|
1 // Copyright (c) 1995-2009 Nokia Corporation and/or its subsidiary(-ies). |
|
2 // All rights reserved. |
|
3 // This component and the accompanying materials are made available |
|
4 // under the terms of the License "Eclipse Public License v1.0" |
|
5 // which accompanies this distribution, and is available |
|
6 // at the URL "http://www.eclipse.org/legal/epl-v10.html". |
|
7 // |
|
8 // Initial Contributors: |
|
9 // Nokia Corporation - initial contribution. |
|
10 // |
|
11 // Contributors: |
|
12 // |
|
13 // Description: |
|
14 // |
|
15 // Collection of common constants, utility functions, etc. for the file server and file systems. |
|
16 // Definitions here must be filesystem-agnostic, i.e. generic enougs to be used by every file system |
|
17 // |
|
18 // This is the internal file and must not be exported. |
|
19 |
|
20 /** |
|
21 @file |
|
22 @internalTechnology |
|
23 */ |
|
24 |
|
25 #if !defined(__FILESYSTEM_UTILS_BIT_VECTOR__) |
|
26 #define __FILESYSTEM_UTILS_BIT_VECTOR__ |
|
27 |
|
28 #if !defined(__FILESYSTEM_UTILS_H__) |
|
29 #include "filesystem_utils.h" |
|
30 #endif |
|
31 |
|
32 |
|
33 //####################################################################################################################################### |
|
34 |
|
35 /** |
|
36 This class represents a bit vector i.e. an array of bits. Vector size can be from 1 to 2^32 bits. |
|
37 This class can be created on a stack (but needs to be placed into cleanup stack) or in a heap with the help of its factory methods Create/CreateL |
|
38 */ |
|
39 class RBitVector |
|
40 { |
|
41 public: |
|
42 |
|
43 RBitVector(); //-- Creates an empty vector. see Create() methods for memory allocation |
|
44 ~RBitVector(); |
|
45 |
|
46 void Close(); |
|
47 |
|
48 TInt Create(TUint32 aNumBits); |
|
49 void CreateL(TUint32 aNumBits); |
|
50 |
|
51 inline TUint32 Size() const; |
|
52 |
|
53 //-- single bit manipulation methods |
|
54 inline TBool operator[](TUint32 aIndex) const; |
|
55 inline void SetBit(TUint32 aIndex); |
|
56 inline void ResetBit(TUint32 aIndex); |
|
57 inline void InvertBit(TUint32 aIndex); |
|
58 inline void SetBitVal(TUint32 aIndex, TBool aVal); |
|
59 |
|
60 void Fill(TBool aVal); |
|
61 void Fill(TUint32 aIndexFrom, TUint32 aIndexTo, TBool aVal); |
|
62 |
|
63 void Invert(); |
|
64 |
|
65 TBool operator==(const RBitVector& aRhs) const; |
|
66 TBool operator!=(const RBitVector& aRhs) const; |
|
67 |
|
68 //-- logical operations between 2 vectors. |
|
69 void And(const RBitVector& aRhs); |
|
70 void Or (const RBitVector& aRhs); |
|
71 void Xor(const RBitVector& aRhs); |
|
72 |
|
73 TBool Diff(const RBitVector& aRhs, TUint32& aDiffIndex) const; |
|
74 |
|
75 TUint32 Num1Bits() const; |
|
76 TUint32 Num1Bits(TUint32 aIndexFrom, TUint32 aIndexTo) const; |
|
77 |
|
78 TUint32 Num0Bits() const; |
|
79 |
|
80 |
|
81 /** Bit search specifiers */ |
|
82 enum TFindDirection |
|
83 { |
|
84 ELeft, ///< Search from the given position to the left (towards lower index) |
|
85 ERight, ///< Search from the given position to the right (towards higher index) |
|
86 ENearestL, ///< Search in both directions starting from the given position; in the case of the equal distances return the position to the left |
|
87 ENearestR ///< Search in both directions starting from the given position; in the case of the equal distances return the position to the right |
|
88 |
|
89 //-- N.B the current position the search starts with isn't included to the search. |
|
90 }; |
|
91 |
|
92 TBool Find(TUint32& aStartPos, TBool aBitVal, TFindDirection aDir) const; |
|
93 |
|
94 /** panic codes */ |
|
95 enum TPanicCode |
|
96 { |
|
97 EIndexOutOfRange, ///< index out of range |
|
98 EWrondFindDirection, ///< a value doesn't belong to TFindDirection |
|
99 ESizeMismatch, ///< Size mismatch for binary operators |
|
100 ENotInitialised, ///< No memory allocated for the array |
|
101 ENotImplemented, ///< functionality isn't implemented |
|
102 |
|
103 EDataAlignment, ///< wrong data alignment when importing / exporting raw data |
|
104 }; |
|
105 |
|
106 protected: |
|
107 |
|
108 //-- these are outlawed. Can't use them because memory allocator can leave and we don't have conthrol on it in these methods. |
|
109 RBitVector(const RBitVector& aRhs); |
|
110 RBitVector& operator=(const RBitVector& aRhs); |
|
111 |
|
112 void* operator new(TUint); //-- disable creating objects on heap. |
|
113 void* operator new(TUint, void*); |
|
