blob: 034b3312600e554cf33863f143e5410cba9262c4 [file] [log] [blame]
// Copyright (c) 2011, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
part of swarmlib;
// TODO(jimhug): Fill out methods, add encoder, move to shared lib.
class Decoder {
int index;
String data;
Decoder(this.data) {
this.index = 0;
}
// Reads numbers in variable-length 7-bit encoding. This matches the
// varint encoding used by protobufs except that it only uses 7
// bits per byte so it can be efficiently passed as UTF8.
// For more info, see appengine/encoder.py.
int readInt() {
var r = 0;
for (var i = 0;; i++) {
var v = data.codeUnitAt(index++);
r |= (v & 0x3F) << (6 * i);
if ((v & 0x40) == 0) break;
}
return r.toInt();
}
bool readBool() {
final ch = data[index++];
assert(ch == 'T' || ch == 'F');
return ch == 'T';
}
String readString() {
int len = readInt();
String s = data.substring(index, index + len);
index += len;
return s;
}
}