tephra-core/src/main/java/org/apache/tephra/inmemory/MinimalTxSystemClient.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.tephra.inmemory;

import org.apache.tephra.InvalidTruncateTimeException;
import org.apache.tephra.Transaction;
import org.apache.tephra.TransactionCouldNotTakeSnapshotException;
import org.apache.tephra.TransactionNotInProgressException;
import org.apache.tephra.TransactionSystemClient;
import org.apache.tephra.TransactionType;
import org.apache.tephra.TxConstants;

import java.io.InputStream;
import java.util.Collection;
import java.util.Set;

/**
 * Dummy implementation of TxSystemClient. May be useful for perf testing.
 */
public class MinimalTxSystemClient implements TransactionSystemClient {
  private long currentTxPointer = 1;

  @Override
  public Transaction startShort() {
    long wp = currentTxPointer++;
    // NOTE: -1 here is because we have logic that uses (readpointer + 1) as a "exclusive stop key" in some datasets
    return new Transaction(
      Long.MAX_VALUE - 1, wp, new long[0], new long[0],
      Transaction.NO_TX_IN_PROGRESS, TransactionType.SHORT);
  }

  @Override
  public Transaction startShort(int timeout) {
    return startShort();
  }

  @Override
  public Transaction startLong() {
    return startShort();
  }

  @Override
  public boolean canCommit(Transaction tx, Collection<byte[]> changeIds) {
    return true;
  }

  @Override
  public boolean canCommitOrThrow(Transaction tx, Collection<byte[]> changeIds) {
    return true;
  }

  @Override
  public boolean commit(Transaction tx) {
    return true;
  }

  @Override
  public void abort(Transaction tx) {
    // do nothing
  }

  @Override
  public boolean invalidate(long tx) {
    return true;
  }

  @Override
  public Transaction checkpoint(Transaction tx) throws TransactionNotInProgressException {
    return tx;
  }

  @Override
  public InputStream getSnapshotInputStream() throws TransactionCouldNotTakeSnapshotException {
    throw new TransactionCouldNotTakeSnapshotException("Not snapshot to take.");
  }

  @Override
  public String status() {
    return TxConstants.STATUS_OK;
  }

  @Override
  public void resetState() {
    // do nothing
  }

  @Override
  public boolean truncateInvalidTx(Set<Long> invalidTxIds) {
    return true;
  }

  @Override
  public boolean truncateInvalidTxBefore(long time) throws InvalidTruncateTimeException {
    return true;
  }

  @Override
  public int getInvalidSize() {
    return 0;
  }

  @Override
  public void pruneNow() {
    // do nothing
  }
}