Arduino-esp32: http.POST() Failure to send large files

[HelloDB]

Hardware:

Board: ESP32 Dev Module
Core Installation/update date: 2018-09-19
IDE name: Platform.io
Flash Frequency: 240Mhz
PSRAM enabled: no
Upload Speed: 115200
Computer OS: Windows 10

Description:

http.POST() Failure to send large files，For example, 30kbyte pictures.
When I narrowed the image to 10KB, I successfully sent it.

Sketch:

if (wifiMulti.run() == WL_CONNECTED) {

    String url = gFace_url_add + "?access_token=" + gFace_TK;

    char *output = new char[b64_enc_len(image_size)];
    size_t len = b64_encode(output, (char *)image, image_size);
    // Serial.write((uint8_t *)output, len);
    String data = "{\"group_id\":\"" + gSN + "\",\"user_id\":\"user_001\",\"user_info\":\"user_test\"," + // 图像信息
                  "\"image_type\":\"BASE64\",\"image\":\"" + output + "\"," +                             // 图像数据
                  "\"quality_control\":\"NORMAL\"," +                                                     // 图像质量要求，这里设置为一般
                  "\"liveness_control\":\"NORMAL\"" +                                                     // 活体检测控制，这是设置为一般
                  "}";

    // delete[] output;

    LOGln(url);
    // LOGln(data);
    HTTPClient http;
    http.begin(url);
    LOGln("http begin...");
    http.addHeader("Content-Type", "application/json");
    int httpCode = http.POST(data);
    if (httpCode > 0) {
        LOGf("POST... code: %d\n", httpCode);
        if (httpCode == HTTP_CODE_OK) {
            String payload = http.getString();
            Serial.println(payload);
        }
    } else {
        LOGf("POST... failed, error: %s\n", http.errorToString(httpCode).c_str());
    }
    http.end();
}

Debug Messages:

[Fn:face_add        :230 ]:http begin...
[Fn:face_add        :248 ]:POST... failed, error: send payload failed 

[mikkel75]

Any workaround or fix for this?

[mikkel75]

I "hacked" the HTTPClient.cpp sendRequest() send Payload part to the following and it works fine now with eg. images of 250+k:

    // send Payload if needed
    if(payload && size > 0) {
        int cIndex;
        for (cIndex = 0; cIndex < size; cIndex = cIndex + 1000) {
          int left = size - cIndex;
          if ( left > 1000 ) {
            if(_client->write(&payload[cIndex], 1000) != 1000) {
              return returnError(HTTPC_ERROR_SEND_PAYLOAD_FAILED);
            }
          }
          else { // write last bit
            if(_client->write(&payload[cIndex], left) != left) {
              return returnError(HTTPC_ERROR_SEND_PAYLOAD_FAILED);
            }
          }
        }
    }

Please make a proper fix for this in sources.....

[mipoat]

I just came across the very same issue:
Sending 32k buffers via http.POST() worked most of the time, but as soon as I tried to send something bigger it failed with "send payload failed".
Applying the hack above solved my issue.

[mikkel75]

Hi,

Why has this not been fixed in master branch yet? Who should I write to...?

Thanks

[PeterKillerio]

Had similar issue with esp32-cam sending img post requests, mikkel75's solution fixed it for me. Thank you so much

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.

[stale[bot]]

This stale issue has been automatically closed. Thank you for your contributions.