add transfer (14-4)

Author: yourtion

source/transfer.c

@@ -0,0 +1,63 @@
+//
+//  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;
+}