content: /*
   * 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.bookkeeper.statelib.api.mvcc;
  
  import static io.netty.util.ReferenceCountUtil.retain;
  
  import java.util.List;
  import java.util.concurrent.CompletableFuture;
  import org.apache.bookkeeper.api.kv.op.CompareOp;
  import org.apache.bookkeeper.api.kv.op.CompareResult;
  import org.apache.bookkeeper.api.kv.op.DeleteOp;
  import org.apache.bookkeeper.api.kv.op.IncrementOp;
  import org.apache.bookkeeper.api.kv.op.OpFactory;
  import org.apache.bookkeeper.api.kv.op.PutOp;
  import org.apache.bookkeeper.api.kv.op.RangeOp;
  import org.apache.bookkeeper.api.kv.op.TxnOp;
  import org.apache.bookkeeper.api.kv.op.TxnOpBuilder;
  import org.apache.bookkeeper.api.kv.options.Options;
  import org.apache.bookkeeper.api.kv.result.Code;
  import org.apache.bookkeeper.api.kv.result.DeleteResult;
  import org.apache.bookkeeper.api.kv.result.KeyValue;
  import org.apache.bookkeeper.api.kv.result.RangeResult;
  import org.apache.bookkeeper.api.kv.result.Result;
  import org.apache.bookkeeper.common.annotation.InterfaceAudience.Public;
  import org.apache.bookkeeper.common.annotation.InterfaceStability.Evolving;
  import org.apache.bookkeeper.common.concurrent.FutureUtils;
  import org.apache.bookkeeper.statelib.api.AsyncStateStore;
  import org.apache.bookkeeper.statelib.api.exceptions.MVCCStoreException;
  
  /**
   * A mvcc store that supports asynchronous operations.
   *
   * @param <K> key type
   * @param <V> value type
   */
  @Public
  @Evolving
  public interface MVCCAsyncStore<K, V>
      extends AsyncStateStore,
      MVCCAsyncStoreWriteView<K, V>,
      MVCCAsyncStoreReadView<K, V> {
  
      static <T> CompletableFuture<T> failWithCode(Code code, String msg) {
          return FutureUtils.exception(new MVCCStoreException(code, msg));
      }
  
      /**
       * Return the operator factory to build operators.
       *
       * @return operator factory.
       */
      OpFactory<K, V> getOpFactory();
  
      default CompareOp<K, V> newCompareCreateRevision(CompareResult result, K key, long revision) {
          return getOpFactory().compareCreateRevision(result, key, revision);
      }
  
      default CompareOp<K, V> newCompareModRevision(CompareResult result, K key, long revision) {
          return getOpFactory().compareModRevision(result, key, revision);
      }
  
      default CompareOp<K, V> newCompareVersion(CompareResult result, K key, long version) {
          return getOpFactory().compareVersion(result, key, version);
      }
  
      default CompareOp<K, V> newCompareValue(CompareResult result, K key, V value) {
          return getOpFactory().compareValue(result, key, value);
      }
  
      default TxnOpBuilder<K, V> newTxn() {
          return getOpFactory().newTxn();
      }
  
      default PutOp<K, V> newPut(K key, V value) {
          return getOpFactory().newPut(
              key,
              value,
              Options.blindPut());
      }
  
      default RangeOp<K, V> newGet(K key) {
          return getOpFactory().newRange(
              key,
              Options.get());
      }
  
      default RangeOp<K, V> newRange(K key, K endKey) {
          return getOpFactory().newRange(
              key,
              getOpFactory().optionFactory().newRangeOption()
                  .endKey(endKey)
                  .limit(-1)
                  .build());
      }
  
      default DeleteOp<K, V> newDelete(K key) {
          return getOpFactory().newDelete(
              key,
              Options.delete());
      }
  
      default DeleteOp<K, V> newDeleteRange(K key, K endKey) {
          return getOpFactory().newDelete(
              key,
              getOpFactory().optionFactory().newDeleteOption()
                  .endKey(endKey)
                  .prevKv(false)
                  .build());
      }
  
      default IncrementOp<K, V> newIncrement(K key, long amount) {
          return getOpFactory().newIncrement(
              key,
              amount,
              Options.blindIncrement());
      }
  
      default IncrementOp<K, V> newIncrementAndGet(K key, long amount) {
          return getOpFactory().newIncrement(
              key,
              amount,
              Options.incrementAndGet());
      }
  
