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
17 #include "AliHLTLogging.h"
18 #include "AliHLTDataTypes.h"
19 #include "AliHLTDefinitions.h"
23 class AliHLTComponent;
24 class AliHLTConsumerDescriptor;
27 * @class AliHLTDataBuffer
28 * @brief Handling of data buffers for the HLT.
30 * The class provides handling of data buffers for HLT tasks. Each task gets
31 * its own Data Buffer instance. The buffer is grouped into different data
32 * segments according to the output of the component.<br>
33 * The Data Buffer keeps control over the data requests of the 'child'
34 * components. Each component can subscribe to a certain segment of the data
35 * buffer. It's state is then changed from 'reserved' to 'active'. After the
36 * data processing, the component has to release the segment and it's state is
37 * set to 'processed'. If all components have requested and released their data,
38 * the Raw Buffer is released and pushed back in the list of available buffers.
40 * @note This class is only used for the @ref alihlt_system.
42 * @ingroup alihlt_system
44 class AliHLTDataBuffer : public TObject, public AliHLTLogging
47 //////////////////////////////////////////////////////////////////////////////
48 // constructors and destructors
50 /* standard constructor
53 /** not a valid copy constructor, defined according to effective C++ style */
54 AliHLTDataBuffer(const AliHLTDataBuffer&);
55 /** not a valid assignment op, but defined according to effective C++ style */
56 AliHLTDataBuffer& operator=(const AliHLTDataBuffer&);
58 virtual ~AliHLTDataBuffer();
60 //////////////////////////////////////////////////////////////////////////////
64 * Add component to the list of consumers
65 * @param pConsumer - a consumer of type AliHLTComponent
67 int SetConsumer(AliHLTComponent* pConsumer);
69 //////////////////////////////////////////////////////////////////////////////
70 // component to component communication
73 * Determine the number of matching data blocks for the component and a
74 * consumer component. <br>
75 * The first approach will support only one output data type for processing
77 * @param pConsumer the component which subscribes to the buffer
78 * @param tgtList (optional) the list to receive the data types
79 * @return: number of data blocks which match the input data types
80 * of the consumer, neg. error code if failed <br>
81 * -EINVAL invalid parameter <br>
83 int FindMatchingDataBlocks(const AliHLTComponent* pConsumer,
84 vector<AliHLTComponentDataType>* tgtList=NULL);
87 * Subscribe to a segment of the data buffer.
88 * The function prepares the block descriptor for subsequent use with the
89 * AliHLTComponent::ProcessEvent method, the method can prepare several block
90 * descriptors up to the array size specified by iArraySize. The return value
91 * is independent from the array size the number of block descriptors which
92 * would have been prepared if there was enough space in the array<br>
93 * The method is used by the consumer component.
94 * @param pConsumer the component which subscribes to the buffer
95 * @param arrayBlockDesc pointer to block descriptor to be filled
96 * @param iArraySize size of the block descriptor array
97 * @return: number of matching data blocks, neg. error code if failed<br>
98 * -EACCESS the consumer state can't be changed (activated)
99 * -EBADF unresolved data segments <br>
100 * -ENOENT consumer component not found <br>
101 * -ENODATA data buffer does not have raw data <br>
102 * -EINVAL invalid parameter <br>
104 int Subscribe(const AliHLTComponent* pConsumer,
105 AliHLTComponentBlockData* arrayBlockDesc,
109 * Release an instance of the data buffer.
110 * Resets the variables of the block descriptor.
111 * If all buffer segments are released, the Data Buffer is reseted
112 * and the Raw Buffer released.<br>
113 * The method is used by the consumer component.
114 * @param pBlockDesc descriptor of the data segment
115 * @param pConsumer the component which subscribes to the buffer
116 * @return: >0 if success, negative error code if failed <br>
117 * -EACCESS the consumer state can not be changed (de-activated)
118 * -ENOENT consumer has not subscribed to the buffer <br>
119 * -EINVAL invalid parameter <br>
121 int Release(AliHLTComponentBlockData* pBlockDesc, const AliHLTComponent* pConsumer);
124 * Get a target buffer of minimum size iMinSize.
125 * The method is used by the component which owns the Data Buffer to
126 * allocate a buffer for the data it is going to produce.
127 * @param iMinSize minumum size of the requested buffer
128 * @return: pointer to target buffer if
130 AliHLTUInt8_t* GetTargetBuffer(int iMinSize);
133 * Set the segments for the data buffer.
134 * This is usually done after the component has written the data to the buffer,
135 * which was requested by the @ref GetTargetBuffer method. The component might
136 * produce different types of data, for each type a segment has to be defined
137 * which describes the data inside the buffer.<br>
138 * The @ref AliHLTComponentBlockData segment descriptor comes directly from
139 * the @ref AliHLTComponent::ProcessEvent method.
140 * @param pTgt the target buffer which the segments refer to
141 * @param arraySegments the output block descriptors of the component
142 * @param iSize size of the array
144 int SetSegments(AliHLTUInt8_t* pTgt, AliHLTComponentBlockData* arraySegments, int iSize);
147 * Check if the data buffer is empty.
148 * @return 1 if empty, 0 if not
153 * Get the total and maximum size of the buffer.
154 * Lets see if this is needed later
156 //int GetTotalSize();
159 * Get the number of segments
160 * @return number of segments
162 int GetNofSegments();
165 * Get the number of consumers
166 * @return number of consumers
168 int GetNofConsumers();
171 * Get the number of active consumers
172 * @return number of active consumers
174 int GetNofActiveConsumers();
177 * Check if a consumer is already in the list
178 * @param pConsumer pointer to consumer component
179 * @param bAllLists search in all lists if 1
180 * search only in fConsumer list if 0
181 * @return 1 if found, 0 if not
183 int FindConsumer(AliHLTComponent* pConsumer, int bAllLists=1);
186 * Public method to reset the buffer.
