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/*
* (c) Copyright 2020 Palantir Technologies Inc. All rights reserved.
*
* 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
*
* http://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.
*/
package com.palantir.timelock.paxos;
import com.google.common.collect.Streams;
import com.palantir.atlasdb.timelock.paxos.BatchPaxosLearnerRpcClient;
import com.palantir.atlasdb.timelock.paxos.PaxosRemoteClients;
import com.palantir.atlasdb.timelock.paxos.PaxosUseCase;
import com.palantir.atlasdb.timelock.paxos.WithDedicatedExecutor;
import com.palantir.common.proxy.PredicateSwitchedProxy;
import com.palantir.logsafe.Preconditions;
import com.palantir.logsafe.exceptions.SafeIllegalArgumentException;
import com.palantir.paxos.Client;
import com.palantir.paxos.PaxosLearner;
import java.util.List;
import java.util.function.Supplier;
import java.util.stream.Collectors;
public final class TimelockPaxosLearnerAdapters {
private TimelockPaxosLearnerAdapters() {
// how many times
}
public static List> create(
PaxosUseCase paxosUseCase,
PaxosRemoteClients remoteClients,
Supplier useBatchedSingleLeader,
Client client) {
switch (paxosUseCase) {
case LEADER_FOR_ALL_CLIENTS:
return Streams.zip(
remoteClients.batchLearner().stream(),
remoteClients.singleLeaderLearner().stream(),
(batch, legacy) -> createSwitchingClient(batch, legacy, useBatchedSingleLeader))
.collect(Collectors.toList());
case LEADER_FOR_EACH_CLIENT:
throw new SafeIllegalArgumentException("This should not be possible and is semantically meaningless");
case TIMESTAMP:
return remoteClients.nonBatchTimestampLearner().stream()
.map(withDedicatedExecutor -> withDedicatedExecutor.transformService(
learner -> new TimelockPaxosLearnerAdapter(paxosUseCase, client.value(), learner)))
.collect(Collectors.toList());
default:
throw new IllegalStateException("Unexpected value: " + paxosUseCase);
}
}
private static WithDedicatedExecutor createSwitchingClient(
WithDedicatedExecutor batched,
WithDedicatedExecutor legacy,
Supplier useBatched) {
Preconditions.checkState(
batched.executor() == legacy.executor(),
"Different executors provided to a switching client! This is unexpected");
return WithDedicatedExecutor.of(
PredicateSwitchedProxy.newProxyInstance(
BatchTimelockPaxosLearnerAdapter.singleLeader(batched.service()),
legacy.service(),
useBatched,
PaxosLearner.class),
batched.executor());
}
}