/*
* Copyright (c) 2012-2013 Spotify AB
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
#ifndef ENDIANTOOLS_H_INCLUDED
#define ENDIANTOOLS_H_INCLUDED

#include <stdio.h>
#include <unistd.h>
#include <stdint.h>

#include "sparkey.h"

typedef union {
  uint32_t i;
  uint8_t c[4];
} endian_union;

/**
 * Writes count bytes of buf to a file with file descriptor fd
 * @param fd file descriptor of a file to write to.
 * @param buf bytes to write to file.
 * Must point to a block of memory at least count long.
 * @param count number of bytes to write.
 * @returns SPARKEY_SUCCESS if all goes well, otherwise a sparkey error code.
 */
sparkey_returncode write_full(int fd, uint8_t *buf, size_t count);

/**
 * Write a 32 bit value to buf in little endian.
 * @param buf buf to write to. Must be at least 4 bytes long.
 * @param value the value to write.
 */
void write_little_endian32(uint8_t *buf, uint32_t value);

/**
 * Write a 32 bit value to file in little endian.
 * @param fd file descriptor of file open for write.
 * @param value the value to write.
 * @returns SPARKEY_SUCCESS if all goes well, a sparkey error if the
 * writing to file fails.
 */
sparkey_returncode fwrite_little_endian32(int fd, uint32_t value);

/**
 * Write a 64 bit value to buf in little endian.
 * @param buf buf to write to. Must be at least 8 bytes long.
 * @param value the value to write.
 */
void write_little_endian64(uint8_t *buf, uint64_t value);

/**
 * Write a 64 bit value to file in little endian.
 * @param fd file descriptor of file open for write.
 * @param value the value to write.
 * @returns SPARKEY_SUCCESS if all goes well, a sparkey error if the
 * writing to file fails.
 */
sparkey_returncode fwrite_little_endian64(int fd, uint64_t value);
uint32_t read_little_endian32(const uint8_t * array, uint64_t pos);
uint64_t read_little_endian64(const uint8_t * array, uint64_t pos);
sparkey_returncode correct_endian_platform();

sparkey_returncode fread_little_endian32(FILE *fp, uint32_t *res);
sparkey_returncode fread_little_endian64(FILE *fp, uint64_t *res);

#endif /* ENDIAN_H_INCLUDED */