/* Copyright (c) 2008-2016, Arvid Norberg All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of the author nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "libtorrent/bitfield.hpp" #include "libtorrent/aux_/cpuid.hpp" #ifdef _MSC_VER #include #endif namespace libtorrent { bool bitfield::all_set() const { const int words = size() / 32; for (int i = 0; i < words; ++i) { if (m_buf[i] != 0xffffffff) return false; } int rest = size() & 31; if (rest > 0) { boost::uint32_t mask = aux::host_to_network(0xffffffff << (32-rest)); if ((m_buf[words] & mask) != mask) return false; } return true; } int bitfield::count() const { int ret = 0; const int words = num_words(); #if TORRENT_HAS_SSE if (aux::mmx_support) { for (int i = 0; i < words; ++i) { #ifdef __GNUC__ ret += __builtin_popcount(m_buf[i]); #else ret += _mm_popcnt_u32(m_buf[i]); #endif } return ret; } #endif // TORRENT_HAS_SSE for (int i = 0; i < words; ++i) { boost::uint32_t v = m_buf[i]; // from: // http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel static const int S[] = {1, 2, 4, 8, 16}; // Magic Binary Numbers static const int B[] = {0x55555555, 0x33333333, 0x0F0F0F0F, 0x00FF00FF, 0x0000FFFF}; boost::uint32_t c = v - ((v >> 1) & B[0]); c = ((c >> S[1]) & B[1]) + (c & B[1]); c = ((c >> S[2]) + c) & B[2]; c = ((c >> S[3]) + c) & B[3]; c = ((c >> S[4]) + c) & B[4]; ret += c; } TORRENT_ASSERT(ret <= size()); TORRENT_ASSERT(ret >= 0); return ret; } void bitfield::resize(int bits, bool val) { if (bits == size()) return; int s = size(); int b = size() & 31; resize(bits); if (s >= size()) return; int old_size_words = (s + 31) / 32; int new_size_words = num_words(); if (val) { if (old_size_words && b) m_buf[old_size_words - 1] |= aux::host_to_network((0xffffffff >> b)); if (old_size_words < new_size_words) std::memset(m_buf + old_size_words, 0xff , size_t((new_size_words - old_size_words) * 4)); clear_trailing_bits(); } else { if (old_size_words < new_size_words) std::memset(m_buf + old_size_words, 0x00 , size_t((new_size_words - old_size_words) * 4)); } TORRENT_ASSERT(size() == bits); } void bitfield::resize(int bits) { if (bits == size()) return; TORRENT_ASSERT(bits >= 0); const int b = (bits + 31) / 32; if (bits == 0) { if (m_buf != NULL) { std::free(m_buf-1); m_buf = NULL; } return; } if (m_buf) { boost::uint32_t* tmp = static_cast(std::realloc(m_buf-1, (b+1) * 4)); #ifndef BOOST_NO_EXCEPTIONS if (tmp == NULL) throw std::bad_alloc(); #endif m_buf = tmp + 1; m_buf[-1] = bits; } else { // +1 because the first word is the size (in bits) boost::uint32_t* tmp = static_cast(std::malloc((b+1) * 4)); #ifndef BOOST_NO_EXCEPTIONS if (tmp == NULL) throw std::bad_alloc(); #endif m_buf = tmp + 1; m_buf[-1] = bits; } clear_trailing_bits(); TORRENT_ASSERT(size() == bits); } }