app: added helm tgz handle

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/compressed.go

@@ -0,0 +1,192 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package packet
+
+import (
+	"compress/bzip2"
+	"compress/flate"
+	"compress/zlib"
+	"io"
+	"strconv"
+
+	"github.com/ProtonMail/go-crypto/openpgp/errors"
+)
+
+// Compressed represents a compressed OpenPGP packet. The decompressed contents
+// will contain more OpenPGP packets. See RFC 4880, section 5.6.
+type Compressed struct {
+	Body io.Reader
+}
+
+const (
+	NoCompression      = flate.NoCompression
+	BestSpeed          = flate.BestSpeed
+	BestCompression    = flate.BestCompression
+	DefaultCompression = flate.DefaultCompression
+)
+
+// CompressionConfig contains compressor configuration settings.
+type CompressionConfig struct {
+	// Level is the compression level to use. It must be set to
+	// between -1 and 9, with -1 causing the compressor to use the
+	// default compression level, 0 causing the compressor to use
+	// no compression and 1 to 9 representing increasing (better,
+	// slower) compression levels. If Level is less than -1 or
+	// more then 9, a non-nil error will be returned during
+	// encryption. See the constants above for convenient common
+	// settings for Level.
+	Level int
+}
+
+// decompressionReader ensures that the whole compression packet is read.
+type decompressionReader struct {
+	compressed   io.Reader
+	decompressed io.ReadCloser
+	readAll      bool
+}
+
+func newDecompressionReader(r io.Reader, decompressor io.ReadCloser) *decompressionReader {
+	return &decompressionReader{
+		compressed:   r,
+		decompressed: decompressor,
+	}
+}
+
+func (dr *decompressionReader) Read(data []byte) (n int, err error) {
+	if dr.readAll {
+		return 0, io.EOF
+	}
+	n, err = dr.decompressed.Read(data)
+	if err == io.EOF {
+		dr.readAll = true
+		// Close the decompressor.
+		if errDec := dr.decompressed.Close(); errDec != nil {
+			return n, errDec
+		}
+		// Consume all remaining data from the compressed packet.
+		consumeAll(dr.compressed)
+	}
+	return n, err
+}
+
+func (c *Compressed) parse(r io.Reader) error {
+	var buf [1]byte
+	_, err := readFull(r, buf[:])
+	if err != nil {
+		return err
+	}
+
+	switch buf[0] {
+	case 0:
+		c.Body = r
+	case 1:
+		c.Body = newDecompressionReader(r, flate.NewReader(r))
+	case 2:
+		decompressor, err := zlib.NewReader(r)
+		if err != nil {
+			return err
+		}
+		c.Body = newDecompressionReader(r, decompressor)
+	case 3:
+		c.Body = newDecompressionReader(r, io.NopCloser(bzip2.NewReader(r)))
+	default:
+		err = errors.UnsupportedError("unknown compression algorithm: " + strconv.Itoa(int(buf[0])))
+	}
+
+	return err
+}
+
+// LimitedBodyReader wraps the provided body reader with a limiter that restricts
+// the number of bytes read to the specified limit.
+// If limit is nil, the reader is unbounded.
+func (c *Compressed) LimitedBodyReader(limit *int64) io.Reader {
+	if limit == nil {
+		return c.Body
+	}
+	return &LimitReader{R: c.Body, N: *limit}
+}
+
+// compressedWriterCloser represents the serialized compression stream
+// header and the compressor. Its Close() method ensures that both the
+// compressor and serialized stream header are closed. Its Write()
+// method writes to the compressor.
+type compressedWriteCloser struct {
+	sh io.Closer      // Stream Header
+	c  io.WriteCloser // Compressor
+}
+
+func (cwc compressedWriteCloser) Write(p []byte) (int, error) {
+	return cwc.c.Write(p)
+}
+
+func (cwc compressedWriteCloser) Close() (err error) {
+	err = cwc.c.Close()
+	if err != nil {
+		return err
+	}
+
+	return cwc.sh.Close()
+}
+
+// SerializeCompressed serializes a compressed data packet to w and
+// returns a WriteCloser to which the literal data packets themselves
+// can be written and which MUST be closed on completion. If cc is
+// nil, sensible defaults will be used to configure the compression
+// algorithm.
+func SerializeCompressed(w io.WriteCloser, algo CompressionAlgo, cc *CompressionConfig) (literaldata io.WriteCloser, err error) {
+	compressed, err := serializeStreamHeader(w, packetTypeCompressed)
+	if err != nil {
+		return
+	}
+
+	_, err = compressed.Write([]byte{uint8(algo)})
+	if err != nil {
+		return
+	}
+
+	level := DefaultCompression
+	if cc != nil {
+		level = cc.Level
+	}
+
+	var compressor io.WriteCloser
+	switch algo {
+	case CompressionZIP:
+		compressor, err = flate.NewWriter(compressed, level)
+	case CompressionZLIB:
+		compressor, err = zlib.NewWriterLevel(compressed, level)
+	default:
+		s := strconv.Itoa(int(algo))
+		err = errors.UnsupportedError("Unsupported compression algorithm: " + s)
+	}
+	if err != nil {
+		return
+	}
+
+	literaldata = compressedWriteCloser{compressed, compressor}
+
+	return
+}
+
+// LimitReader is an io.Reader that fails with MessageToLarge if read bytes exceed N.
+type LimitReader struct {
+	R io.Reader // underlying reader
+	N int64     // max bytes allowed
+}
+
+func (l *LimitReader) Read(p []byte) (int, error) {
+	if l.N <= 0 {
+		return 0, errors.ErrMessageTooLarge
+	}
+
+	n, err := l.R.Read(p)
+	l.N -= int64(n)
+
+	if err == nil && l.N <= 0 {
+		err = errors.ErrMessageTooLarge
+	}
+
+	return n, err
+}