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"
20 class AliHLTComponent;
21 class AliHLTConsumerDescriptor;
24 * @class AliHLTDataBuffer
25 * @brief Handling of data buffers for the HLT.
27 * The class provides handling of data buffers for HLT tasks. Each task gets
28 * its own Data Buffer instance. The buffer is grouped into different data
29 * segments according to the output of the component.<br>
30 * The Data Buffer keeps control over the data requests of the 'child'
31 * components. Each component can subscribe to a certain segment of the data
32 * buffer. It's state is then changed from 'reserved' to 'active'. After the
33 * data processing, the component has to release the segment and it's state is
34 * set to 'processed'. If all components have requested and released their data,
35 * the Raw Buffer is released and pushed back in the list of available buffers.
37 * @note This class is only used for the @ref alihlt_system.
39 * @ingroup alihlt_system
41 class AliHLTDataBuffer : public TObject, public AliHLTLogging
44 //////////////////////////////////////////////////////////////////////////////
45 // constructors and destructors
47 /* standard constructor
50 /** not a valid copy constructor, defined according to effective C++ style */
51 AliHLTDataBuffer(const AliHLTDataBuffer&);
52 /** not a valid assignment op, but defined according to effective C++ style */
53 AliHLTDataBuffer& operator=(const AliHLTDataBuffer&);
55 virtual ~AliHLTDataBuffer();
57 //////////////////////////////////////////////////////////////////////////////
61 * Add component to the list of consumers
62 * @param pConsumer - a consumer of type AliHLTComponent
64 int SetConsumer(AliHLTComponent* pConsumer);
66 //////////////////////////////////////////////////////////////////////////////
67 // component to component communication
70 * Determine the number of matching data blocks for the component and a
71 * consumer component. <br>
72 * The first approach will support only one output data type for processing
74 * @param pConsumer the component which subscribes to the buffer
75 * @param tgtList (optional) the list to receive the data types
76 * @return: number of data blocks which match the input data types
77 * of the consumer, neg. error code if failed <br>
78 * -EINVAL invalid parameter <br>
80 int FindMatchingDataBlocks(const AliHLTComponent* pConsumer,
81 vector<AliHLTComponentDataType>* tgtList=NULL);
84 * Subscribe to a segment of the data buffer.
85 * The function prepares the block descriptor for subsequent use with the
86 * AliHLTComponent::ProcessEvent method, the method can prepare several block
87 * descriptors up to the array size specified by iArraySize. The return value
88 * is independent from the array size the number of block descriptors which
89 * would have been prepared if there was enough space in the array<br>
90 * The method is used by the consumer component.
91 * @param pConsumer the component which subscribes to the buffer
92 * @param arrayBlockDesc pointer to block descriptor to be filled
93 * @param iArraySize size of the block descriptor array
94 * @return: number of matching data blocks, neg. error code if failed<br>
95 * -EACCESS the consumer state can't be changed (activated)
96 * -EBADF unresolved data segments <br>
97 * -ENOENT consumer component not found <br>
98 * -ENODATA data buffer does not have raw data <br>
99 * -EINVAL invalid parameter <br>
101 int Subscribe(const AliHLTComponent* pConsumer,
102 AliHLTComponentBlockData* arrayBlockDesc,
106 * Release an instance of the data buffer.
107 * Resets the variables of the block descriptor.
108 * If all buffer segments are released, the Data Buffer is reseted
109 * and the Raw Buffer released.<br>
110 * The method is used by the consumer component.
111 * @param pBlockDesc descriptor of the data segment
112 * @param pConsumer the component which subscribes to the buffer
113 * @return: >0 if success, negative error code if failed <br>
114 * -EACCESS the consumer state can not be changed (de-activated)
115 * -ENOENT consumer has not subscribed to the buffer <br>
116 * -EINVAL invalid parameter <br>
118 int Release(AliHLTComponentBlockData* pBlockDesc, const AliHLTComponent* pConsumer);
121 * Get a target buffer of minimum size iMinSize.
122 * The method is used by the component which owns the Data Buffer to
123 * allocate a buffer for the data it is going to produce.
