本文整理了Java中org.rocksdb.RocksDB.getSnapshot方法的一些代码示例，展示了RocksDB.getSnapshot的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。RocksDB.getSnapshot方法的具体详情如下：
包路径：org.rocksdb.RocksDB
类名称：RocksDB
方法名：getSnapshot

RocksDB.getSnapshot介绍

[英]Return a handle to the current DB state. Iterators created with this handle will all observe a stable snapshot of the current DB state. The caller must call ReleaseSnapshot(result) when the snapshot is no longer needed.

nullptr will be returned if the DB fails to take a snapshot or does not support snapshot.
[中]将句柄返回到当前DB状态。使用此句柄创建的迭代器都将观察当前数据库状态的稳定快照。当不再需要快照时，调用方必须调用ReleaseSnapshot（结果）。
如果数据库无法获取快照或不支持快照，则会返回nullptr。

代码示例

代码示例来源：origin: apache/flink

@Nonnull
@Override
public RunnableFuture<SnapshotResult<KeyedStateHandle>> doSnapshot(
  long checkpointId,
  long timestamp,
  @Nonnull CheckpointStreamFactory primaryStreamFactory,
  @Nonnull CheckpointOptions checkpointOptions) throws Exception {
  final SupplierWithException<CheckpointStreamWithResultProvider, Exception> checkpointStreamSupplier =
    createCheckpointStreamSupplier(checkpointId, primaryStreamFactory, checkpointOptions);
  final List<StateMetaInfoSnapshot> stateMetaInfoSnapshots = new ArrayList<>(kvStateInformation.size());
  final List<Tuple2<ColumnFamilyHandle, RegisteredStateMetaInfoBase>> metaDataCopy =
    new ArrayList<>(kvStateInformation.size());
  for (Tuple2<ColumnFamilyHandle, RegisteredStateMetaInfoBase> tuple2 : kvStateInformation.values()) {
    // snapshot meta info
    stateMetaInfoSnapshots.add(tuple2.f1.snapshot());
    metaDataCopy.add(tuple2);
  }
  final ResourceGuard.Lease lease = rocksDBResourceGuard.acquireResource();
  final Snapshot snapshot = db.getSnapshot();
  final SnapshotAsynchronousPartCallable asyncSnapshotCallable =
    new SnapshotAsynchronousPartCallable(
      checkpointStreamSupplier,
      lease,
      snapshot,
      stateMetaInfoSnapshots,
      metaDataCopy,
      primaryStreamFactory.toString());
  return asyncSnapshotCallable.toAsyncSnapshotFutureTask(cancelStreamRegistry);
}

代码示例来源：origin: apache/flink

AbstractRocksDBState<?, ?, SV> rocksDBState = (AbstractRocksDBState<?, ?, SV>) state;
Snapshot rocksDBSnapshot = db.getSnapshot();
try (
  RocksIteratorWrapper iterator = getRocksIterator(db, stateMetaInfo.f0);

代码示例来源：origin: org.jsimpledb/jsimpledb-kv-rocksdb

/**
 * Constructor.
 *
 * @param db RocksDB database to snapshot
 * @throws NullPointerException if {@code db} is null
 */
public SnapshotRocksDBKVStore(RocksDB db) {
  this(db, db.getSnapshot());
}

代码示例来源：origin: org.apache.flink/flink-statebackend-rocksdb_2.10

/**
 * 1) Create a snapshot object from RocksDB.
 *
 * @param checkpointId id of the checkpoint for which we take the snapshot
 * @param checkpointTimeStamp timestamp of the checkpoint for which we take the snapshot
 */
public void takeDBSnapShot(long checkpointId, long checkpointTimeStamp) {
  Preconditions.checkArgument(snapshot == null, "Only one ongoing snapshot allowed!");
  this.kvStateIterators = new ArrayList<>(stateBackend.kvStateInformation.size());
  this.checkpointId = checkpointId;
  this.checkpointTimeStamp = checkpointTimeStamp;
  this.snapshot = stateBackend.db.getSnapshot();
}

代码示例来源：origin: org.rocksdb/rocksdbjni

/**
 * <p>Return a handle to the current DB state. Iterators created with
 * this handle will all observe a stable snapshot of the current DB
 * state. The caller must call ReleaseSnapshot(result) when the
 * snapshot is no longer needed.</p>
 *
 * <p>nullptr will be returned if the DB fails to take a snapshot or does
 * not support snapshot.</p>
 *
 * @return Snapshot {@link Snapshot} instance
 */
public Snapshot getSnapshot() {
 long snapshotHandle = getSnapshot(nativeHandle_);
 if (snapshotHandle != 0) {
  return new Snapshot(snapshotHandle);
 }
 return null;
}

