63 lines
2.1 KiB
C++
63 lines
2.1 KiB
C++
/*
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* SpanContextMessage.h
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*
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* This source file is part of the FoundationDB open source project
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*
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* Copyright 2013-2020 Apple Inc. and the FoundationDB project authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef FDBSERVER_SPANCONTEXTMESSAGE_H
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#define FDBSERVER_SPANCONTEXTMESSAGE_H
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#pragma once
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#include "fdbclient/FDBTypes.h"
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#include "fdbclient/CommitTransaction.h"
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struct SpanContextMessage {
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// This message is pushed into the the transaction logs' memory to inform
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// it what transaction subsequent mutations were a part of. This allows
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// transaction logs and storage servers to associate mutations with a
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// transaction identifier, called a span context.
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//
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// This message is similar to LogProtocolMessage. Storage servers read the
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// first byte of this message to uniquely identify it, meaning it will
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// never be mistaken for another message. See LogProtocolMessage.h for more
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// information.
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SpanID spanContext;
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SpanContextMessage() {}
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SpanContextMessage(SpanID const& spanContext) : spanContext(spanContext) {}
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std::string toString() const {
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return format(
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"code: %d, span context: %s", MutationRef::Reserved_For_SpanContextMessage, spanContext.toString().c_str());
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}
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template <class Ar>
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void serialize(Ar& ar) {
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uint8_t poly = MutationRef::Reserved_For_SpanContextMessage;
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serializer(ar, poly, spanContext);
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}
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static bool startsSpanContextMessage(uint8_t byte) { return byte == MutationRef::Reserved_For_SpanContextMessage; }
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template <class Ar>
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static bool isNextIn(Ar& ar) {
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return startsSpanContextMessage(*(const uint8_t*)ar.peekBytes(1));
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}
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};
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#endif
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