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
56 /** not a valid copy constructor, defined according to effective C++ style */
57 AliHLTDataBuffer(const AliHLTDataBuffer&);
58 /** not a valid assignment op, but defined according to effective C++ style */
59 AliHLTDataBuffer& operator=(const AliHLTDataBuffer&);
61 virtual ~AliHLTDataBuffer();
63 //////////////////////////////////////////////////////////////////////////////
67 * Add component to the list of consumers
68 * @param pConsumer - a consumer of type AliHLTComponent
70 int SetConsumer(AliHLTComponent* pConsumer);
72 //////////////////////////////////////////////////////////////////////////////
73 // component to component communication
76 * Determine the number of matching data blocks for the component and a
77 * consumer component. <br>
78 * The first approach will support only one output data type for processing
80 * @param pConsumer the component which subscribes to the buffer
81 * @param tgtList (optional) the list to receive the data types
82 * @return: number of data blocks which match the input data types
83 * of the consumer, neg. error code if failed <br>
84 * -EINVAL invalid parameter <br>
86 int FindMatchingDataBlocks(const AliHLTComponent* pConsumer,
87 vector<AliHLTComponentDataType>* tgtList=NULL);
90 * Subscribe to a segment of the data buffer.
91 * The function prepares the block descriptor for subsequent use with the
92 * AliHLTComponent::ProcessEvent method, the method can prepare several block
93 * descriptors up to the array size specified by iArraySize. The return value
94 * is independent from the array size the number of block descriptors which
95 * would have been prepared if there was enough space in the array<br>
96 * The method is used by the consumer component.
97 * @param pConsumer the component which subscribes to the buffer
98 * @param arrayBlockDesc pointer to block descriptor to be filled
99 * @param iArraySize size of the block descriptor array
100 * @return: number of matching data blocks, neg. error code if failed<br>
101 * -EACCESS the consumer state can't be changed (activated)
102 * -EBADF unresolved data segments <br>
103 * -ENOENT consumer component not found <br>
104 * -ENODATA data buffer does not have raw data <br>
105 * -EINVAL invalid parameter <br>
107 int Subscribe(const AliHLTComponent* pConsumer,
108 AliHLTComponentBlockData* arrayBlockDesc,
112 * Release an instance of the data buffer.
113 * Resets the variables of the block descriptor.
114 * If all buffer segments are released, the Data Buffer is reseted
115 * and the Raw Buffer released.<br>
116 * The method is used by the consumer component.
117 * @param pBlockDesc descriptor of the data segment
118 * @param pConsumer the component which subscribes to the buffer
119 * @return: >0 if success, negative error code if failed <br>
120 * -EACCESS the consumer state can not be changed (de-activated)
121 * -ENOENT consumer has not subscribed to the buffer <br>
122 * -EINVAL invalid parameter <br>
124 int Release(AliHLTComponentBlockData* pBlockDesc, const AliHLTComponent* pConsumer);
127 * Get a target buffer of minimum size iMinSize.
128 * The method is used by the component which owns the Data Buffer to
129 * allocate a buffer for the data it is going to produce.
130 * @param iMinSize minumum size of the requested buffer
131 * @return: pointer to target buffer if
133 AliHLTUInt8_t* GetTargetBuffer(int iMinSize);
136 * Set the segments for the data buffer.
137 * This is usually done after the component has written the data to the buffer,
138 * which was requested by the @ref GetTargetBuffer method. The component might
139 * produce different types of data, for each type a segment has to be defined
140 * which describes the data inside the buffer.<br>
141 * The @ref AliHLTComponentBlockData segment descriptor comes directly from
142 * the @ref AliHLTComponent::ProcessEvent method.
143 * @param pTgt the target buffer which the segments refer to
144 * @param arraySegments the output block descriptors of the component
145 * @param iSize size of the array
147 int SetSegments(AliHLTUInt8_t* pTgt, AliHLTComponentBlockData* arraySegments, int iSize);
150 * Check if the data buffer is empty.
151 * @return 1 if empty, 0 if not
156 * Get the total and maximum size of the buffer.
157 * Lets see if this is needed later
159 //int GetTotalSize();
162 * Get the number of segments
163 * @return number of segments
165 int GetNofSegments();
168 * Get the number of consumers
169 * @return number of consumers
171 int GetNofConsumers();
174 * Get the number of active consumers
175 * @return number of active consumers
177 int GetNofActiveConsumers();
180 * Check if a consumer is already in the list
181 * @param pConsumer pointer to consumer component
182 * @param bAllLists search in all lists if 1
183 * search only in fConsumer list if 0
184 * @return 1 if found, 0 if not
186 int FindConsumer(AliHLTComponent* pConsumer, int bAllLists=1);
189 * Public method to reset the buffer.
190 * Eventually with some additional checks. In normal operation,
191 * an external reset should not be necessary.
196 * @class AliHLTDataSegment
197 * @brief Descriptor of a data segment within the buffer.
199 class AliHLTDataSegment {
200 friend class AliHLTDataBuffer;
201 friend class AliHLTConsumerDescriptor;
210 memset(&fDataType, 0, sizeof(AliHLTComponentDataType));
212 AliHLTDataSegment(AliHLTUInt32_t offset, AliHLTUInt32_t size)
215 fSegmentOffset(offset),
219 memset(&fDataType, 0, sizeof(AliHLTComponentDataType));
222 /** the data type of this segment */
223 AliHLTComponentDataType fDataType; // see above
224 /** offset in byte within the data buffer */
225 AliHLTUInt32_t fSegmentOffset; // see above
226 /** size of the actual content */
227 AliHLTUInt32_t fSegmentSize; // see above
228 /** data specification */
229 AliHLTUInt32_t fSpecification; // see above
233 * @class AliHLTRawBuffer
234 * @brief Descriptor of the raw data buffer which can host several segments.
