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
16 #include "AliHLTLogging.h"
17 #include "AliHLTDataTypes.h"
18 //#include "AliHLTDefinitions.h"
22 class AliHLTComponent;
23 class AliHLTConsumerDescriptor;
26 * @class AliHLTDataBuffer
27 * @brief Handling of data buffers for the HLT.
29 * The class provides handling of data buffers for HLT tasks. Each task gets
30 * its own Data Buffer instance. The buffer is grouped into different data
31 * segments according to the output of the component.<br>
32 * The Data Buffer keeps control over the data requests of the 'child'
33 * components. Each component can subscribe to a certain segment of the data
34 * buffer. It's state is then changed from 'reserved' to 'active'. After the
35 * data processing, the component has to release the segment and it's state is
36 * set to 'processed'. If all components have requested and released their data,
37 * the Raw Buffer is released and pushed back in the list of available buffers.
39 * @note This class is only used for the @ref alihlt_system.
41 * @ingroup alihlt_system
43 class AliHLTDataBuffer : public TObject, public AliHLTLogging
46 //////////////////////////////////////////////////////////////////////////////
47 // constructors and destructors
49 /* standard constructor
52 /** not a valid copy constructor, defined according to effective C++ style */
53 AliHLTDataBuffer(const AliHLTDataBuffer&);
54 /** not a valid assignment op, but defined according to effective C++ style */
55 AliHLTDataBuffer& operator=(const AliHLTDataBuffer&);
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 number of consumers
165 * @return number of consumers
167 int GetNofConsumers();
170 * Get the number of active consumers
171 * @return number of active consumers
173 int GetNofActiveConsumers();
176 * Check if a consumer is already in the list
177 * @param pConsumer pointer to consumer component
178 * @param bAllLists search in all lists if 1
179 * search only in fConsumer list if 0
180 * @return 1 if found, 0 if not
182 int FindConsumer(AliHLTComponent* pConsumer, int bAllLists=1);
185 * Public method to reset the buffer.
186 * Eventually with some additional checks. In normal operation,
187 * an external reset should not be necessary.
192 * @class AliHLTDataSegment
193 * @brief Descriptor of a data segment within the buffer.
195 class AliHLTDataSegment {
204 memset(&fDataType, 0, sizeof(AliHLTComponentDataType));
206 AliHLTDataSegment(AliHLTUInt32_t offset, AliHLTUInt32_t size)
209 fSegmentOffset(offset),
213 memset(&fDataType, 0, sizeof(AliHLTComponentDataType));
215 /** the data type of this segment */
216 AliHLTComponentDataType fDataType; // see above
217 /** offset in byte within the data buffer */
218 AliHLTUInt32_t fSegmentOffset; // see above
219 /** size of the actual content */
220 AliHLTUInt32_t fSegmentSize; // see above
221 /** data specification */
222 AliHLTUInt32_t fSpecification; // see above
226 * @class AliHLTRawBuffer
227 * @brief Descriptor of the raw data buffer which can host several segments.
229 class AliHLTRawBuffer {
231 /** standard constructor */
232 AliHLTRawBuffer() : fSize(0), fTotalSize(0), fPtr(NULL) {}
233 /** not a valid copy constructor, defined according to effective C++ style */
234 AliHLTRawBuffer(const AliHLTRawBuffer&) : fSize(0), fTotalSize(0), fPtr(NULL) {}
235 /** not a valid assignment op, but defined according to effective C++ style */
236 AliHLTRawBuffer& operator=(const AliHLTRawBuffer&) {return *this;}
237 /** standard destructor */
238 virtual ~AliHLTRawBuffer() {}
239 /** size of the currently occupied partition of the buffer */
240 AliHLTUInt32_t fSize; // see above
241 /** total size of the buffer, including safety margin */
242 AliHLTUInt32_t fTotalSize; // see above
244 void* fPtr; //! transient
248 /* lets see if this is needed
249 AliHLTDataSegment* FindDataSegment(AliHLTComponentDataType datatype);
253 * Find those data segments which match the input types of a component.
254 * @param pConsumer the component which subscribes to the buffer
255 * @param tgtList the list to receive the data segment descriptors
256 * @return: number of data blocks which match the input data types
257 * of the consumer, neg. error code if failed <br>
258 * -EINVAL invalid parameter <br>
260 int FindMatchingDataSegments(const AliHLTComponent* pConsumer,
261 vector<AliHLTDataBuffer::AliHLTDataSegment>& tgtList);
264 * Reset the data buffer.
