C gzip圧縮 httpサーバー送信

#include <stdio.h>
#include <string.h>
#include <zlib.h>

int compress_gzfile_puts(const char* filename, char* source)
{
    gzFile zp;

    zp = gzopen(filename, "w9");
    if(zp == NULL){
        fprintf(stderr, "gzopen error\n");
        return -1;
    }

    gzwrite(zp, source, strlen(source));

    gzclose(zp);

    return 0;
}

static bool httpUploadGzipFile(const char* filename, char* source)
{
    CURLcode res;
    long statusCode= -1;
    struct stat file_info;
    FILE *fd;

    //gzip圧縮
    compress_gzfile_puts(filename, source);

    //open file to upload
  fd = fopen(filename, "rb");
    //can't continue
    if(!fd) {
    return false;
    }
  //to get the file size
  if(fstat(fileno(fd), &file_info) != 0) {
    return false;
    }

    //Post
    curl_easy_setopt(m_curl, CURLOPT_CUSTOMREQUEST, "POST");
    curl_easy_setopt(m_curl, CURLOPT_POST, 1);

    /*圧縮じゃない方法でデータをサーバー送る
    curl_easy_setopt(m_curl, CURLOPT_POSTFIELDS, postthis);
    curl_easy_setopt(m_curl, CURLOPT_POSTFIELDSIZE, strlen(postthis));
    */

    //tell it to "upload" to the URL
  curl_easy_setopt(m_curl, CURLOPT_UPLOAD, 1L);

  //set where to read from (on Windows you need to use READFUNCTION too)
  curl_easy_setopt(m_curl, CURLOPT_READDATA, fd);

  //and give the size of the upload (optional)
  curl_easy_setopt(m_curl, CURLOPT_INFILESIZE_LARGE, (curl_off_t)file_info.st_size);

    //Set the default value: strict certificate check please
    curl_easy_setopt(m_curl, CURLOPT_SSL_VERIFYPEER, 0L);

    //実行
    curl_easy_perform(m_curl);

  res = curl_easy_getinfo( m_curl, CURLINFO_RESPONSE_CODE, &statusCode);
    if(res != CURLE_OK) {
    return false;
  }

    return true;
}