1 #ifndef ALIHLTMUONDATABLOCKWRITER_H
2 #define ALIHLTMUONDATABLOCKWRITER_H
3 /**************************************************************************
4 * Copyright(c) 1998-2007, ALICE Experiment at CERN, All rights reserved. *
6 * Author: The ALICE Off-line Project. *
7 * Contributors are mentioned in the code where appropriate. *
9 * Permission to use, copy, modify and distribute this software and its *
10 * documentation strictly for non-commercial purposes is hereby granted *
11 * without fee, provided that the above copyright notice appears in all *
12 * copies and that both the copyright notice and this permission notice *
13 * appear in the supporting documentation. The authors make no claims *
14 * about the suitability of this software for any purpose. It is *
15 * provided "as is" without express or implied warranty. *
16 **************************************************************************/
21 * @file AliHLTMUONDataBlockWriter.h
22 * @author Artur Szostak <artursz@iafrica.com>
24 * @brief Definition of a writer class for internal dimuon HLT raw data blocks.
27 #include "AliHLTMUONDataTypes.h"
30 #include "AliHLTMUONTriggerRecordsBlockStruct.h"
31 #include "AliHLTMUONTrigRecsDebugBlockStruct.h"
32 #include "AliHLTMUONTriggerChannelsBlockStruct.h"
33 #include "AliHLTMUONRecHitsBlockStruct.h"
34 #include "AliHLTMUONClustersBlockStruct.h"
35 #include "AliHLTMUONChannelsBlockStruct.h"
36 #include "AliHLTMUONMansoTracksBlockStruct.h"
37 #include "AliHLTMUONMansoCandidatesBlockStruct.h"
38 #include "AliHLTMUONSinglesDecisionBlockStruct.h"
39 #include "AliHLTMUONPairsDecisionBlockStruct.h"
42 * A light weight class for writing an internal dimuon HLT data block.
43 * Suppose we are given a pointer 'buffer' to some empty memory buffer where we
44 * can store our new data block and the size of the data block is given by the
45 * variable 'size'. The data block is of type 'block_type', the data block entries
46 * are of type 'entries_type' and the data block type code is 'type_code'.
47 * The data block can be written in the following way:
49 * void* buffer = somebuffer;
50 * AliHLTUInt32_t size = somebuffer_size;
52 * // Initialise the data block writer.
53 * AliHLTMUONDataBlockWriter<block_type, entries_type, type_code>
54 * block(buffer, size);
56 * // Initialise the block header
57 * if (not block.InitCommonHeader())
59 * // handle error and exit...
62 * // Tell the writer how many entries we are going to use.
63 * if (not block.SetNumberOfEntries(somevalue))
65 * // handle error and exit...
68 * // Add all the entries to the data block.
69 * for (AliHLTUInt32_t i = 0; i < block.Nentries(); i++)
71 * entries_type& entry = block[i];
72 * // fill the new entry...
73 * entry.somefield = somevalue;
76 * The slightly slower but safer method is to do the following:
78 * AliHLTMUONDataBlockWriter<block_type, entries_type, type_code>
79 * block(buffer, size);
80 * if (not block.InitCommonHeader())
82 * // handle error and exit...
85 * // For each new entry add it to the data block.
86 * while (HaveMoreEntries())
88 * entries_type* entry = block.AddEntry();
91 * // handle buffer overflow and exit...
93 * // fill the new entry...
94 * entry->somefield = somevalue;
100 class DataElementType,
101 AliHLTMUONDataBlockType blockTypeCode
103 class AliHLTMUONDataBlockWriter
106 typedef DataBlockType HeaderType;
107 typedef DataElementType ElementType;
110 * Constructor that sets the internal pointer to the start of the buffer
111 * space to write to and the total size of the buffer in bytes.
112 * @param buffer The pointer to the first byte of the memory buffer.
113 * @param size The total size of the buffer in bytes.
