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 "AliHLTMUONSinglesDecisionBlockStruct.h"
38 #include "AliHLTMUONPairsDecisionBlockStruct.h"
41 * A light weight class for reading the contents of an internal dimuon HLT
43 * Suppose we are given a pointer 'buffer' to the buffer where a data block is
44 * stored in memory and the size of the data block is given by the variable 'size'.
45 * The data block is of type 'block_type' and the data block entries are of type
46 * 'entries_type'. The data block can be accessed in the following way:
48 * void* buffer = somebuffer;
49 * AliHLTUInt32_t size = somebuffer_size;
51 * // Initialise the data block reader.
52 * AliHLTMUONDataBlockReader<block_type, entries_type> block(buffer, size);
54 * // Check that the buffer has the expected size.
55 * if (not block.BufferSizeOk())
60 * // Find the number of entries in the data block.
61 * AliHLTUInt32_t nentries = block.Nentries();
63 * // Loop over all entries in the data block.
64 * for (AliHLTUInt32_t i = 0; i < nentries; i++)
66 * const entries_type& entry = block[i];
67 * // Do something with the entry...
71 template <class DataBlockType, class DataElementType>
72 class AliHLTMUONDataBlockReader
75 typedef DataBlockType HeaderType;
76 typedef DataElementType ElementType;
79 * Constructor that sets the internal pointer to the start of the data
80 * block and the total size of the block in bytes.
81 * @param buffer The pointer to the first byte of the block in memory.
82 * @param size The total size of the data block in bytes.
84 AliHLTMUONDataBlockReader(const void* buffer, AliHLTUInt32_t size) :
86 fBlock(reinterpret_cast<const DataBlockType*>(buffer)),
87 fData(reinterpret_cast<const DataElementType*>(
88 reinterpret_cast<const DataBlockType*>(buffer) + 1
91 assert( buffer != NULL );
95 * Copy constructor that performs a shallow copy.
96 * Since this class does not take direct ownership of the buffer, never
97 * allocates or deallocates memory, this can be allowed.
99 AliHLTMUONDataBlockReader(const AliHLTMUONDataBlockReader& reader)
101 fSize = reader.fSize;
102 fBlock = reader.fBlock;
103 fData = reader.fData;
107 * Assignment operator performs a shallow copy.
108 * This is OK because this class does not take direct ownership of the
109 * output memory buffer.
111 AliHLTMUONDataBlockReader& operator = (const AliHLTMUONDataBlockReader& reader)
113 fSize = reader.fSize;
114 fBlock = reader.fBlock;
115 fData = reader.fData;
120 * Checks that the size of the buffer storing the data block is correct.
121 * Basic sanity checks are performed such as seeing if the data block
122 * size corresponds to the number of reconstructed hits stored and that
123 * the size of the buffer is at least sizeof(DataBlockType) bytes big.
125 bool BufferSizeOk() const
127 // The block size must be at least sizeof(DataBlockType) bytes.
128 // Do not try read the header otherwise, because we could get a
130 if (fSize < sizeof(DataBlockType)) return false;
132 // Now check if the size of the data block corresponds to the
133 // number of entries it claims to contain.
134 AliHLTUInt32_t arraysize = fSize - sizeof(DataBlockType);
135 return arraysize == Nentries() * sizeof(DataElementType);
139 * Returns the common data block header.
141 const AliHLTMUONDataBlockHeader& CommonBlockHeader() const
143 return fBlock->fHeader;
147 * Returns the whole data block header.
149 const DataBlockType& BlockHeader() const
155 * Returns the total number of entries in the data block.
157 AliHLTUInt32_t Nentries() const { return fBlock->fHeader.fNrecords; }
160 * Returns a pointer to the i'th entry.
161 * If the index 'i' is out of bounds then NULL is returned.
162 * This is a safe access method because it does bounds checking but is
163 * a little slower than the array operator.
164 * @param i The index number of the entry to be returned.
165 * @return A pointer to the entry or NULL.
167 const DataElementType* Entry(AliHLTUInt32_t i) const
169 return (i < Nentries()) ? &fData[i] : NULL;
173 * Array operator for accessing the data entries directly.
174 * The index variable 'i' is not checked (except in debug compilations)
175 * so one should make sure they are within the valid range.
177 const DataElementType& operator [] (AliHLTUInt32_t i) const
179 assert( i < Nentries() );
184 * Returns a pointer to the array of elements in the data block.
185 * Care must be taken not to read beyond the array limits given by
188 const DataElementType* GetArray() const { return fData; }
191 * Calculates the number of bytes used for the data block in the buffer.
192 * This value should be the same as what is returned by BufferSize()
193 * unless too much buffer space was allocated.
195 AliHLTUInt32_t BytesUsed() const
197 assert( sizeof(DataElementType) == fBlock->fHeader.fRecordWidth);
198 return sizeof(DataBlockType) + Nentries() * sizeof(DataElementType);
201 AliHLTUInt32_t BufferSize() const { return fSize; }
205 AliHLTUInt32_t fSize; // Size of the data block in bytes.
206 const DataBlockType* fBlock; // Pointer to the data block buffer.
207 const DataElementType* fData; // Pointer to the data array.
211 // We now define the reader classes for the various data block types from the
212 // template class AliHLTMUONDataBlockReader.
214 typedef AliHLTMUONDataBlockReader<
215 AliHLTMUONTriggerRecordsBlockStruct,
216 AliHLTMUONTriggerRecordStruct
217 > AliHLTMUONTriggerRecordsBlockReader;
219 typedef AliHLTMUONDataBlockReader<
220 AliHLTMUONTrigRecsDebugBlockStruct,
221 AliHLTMUONTrigRecInfoStruct
222 > AliHLTMUONTrigRecsDebugBlockReader;
224 typedef AliHLTMUONDataBlockReader<
225 AliHLTMUONRecHitsBlockStruct,
226 AliHLTMUONRecHitStruct
227 > AliHLTMUONRecHitsBlockReader;
229 typedef AliHLTMUONDataBlockReader<
230 AliHLTMUONClustersBlockStruct,
231 AliHLTMUONClusterStruct
232 > AliHLTMUONClustersBlockReader;
234 typedef AliHLTMUONDataBlockReader<
235 AliHLTMUONChannelsBlockStruct,
236 AliHLTMUONChannelStruct
237 > AliHLTMUONChannelsBlockReader;
239 typedef AliHLTMUONDataBlockReader<
240 AliHLTMUONMansoTracksBlockStruct,
241 AliHLTMUONMansoTrackStruct
242 > AliHLTMUONMansoTracksBlockReader;
244 typedef AliHLTMUONDataBlockReader<
245 AliHLTMUONMansoCandidatesBlockStruct,
246 AliHLTMUONMansoCandidateStruct
247 > AliHLTMUONMansoCandidatesBlockReader;
249 typedef AliHLTMUONDataBlockReader<
250 AliHLTMUONSinglesDecisionBlockStruct,
251 AliHLTMUONTrackDecisionStruct
252 > AliHLTMUONSinglesDecisionBlockReader;
254 typedef AliHLTMUONDataBlockReader<
255 AliHLTMUONPairsDecisionBlockStruct,
256 AliHLTMUONPairDecisionStruct
257 > AliHLTMUONPairsDecisionBlockReader;
259 #endif // ALIHLTMUONDATABLOCKREADER_H