| /* |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| |
| /* |
| * |
| * (C) Copyright IBM Corp. 1998-2010 - All Rights Reserved |
| * |
| */ |
| |
| #ifndef __LESWAPS_H |
| #define __LESWAPS_H |
| |
| #include "LETypes.h" |
| |
| /** |
| * \file |
| * \brief C++ API: Endian independent access to data for LayoutEngine |
| */ |
| |
| U_NAMESPACE_BEGIN |
| |
| /** |
| * A convenience macro which invokes the swapWord member function |
| * from a concise call. |
| * |
| * @stable ICU 2.8 |
| */ |
| #if defined(U_IS_BIG_ENDIAN) |
| #if U_IS_BIG_ENDIAN |
| #define SWAPW(value) (value) |
| #else |
| #define SWAPW(value) LESwaps::swapWord(value) |
| #endif |
| #else |
| #define SWAPW(value) (LESwaps::isBigEndian() ? (value) : LESwaps::swapWord(value)) |
| #endif |
| |
| /** |
| * A convenience macro which invokes the swapLong member function |
| * from a concise call. |
| * |
| * @stable ICU 2.8 |
| */ |
| #if defined(U_IS_BIG_ENDIAN) |
| #if U_IS_BIG_ENDIAN |
| #define SWAPL(value) (value) |
| #else |
| #define SWAPL(value) LESwaps::swapLong(value) |
| #endif |
| #else |
| #define SWAPL(value) (LESwaps::isBigEndian() ? (value) : LESwaps::swapLong(value)) |
| #endif |
| |
| /** |
| * This class is used to access data which stored in big endian order |
| * regardless of the conventions of the platform. It has been designed |
| * to automatically detect the endian-ness of the platform, so that a |
| * compilation flag is not needed. |
| * |
| * All methods are static and inline in an attempt to induce the compiler |
| * to do most of the calculations at compile time. |
| * |
| * @stable ICU 2.8 |
| */ |
| class U_LAYOUT_API LESwaps /* not : public UObject because all methods are static */ { |
| public: |
| |
| #if !defined(U_IS_BIG_ENDIAN) |
| /** |
| * This method detects the endian-ness of the platform by |
| * casting a pointer to a word to a pointer to a byte. On |
| * big endian platforms the FF will be in the byte with the |
| * lowest address. On little endian platforms, the FF will |
| * be in the byte with the highest address. |
| * |
| * @return TRUE if the platform is big endian |
| * |
| * @stable ICU 2.8 |
| */ |
| static le_uint8 isBigEndian() |
| { |
| const le_uint16 word = 0xFF00; |
| |
| return *((le_uint8 *) &word); |
| }; |
| #endif |
| |
| /** |
| * This method does the byte swap required on little endian platforms |
| * to correctly access a (16-bit) word. |
| * |
| * @param value - the word to be byte swapped |
| * |
| * @return the byte swapped word |
| * |
| * @stable ICU 2.8 |
| */ |
| static le_uint16 swapWord(le_uint16 value) |
| { |
| return (((le_uint8) (value >> 8)) | (value << 8)); |
| }; |
| |
| /** |
| * This method does the byte swapping required on little endian platforms |
| * to correctly access a (32-bit) long. |
| * |
| * @param value - the long to be byte swapped |
| * |
| * @return the byte swapped long |
| * |
| * @stable ICU 2.8 |
| */ |
| static le_uint32 swapLong(le_uint32 value) |
| { |
| return swapWord((le_uint16) (value >> 16)) | (swapWord((le_uint16) value) << 16); |
| }; |
| |
| private: |
| LESwaps() {} // private - forbid instantiation |
| }; |
| |
| U_NAMESPACE_END |
| #endif |