platform_bionic/libc/bionic/swab.cpp
Elliott Hughes fa386e0d1e Add POSIX swab.
Surprisingly to me, there are actual uses of `swab` in the codebases
I have available to search, including one with a #ifndef __ANDROID__
around it.

Bug: N/A
Test: ran tests
Change-Id: Ic91b78ae22bb65c346cb46dd38916f48d979abe0
2017-10-18 13:34:32 -07:00

41 lines
1.7 KiB
C++

/*
* Copyright (C) 2017 The Android Open Source Project
* 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.
*
* 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, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <unistd.h>
void swab(const void* void_src, void* void_dst, ssize_t byte_count) {
const uint8_t* src = static_cast<const uint8_t*>(void_src);
uint8_t* dst = static_cast<uint8_t*>(void_dst);
while (byte_count > 1) {
uint8_t x = *src++;
uint8_t y = *src++;
*dst++ = y;
*dst++ = x;
byte_count -= 2;
}
}