transfer.c

//
//  transfer.c
//  Algorithms - Network transfer
//
//  Created by YourtionGuo on 18/05/2017.
//  Copyright © 2017 Yourtion. All rights reserved.
//

#include <sys/types.h>
#include <sys/socket.h>

#include "compress.h"
#include "transfer.h"

#pragma mark - Public


int send_comp(int s, const unsigned char *data, int size, int flags)
{
  unsigned char   *compressed;
  int             size_comp;

  /// 压缩数据
  if ((size_comp = huffman_compress(data, &compressed, size)) < 0) return -1;

  /// 发送压缩数据及大小

  if (send(s, (char *)&size_comp, sizeof(int), flags) != sizeof(int)) return -1;

  if (send(s, (char *)compressed, size_comp, flags) != size_comp) return -1;

  /// 释放已压缩数据
  free(compressed);

  return 0;
}


int recv_comp(int s, unsigned char **data, int *size, int flags)
{
  unsigned char   *compressed;
  int             size_comp;

  /// 根据数据大小接收压缩数据

  if (recv(s, (char *)&size_comp, sizeof(int), flags) != sizeof(int)) return -1;

  if ((compressed = (unsigned char *)malloc(size_comp)) == NULL) return -1;

  if (recv(s, (char *)compressed, size_comp, flags) != size_comp) {

    free(compressed);
    return -1;
  }

  /// 解压数据
  if ((*size = huffman_uncompress(compressed, data)) < 0) return -1;

  /// 释放收到的压缩数据
  free(compressed);
  
  return 0;
}