1 #ifndef ALIHLTMUONDATABLOCKREADER_H
2 #define ALIHLTMUONDATABLOCKREADER_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 AliHLTMUONDataBlockReader.h
22 * @author Artur Szostak <artursz@iafrica.com>
24 * @brief Definition of a reader class for internal dimuon HLT raw data blocks.
27 #include "AliHLTMUONDataTypes.h"
30 #include "AliHLTMUONTriggerRecordsBlockStruct.h"
31 #include "AliHLTMUONTrigRecsDebugBlockStruct.h"
32 #include "AliHLTMUONRecHitsBlockStruct.h"
33 #include "AliHLTMUONClustersBlockStruct.h"
34 #include "AliHLTMUONChannelsBlockStruct.h"
35 #include "AliHLTMUONMansoTracksBlockStruct.h"
36 #include "AliHLTMUONMansoCandidatesBlockStruct.h"
37 #include "AliHLTMUONTracksBlockStruct.h"
38 #include "AliHLTMUONSinglesDecisionBlockStruct.h"
39 #include "AliHLTMUONPairsDecisionBlockStruct.h"
42 * A light weight class for reading the contents of an internal dimuon HLT
44 * Suppose we are given a pointer 'buffer' to the buffer where a data block is
45 * stored in memory and the size of the data block is given by the variable 'size'.
46 * The data block is of type 'block_type' and the data block entries are of type
47 * 'entries_type'. The data block can be accessed in the following way:
49 * void* buffer = somebuffer;
50 * AliHLTUInt32_t size = somebuffer_size;
52 * // Initialise the data block reader.
53 * AliHLTMUONDataBlockReader<block_type, entries_type> block(buffer, size);
55 * // Check that the buffer has the expected size.
56 * if (not block.BufferSizeOk())
61 * // Find the number of entries in the data block.
62 * AliHLTUInt32_t nentries = block.Nentries();
64 * // Loop over all entries in the data block.
65 * for (AliHLTUInt32_t i = 0; i < nentries; i++)
67 * const entries_type& entry = block[i];
68 * // Do something with the entry...
72 template <class DataBlockType, class DataElementType>
73 class AliHLTMUONDataBlockReader
76 typedef DataBlockType HeaderType;
77 typedef DataElementType ElementType;
80 * Constructor that sets the internal pointer to the start of the data
81 * block and the total size of the block in bytes.
82 * @param buffer The pointer to the first byte of the block in memory.
83 * @param size The total size of the data block in bytes.
85 AliHLTMUONDataBlockReader(const void* buffer, AliHLTUInt32_t size) :
87 fBlock(reinterpret_cast<const DataBlockType*>(buffer)),
88 fData(reinterpret_cast<const DataElementType*>(
89 reinterpret_cast<const DataBlockType*>(buffer) + 1
92 assert( buffer != NULL );
96 * Copy constructor that performs a shallow copy.
97 * Since this class does not take direct ownership of the buffer, never
98 * allocates or deallocates memory, this can be allowed.
100 AliHLTMUONDataBlockReader(const AliHLTMUONDataBlockReader& reader)
102 fSize = reader.fSize;
103 fBlock = reader.fBlock;
104 fData = reader.fData;
108 * Assignment operator performs a shallow copy.
109 * This is OK because this class does not take direct ownership of the
110 * output memory buffer.
112 AliHLTMUONDataBlockReader& operator = (const AliHLTMUONDataBlockReader& reader)
114 fSize = reader.fSize;
115 fBlock = reader.fBlock;
116 fData = reader.fData;
121 * Checks that the size of the buffer storing the data block is correct.
122 * Basic sanity checks are performed such as seeing if the data block
123 * size corresponds to the number of reconstructed hits stored and that
124 * the size of the buffer is at least sizeof(DataBlockType) bytes big.
126 bool BufferSizeOk() const
128 // The block size must be at least sizeof(DataBlockType) bytes.
129 // Do not try read the header otherwise, because we could get a
131 if (fSize < sizeof(DataBlockType)) return false;
133 // Now check if the size of the data block corresponds to the
134 // number of entries it claims to contain.
135 AliHLTUInt32_t arraysize = fSize - sizeof(DataBlockType);
136 return arraysize == Nentries() * sizeof(DataElementType);
140 * Returns the common data block header.