      @Override
      default CompletableFuture<V> get(K key) {
          RangeOp<K, V> op = getOpFactory().newRange(
              key,
              Options.get());
          return range(op).thenCompose(result -> {
              try {
                  if (Code.OK == result.code()) {
                      if (result.kvs().isEmpty()) {
                          return FutureUtils.value(null);
                      } else {
                          return FutureUtils.value(retain(result.kvs().get(0).value()));
                      }
                  } else {
                      return failWithCode(result.code(), "Failed to retrieve key " + key + " from store " + name());
                  }
              } finally {
                  result.close();
              }
          });
      }
  
      @Override
      default CompletableFuture<KeyValue<K, V>> getKeyValue(K key) {
          RangeOp<K, V> op = newGet(key);
          return range(op).thenCompose(result -> {
              try {
                  if (Code.OK == result.code()) {
                      if (result.kvs().isEmpty()) {
                          return FutureUtils.value(null);
                      }
                      List<KeyValue<K, V>> records = result.getKvsAndClear();
                      KeyValue<K, V> record = records.get(0);
                      return FutureUtils.value(record);
                  } else {
                      return failWithCode(result.code(), "Failed to retrieve key " + key + " from store " + name());
                  }
              } finally {
                  result.close();
              }
          });
      }
  
      @Override
      default CompletableFuture<List<KeyValue<K, V>>> range(K key, K endKey) {
          RangeOp<K, V> op = newRange(key, endKey);
          return range(op).thenCompose(result -> {
              try {
                  if (Code.OK == result.code()) {
                      return FutureUtils.value(result.getKvsAndClear());
                  } else {
                      return failWithCode(result.code(),
                          "Failed to retrieve range [" + key + ", " + endKey + "] from store " + name());
                  }
              } finally {
                  result.close();
              }
          });
      }
  
      @Override
      default CompletableFuture<Void> put(K k, V v) {
          if (v == null) {
              return delete(k).thenApply(ignored -> null);
          }
  
          PutOp<K, V> op = newPut(k, v);
          return put(op).thenCompose(result -> {
              try {
                  if (Code.OK == result.code()) {
                      return FutureUtils.Void();
                  } else {
                      return failWithCode(result.code(),
                          "Failed to put (" + k + ", " + v + ") to store " + name());
                  }
              } finally {
                  result.close();
              }
          });
      }
  
      @Override
      default CompletableFuture<V> putIfAbsent(K k, V v) {
          TxnOp<K, V> op = getOpFactory().newTxn()
              .If(newCompareValue(CompareResult.EQUAL, k, null))
              .Then(newPut(k, v))
              .Else(newGet(k))
              .build();
          return txn(op).thenCompose(result -> {
              try {
                  Code code = result.code();
                  if (Code.OK == code) {
                      if (result.isSuccess()) {
                          return FutureUtils.value(null);
                      } else {
                          RangeResult<K, V> rangeResult = (RangeResult<K, V>) result.results().get(0);
                          if (rangeResult.kvs().isEmpty()) {
                              return failWithCode(Code.UNEXPECTED,
                                  "Key " + k + " not found when putIfAbsent failed at store " + name());
                          } else {
                              return FutureUtils.value(retain(rangeResult.kvs().get(0).value()));
                          }
                      }
                  } else {
                      return failWithCode(result.code(),
                          "Failed to putIfAbsent (" + k + ", " + v + ") to store " + name());
                  }
              } finally {
                  result.close();
              }
          });
      }
  
