panda3d/direct/src/plugin/p3dDownload.cxx

/**
 * PANDA 3D SOFTWARE
 * Copyright (c) Carnegie Mellon University.  All rights reserved.
 *
 * All use of this software is subject to the terms of the revised BSD
 * license.  You should have received a copy of this license along
 * with this source code in a file named "LICENSE."
 *
 * @file p3dDownload.cxx
 * @author drose
 * @date 2009-06-11
 */

#include "p3dDownload.h"

/**
 *
 */
P3DDownload::
P3DDownload() {
  _status = P3D_RC_in_progress;
  _http_status_code = 0;
  _total_data = 0;
  _total_expected_data = 0;
  _last_reported_time = 0;
  _progress_known = false;

  _canceled = false;
  _download_id = 0;
  _instance = nullptr;
}

/**
 *
 */
P3DDownload::
P3DDownload(const P3DDownload &copy) :
  _url(copy._url),
  _total_expected_data(copy._total_expected_data),
  _progress_known(copy._progress_known)
{
  _status = P3D_RC_in_progress;
  _http_status_code = 0;
  _total_data = 0;
  _last_reported_time = 0;

  _canceled = false;
  _download_id = 0;
  _instance = nullptr;
}

/**
 *
 */
P3DDownload::
~P3DDownload() {
}

/**
 * Supplies the source URL for the download.
 */
void P3DDownload::
set_url(const string &url) {
  _url = url;
}

/**
 * Cancels a running download.  download_finished() will not be called, but
 * the P3DDownload object itself will eventually be deleted by its owning
 * P3DInstance.
 */
void P3DDownload::
cancel() {
  _canceled = true;
  if (_status == P3D_RC_in_progress) {
    _status = P3D_RC_generic_error;
  }
}

/**
 * Resets the download to its initial state, for re-trying the same download.
 */
void P3DDownload::
clear() {
  _status = P3D_RC_in_progress;
  _http_status_code = 0;
  _total_data = 0;
  _last_reported_time = 0;

  _canceled = false;
  _download_id = 0;
}

/**
 * Called by P3DInstance as more data arrives from the host.  Returns true on
 * success, false if the download should be aborted.
 */
bool P3DDownload::
feed_url_stream(P3D_result_code result_code,
                int http_status_code,
                size_t total_expected_data,
                const unsigned char *this_data,
                size_t this_data_size) {
  if (_canceled) {
    return false;
  }

  _status = result_code;
  _http_status_code = http_status_code;

  if (this_data_size != 0) {
    if (!receive_data(this_data, this_data_size)) {
      // Failure writing to disk or some such.
      _status = P3D_RC_generic_error;
      download_finished(false);
      return false;
    }

    _total_data += this_data_size;
  }

  total_expected_data = max(total_expected_data, _total_data);
  if (total_expected_data > _total_expected_data) {
    // If the expected data grows during the download, we don't really know
    // how much we're getting.
    _progress_known = false;
    _total_expected_data = total_expected_data;
  }
  if (_total_expected_data > 0 &&
      (double)_total_data / (double)_total_expected_data < 0.9) {
    // But if we're not close to our target yet, let's say we do know (at
    // least until we get there and the target moves again).
    _progress_known = true;
  }

  download_progress();

  if (_status != P3D_RC_in_progress) {
    // We're done.
    if (get_download_success()) {
      _progress_known = true;
    }
    download_finished(get_download_success());
  }

  return true;
}


/**
 * Called as new data is downloaded.  Returns true on success, false on
 * failure.
 */
bool P3DDownload::
receive_data(const unsigned char *this_data, size_t this_data_size) {
  return false;
}

/**
 * Intended to be overloaded to generate an occasional callback as new data
 * comes in.
 */
void P3DDownload::
download_progress() {
  time_t now = time(nullptr);
  if (now - _last_reported_time > 10) {
    _last_reported_time = now;
    nout << "Downloading " << get_url() << ": ";
    if (_progress_known) {
      nout << int(get_download_progress() * 1000.0) / 10.0 << "%";
    } else {
      nout << int((double)get_total_data() / 104857.6) / 10.0 << "M";
    }
    nout << ", " << this << "\n";
  }
}

/**
 * Intended to be overloaded to generate a callback when the download
 * finishes, either successfully or otherwise.  The bool parameter is true if
 * the download was successful.
 */
void P3DDownload::
download_finished(bool success) {
  nout << "Downloaded " << get_url() << ": ";
  if (_progress_known) {
    nout << int(get_download_progress() * 1000.0) / 10.0 << "%";
  } else {
    nout << int((double)get_total_data() / 104857.6) / 10.0 << "M";
  }
  nout << ", " << this << ", success = " << success << "\n";
}