115 AliHLTMUONDataBlockWriter(void* buffer, AliHLTUInt32_t size) :
117 fMaxArraySize(size > sizeof(DataBlockType) ? size - sizeof(DataBlockType) : 0),
118 fBlock(reinterpret_cast<DataBlockType*>(buffer)),
119 fData(reinterpret_cast<DataElementType*>(
120 reinterpret_cast<DataBlockType*>(buffer) + 1
123 assert( buffer != NULL );
127 * Copy constructor that performs a shallow copy.
128 * Since this class does not take direct ownership of the buffer, never
129 * allocates or deallocates memory, this can be allowed.
131 AliHLTMUONDataBlockWriter(const AliHLTMUONDataBlockWriter& writer)
133 fSize = writer.fSize;
134 fMaxArraySize = writer.fMaxArraySize;
135 fBlock = writer.fBlock;
136 fData = writer.fData;
140 * Assignment operator performs a shallow copy.
141 * This is OK because this class does not take direct ownership of the
142 * output memory buffer.
144 AliHLTMUONDataBlockWriter& operator = (const AliHLTMUONDataBlockWriter& writer)
146 fSize = writer.fSize;
147 fMaxArraySize = writer.fMaxArraySize;
148 fBlock = writer.fBlock;
149 fData = writer.fData;
154 * Initialises the common data block header by setting the type and record
155 * width fields. If the buffer size was to small to create the header then
156 * this method returns false, otherwise true on success.
158 bool InitCommonHeader() const
160 // The block size must be at least sizeof(DataBlockType) bytes.
161 if (fSize < sizeof(DataBlockType)) return false;
163 // Now fill the fields in the header.
164 fBlock->fHeader.fType = blockTypeCode;
165 fBlock->fHeader.fRecordWidth = sizeof(DataElementType);
166 fBlock->fHeader.fNrecords = 0;
171 * Returns the common data block header.
173 const AliHLTMUONDataBlockHeader& CommonBlockHeader() const
175 return fBlock->fHeader;
179 * Returns the whole data block header.
181 DataBlockType& BlockHeader()
186 const DataBlockType& BlockHeader() const
192 * Returns a pointer to the next location where a data entry can be
193 * written and increments the number of entries.
194 * If the buffer is already full then NULL is returned and the number of
195 * entries is not changed.
197 DataElementType* AddEntry() const
199 if ( (Nentries() + 1) * sizeof(DataElementType) > fMaxArraySize )
201 DataElementType* newentry = &fData[fBlock->fHeader.fNrecords];
202 fBlock->fHeader.fNrecords++;
207 * Sets the number of entries that will be filled into the buffer.
208 * If the number of entries is to many to fit into the buffer then this
209 * method returns false, otherwise true.
211 bool SetNumberOfEntries(AliHLTUInt32_t n) const
213 if (n * sizeof(DataElementType) > fMaxArraySize) return false;
214 fBlock->fHeader.fNrecords = n;
219 * Returns the total number of entries already added to the data block.
221 AliHLTUInt32_t Nentries() const { return fBlock->fHeader.fNrecords; }
224 * Returns a pointer to the i'th entry.
225 * If the index 'i' is out of bounds then NULL is returned.
226 * This is a safe access method because it does bounds checking but is
227 * a little slower than the array operators.
228 * @param i The index number of the entry to be returned.
229 * @return A pointer to the entry or NULL.
231 DataElementType* Entry(AliHLTUInt32_t i)
233 return (i < Nentries()) ? &fData[i] : NULL;
236 const DataElementType* Entry(AliHLTUInt32_t i) const
238 return (i < Nentries()) ? &fData[i] : NULL;
242 * Array operator for accessing the data entries directly.
243 * The index variable 'i' is not checked (except in debug compilations)
244 * so one should make sure they are within the valid range.
246 DataElementType& operator [] (AliHLTUInt32_t i)
248 assert( i < Nentries() );
252 const DataElementType& operator [] (AliHLTUInt32_t i) const
254 assert( i < Nentries() );
259 * Returns a pointer to the array of elements in the data block.
