Compression.h (2604B)
1 /* GRAPHITE2 LICENSING 2 3 Copyright 2015, SIL International 4 All rights reserved. 5 6 This library is free software; you can redistribute it and/or modify 7 it under the terms of the GNU Lesser General Public License as published 8 by the Free Software Foundation; either version 2.1 of License, or 9 (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 Lesser General Public License for more details. 15 16 You should also have received a copy of the GNU Lesser General Public 17 License along with this library in the file named "LICENSE". 18 If not, write to the Free Software Foundation, 51 Franklin Street, 19 Suite 500, Boston, MA 02110-1335, USA or visit their web page on the 20 internet at http://www.fsf.org/licenses/lgpl.html. 21 22 Alternatively, the contents of this file may be used under the terms of the 23 Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public 24 License, as published by the Free Software Foundation, either version 2 25 of the License or (at your option) any later version. 26 */ 27 28 #pragma once 29 30 #include <cassert> 31 #include <cstddef> 32 #include <cstring> 33 34 namespace 35 { 36 37 #if defined(_MSC_VER) 38 typedef unsigned __int8 u8; 39 typedef unsigned __int16 u16; 40 typedef unsigned __int32 u32; 41 typedef unsigned __int64 u64; 42 #else 43 #include <stdint.h> 44 typedef uint8_t u8; 45 typedef uint16_t u16; 46 typedef uint32_t u32; 47 typedef uint64_t u64; 48 #endif 49 50 ptrdiff_t const MINMATCH = 4, 51 LASTLITERALS = 5, 52 MINCODA = LASTLITERALS+1, 53 MINSRCSIZE = 13; 54 55 template<int S> 56 inline 57 void unaligned_copy(void * d, void const * s) { 58 ::memcpy(d, s, S); 59 } 60 61 inline 62 size_t align(size_t p) { 63 return (p + sizeof(unsigned long)-1) & ~(sizeof(unsigned long)-1); 64 } 65 66 inline 67 u8 * safe_copy(u8 * d, u8 const * s, size_t n) { 68 while (n--) *d++ = *s++; 69 return d; 70 } 71 72 inline 73 u8 * overrun_copy(u8 * d, u8 const * s, size_t n) { 74 size_t const WS = sizeof(unsigned long); 75 u8 const * e = s + n; 76 do 77 { 78 unaligned_copy<WS>(d, s); 79 d += WS; 80 s += WS; 81 } 82 while (s < e); 83 d-=(s-e); 84 85 return d; 86 } 87 88 89 inline 90 u8 * fast_copy(u8 * d, u8 const * s, size_t n) { 91 size_t const WS = sizeof(unsigned long); 92 size_t wn = n/WS; 93 while (wn--) 94 { 95 unaligned_copy<WS>(d, s); 96 d += WS; 97 s += WS; 98 } 99 n &= WS-1; 100 return safe_copy(d, s, n); 101 } 102 103 104 } // end of anonymous namespace