def _download_url()

in lib64/python3.6/dist-packages/pip/_internal/download.py [0:0]

• 60 lines of code
• 21 McCabe index (conditional complexity)

def _download_url(resp, link, content_file, hashes, progress_bar):
    try:
        total_length = int(resp.headers['content-length'])
    except (ValueError, KeyError, TypeError):
        total_length = 0

    cached_resp = getattr(resp, "from_cache", False)
    if logger.getEffectiveLevel() > logging.INFO:
        show_progress = False
    elif cached_resp:
        show_progress = False
    elif total_length > (40 * 1000):
        show_progress = True
    elif not total_length:
        show_progress = True
    else:
        show_progress = False

    show_url = link.show_url

    def resp_read(chunk_size):
        try:
            # Special case for urllib3.
            for chunk in resp.raw.stream(
                    chunk_size,
                    # We use decode_content=False here because we don't
                    # want urllib3 to mess with the raw bytes we get
                    # from the server. If we decompress inside of
                    # urllib3 then we cannot verify the checksum
                    # because the checksum will be of the compressed
                    # file. This breakage will only occur if the
                    # server adds a Content-Encoding header, which
                    # depends on how the server was configured:
                    # - Some servers will notice that the file isn't a
                    #   compressible file and will leave the file alone
                    #   and with an empty Content-Encoding
                    # - Some servers will notice that the file is
                    #   already compressed and will leave the file
                    #   alone and will add a Content-Encoding: gzip
                    #   header
                    # - Some servers won't notice anything at all and
                    #   will take a file that's already been compressed
                    #   and compress it again and set the
                    #   Content-Encoding: gzip header
                    #
                    # By setting this not to decode automatically we
                    # hope to eliminate problems with the second case.
                    decode_content=False):
                yield chunk
        except AttributeError:
            # Standard file-like object.
            while True:
                chunk = resp.raw.read(chunk_size)
                if not chunk:
                    break
                yield chunk

    def written_chunks(chunks):
        for chunk in chunks:
            content_file.write(chunk)
            yield chunk

    progress_indicator = _progress_indicator

    if link.netloc == PyPI.netloc:
        url = show_url
    else:
        url = link.url_without_fragment

    if show_progress:  # We don't show progress on cached responses
        progress_indicator = DownloadProgressProvider(progress_bar,
                                                      max=total_length)
        if total_length:
            logger.info("Downloading %s (%s)", url, format_size(total_length))
        else:
            logger.info("Downloading %s", url)
    elif cached_resp:
        logger.info("Using cached %s", url)
    else:
        logger.info("Downloading %s", url)

    logger.debug('Downloading from URL %s', link)

    downloaded_chunks = written_chunks(
        progress_indicator(
            resp_read(CONTENT_CHUNK_SIZE),
            CONTENT_CHUNK_SIZE
        )
    )
    if hashes:
        hashes.check_against_chunks(downloaded_chunks)
    else:
        consume(downloaded_chunks)