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authorOndřej Surý <ondrej@sury.org>2011-09-13 13:13:40 +0200
committerOndřej Surý <ondrej@sury.org>2011-09-13 13:13:40 +0200
commit5ff4c17907d5b19510a62e08fd8d3b11e62b431d (patch)
treec0650497e988f47be9c6f2324fa692a52dea82e1 /src/pkg/crypto/openpgp/packet/reader.go
parent80f18fc933cf3f3e829c5455a1023d69f7b86e52 (diff)
downloadgolang-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.go63
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},
+ }
+}