| /* |
| * Copyright (c) 2015, 2016, Oracle and/or its affiliates. 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 Oracle 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, |
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| * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #ifndef LIBJIMAGE_ENDIAN_HPP |
| #define LIBJIMAGE_ENDIAN_HPP |
| |
| #include "inttypes.hpp" |
| |
| // Selectable endian handling. Endian handlers are used when accessing values |
| // that are of unknown (until runtime) endian. The only requirement of the values |
| // accessed are that they are aligned to proper size boundaries (no misalignment.) |
| // To select an endian handler, one should call Endian::get_handler(big_endian); |
| // Where big_endian is true if big endian is required and false otherwise. The |
| // native endian handler can be fetched with Endian::get_native_handler(); |
| // To retrieve a value using the approprate endian, use one of the overloaded |
| // calls to get. To set a value, then use one of the overloaded set calls. |
| // Ex. |
| // s4 value; // Imported value; |
| // ... |
| // Endian* endian = Endian::get_handler(true); // Use big endian |
| // s4 corrected = endian->get(value); |
| // endian->set(value, 1); |
| // |
| class Endian { |
| public: |
| virtual u2 get(u2 x) = 0; |
| virtual u4 get(u4 x) = 0; |
| virtual u8 get(u8 x) = 0; |
| virtual s2 get(s2 x) = 0; |
| virtual s4 get(s4 x) = 0; |
| virtual s8 get(s8 x) = 0; |
| |
| virtual void set(u2& x, u2 y) = 0; |
| virtual void set(u4& x, u4 y) = 0; |
| virtual void set(u8& x, u8 y) = 0; |
| virtual void set(s2& x, s2 y) = 0; |
| virtual void set(s4& x, s4 y) = 0; |
| virtual void set(s8& x, s8 y) = 0; |
| |
| // Quick little endian test. |
| static bool is_little_endian() { u4 x = 1; return *(u1 *)&x != 0; } |
| |
| // Quick big endian test. |
| static bool is_big_endian() { return !is_little_endian(); } |
| |
| // Select an appropriate endian handler. |
| static Endian* get_handler(bool big_endian); |
| |
| // Return the native endian handler. |
| static Endian* get_native_handler(); |
| |
| // get platform u2 from Java Big endian |
| static u2 get_java(u1* x); |
| // set platform u2 to Java Big endian |
| static void set_java(u1* p, u2 x); |
| }; |
| |
| // Normal endian handling. |
| class NativeEndian : public Endian { |
| private: |
| static NativeEndian _native; |
| |
| public: |
| u2 get(u2 x); |
| u4 get(u4 x); |
| u8 get(u8 x); |
| s2 get(s2 x); |
| s4 get(s4 x); |
| s8 get(s8 x); |
| |
| void set(u2& x, u2 y); |
| void set(u4& x, u4 y); |
| void set(u8& x, u8 y); |
| void set(s2& x, s2 y); |
| void set(s4& x, s4 y); |
| void set(s8& x, s8 y); |
| |
| static Endian* get_native() { return &_native; } |
| }; |
| |
| // Swapping endian handling. |
| class SwappingEndian : public Endian { |
| private: |
| static SwappingEndian _swapping; |
| |
| public: |
| u2 get(u2 x); |
| u4 get(u4 x); |
| u8 get(u8 x); |
| s2 get(s2 x); |
| s4 get(s4 x); |
| s8 get(s8 x); |
| |
| void set(u2& x, u2 y); |
| void set(u4& x, u4 y); |
| void set(u8& x, u8 y); |
| void set(s2& x, s2 y); |
| void set(s4& x, s4 y); |
| void set(s8& x, s8 y); |
| |
| static Endian* get_swapping() { return &_swapping; } |
| }; |
| #endif // LIBJIMAGE_ENDIAN_HPP |