diff options
Diffstat (limited to '')
-rw-r--r-- | gfx/graphite2/src/inc/Endian.h | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/gfx/graphite2/src/inc/Endian.h b/gfx/graphite2/src/inc/Endian.h new file mode 100644 index 0000000000..56ecfd8667 --- /dev/null +++ b/gfx/graphite2/src/inc/Endian.h @@ -0,0 +1,111 @@ +/* GRAPHITE2 LICENSING + + Copyright 2011, SIL International + All rights reserved. + + This library is free software; you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as published + by the Free Software Foundation; either version 2.1 of 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 + Lesser General Public License for more details. + + You should also have received a copy of the GNU Lesser General Public + License along with this library in the file named "LICENSE". + If not, write to the Free Software Foundation, 51 Franklin Street, + Suite 500, Boston, MA 02110-1335, USA or visit their web page on the + internet at http://www.fsf.org/licenses/lgpl.html. + +Alternatively, the contents of this file may be used under the terms of the +Mozilla Public License (http://mozilla.org/MPL) or 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. +*/ + +/* +Description: + A set of fast template based decoders for decoding values of any C integer + type up to long int size laid out with most significant byte first or least + significant byte first (aka big endian or little endian). These are CPU + byte order agnostic and will function the same regardless of the CPUs native + byte order. + + Being template based means if the either le or be class is not used then + template code of unused functions will not be instantiated by the compiler + and thus shouldn't cause any overhead. +*/ + +#include <cstddef> + +#pragma once + + +class be +{ + template<int S> + inline static unsigned long int _peek(const unsigned char * p) { + return _peek<S/2>(p) << (S/2)*8 | _peek<S/2>(p+S/2); + } +public: + template<typename T> + inline static T peek(const void * p) { + return T(_peek<sizeof(T)>(static_cast<const unsigned char *>(p))); + } + + template<typename T> + inline static T read(const unsigned char * &p) { + const T r = T(_peek<sizeof(T)>(p)); + p += sizeof r; + return r; + } + + template<typename T> + inline static T swap(const T x) { + return T(_peek<sizeof(T)>(reinterpret_cast<const unsigned char *>(&x))); + } + + template<typename T> + inline static void skip(const unsigned char * &p, size_t n=1) { + p += sizeof(T)*n; + } +}; + +template<> +inline unsigned long int be::_peek<1>(const unsigned char * p) { return *p; } + + +class le +{ + template<int S> + inline static unsigned long int _peek(const unsigned char * p) { + return _peek<S/2>(p) | _peek<S/2>(p+S/2) << (S/2)*8; + } +public: + template<typename T> + inline static T peek(const void * p) { + return T(_peek<sizeof(T)>(static_cast<const unsigned char *>(p))); + } + + template<typename T> + inline static T read(const unsigned char * &p) { + const T r = T(_peek<sizeof(T)>(p)); + p += sizeof r; + return r; + } + + template<typename T> + inline static T swap(const T x) { + return T(_peek<sizeof(T)>(reinterpret_cast<const unsigned char *>(&x))); + } + + template<typename T> + inline static void skip(const unsigned char * &p, size_t n=1) { + p += sizeof(T)*n; + } +}; + +template<> +inline unsigned long int le::_peek<1>(const unsigned char * p) { return *p; } |