src/core/bitfield.cpp

   1 /***************************************************************************
   2  *                                                                         *
   3  *   Copyright (C) 2006 David Brodsky                                      *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or         *
   6  *   modify it under the terms of the GNU General Public License as        *
   7  *   published by the Free Software Foundation and appearing               *
   8  *   in the file LICENSE.GPL included in the packaging of this file.       *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU      *
  13  *   General Public License for more details.                              *
  14  *                                                                         *
  15  ***************************************************************************/
  16
  17 #include "bitfield.h"
  18
  19 namespace Tairent
  20 {
  21
  22 namespace Core
  23 {
  24
  25 /* {{{ BitField::BitField(size_t) */
  26 BitField::BitField(size_t len) : length(len), remaining(length)
  27 {
  28         size_t s = (len >> 3) + (len & 0x07 ? 1 : 0);
  29         data = new char[s];
  30         memset(data, 0, s);
  31 }
  32 /* }}} */
  33
  34 /* {{{ BitField::BitField(const char *, size_t) */
  35 BitField::BitField(const char *mem, size_t len) : length(len), remaining(length)
  36 {
  37         size_t s = (len >> 3) + (len & 0x07 ? 1 : 0);
  38         data = new char[s];
  39         memcpy(data, mem, s);
  40
  41         for (size_t i = 0; i < len; ++i)
  42                 if (getBit(i))
  43                         remaining -= 1;
  44 }
  45 /* }}} */
  46
  47 /* {{{ BitField::~BitField() */
  48 BitField::~BitField()
  49 {
  50         delete [] data;
  51 }
  52 /* }}} */
  53
  54 /* {{{ BitField::getBit(size_t) */
  55 bool BitField::getBit(size_t index)
  56 {
  57         return data[index >> 3] & (0x80 >> (index & 0x07));
  58 }
  59 /* }}} */
  60
  61 /* {{{ BitField::setAll(bool) */
  62 void BitField::setAll(bool value)
  63 {
  64         size_t s = (length >> 3) + (length & 0x07 ? 1 : 0);
  65         memset(data, value ? 0xff : 0x00, s);
  66         remaining = 0;
  67 }
  68 /* }}} */
  69
  70 /* {{{ BitField::setBit(size_t, bool) */
  71 void BitField::setBit(size_t index, bool value)
  72 {
  73         char orig = data[index >> 3];
  74         if (value) {
  75                 data[index >> 3] |= 0x80 >> (index & 0x07);
  76                 remaining -= orig ^ data[index >> 3] ? 1 : 0;
  77         } else {
  78                 data[index >> 3] &= 0x7f >> (index & 0x07);
  79                 remaining += orig ^ data[index >> 3] ? 1 : 0;
  80         }
  81 }
  82 /* }}} */
  83
  84 }; // namespace Core
  85
  86 }; // namespace Tairent
  87
  88 // vim: ai sw=4 ts=4 noet fdm=marker