Function DownloadTryCompression

http/compression.go:42–95

DownloadTryCompression tries to download from URL .bz2, .gz and raw extension until it finds existing file.

(ctx context.Context, downloader aptly.Downloader, baseURL *url.URL, path string, expectedChecksums map[string]utils.ChecksumInfo, ignoreMismatch bool)

// DownloadTryCompression tries to download from URL .bz2, .gz and raw extension until
// it finds existing file.
func DownloadTryCompression(ctx context.Context, downloader aptly.Downloader, baseURL *url.URL, path string, expectedChecksums map[string]utils.ChecksumInfo, ignoreMismatch bool) (io.Reader, *os.File, error) {
	var err error

	for _, method := range compressionMethods {
		var file *os.File

		tryPath := path + method.extenstion
		foundChecksum := false

		bestSuffix := ""

		for suffix := range expectedChecksums {
			if strings.HasSuffix(tryPath, suffix) {
				foundChecksum = true
				if len(suffix) > len(bestSuffix) {
					bestSuffix = suffix
				}
			}
		}

		tryURL := baseURL.ResolveReference(&url.URL{Path: tryPath})

		if foundChecksum {
			expected := expectedChecksums[bestSuffix]
			file, err = DownloadTempWithChecksum(ctx, downloader, tryURL.String(), &expected, ignoreMismatch)
		} else {
			if !ignoreMismatch {
				continue
			}

			file, err = DownloadTemp(ctx, downloader, tryURL.String())
		}

		if err != nil {
			if err1, ok := err.(*Error); ok && (err1.Code == 404 || err1.Code == 403) {
				continue
			}
			return nil, nil, err
		}

		var uncompressed io.Reader
		uncompressed, err = method.transformation(file)
		if err != nil {
			return nil, nil, err
		}

		return uncompressed, file, err
	}

	if err == nil {
		return nil, nil, &NoCandidateFoundError{URL: baseURL.ResolveReference(&url.URL{Path: path})}
	}
	return nil, nil, err
}