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Diffstat (limited to 'libktorrent/util/bitset.h')
| -rw-r--r-- | libktorrent/util/bitset.h | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/libktorrent/util/bitset.h b/libktorrent/util/bitset.h new file mode 100644 index 0000000..32e7e48 --- /dev/null +++ b/libktorrent/util/bitset.h @@ -0,0 +1,157 @@ +/*************************************************************************** + * Copyright (C) 2005 by Joris Guisson * + * joris.guisson@gmail.com * + * * + * This program is free software; you can redistribute it and/or modify * + * it under the terms of the GNU General Public License as published by * + * the Free Software Foundation; either version 2 of the License, or * + * (at your option) any later version. * + * * + * This program is distributed in the hope that it will be useful, * + * but WITHOUT ANY WARRANTY; without even the implied warranty of * + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * + * GNU General Public License for more details. * + * * + * You should have received a copy of the GNU General Public License * + * along with this program; if not, write to the * + * Free Software Foundation, Inc., * + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. * + ***************************************************************************/ +#ifndef BTBITSET_H +#define BTBITSET_H + +#include "constants.h" + +namespace bt +{ + + /** + * @author Joris Guisson + * @brief Simple implementation of a BitSet + * + * Simple implementation of a BitSet, can only turn on and off bits. + * BitSet's are used to indicate which chunks we have or not. + */ + class BitSet + { + Uint32 num_bits,num_bytes; + Uint8* data; + Uint32 num_on; + public: + /** + * Constructor. + * @param num_bits The number of bits + */ + BitSet(Uint32 num_bits = 8); + + /** + * Manually set data. + * @param data The data + * @param num_bits The number of bits + */ + BitSet(const Uint8* data,Uint32 num_bits); + + /** + * Copy constructor. + * @param bs BitSet to copy + * @return + */ + BitSet(const BitSet & bs); + virtual ~BitSet(); + + /// See if the BitSet is null + bool isNull() const {return num_bits == 0;} + + /** + * Get the value of a bit, false means 0, true 1. + * @param i Index of Bit + */ + bool get(Uint32 i) const; + + /** + * Set the value of a bit, false means 0, true 1. + * @param i Index of Bit + * @param on False means 0, true 1 + */ + void set(Uint32 i,bool on); + + /// Set all bits on or off + void setAll(bool on); + + Uint32 getNumBytes() const {return num_bytes;} + Uint32 getNumBits() const {return num_bits;} + const Uint8* getData() const {return data;} + Uint8* getData() {return data;} + + /// Get the number of on bits + Uint32 numOnBits() const {return num_on;} + + /** + * Set all bits to 0 + */ + void clear(); + + /** + * or this BitSet with another. + * @param other The other BitSet + */ + void orBitSet(const BitSet & other); + + /** + * Assignment operator. + * @param bs BitSet to copy + * @return *this + */ + BitSet & operator = (const BitSet & bs); + + /// Check if all bit are set to 1 + bool allOn() const; + + /** + * Check for equality of bitsets + * @param bs BitSet to compare + * @return true if equal + */ + bool operator == (const BitSet & bs); + + /** + * Opposite of operator == + */ + bool operator != (const BitSet & bs) {return ! operator == (bs);} + + static BitSet null; + }; + + inline bool BitSet::get(Uint32 i) const + { + if (i >= num_bits) + return false; + + Uint32 byte = i / 8; + Uint32 bit = i % 8; + Uint8 b = data[byte] & (0x01 << (7 - bit)); + return b != 0x00; + } + + inline void BitSet::set(Uint32 i,bool on) + { + if (i >= num_bits) + return; + + Uint32 byte = i / 8; + Uint32 bit = i % 8; + if (on && !get(i)) + { + num_on++; + data[byte] |= (0x01 << (7 - bit)); + } + else if (!on && get(i)) + { + num_on--; + Uint8 b = (0x01 << (7 - bit)); + data[byte] &= (~b); + } + } +} + +#endif |