diff options
author | Ondřej Surý <ondrej@sury.org> | 2011-09-13 13:13:40 +0200 |
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committer | Ondřej Surý <ondrej@sury.org> | 2011-09-13 13:13:40 +0200 |
commit | 5ff4c17907d5b19510a62e08fd8d3b11e62b431d (patch) | |
tree | c0650497e988f47be9c6f2324fa692a52dea82e1 /src/pkg/crypto/openpgp/packet/reader.go | |
parent | 80f18fc933cf3f3e829c5455a1023d69f7b86e52 (diff) | |
download | golang-upstream/60.tar.gz |
Imported Upstream version 60upstream/60
Diffstat (limited to 'src/pkg/crypto/openpgp/packet/reader.go')
-rw-r--r-- | src/pkg/crypto/openpgp/packet/reader.go | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/src/pkg/crypto/openpgp/packet/reader.go b/src/pkg/crypto/openpgp/packet/reader.go new file mode 100644 index 000000000..5febc3bc8 --- /dev/null +++ b/src/pkg/crypto/openpgp/packet/reader.go @@ -0,0 +1,63 @@ +// 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 ( + "crypto/openpgp/error" + "io" + "os" +) + +// Reader reads packets from an io.Reader and allows packets to be 'unread' so +// that they result from the next call to Next. +type Reader struct { + q []Packet + readers []io.Reader +} + +// Next returns the most recently unread Packet, or reads another packet from +// the top-most io.Reader. Unknown packet types are skipped. +func (r *Reader) Next() (p Packet, err os.Error) { + if len(r.q) > 0 { + p = r.q[len(r.q)-1] + r.q = r.q[:len(r.q)-1] + return + } + + for len(r.readers) > 0 { + p, err = Read(r.readers[len(r.readers)-1]) + if err == nil { + return + } + if err == os.EOF { + r.readers = r.readers[:len(r.readers)-1] + continue + } + if _, ok := err.(error.UnknownPacketTypeError); !ok { + return nil, err + } + } + + return nil, os.EOF +} + +// Push causes the Reader to start reading from a new io.Reader. When an EOF +// error is seen from the new io.Reader, it is popped and the Reader continues +// to read from the next most recent io.Reader. +func (r *Reader) Push(reader io.Reader) { + r.readers = append(r.readers, reader) +} + +// Unread causes the given Packet to be returned from the next call to Next. +func (r *Reader) Unread(p Packet) { + r.q = append(r.q, p) +} + +func NewReader(r io.Reader) *Reader { + return &Reader{ + q: nil, + readers: []io.Reader{r}, + } +} |