236 class AliHLTRawBuffer {
237 friend class AliHLTDataBuffer;
239 /** standard constructor */
240 AliHLTRawBuffer() : fSize(0), fTotalSize(0), fPtr(NULL) {}
241 /** not a valid copy constructor, defined according to effective C++ style */
242 AliHLTRawBuffer(const AliHLTRawBuffer&) : fSize(0), fTotalSize(0), fPtr(NULL) {}
243 /** not a valid assignment op, but defined according to effective C++ style */
244 AliHLTRawBuffer& operator=(const AliHLTRawBuffer&) {return *this;}
245 /** standard destructor */
246 virtual ~AliHLTRawBuffer() {}
248 /** size of the currently occupied partition of the buffer */
249 AliHLTUInt32_t fSize; // see above
250 /** total size of the buffer, including safety margin */
251 AliHLTUInt32_t fTotalSize; // see above
253 void* fPtr; //! transient
257 /* lets see if this is needed
258 AliHLTDataSegment* FindDataSegment(AliHLTComponentDataType datatype);
262 * Find those data segments which match the input types of a component.
263 * @param pConsumer the component which subscribes to the buffer
264 * @param tgtList the list to receive the data segment descriptors
265 * @return: number of data blocks which match the input data types
266 * of the consumer, neg. error code if failed <br>
267 * -EINVAL invalid parameter <br>
269 int FindMatchingDataSegments(const AliHLTComponent* pConsumer,
270 vector<AliHLTDataBuffer::AliHLTDataSegment>& tgtList);
273 * Reset the data buffer.
274 * Removes all consumers back to the @ref fConsumers list, deletes
275 * segments and releases the Raw Buffer.
277 int ResetDataBuffer();
279 //////////////////////////////////////////////////////////////////////////////
281 // the data description
283 // the data segments within this buffer
284 vector<AliHLTDataSegment> fSegments; // see above
286 // the list of all consumers which are going to subscribe to the buffer
287 vector<AliHLTConsumerDescriptor*> fConsumers; // see above
288 // the list of all consumers which are currently subscribed to the buffer
289 vector<AliHLTConsumerDescriptor*> fActiveConsumers; // see above
290 // the list of all consumers which are already released for the current event
291 vector<AliHLTConsumerDescriptor*> fReleasedConsumers; // see above
293 // the buffer instance
294 AliHLTRawBuffer* fpBuffer; //! transient
296 // flags indicating the state of the buffer
297 AliHLTUInt32_t fFlags; // see above
299 //////////////////////////////////////////////////////////////////////////////
300 // global buffer handling, internal use only
303 * Create a raw buffer of a certain size.
304 * The function tries to find a buffer of the given size (or a bit bigger by a
305 * certain margin @ref fgMargin) from the list of free buffers.
306 * If no buffer is available, a new one is created and added to the buffer handling.
307 * @param size min. size of the requested buffer
308 * @return pointer to raw buffer
310 static AliHLTRawBuffer* CreateRawBuffer(AliHLTUInt32_t size);
313 * Mark a buffer as free.
314 * After the Data Buffer has finnished using the raw buffer, it is released
315 * and added to the list of available buffers.
316 * @param pBuffer the raw buffer to release
317 * @return >=0 if succeeded, neg. error code if failed
319 static int ReleaseRawBuffer(AliHLTRawBuffer* pBuffer);
322 * Deletes all the raw buffers.
323 * When the last Data Buffer object is destructed, all raw data buffers are
326 static int DeleteRawBuffers();
329 * Number of instances of AliHLTDataBuffer.
330 * The statice variable is incremented and decremented in the constructor/
331 * destructor. All internal data structures are cleaned up when the last
332 * instance is exiting.
334 static int fgNofInstances; // see above
335 /** global list of free raw buffers */
336 static vector<AliHLTRawBuffer*> fgFreeBuffers; // see above
337 /** global list of currently active raw buffers */
338 static vector<AliHLTRawBuffer*> fgActiveBuffers; // see above
339 /** determines the raw buffer size margin at buffer requests */
340 static AliHLTUInt32_t fgMargin; // see above
342 /** global instance to HLT logging class for static methods */
343 static AliHLTLogging fgLogging; // see above
345 /** size of the safety pattern */
346 static const Int_t fgkSafetyPatternSize; // see above
348 /** the safety pattern */
349 static const char fgkSafetyPattern[]; //!transient
351 //////////////////////////////////////////////////////////////////////////////
352 // internal helper functions
355 * Find the consumer descriptor for a certain component and data type in
356 * a list of consumers.<br>
357 * <b>Note:</b> There are three lists which contain the consumers in the
359 * @param pConsumer pointer to consumer component
360 * @param list list where to search for the consumer
362 AliHLTConsumerDescriptor* FindConsumer(const AliHLTComponent* pConsumer,
363 vector<AliHLTConsumerDescriptor*> &list) const;
366 * Change the state of a consumer.
367 * The state of a consumer is determined by the list it is strored in, the
368 * method moves a consumer from the source to the target list.
369 * @param pDesc pointer to consumer descriptor
370 * @param srcList list where the consumer is currently to be found
371 * @param tgtList list where to move the consumer
373 int ChangeConsumerState(AliHLTConsumerDescriptor* pDesc,
374 vector<AliHLTConsumerDescriptor*> &srcList,
375 vector<AliHLTConsumerDescriptor*> &tgtList);
378 * Cleanup a consumer list.
379 * Release all allocated data structures. <b>Note:</b> Not the component itself!
381 int CleanupConsumerList();
383 ClassDef(AliHLTDataBuffer, 0)
386 #endif // ALIHLTDATABUFFER_H