265 * Removes all consumers back to the @ref fConsumers list, deletes
266 * segments and releases the Raw Buffer.
268 int ResetDataBuffer();
270 //////////////////////////////////////////////////////////////////////////////
272 // the data description
274 // the data segments within this buffer
275 vector<AliHLTDataSegment> fSegments; // see above
277 // the list of all consumers which are going to subscribe to the buffer
278 vector<AliHLTConsumerDescriptor*> fConsumers; // see above
279 // the list of all consumers which are currently subscribed to the buffer
280 vector<AliHLTConsumerDescriptor*> fActiveConsumers; // see above
281 // the list of all consumers which are already released for the current event
282 vector<AliHLTConsumerDescriptor*> fReleasedConsumers; // see above
284 // the buffer instance
285 AliHLTRawBuffer* fpBuffer; //! transient
287 // flags indicating the state of the buffer
288 AliHLTUInt32_t fFlags; // see above
290 //////////////////////////////////////////////////////////////////////////////
291 // global buffer handling, internal use only
294 * Create a raw buffer of a certain size.
295 * The function tries to find a buffer of the given size (or a bit bigger by a
296 * certain margin @ref fgMargin) from the list of free buffers.
297 * If no buffer is available, a new one is created and added to the buffer handling.
298 * @param size min. size of the requested buffer
299 * @return pointer to raw buffer
301 static AliHLTRawBuffer* CreateRawBuffer(AliHLTUInt32_t size);
304 * Mark a buffer as free.
305 * After the Data Buffer has finnished using the raw buffer, it is released
306 * and added to the list of available buffers.
307 * @param pBuffer the raw buffer to release
308 * @return >=0 if succeeded, neg. error code if failed
310 static int ReleaseRawBuffer(AliHLTRawBuffer* pBuffer);
313 * Deletes all the raw buffers.
314 * When the last Data Buffer object is destructed, all raw data buffers are
317 static int DeleteRawBuffers();
320 * Number of instances of AliHLTDataBuffer.
321 * The statice variable is incremented and decremented in the constructor/
322 * destructor. All internal data structures are cleaned up when the last
323 * instance is exiting.
325 static int fgNofInstances; // see above
326 /** global list of free raw buffers */
327 static vector<AliHLTRawBuffer*> fgFreeBuffers; // see above
328 /** global list of currently active raw buffers */
329 static vector<AliHLTRawBuffer*> fgActiveBuffers; // see above
330 /** determines the raw buffer size margin at buffer requests */
331 static AliHLTUInt32_t fgMargin; // see above
333 /** global instance to HLT logging class for static methods */
334 static AliHLTLogging fgLogging; // see above
336 /** size of the safety pattern */
337 static const Int_t fgkSafetyPatternSize; // see above
339 /** the safety pattern */
340 static const char fgkSafetyPattern[]; //!transient
342 //////////////////////////////////////////////////////////////////////////////
343 // internal helper functions
346 * Find the consumer descriptor for a certain component and data type in
347 * a list of consumers.<br>
348 * <b>Note:</b> There are three lists which contain the consumers in the
350 * @param pConsumer pointer to consumer component
351 * @param list list where to search for the consumer
353 AliHLTConsumerDescriptor* FindConsumer(const AliHLTComponent* pConsumer,
354 vector<AliHLTConsumerDescriptor*> &list) const;
357 * Change the state of a consumer.
358 * The state of a consumer is determined by the list it is strored in, the
359 * method moves a consumer from the source to the target list.
360 * @param pDesc pointer to consumer descriptor
361 * @param srcList list where the consumer is currently to be found
362 * @param tgtList list where to move the consumer
364 int ChangeConsumerState(AliHLTConsumerDescriptor* pDesc,
365 vector<AliHLTConsumerDescriptor*> &srcList,
366 vector<AliHLTConsumerDescriptor*> &tgtList);
369 * Cleanup a consumer list.
370 * Release all allocated data structures. <b>Note:</b> Not the component itself!
372 int CleanupConsumerList();
374 ClassDef(AliHLTDataBuffer, 0)
377 #endif // ALIHLTDATABUFFER_H