187 * Eventually with some additional checks. In normal operation,
188 * an external reset should not be necessary.
193 * @struct AliHLTDataSegment
194 * @brief Descriptor of a data segment within the buffer.
196 struct 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 * @struct AliHLTRawBuffer
227 * @brief Descriptor of the raw data buffer which can host several segments.
229 struct AliHLTRawBuffer {
230 /** size of the currently occupied partition of the buffer */
231 AliHLTUInt32_t fSize; // see above
232 /** total size of the buffer, including safety margin */
233 AliHLTUInt32_t fTotalSize; // see above
235 void* fPtr; //! transient
239 /* lets see if this is needed
240 AliHLTDataSegment* FindDataSegment(AliHLTComponentDataType datatype);
244 * Find those data segments which match the input types of a component.
245 * @param pConsumer the component which subscribes to the buffer
246 * @param tgtList the list to receive the data segment descriptors
247 * @return: number of data blocks which match the input data types
248 * of the consumer, neg. error code if failed <br>
249 * -EINVAL invalid parameter <br>
251 int FindMatchingDataSegments(const AliHLTComponent* pConsumer,
252 vector<AliHLTDataBuffer::AliHLTDataSegment>& tgtList);
255 * Reset the data buffer.
256 * Removes all consumers back to the @ref fConsumers list, deletes
257 * segments and releases the Raw Buffer.
259 int ResetDataBuffer();
261 //////////////////////////////////////////////////////////////////////////////
263 // the data description
265 // the data segments within this buffer
266 vector<AliHLTDataSegment> fSegments; // see above
268 // the list of all consumers which are going to subscribe to the buffer
269 vector<AliHLTConsumerDescriptor*> fConsumers; // see above
270 // the list of all consumers which are currently subscribed to the buffer
271 vector<AliHLTConsumerDescriptor*> fActiveConsumers; // see above
272 // the list of all consumers which are already released for the current event
273 vector<AliHLTConsumerDescriptor*> fReleasedConsumers; // see above
275 // the buffer instance
276 AliHLTRawBuffer* fpBuffer; //! transient
278 // flags indicating the state of the buffer
279 AliHLTUInt32_t fFlags; // see above
281 //////////////////////////////////////////////////////////////////////////////
282 // global buffer handling, internal use only
285 * Create a raw buffer of a certain size.
286 * The function tries to find a buffer of the given size (or a bit bigger by a
287 * certain margin @ref fgMargin) from the list of free buffers.
288 * If no buffer is available, a new one is created and added to the buffer handling.
289 * @param size min. size of the requested buffer
290 * @return pointer to raw buffer
292 static AliHLTRawBuffer* CreateRawBuffer(AliHLTUInt32_t size);
295 * Mark a buffer as free.
296 * After the Data Buffer has finnished using the raw buffer, it is released
297 * and added to the list of available buffers.
298 * @param pBuffer the raw buffer to release
299 * @return >=0 if succeeded, neg. error code if failed
301 static int ReleaseRawBuffer(AliHLTRawBuffer* pBuffer);
304 * Deletes all the raw buffers.
305 * When the last Data Buffer object is destructed, all raw data buffers are
308 static int DeleteRawBuffers();
311 * Number of instances of AliHLTDataBuffer.
312 * The statice variable is incremented and decremented in the constructor/
313 * destructor. All internal data structures are cleaned up when the last
314 * instance is exiting.
316 static int fgNofInstances; // see above
317 /** global list of free raw buffers */
318 static vector<AliHLTRawBuffer*> fgFreeBuffers; // see above
319 /** global list of currently active raw buffers */
320 static vector<AliHLTRawBuffer*> fgActiveBuffers; // see above
321 /** determines the raw buffer size margin at buffer requests */
322 static AliHLTUInt32_t fgMargin; // see above
324 /** global instance to HLT logging class for static methods */
325 static AliHLTLogging fgLogging; // see above
327 /** size of the safety pattern */
328 static const Int_t fgkSafetyPatternSize; // see above
330 /** the safety pattern */
331 static const char fgkSafetyPattern[]; //!transient
333 //////////////////////////////////////////////////////////////////////////////
334 // internal helper functions
337 * Find the consumer descriptor for a certain component and data type in
338 * a list of consumers.<br>
339 * <b>Note:</b> There are three lists which contain the consumers in the
341 * @param pConsumer pointer to consumer component
342 * @param list list where to search for the consumer
344 AliHLTConsumerDescriptor* FindConsumer(const AliHLTComponent* pConsumer,
345 vector<AliHLTConsumerDescriptor*> &list) const;
348 * Change the state of a consumer.
349 * The state of a consumer is determined by the list it is strored in, the
350 * method moves a consumer from the source to the target list.
351 * @param pDesc pointer to consumer descriptor
352 * @param srcList list where the consumer is currently to be found
353 * @param tgtList list where to move the consumer
355 int ChangeConsumerState(AliHLTConsumerDescriptor* pDesc,
356 vector<AliHLTConsumerDescriptor*> &srcList,
357 vector<AliHLTConsumerDescriptor*> &tgtList);
360 * Cleanup a consumer list.
361 * Release all allocated data structures. <b>Note:</b> Not the component itself!
363 int CleanupConsumerList();
365 ClassDef(AliHLTDataBuffer, 0)
368 #endif // ALIHLTDATABUFFER_H