124 * @param iMinSize minumum size of the requested buffer
125 * @return: pointer to target buffer if
127 AliHLTUInt8_t* GetTargetBuffer(int iMinSize);
130 * Set the segments for the data buffer.
131 * This is usually done after the component has written the data to the buffer,
132 * which was requested by the @ref GetTargetBuffer method. The component might
133 * produce different types of data, for each type a segment has to be defined
134 * which describes the data inside the buffer.<br>
135 * The @ref AliHLTComponentBlockData segment descriptor comes directly from
136 * the @ref AliHLTComponent::ProcessEvent method.
137 * @param pTgt the target buffer which the segments refer to
138 * @param arraySegments the output block descriptors of the component
139 * @param iSize size of the array
141 int SetSegments(AliHLTUInt8_t* pTgt, AliHLTComponentBlockData* arraySegments, int iSize);
144 * Check if the data buffer is empty.
145 * @return 1 if empty, 0 if not
150 * Get the total and maximum size of the buffer.
151 * Lets see if this is needed later
153 //int GetTotalSize();
156 * Get the number of segments
157 * @return number of segments
159 int GetNofSegments();
162 * Get the number of consumers
163 * @return number of consumers
165 int GetNofConsumers();
168 * Get the number of active consumers
169 * @return number of active consumers
171 int GetNofActiveConsumers();
174 * Check if a consumer is already in the list
175 * @param pConsumer pointer to consumer component
176 * @param bAllLists search in all lists if 1
177 * search only in fConsumer list if 0
178 * @return 1 if found, 0 if not
180 int FindConsumer(AliHLTComponent* pConsumer, int bAllLists=1);
183 * Public method to reset the buffer.
184 * Eventually with some additional checks. In normal operation,
185 * an external reset should not be necessary.
190 * @class AliHLTDataSegment
191 * @brief Descriptor of a data segment within the buffer.
193 class AliHLTDataSegment {
194 friend class AliHLTDataBuffer;
195 friend class AliHLTConsumerDescriptor;
204 memset(&fDataType, 0, sizeof(AliHLTComponentDataType));
206 AliHLTDataSegment(AliHLTUInt32_t offset, AliHLTUInt32_t size)
209 fSegmentOffset(offset),
213 memset(&fDataType, 0, sizeof(AliHLTComponentDataType));
216 /** the data type of this segment */
217 AliHLTComponentDataType fDataType; // see above
218 /** offset in byte within the data buffer */
219 AliHLTUInt32_t fSegmentOffset; // see above
220 /** size of the actual content */
221 AliHLTUInt32_t fSegmentSize; // see above
222 /** data specification */
223 AliHLTUInt32_t fSpecification; // see above
227 * @class AliHLTRawBuffer
228 * @brief Descriptor of the raw data buffer which can host several segments.
230 class AliHLTRawBuffer {
231 friend class AliHLTDataBuffer;
233 /** standard constructor */
234 AliHLTRawBuffer() : fSize(0), fTotalSize(0), fPtr(NULL) {}
235 /** not a valid copy constructor, defined according to effective C++ style */
236 AliHLTRawBuffer(const AliHLTRawBuffer&) : fSize(0), fTotalSize(0), fPtr(NULL) {}
237 /** not a valid assignment op, but defined according to effective C++ style */
238 AliHLTRawBuffer& operator=(const AliHLTRawBuffer&) {return *this;}
239 /** standard destructor */
240 virtual ~AliHLTRawBuffer() {}
242 /** size of the currently occupied partition of the buffer */
243 AliHLTUInt32_t fSize; // see above
244 /** total size of the buffer, including safety margin */
245 AliHLTUInt32_t fTotalSize; // see above
247 void* fPtr; //! transient
251 /* lets see if this is needed
252 AliHLTDataSegment* FindDataSegment(AliHLTComponentDataType datatype);
256 * Find those data segments which match the input types of a component.
257 * @param pConsumer the component which subscribes to the buffer
258 * @param tgtList the list to receive the data segment descriptors
259 * @return: number of data blocks which match the input data types
260 * of the consumer, neg. error code if failed <br>
261 * -EINVAL invalid parameter <br>
263 int FindMatchingDataSegments(const AliHLTComponent* pConsumer,
264 vector<AliHLTDataBuffer::AliHLTDataSegment>& tgtList);
267 * Reset the data buffer.
