io.etcd.jetcd.op.TxnImpl Maven / Gradle / Ivy

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/*
 * Copyright 2016-2019 The jetcd 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
 *
 *     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 io.etcd.jetcd.op;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ImmutableList;
import io.etcd.jetcd.ByteSequence;
import io.etcd.jetcd.Txn;
import io.etcd.jetcd.api.TxnRequest;
import io.etcd.jetcd.kv.TxnResponse;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.function.Function;

/**
 * Build an etcd transaction.
 */
public class TxnImpl implements Txn {

  public static TxnImpl newTxn(
      Function> f, ByteSequence namespace) {
    return new TxnImpl(f, namespace);
  }

  @VisibleForTesting
  static TxnImpl newTxn(Function> f) {
    return newTxn(f, ByteSequence.EMPTY);
  }

  private final ByteSequence namespace;

  private List cmpList = new ArrayList<>();
  private List successOpList = new ArrayList<>();
  private List failureOpList = new ArrayList<>();
  private Function> requestF;

  private boolean seenThen = false;
  private boolean seenElse = false;

  private TxnImpl(Function> f, ByteSequence namespace) {
    this.requestF = f;
    this.namespace = namespace;
  }

  //CHECKSTYLE:OFF
  public TxnImpl If(Cmp... cmps) {
    //CHECKSTYLE:ON
    return If(ImmutableList.copyOf(cmps));
  }

  //CHECKSTYLE:OFF
  TxnImpl If(List cmps) {
    //CHECKSTYLE:ON
    if (this.seenThen) {
      throw new IllegalArgumentException("cannot call If after Then!");
    }
    if (this.seenElse) {
      throw new IllegalArgumentException("cannot call If after Else!");
    }

    cmpList.addAll(cmps);
    return this;
  }

  //CHECKSTYLE:OFF
  public TxnImpl Then(Op... ops) {
    //CHECKSTYLE:ON
    return Then(ImmutableList.copyOf(ops));
  }

  //CHECKSTYLE:OFF
  TxnImpl Then(List ops) {
    //CHECKSTYLE:ON
    if (this.seenElse) {
      throw new IllegalArgumentException("cannot call Then after Else!");
    }

    this.seenThen = true;

    successOpList.addAll(ops);
    return this;
  }

  //CHECKSTYLE:OFF
  public TxnImpl Else(Op... ops) {
    //CHECKSTYLE:ON
    return Else(ImmutableList.copyOf(ops));
  }

  //CHECKSTYLE:OFF
  TxnImpl Else(List ops) {
    //CHECKSTYLE:ON
    this.seenElse = true;

    failureOpList.addAll(ops);
    return this;
  }

  public CompletableFuture commit() {
    return this.requestF.apply(this.toTxnRequest());
  }

  private TxnRequest toTxnRequest() {
    TxnRequest.Builder requestBuilder = TxnRequest.newBuilder();

    for (Cmp c : this.cmpList) {
      requestBuilder.addCompare(c.toCompare(namespace));
    }

    for (Op o : this.successOpList) {
      requestBuilder.addSuccess(o.toRequestOp(namespace));
    }

    for (Op o : this.failureOpList) {
      requestBuilder.addFailure(o.toRequestOp(namespace));
    }

    return requestBuilder.build();
  }
}