Files
proxypin/lib/network/http/h2/frame.dart
wanghongenpin ba4072691e http2协议
2023-12-28 16:12:44 +08:00

89 lines
2.5 KiB
Dart

/*
* Copyright 2023 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
enum FrameType { data, headers, priority, rstStream, settings, pushPromise, ping, goaway, windowUpdate, continuation }
class FrameHeader {
static const flagsEndStream = 0x01;
static const flagsEndHeaders = 0x04;
final int length;
final FrameType type;
int flags; // 8 bits
final int streamIdentifier;
FrameHeader(this.length, this.type, this.flags, this.streamIdentifier);
bool get hasPaddedFlag => (flags & 0x08) == 0x08;
bool get hasPriorityFlag => (flags & 0x20) == 0x20;
bool get hasEndHeadersFlag => (flags & flagsEndHeaders) == flagsEndHeaders;
bool get hasEndStreamFlag => (flags & flagsEndStream) == flagsEndStream;
bool get hasAckFlag => (flags & 0x01) == 0x01;
List<int> encode() {
var result = <int>[];
result.addAll(_intToBytes(length, 3)); // length is 24 bits
result.add(type.index); // type is 8 bits
result.add(flags); // flags is 8 bits
result.addAll(_intToBytes(streamIdentifier, 4)); // streamIdentifier is 32 bits
return result;
}
List<int> _intToBytes(int value, int byteCount) {
var bytes = <int>[];
for (var i = 0; i < byteCount; i++) {
bytes.insert(0, value & 0xff);
value >>= 8;
}
return bytes;
}
}
class Frame {
final FrameHeader header;
Frame(this.header);
Map toJson() => {
'length': header.length,
'type': header.type.toString().split('.')[1],
'flags': header.flags,
'streamIdentifier': header.streamIdentifier
};
}
class HeadersFrame extends Frame {
final int padLength;
final bool exclusiveDependency;
final int? streamDependency;
final int? weight;
final List<int> headerBlockFragment;
HeadersFrame(super.header, this.padLength, this.exclusiveDependency, this.streamDependency, this.weight,
this.headerBlockFragment);
}
class DataFrame extends Frame {
final int padLength;
final List<int> data;
DataFrame(super.header, this.padLength, this.data);
}