static size_t callbackfunction(void *ptr, size_t size, size_t nmemb, void* userdata)

{

    FILE* stream = (FILE*)userdata;

    if (!stream) {

        printf("!!! No stream\n");

        return 0;

    }

    size_t written = fwrite((FILE*)ptr, size, nmemb, stream);

    return written;

}

 

unsigned char* HttpsRequest::requestOnlineImage(const char* url, int& resultLen)

{

    FILE* fp = fopen("D:\\out.png", "wb");

    if (!fp) {

        printf("!!! Failed to create file on the disk\n");

        return false;

    }

    unsigned char* result = NULL;

    CURL* mCurl = curl_easy_init();

    if (!mCurl) {

        return NULL;

    }

    //struct curl_slist* mHeaders = NULL;

    //mHeaders = curl_slist_append(mHeaders, "Cache-Control:max-age=0");

    //mHeaders = curl_slist_append(mHeaders, "Connection:keep-alive");

    //mHeaders = curl_slist_append(mHeaders, "*/*");

    //mHeaders = curl_slist_append(mHeaders, "Host:cpi.cn-hangzhou.oss-pub.aliyun-inc.com");

    // mHeaders = curl_slist_append(mHeaders, "User-Agent:com.yunos.map/pc");

    //mHeaders = curl_slist_append(mHeaders, "Content-type:image/png");

    //mHeaders = curl_slist_append(mHeaders, "Response-type:application/octet-stream");

    //mHeaders = curl_slist_append(mHeaders, "Accept-Encoding:gzip, deflate");

    struct MemoryStruct chunk;

    chunk.memory = (unsigned char*)malloc(1);

    chunk.size = 0;

    curl_easy_setopt(mCurl, CURLOPT_URL, url);

    //curl_easy_setopt(mCurl, CURLOPT_HTTPHEADER, mHeaders);

    curl_easy_setopt(mCurl, CURLOPT_WRITEFUNCTION, callbackfunction);

    curl_easy_setopt(mCurl, CURLOPT_WRITEDATA, fp);

    CURLcode mRes = curl_easy_perform(mCurl);

    if (mRes != CURLE_OK){

        fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(mRes));

    }

    else {

        printf("%s\n", chunk.memory);

        if (chunk.size > 0) {

            result = (unsigned char*)malloc(chunk.size);

            memcpy(result, chunk.memory, chunk.size);

            resultLen = chunk.size;

        }

    }

    curl_slist_free_all(mHeaders);

    free(chunk.memory); 

    curl_easy_cleanup(mCurl);

    mCurl = NULL;

    return result;

}