114 //------------------------------------- |
|
115 |
|
116 |
|
117 void Panic(TPanicCode aPanicCode) const; |
|
118 |
|
119 inline TUint32 WordNum(TUint32 aBitPos) const; |
|
120 inline TUint32 BitInWord(TUint32 aBitPos) const; |
|
121 |
|
122 protected: |
|
123 //-- special interface to acecess raw internal data. It's protected. Derive appropriate class from this one if you wan to use it |
|
124 void DoImportData(TUint32 aStartBit, TUint32 aNumBits, const TAny* apData); |
|
125 void DoExportData(TUint32 aStartBit, TUint32 aNumBits, TDes8& aData) const; |
|
126 |
|
127 |
|
128 private: |
|
129 TBool FindToRight(TUint32& aStartPos, TBool aBitVal) const; |
|
130 TBool FindToLeft (TUint32& aStartPos, TBool aBitVal) const; |
|
131 TBool FindNearest(TUint32& aStartPos, TBool aBitVal, TBool aToLeft) const; |
|
132 |
|
133 inline TUint32 MaskLastWord(TUint32 aVal) const; |
|
134 inline TBool ItrLeft(TUint32& aIdx) const; |
|
135 inline TBool ItrRight(TUint32& aIdx) const; |
|
136 |
|
137 |
|
138 protected: |
|
139 |
|
140 TUint32 iNumBits; ///< number of bits in the vector |
|
141 TUint32* ipData; ///< pointer to the data |
|
142 TUint32 iNumWords;///< number of 32-bit words that store bits |
|
143 }; |
|
144 |
|
145 |
|
146 //####################################################################################################################################### |
|
147 //# inline functions area |
|
148 //####################################################################################################################################### |
|
149 |
|
150 |
|
151 //--------------------------------------------------------------------------------------------------------------------------------- |
|
152 //-- class RBitVector |
|
153 |
|
154 /** @return size of the vector (number of bits) */ |
|
155 inline TUint32 RBitVector::Size() const |
|
156 { |
|
157 return iNumBits; |
|
158 } |
|
159 |
|
160 /** |
|
161 Get a bit by index |
|
162 |
|
163 @param aIndex index in a bit vector |
|
164 @return 0 if the bit at pos aIndex is 0, not zero otherwise |
|
165 @panic EIndexOutOfRange if aIndex is out of range |
|
166 */ |
|
167 inline TBool RBitVector::operator[](TUint32 aIndex) const |
|
168 { |
|
169 __ASSERT_ALWAYS(aIndex < iNumBits, Panic(EIndexOutOfRange)); |
|
170 return (ipData[WordNum(aIndex)] & (1<<BitInWord(aIndex))); |
|
171 } |
|
172 |
|
173 /** |
|
174 Set a bit at pos aIndex to '1' |
|
175 @param aIndex index in a bit vector |
|
176 @panic EIndexOutOfRange if aIndex is out of range |
|
177 */ |
|
178 inline void RBitVector::SetBit(TUint32 aIndex) |
|
179 { |
|
180 __ASSERT_ALWAYS(aIndex < iNumBits, Panic(EIndexOutOfRange)); |
|
181 ipData[WordNum(aIndex)] |= (1<<BitInWord(aIndex)); |
|
182 } |
|
183 |
|
184 /** |
|
185 Set a bit at pos aIndex to '0' |
|
186 @param aIndex index in a bit vector |
|
187 @panic EIndexOutOfRange if aIndex is out of range |
|
188 */ |
|
189 inline void RBitVector::ResetBit(TUint32 aIndex) |
|
190 { |
|
191 __ASSERT_ALWAYS(aIndex < iNumBits, Panic(EIndexOutOfRange)); |
|
192 ipData[WordNum(aIndex)] &= ~(1<<BitInWord(aIndex)); |
|
193 } |
|
194 |
|
195 /** |
|
196 Invert a bit at pos aIndex |
|
197 @param aIndex index in a bit vector |
|
198 @panic EIndexOutOfRange if aIndex is out of range |
|
199 */ |
|
200 inline void RBitVector::InvertBit(TUint32 aIndex) |
|
201 { |
|
202 __ASSERT_ALWAYS(aIndex < iNumBits, Panic(EIndexOutOfRange)); |
|
203 ipData[WordNum(aIndex)] ^= (1<<BitInWord(aIndex)); |
|
204 } |
|
205 |
|
206 /** |
|
207 Set bit value at position aIndex |
|
208 @param aIndex index in a bit vector |
|
209 @panic EIndexOutOfRange if aIndex is out of range |
|
210 */ |
|
211 inline void RBitVector::SetBitVal(TUint32 aIndex, TBool aVal) |
|
212 { |
|
213 if(aVal) |
|
214 SetBit(aIndex); |
|
215 else |
|
216 ResetBit(aIndex); |
|
217 } |
|
218 |
|
219 |
|
220 inline TUint32 RBitVector::MaskLastWord(TUint32 aVal) const |
|
221 { |
|
222 const TUint32 shift = (32-(iNumBits & 0x1F)) & 0x1F; |
|
223 return (aVal << shift) >> shift; //-- mask unused high bits |
|
224 } |
|
225 |
|
226 inline TUint32 RBitVector::WordNum(TUint32 aBitPos) const |
|
227 { |
|
228 return aBitPos >> 5; |
|
229 } |
|
230 |
|
231 inline TUint32 RBitVector::BitInWord(TUint32 aBitPos) const |
|
232 { |
|
233 return aBitPos & 0x1F; |
|
234 } |
|
235 |
|
236 |
|
237 |
|
238 #endif //__FILESYSTEM_UTILS_BIT_VECTOR__ |
|
239 |
|
240 |
|
241 |
|
242 |
|
243 |
|
244 |
|
245 |
|
246 |
|
247 |
|
248 |
|
249 |
|
250 |
|
251 |