use a fraction of the buffer.
251 * @param size size in bytes to be used
252 * @return pointer to buffer
254 AliHLTUInt8_t* UseBuffer(AliHLTUInt32_t size);
257 * Check whether buffer fits for a request.
258 * @param size size of the request in bytes
259 * @return 1 if buffer is big enough, 0 if not
261 int CheckSize(AliHLTUInt32_t size) const;
264 * Get used size of the buffer
266 AliHLTUInt32_t GetUsedSize() const {return fSize;}
269 * Get total size of the buffer
271 AliHLTUInt32_t GetTotalSize() const {return fTotalSize;}
274 * Get pointer of data buffer
276 AliHLTUInt8_t* GetPointer() const {return fPtr;}
279 * Write check pattern
281 int WritePattern(const char* pattern, int size);
286 int CheckPattern(const char* pattern, int size) const;
290 * Data buffer remains allocated, used size set to 0
294 int operator==(void*) const;
295 int operator==(AliHLTUInt8_t* ptr) const {return fPtr==ptr;}
296 int operator<=(void*) const;
297 int operator>(void*) const;
298 int operator-(void*) const;
300 operator void*() const {return fPtr;}
301 operator AliHLTUInt8_t*() const {return fPtr;}
304 /** copy constructor prohibited */
305 AliHLTRawBuffer(const AliHLTRawBuffer&);
306 /** assignment operator prohibited */
307 AliHLTRawBuffer& operator=(const AliHLTRawBuffer&);
309 /** size of the currently occupied partition of the buffer */
310 AliHLTUInt32_t fSize; // see above
311 /** total size of the buffer, including safety margin */
312 AliHLTUInt32_t fTotalSize; // see above
314 AliHLTUInt8_t* fPtr; //! transient
318 /** copy constructor prohibited */
319 AliHLTDataBuffer(const AliHLTDataBuffer&);
320 /** assignment operator prohibited */
321 AliHLTDataBuffer& operator=(const AliHLTDataBuffer&);
323 /* lets see if this is needed
324 AliHLTDataSegment* FindDataSegment(AliHLTComponentDataType datatype);
328 * Find those data segments which match the input types of a component.
329 * @param pConsumer the component which subscribes to the buffer
330 * @param tgtList the list to receive the data segment descriptors
331 * @return: number of data blocks which match the input data types
332 * of the consumer, neg. error code if failed <br>
333 * -EINVAL invalid parameter <br>
335 int FindMatchingDataSegments(const AliHLTComponent* pConsumer,
336 vector<AliHLTDataBuffer::AliHLTDataSegment>& tgtList);
339 * Reset the data buffer.
340 * Removes all consumers back to the @ref fConsumers list, deletes
341 * segments and releases the Raw Buffer.
343 int ResetDataBuffer();
345 //////////////////////////////////////////////////////////////////////////////
347 // the data description
349 // the data segments within this buffer
350 vector<AliHLTDataSegment> fSegments; // see above
352 // the list of all consumers which are going to subscribe to the buffer
353 vector<AliHLTConsumerDescriptor*> fConsumers; // see above
354 // the list of all consumers which are currently subscribed to the buffer
355 vector<AliHLTConsumerDescriptor*> fActiveConsumers; // see above
356 // the list of all consumers which are already released for the current event
357 vector<AliHLTConsumerDescriptor*> fReleasedConsumers; // see above
359 // the buffer instance
360 AliHLTRawBuffer* fpBuffer; //! transient
362 // flags indicating the state of the buffer
363 AliHLTUInt32_t fFlags; // see above
365 //////////////////////////////////////////////////////////////////////////////
366 // global buffer handling, internal use only
369 * Create a raw buffer of a certain size.
370 * The function tries to find a buffer of the given size (or a bit bigger by a
371 * certain margin @ref fgMargin) from the list of free buffers.
372 * If no buffer is available, a new one is created and added to the buffer handling.
373 * @param size min. size of the requested buffer
374 * @return pointer to raw buffer
376 static AliHLTRawBuffer* CreateRawBuffer(AliHLTUInt32_t size);
379 * Mark a buffer as free.
380 * After the Data Buffer has finnished using the raw buffer, it is released
381 * and added to the list of available buffers.
382 * @param pBuffer the raw buffer to release
383 * @return >=0 if succeeded, neg. error code if failed
385 static int ReleaseRawBuffer(AliHLTRawBuffer* pBuffer);
388 * Deletes all the raw buffers.
389 * When the last Data Buffer object is destructed, all raw data buffers are
392 static int DeleteRawBuffers();
395 * Number of instances of AliHLTDataBuffer.
396 * The statice variable is incremented and decremented in the constructor/
397 * destructor. All internal data structures are cleaned up when the last
398 * instance is exiting.
400 static int fgNofInstances; // see above
401 /** global list of free raw buffers */
402 static vector<AliHLTRawBuffer*> fgFreeBuffers; // see above
403 /** global list of currently active raw buffers */
404 static vector<AliHLTRawBuffer*> fgActiveBuffers; // see above
405 /** determines the raw buffer size margin at buffer requests */
406 static AliHLTUInt32_t fgMargin; // see above
408 /** global instance to HLT logging class for static methods */
409 static AliHLTLogging fgLogging; // see above
411 /** size of the safety pattern */
412 static const Int_t fgkSafetyPatternSize; // see above
414 /** the safety pattern */
415 static const char fgkSafetyPattern[]; //!transient
417 //////////////////////////////////////////////////////////////////////////////
418 // internal helper functions
421 * Find the consumer descriptor for a certain component and data type in
422 * a list of consumers.<br>
423 * <b>Note:</b> There are three lists which contain the consumers in the
425 * @param pConsumer pointer to consumer component
426 * @param list list where to search for the consumer
428 AliHLTConsumerDescriptor* FindConsumer(const AliHLTComponent* pConsumer,
429 vector<AliHLTConsumerDescriptor*> &list) const;
432 * Change the state of a consumer.
433 * The state of a consumer is determined by the list it is strored in, the
434 * method moves a consumer from the source to the target list.
435 * @param pDesc pointer to consumer descriptor
436 * @param srcList list where the consumer is currently to be found
437 * @param tgtList list where to move the consumer
439 int ChangeConsumerState(AliHLTConsumerDescriptor* pDesc,
440 vector<AliHLTConsumerDescriptor*> &srcList,
441 vector<AliHLTConsumerDescriptor*> &tgtList);
444 * Cleanup a consumer list.
445 * Release all allocated data structures. <b>Note:</b> Not the component itself!
447 int CleanupConsumerList();
449 ClassDef(AliHLTDataBuffer, 0)
452 #endif // ALIHLTDATABUFFER_H