代码示例来源：origin: org.apache.flink/flink-statebackend-rocksdb

@Nonnull
@Override
public RunnableFuture<SnapshotResult<KeyedStateHandle>> doSnapshot(
  long checkpointId,
  long timestamp,
  @Nonnull CheckpointStreamFactory primaryStreamFactory,
  @Nonnull CheckpointOptions checkpointOptions) throws Exception {
  final SupplierWithException<CheckpointStreamWithResultProvider, Exception> checkpointStreamSupplier =
    createCheckpointStreamSupplier(checkpointId, primaryStreamFactory, checkpointOptions);
  final List<StateMetaInfoSnapshot> stateMetaInfoSnapshots = new ArrayList<>(kvStateInformation.size());
  final List<Tuple2<ColumnFamilyHandle, RegisteredStateMetaInfoBase>> metaDataCopy =
    new ArrayList<>(kvStateInformation.size());
  for (Tuple2<ColumnFamilyHandle, RegisteredStateMetaInfoBase> tuple2 : kvStateInformation.values()) {
    // snapshot meta info
    stateMetaInfoSnapshots.add(tuple2.f1.snapshot());
    metaDataCopy.add(tuple2);
  }
  final ResourceGuard.Lease lease = rocksDBResourceGuard.acquireResource();
  final Snapshot snapshot = db.getSnapshot();
  final SnapshotAsynchronousPartCallable asyncSnapshotCallable =
    new SnapshotAsynchronousPartCallable(
      checkpointStreamSupplier,
      lease,
      snapshot,
      stateMetaInfoSnapshots,
      metaDataCopy,
      primaryStreamFactory.toString());
  return asyncSnapshotCallable.toAsyncSnapshotFutureTask(cancelStreamRegistry);
}

代码示例来源：origin: org.apache.flink/flink-statebackend-rocksdb_2.11

@Nonnull
@Override
public RunnableFuture<SnapshotResult<KeyedStateHandle>> doSnapshot(
  long checkpointId,
  long timestamp,
  @Nonnull CheckpointStreamFactory primaryStreamFactory,
  @Nonnull CheckpointOptions checkpointOptions) throws Exception {
  final SupplierWithException<CheckpointStreamWithResultProvider, Exception> checkpointStreamSupplier =
    createCheckpointStreamSupplier(checkpointId, primaryStreamFactory, checkpointOptions);
  final List<StateMetaInfoSnapshot> stateMetaInfoSnapshots = new ArrayList<>(kvStateInformation.size());
  final List<Tuple2<ColumnFamilyHandle, RegisteredStateMetaInfoBase>> metaDataCopy =
    new ArrayList<>(kvStateInformation.size());
  for (Tuple2<ColumnFamilyHandle, RegisteredStateMetaInfoBase> tuple2 : kvStateInformation.values()) {
    // snapshot meta info
    stateMetaInfoSnapshots.add(tuple2.f1.snapshot());
    metaDataCopy.add(tuple2);
  }
  final ResourceGuard.Lease lease = rocksDBResourceGuard.acquireResource();
  final Snapshot snapshot = db.getSnapshot();
  final SnapshotAsynchronousPartCallable asyncSnapshotCallable =
    new SnapshotAsynchronousPartCallable(
      checkpointStreamSupplier,
      lease,
      snapshot,
      stateMetaInfoSnapshots,
      metaDataCopy,
      primaryStreamFactory.toString());
  return asyncSnapshotCallable.toAsyncSnapshotFutureTask(cancelStreamRegistry);
}

代码示例来源：origin: org.apache.flink/flink-statebackend-rocksdb_2.11

AbstractRocksDBState<?, ?, SV, S> rocksDBState = (AbstractRocksDBState<?, ?, SV, S>) state;
Snapshot rocksDBSnapshot = db.getSnapshot();
try (
  RocksIteratorWrapper iterator = getRocksIterator(db, stateMetaInfo.f0);

代码示例来源：origin: org.apache.flink/flink-statebackend-rocksdb

AbstractRocksDBState<?, ?, SV, S> rocksDBState = (AbstractRocksDBState<?, ?, SV, S>) state;
Snapshot rocksDBSnapshot = db.getSnapshot();
try (
  RocksIteratorWrapper iterator = getRocksIterator(db, stateMetaInfo.f0);