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/*
* This file is part of the libjaylink project.
*
* Copyright (C) 2014-2015 Marc Schink <jaylink-dev@marcschink.de>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of 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.
*
* 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdint.h>
#include <string.h>
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "libjaylink-internal.h"
/**
* @file
*
* Buffer helper functions.
*/
/**
* Write a 16-bit unsigned integer value to a buffer.
*
* The value is stored in the buffer in device byte order.
*
* @param[out] buffer Buffer to write the value into.
* @param[in] value Value to write into the buffer in host byte order.
* @param[in] offset Offset of the value within the buffer in bytes.
*/
JAYLINK_PRIV void buffer_set_u16(uint8_t *buffer, uint16_t value,
size_t offset)
{
/*
* Store the value in the buffer and swap byte order depending on the
* host byte order.
*/
#ifdef WORDS_BIGENDIAN
buffer[offset + 0] = value;
buffer[offset + 1] = value >> 8;
#else
memcpy(buffer + offset, &value, sizeof(value));
#endif
}
/**
* Read a 16-bit unsigned integer value from a buffer.
*
* The value in the buffer is expected to be stored in device byte order.
*
* @param[in] buffer Buffer to read the value from.
* @param[in] offset Offset of the value within the buffer in bytes.
*
* @return The value read from the buffer in host byte order.
*/
JAYLINK_PRIV uint16_t buffer_get_u16(const uint8_t *buffer, size_t offset)
{
uint16_t value;
/*
* Read the value from the buffer and swap byte order depending on the
* host byte order.
*/
#ifdef WORDS_BIGENDIAN
value = (((uint16_t)buffer[offset + 1])) |
(((uint16_t)buffer[offset + 0]) << 8);
#else
memcpy(&value, buffer + offset, sizeof(value));
#endif
return value;
}
/**
* Write a 32-bit unsigned integer value to a buffer.
*
* The value is stored in the buffer in device byte order.
*
* @param[out] buffer Buffer to write the value into.
* @param[in] value Value to write into the buffer in host byte order.
* @param[in] offset Offset of the value within the buffer in bytes.
*/
JAYLINK_PRIV void buffer_set_u32(uint8_t *buffer, uint32_t value,
size_t offset)
{
/*
* Store the value in the buffer and swap byte order depending on the
* host byte order.
*/
#ifdef WORDS_BIGENDIAN
buffer[offset + 0] = value;
buffer[offset + 1] = value >> 8;
buffer[offset + 2] = value >> 16;
buffer[offset + 3] = value >> 24;
#else
memcpy(buffer + offset, &value, sizeof(value));
#endif
}
/**
* Read a 32-bit unsigned integer value from a buffer.
*
* The value in the buffer is expected to be stored in device byte order.
*
* @param[in] buffer Buffer to read the value from.
* @param[in] offset Offset of the value within the buffer in bytes.
*
* @return The value read from the buffer in host byte order.
*/
JAYLINK_PRIV uint32_t buffer_get_u32(const uint8_t *buffer, size_t offset)
{
uint32_t value;
/*
* Read the value from the buffer and swap byte order depending on the
* host byte order.
*/
#ifdef WORDS_BIGENDIAN
value = (((uint32_t)buffer[offset + 3])) |
(((uint32_t)buffer[offset + 2]) << 8) |
(((uint32_t)buffer[offset + 1]) << 16) |
(((uint32_t)buffer[offset + 0]) << 24);
#else
memcpy(&value, buffer + offset, sizeof(value));
#endif
return value;
}
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