268 * Removes all consumers back to the @ref fConsumers list, deletes
269 * segments and releases the Raw Buffer.
271 int ResetDataBuffer();
273 //////////////////////////////////////////////////////////////////////////////
275 // the data description
277 // the data segments within this buffer
278 vector<AliHLTDataSegment> fSegments; // see above
280 // the list of all consumers which are going to subscribe to the buffer
281 vector<AliHLTConsumerDescriptor*> fConsumers; // see above
282 // the list of all consumers which are currently subscribed to the buffer
283 vector<AliHLTConsumerDescriptor*> fActiveConsumers; // see above
284 // the list of all consumers which are already released for the current event
285 vector<AliHLTConsumerDescriptor*> fReleasedConsumers; // see above
287 // the buffer instance
288 AliHLTRawBuffer* fpBuffer; //! transient
290 // flags indicating the state of the buffer
291 AliHLTUInt32_t fFlags; // see above
293 //////////////////////////////////////////////////////////////////////////////
294 // global buffer handling, internal use only
297 * Create a raw buffer of a certain size.
298 * The function tries to find a buffer of the given size (or a bit bigger by a
299 * certain margin @ref fgMargin) from the list of free buffers.
300 * If no buffer is available, a new one is created and added to the buffer handling.
301 * @param size min. size of the requested buffer
302 * @return pointer to raw buffer
304 static AliHLTRawBuffer* CreateRawBuffer(AliHLTUInt32_t size);
307 * Mark a buffer as free.
308 * After the Data Buffer has finnished using the raw buffer, it is released
309 * and added to the list of available buffers.
310 * @param pBuffer the raw buffer to release
311 * @return >=0 if succeeded, neg. error code if failed
313 static int ReleaseRawBuffer(AliHLTRawBuffer* pBuffer);
316 * Deletes all the raw buffers.
317 * When the last Data Buffer object is destructed, all raw data buffers are
320 static int DeleteRawBuffers();
323 * Number of instances of AliHLTDataBuffer.
324 * The statice variable is incremented and decremented in the constructor/
325 * destructor. All internal data structures are cleaned up when the last
326 * instance is exiting.
328 static int fgNofInstances; // see above
329 /** global list of free raw buffers */
330 static vector<AliHLTRawBuffer*> fgFreeBuffers; // see above
331 /** global list of currently active raw buffers */
332 static vector<AliHLTRawBuffer*> fgActiveBuffers; // see above
333 /** determines the raw buffer size margin at buffer requests */
334 static AliHLTUInt32_t fgMargin; // see above
336 /** global instance to HLT logging class for static methods */
337 static AliHLTLogging fgLogging; // see above
339 /** size of the safety pattern */
340 static const Int_t fgkSafetyPatternSize; // see above
342 /** the safety pattern */
343 static const char fgkSafetyPattern[]; //!transient
345 //////////////////////////////////////////////////////////////////////////////
346 // internal helper functions
349 * Find the consumer descriptor for a certain component and data type in
350 * a list of consumers.<br>
351 * <b>Note:</b> There are three lists which contain the consumers in the
353 * @param pConsumer pointer to consumer component
354 * @param list list where to search for the consumer
356 AliHLTConsumerDescriptor* FindConsumer(const AliHLTComponent* pConsumer,
357 vector<AliHLTConsumerDescriptor*> &list) const;
360 * Change the state of a consumer.
361 * The state of a consumer is determined by the list it is strored in, the
362 * method moves a consumer from the source to the target list.
363 * @param pDesc pointer to consumer descriptor
364 * @param srcList list where the consumer is currently to be found
365 * @param tgtList list where to move the consumer
367 int ChangeConsumerState(AliHLTConsumerDescriptor* pDesc,
368 vector<AliHLTConsumerDescriptor*> &srcList,
369 vector<AliHLTConsumerDescriptor*> &tgtList);
372 * Cleanup a consumer list.
373 * Release all allocated data structures. <b>Note:</b> Not the component itself!
375 int CleanupConsumerList();
377 ClassDef(AliHLTDataBuffer, 0)
380 #endif // ALIHLTDATABUFFER_H