103 lines
2.9 KiB
C++
103 lines
2.9 KiB
C++
// Copyright (C) 2016 and later: Unicode, Inc. and others.
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// License & terms of use: http://www.unicode.org/copyright.html
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/*
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*
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* (C) Copyright IBM Corp. 1998-2014 - All Rights Reserved
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*
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*/
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#ifndef __LESWAPS_H
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#define __LESWAPS_H
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#include "LETypes.h"
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/**
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* \file
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* \brief C++ API: Endian independent access to data for LayoutEngine
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*/
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U_NAMESPACE_BEGIN
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/**
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* A convenience macro which invokes the swapWord member function
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* from a concise call.
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*
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* @deprecated ICU 54. See {@link icu::LayoutEngine}
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*/
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#define SWAPW(value) LESwaps::swapWord((le_uint16)(value))
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/**
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* A convenience macro which invokes the swapLong member function
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* from a concise call.
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*
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* @deprecated ICU 54. See {@link icu::LayoutEngine}
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*/
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#define SWAPL(value) LESwaps::swapLong((le_uint32)(value))
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/**
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* This class is used to access data which stored in big endian order
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* regardless of the conventions of the platform.
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*
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* All methods are static and inline in an attempt to induce the compiler
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* to do most of the calculations at compile time.
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*
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* @deprecated ICU 54. See {@link icu::LayoutEngine}
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*/
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class U_LAYOUT_API LESwaps /* not : public UObject because all methods are static */ {
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public:
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/**
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* Reads a big-endian 16-bit word and returns a native-endian value.
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* No-op on a big-endian platform, byte-swaps on a little-endian platform.
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*
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* @param value - the word to be byte swapped
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*
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* @return the byte swapped word
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*
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* @deprecated ICU 54. See {@link icu::LayoutEngine}
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*/
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static le_uint16 swapWord(le_uint16 value)
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{
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#if (defined(U_IS_BIG_ENDIAN) && U_IS_BIG_ENDIAN) || \
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(defined(BYTE_ORDER) && defined(BIG_ENDIAN) && (BYTE_ORDER == BIG_ENDIAN)) || \
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defined(__BIG_ENDIAN__)
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// Fastpath when we know that the platform is big-endian.
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return value;
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#else
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// Reads a big-endian value on any platform.
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const le_uint8 *p = reinterpret_cast<const le_uint8 *>(&value);
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return (le_uint16)((p[0] << 8) | p[1]);
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#endif
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};
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/**
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* Reads a big-endian 32-bit word and returns a native-endian value.
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* No-op on a big-endian platform, byte-swaps on a little-endian platform.
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*
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* @param value - the long to be byte swapped
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*
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* @return the byte swapped long
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*
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* @deprecated ICU 54. See {@link icu::LayoutEngine}
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*/
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static le_uint32 swapLong(le_uint32 value)
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{
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#if (defined(U_IS_BIG_ENDIAN) && U_IS_BIG_ENDIAN) || \
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(defined(BYTE_ORDER) && defined(BIG_ENDIAN) && (BYTE_ORDER == BIG_ENDIAN)) || \
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defined(__BIG_ENDIAN__)
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// Fastpath when we know that the platform is big-endian.
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return value;
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#else
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// Reads a big-endian value on any platform.
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const le_uint8 *p = reinterpret_cast<const le_uint8 *>(&value);
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return (le_uint32)((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]);
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#endif
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};
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private:
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LESwaps() {} // private - forbid instantiation
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};
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U_NAMESPACE_END
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#endif
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