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https://github.com/facebookincubator/mvfst.git
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9a9dcca57c
Summary: This is an API break, but it should mostly be a manageable one. We want to be able to compile mvfst internally without exceptions, and folly::Optional is one dependency that makes this challenging. Additionally, we already have an imported secondary optional type for performance/struct size reasons, tiny-optional. This second optional interface is mostly compatible in an API sense (including the use of std::nullopt) with std::optional. Thus our approach is to remove the dependency on folly::Optional, and offer a quic::Optional instead. The next diff will properly vendor tiny-optional so that quic::Optional is an independent version of it. Reviewed By: sharmafb, kvtsoy Differential Revision: D74133131 fbshipit-source-id: 715f8bb5043ba3bb876cacfe54236887e0686b30
49 lines
1.6 KiB
C++
49 lines
1.6 KiB
C++
/*
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* Copyright (c) Meta Platforms, Inc. and affiliates.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*/
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#include <quic/codec/QuicHeaderCodec.h>
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#include <quic/codec/Decode.h>
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namespace quic {
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ParsedHeaderResult::ParsedHeaderResult(
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bool isVersionNegotiationIn,
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Optional<PacketHeader> parsedHeaderIn)
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: isVersionNegotiation(isVersionNegotiationIn),
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parsedHeader(std::move(parsedHeaderIn)) {
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CHECK(isVersionNegotiation || parsedHeader);
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}
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folly::Expected<ParsedHeaderResult, TransportErrorCode> parseHeader(
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const folly::IOBuf& data) {
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Cursor cursor(&data);
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if (!cursor.canAdvance(sizeof(uint8_t))) {
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return folly::makeUnexpected(TransportErrorCode::FRAME_ENCODING_ERROR);
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}
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uint8_t initialByte = cursor.readBE<uint8_t>();
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if (getHeaderForm(initialByte) == HeaderForm::Long) {
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return parseLongHeader(initialByte, cursor)
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.then([](ParsedLongHeaderResult&& parsedLongHeaderResult) {
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if (parsedLongHeaderResult.isVersionNegotiation) {
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return ParsedHeaderResult(true, std::nullopt);
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}
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// We compensate for the type byte length by adding it back.
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DCHECK(parsedLongHeaderResult.parsedLongHeader);
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return ParsedHeaderResult(
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false,
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PacketHeader(
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std::move(parsedLongHeaderResult.parsedLongHeader->header)));
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});
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} else {
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return parseShortHeader(initialByte, cursor).then([](ShortHeader&& header) {
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return ParsedHeaderResult(false, PacketHeader(std::move(header)));
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});
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}
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}
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} // namespace quic
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