      @Override
      default CompletableFuture<Long> vPut(K k, V v, long expectedVersion) {
          TxnOp<K, V> op = getOpFactory().newTxn()
              .If(newCompareVersion(CompareResult.EQUAL, k, expectedVersion))
              .Then(newPut(k, v))
              .build();
  
          return txn(op).thenCompose(result -> {
              try {
                  Code code = result.code();
                  if (Code.OK == code && !result.isSuccess()) {
                      code = Code.BAD_REVISION;
                  }
                  if (Code.OK == code) {
                      return FutureUtils.value(expectedVersion + 1);
                  } else {
                      return failWithCode(result.code(),
                          "Failed to vPut (" + k + ", " + v + ")@version=" + expectedVersion + " to store " + name());
                  }
              } finally {
                  result.close();
              }
          });
      }
  
      @Override
      default CompletableFuture<Long> rPut(K k, V v, long expectedRevision) {
          TxnOp<K, V> op = getOpFactory().newTxn()
              .If(newCompareModRevision(CompareResult.EQUAL, k, expectedRevision))
              .Then(newPut(k, v))
              .build();
  
          return txn(op).thenCompose(result -> {
              try {
                  Code code = result.code();
                  if (Code.OK == code && !result.isSuccess()) {
                      code = Code.BAD_REVISION;
                  }
                  if (Code.OK == code) {
                      return FutureUtils.value(result.revision());
                  } else {
                      return failWithCode(result.code(),
                          "Failed to vPut (" + k + ", " + v + ")@revision=" + expectedRevision + " to store " + name());
                  }
              } finally {
                  result.close();
              }
          });
      }
  
      @Override
      default CompletableFuture<V> delete(K k) {
          DeleteOp<K, V> op = getOpFactory().newDelete(
              k,
              Options.deleteAndGet());
          return delete(op).thenCompose(result -> {
              try {
                  if (Code.OK == result.code()) {
                      List<KeyValue<K, V>> prevKvs = result.prevKvs();
                      if (prevKvs.isEmpty()) {
                          return FutureUtils.value(null);
                      } else {
                          return FutureUtils.value(prevKvs.get(0).value());
                      }
                  } else {
                      return failWithCode(result.code(),
                          "Fail to delete key " + k + " from store " + name());
                  }
              } finally {
                  result.close();
              }
          });
      }
  
      @Override
      default CompletableFuture<List<KeyValue<K, V>>> deleteRange(K key, K endKey) {
          DeleteOp<K, V> op = getOpFactory().newDelete(
              key,
              getOpFactory().optionFactory().newDeleteOption()
                  .endKey(endKey)
                  .prevKv(true)
                  .build());
          return delete(op).thenCompose(result -> {
              try {
                  if (Code.OK == result.code()) {
                      List<KeyValue<K, V>> prevKvs = result.getPrevKvsAndClear();
                      return FutureUtils.value(prevKvs);
                  } else {
                      return failWithCode(result.code(),
                          "Fail to delete key range [" + key + ", " + endKey + "] from store " + name());
                  }
              } finally {
                  result.close();
              }
          });
      }
  
      @Override
      default CompletableFuture<KeyValue<K, V>> vDelete(K k, long expectedVersion) {
          TxnOp<K, V> op = getOpFactory().newTxn()
              .If(newCompareVersion(CompareResult.EQUAL, k, expectedVersion))
              .Then(getOpFactory().newDelete(
                  k,
                  Options.deleteAndGet()))
              .build();
          return txn(op).thenCompose(result -> {
              try {
                  Code code = result.code();
                  if (Code.OK == code && !result.isSuccess()) {
                      code = Code.BAD_REVISION;
                  }
                  if (Code.OK == code) {
                      List<Result<K, V>> subResults = result.results();
                      DeleteResult<K, V> deleteResult = (DeleteResult<K, V>) subResults.get(0);
                      List<KeyValue<K, V>> prevKvs = deleteResult.getPrevKvsAndClear();
                      if (prevKvs.isEmpty()) {
                          return FutureUtils.value(null);
                      } else {
                          return FutureUtils.value(prevKvs.get(0));
                      }
                  } else {
                      return failWithCode(code,
                          "Failed to vDelete key " + k + " (version=" + expectedVersion + ") to store " + name());
                  }
              } finally {
                  result.close();
              }
          });
      }
  