260 * Care must be taken not to read beyond the array limits given by
263 DataElementType* GetArray() { return fData; }
264 const DataElementType* GetArray() const { return fData; }
267 * Calculates the number of bytes used for the data block in the buffer.
268 * This value will only make sense if a call to InitCommonHeader() was
269 * made and it returned true.
271 AliHLTUInt32_t BytesUsed() const
273 assert( sizeof(DataElementType) == fBlock->fHeader.fRecordWidth);
274 return sizeof(DataBlockType) + Nentries() * sizeof(DataElementType);
278 * Calculates the maximum number of entries that will fit into the
281 AliHLTUInt32_t MaxNumberOfEntries() const
283 return fMaxArraySize / sizeof(DataElementType);
286 AliHLTUInt32_t BufferSize() { return fSize; }
290 AliHLTUInt32_t fSize; // Size of the buffer in bytes.
291 AliHLTUInt32_t fMaxArraySize; // Maximum size of the fData array in bytes.
292 DataBlockType* fBlock; // Pointer to the start of the data block.
293 DataElementType* fData; // Pointer to the start of the data array.
297 // We now define the writer classes for the various data block types from the
298 // template class AliHLTMUONDataBlockWriter.
300 typedef AliHLTMUONDataBlockWriter<
301 AliHLTMUONTriggerRecordsBlockStruct,
302 AliHLTMUONTriggerRecordStruct,
303 kTriggerRecordsDataBlock
304 > AliHLTMUONTriggerRecordsBlockWriter;
306 typedef AliHLTMUONDataBlockWriter<
307 AliHLTMUONTrigRecsDebugBlockStruct,
308 AliHLTMUONTrigRecInfoStruct,
309 kTrigRecsDebugDataBlock
310 > AliHLTMUONTrigRecsDebugBlockWriter;
312 typedef AliHLTMUONDataBlockWriter<
313 AliHLTMUONTriggerChannelsBlockStruct,
314 AliHLTMUONTriggerChannelStruct,
315 kTriggerChannelsDataBlock
316 > AliHLTMUONTriggerChannelsBlockWriter;
318 typedef AliHLTMUONDataBlockWriter<
319 AliHLTMUONRecHitsBlockStruct,
320 AliHLTMUONRecHitStruct,
322 > AliHLTMUONRecHitsBlockWriter;
324 typedef AliHLTMUONDataBlockWriter<
325 AliHLTMUONClustersBlockStruct,
326 AliHLTMUONClusterStruct,
328 > AliHLTMUONClustersBlockWriter;
330 typedef AliHLTMUONDataBlockWriter<
331 AliHLTMUONChannelsBlockStruct,
332 AliHLTMUONChannelStruct,
334 > AliHLTMUONChannelsBlockWriter;
336 typedef AliHLTMUONDataBlockWriter<
337 AliHLTMUONMansoTracksBlockStruct,
338 AliHLTMUONMansoTrackStruct,
339 kMansoTracksDataBlock
340 > AliHLTMUONMansoTracksBlockWriter;
342 typedef AliHLTMUONDataBlockWriter<
343 AliHLTMUONMansoCandidatesBlockStruct,
344 AliHLTMUONMansoCandidateStruct,
345 kMansoCandidatesDataBlock
346 > AliHLTMUONMansoCandidatesBlockWriter;
348 typedef AliHLTMUONDataBlockWriter<
349 AliHLTMUONSinglesDecisionBlockStruct,
350 AliHLTMUONTrackDecisionStruct,
351 kSinglesDecisionDataBlock
352 > AliHLTMUONSinglesDecisionBlockWriter;
354 typedef AliHLTMUONDataBlockWriter<
355 AliHLTMUONPairsDecisionBlockStruct,
356 AliHLTMUONPairDecisionStruct,
357 kPairsDecisionDataBlock
358 > AliHLTMUONPairsDecisionBlockWriter;
360 #endif // ALIHLTMUONDATABLOCKWRITER_H