142 const AliHLTMUONDataBlockHeader& CommonBlockHeader() const
144 return fBlock->fHeader;
148 * Returns the whole data block header.
150 const DataBlockType& BlockHeader() const
156 * Returns the total number of entries in the data block.
158 AliHLTUInt32_t Nentries() const { return fBlock->fHeader.fNrecords; }
161 * Returns a pointer to the i'th entry.
162 * If the index 'i' is out of bounds then NULL is returned.
163 * This is a safe access method because it does bounds checking but is
164 * a little slower than the array operator.
165 * @param i The index number of the entry to be returned.
166 * @return A pointer to the entry or NULL.
168 const DataElementType* Entry(AliHLTUInt32_t i) const
170 return (i < Nentries()) ? &fData[i] : NULL;
174 * Array operator for accessing the data entries directly.
175 * The index variable 'i' is not checked (except in debug compilations)
176 * so one should make sure they are within the valid range.
178 const DataElementType& operator [] (AliHLTUInt32_t i) const
180 assert( i < Nentries() );
185 * Returns a pointer to the array of elements in the data block.
186 * Care must be taken not to read beyond the array limits given by
189 const DataElementType* GetArray() const { return fData; }
192 * Calculates the number of bytes used for the data block in the buffer.
193 * This value should be the same as what is returned by BufferSize()
194 * unless too much buffer space was allocated.
196 AliHLTUInt32_t BytesUsed() const
198 assert( sizeof(DataElementType) == fBlock->fHeader.fRecordWidth);
199 return sizeof(DataBlockType) + Nentries() * sizeof(DataElementType);
202 AliHLTUInt32_t BufferSize() const { return fSize; }
206 AliHLTUInt32_t fSize; // Size of the data block in bytes.
207 const DataBlockType* fBlock; // Pointer to the data block buffer.
208 const DataElementType* fData; // Pointer to the data array.
212 // We now define the reader classes for the various data block types from the
213 // template class AliHLTMUONDataBlockReader.
215 typedef AliHLTMUONDataBlockReader<
216 AliHLTMUONTriggerRecordsBlockStruct,
217 AliHLTMUONTriggerRecordStruct
218 > AliHLTMUONTriggerRecordsBlockReader;
220 typedef AliHLTMUONDataBlockReader<
221 AliHLTMUONTrigRecsDebugBlockStruct,
222 AliHLTMUONTrigRecInfoStruct
223 > AliHLTMUONTrigRecsDebugBlockReader;
225 typedef AliHLTMUONDataBlockReader<
226 AliHLTMUONRecHitsBlockStruct,
227 AliHLTMUONRecHitStruct
228 > AliHLTMUONRecHitsBlockReader;
230 typedef AliHLTMUONDataBlockReader<
231 AliHLTMUONClustersBlockStruct,
232 AliHLTMUONClusterStruct
233 > AliHLTMUONClustersBlockReader;
235 typedef AliHLTMUONDataBlockReader<
236 AliHLTMUONChannelsBlockStruct,
237 AliHLTMUONChannelStruct
238 > AliHLTMUONChannelsBlockReader;
240 typedef AliHLTMUONDataBlockReader<
241 AliHLTMUONMansoTracksBlockStruct,
242 AliHLTMUONMansoTrackStruct
243 > AliHLTMUONMansoTracksBlockReader;
245 typedef AliHLTMUONDataBlockReader<
246 AliHLTMUONMansoCandidatesBlockStruct,
247 AliHLTMUONMansoCandidateStruct
248 > AliHLTMUONMansoCandidatesBlockReader;
250 typedef AliHLTMUONDataBlockReader<
251 AliHLTMUONTracksBlockStruct,
252 AliHLTMUONTrackStruct
253 > AliHLTMUONTracksBlockReader;
255 typedef AliHLTMUONDataBlockReader<
256 AliHLTMUONSinglesDecisionBlockStruct,
257 AliHLTMUONTrackDecisionStruct
258 > AliHLTMUONSinglesDecisionBlockReader;
260 typedef AliHLTMUONDataBlockReader<
261 AliHLTMUONPairsDecisionBlockStruct,
262 AliHLTMUONPairDecisionStruct
263 > AliHLTMUONPairsDecisionBlockReader;
265 #endif // ALIHLTMUONDATABLOCKREADER_H