      @Override
      default CompletableFuture<KeyValue<K, V>> rDelete(K k, long expectedRevision) {
          TxnOp<K, V> op = getOpFactory().newTxn()
              .If(newCompareModRevision(CompareResult.EQUAL, k, expectedRevision))
              .Then(getOpFactory().newDelete(
                  k,
                  Options.deleteAndGet()))
              .build();
          return txn(op).thenCompose(result -> {
              try {
                  Code code = result.code();
                  if (Code.OK == code && !result.isSuccess()) {
                      code = Code.BAD_REVISION;
                  }
                  if (Code.OK == code) {
                      List<Result<K, V>> subResults = result.results();
                      DeleteResult<K, V> deleteResult = (DeleteResult<K, V>) subResults.get(0);
                      List<KeyValue<K, V>> prevKvs = deleteResult.getPrevKvsAndClear();
                      if (prevKvs.isEmpty()) {
                          return FutureUtils.value(null);
                      } else {
                          return FutureUtils.value(prevKvs.get(0));
                      }
                  } else {
                      return failWithCode(code,
                          "Failed to rDelete key " + k + " (mod_rev=" + expectedRevision + ") to store " + name());
                  }
              } finally {
                  result.close();
              }
          });
      }
  
      @Override
      default CompletableFuture<Boolean> delete(K k, V v) {
          TxnOp<K, V> op = getOpFactory().newTxn()
              .If(newCompareValue(CompareResult.EQUAL, k, v))
              .Then(getOpFactory().newDelete(
                  k,
                  Options.deleteAndGet()))
              .build();
          return txn(op).thenCompose(result -> {
              try {
                  Code code = result.code();
                  if (Code.OK == code && !result.isSuccess()) {
                      code = Code.BAD_REVISION;
                  }
                  if (Code.OK == code) {
                      return FutureUtils.value(!result.results().isEmpty());
                  } else if (Code.BAD_REVISION == code) {
                      return FutureUtils.value(false);
                  } else {
                      return failWithCode(code,
                          "Failed to delete (" + k + ", " + v + ") to store " + name());
                  }
              } finally {
                  result.close();
              }
          });
      }
  
      @Override
      default CompletableFuture<Void> increment(K k, long amount) {
          IncrementOp<K, V> op = getOpFactory().newIncrement(
              k,
              amount,
              Options.blindIncrement());
          return increment(op).thenCompose(result -> {
              try {
                  Code code = result.code();
                  if (Code.OK == code) {
                      return FutureUtils.Void();
                  } else {
                      return failWithCode(code,
                          "Failed to increment(" + k + ", " + amount + ") to store " + name());
                  }
              } finally {
                  result.close();
              }
          });
      }
  
      @Override
      default CompletableFuture<Long> incrementAndGet(K k, long amount) {
          IncrementOp<K, V> op = getOpFactory().newIncrement(
              k,
              amount,
              Options.incrementAndGet());
          return increment(op).thenCompose(result -> {
              try {
                  Code code = result.code();
                  if (Code.OK == code) {
                      return FutureUtils.value(result.totalAmount());
                  } else {
                      return failWithCode(code,
                          "Failed to increment(" + k + ", " + amount + ") to store " + name());
                  }
              } finally {
                  result.close();
              }
          });
      }
  
      @Override
      default CompletableFuture<Long> getAndIncrement(K k, long amount) {
          IncrementOp<K, V> op = getOpFactory().newIncrement(
              k,
              amount,
              Options.incrementAndGet());
          return increment(op).thenCompose(result -> {
              try {
                  Code code = result.code();
                  if (Code.OK == code) {
                      return FutureUtils.value(result.totalAmount() - amount);
                  } else {
                      return failWithCode(code,
                          "Failed to increment(" + k + ", " + amount + ") to store " + name());
                  }
              } finally {
                  result.close();
              }
          });
      }
  }
  