org.rocksdb.RocksDB.get()方法的使用及代码示例

x33g5p2x  于2022-01-28 转载在 其他  
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本文整理了Java中org.rocksdb.RocksDB.get方法的一些代码示例，展示了RocksDB.get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.get方法的具体详情如下：
包路径：org.rocksdb.RocksDB
类名称：RocksDB
方法名：get

RocksDB.get介绍

[英]The simplified version of get which returns a new byte array storing the value associated with the specified input key if any. null will be returned if the specified key is not found.
[中]get的简化版本，它返回一个新字节数组，存储与指定输入键（如果有）关联的值。如果找不到指定的密钥，则返回null。

代码示例

代码示例来源：origin: apache/flink

  1. @Override
  2. public boolean contains(UK userKey) throws IOException, RocksDBException {
  3.   byte[] rawKeyBytes = serializeCurrentKeyWithGroupAndNamespacePlusUserKey(userKey, userKeySerializer);
  4.   byte[] rawValueBytes = backend.db.get(columnFamily, rawKeyBytes);
  5.   return (rawValueBytes != null);
  6. }

代码示例来源：origin: Alluxio/alluxio

  1. @Override
  2. public Optional<Long> getChildId(Long inodeId, String name) {
  3.  byte[] id;
  4.  try {
  5.   id = mDb.get(mEdgesColumn, RocksUtils.toByteArray(inodeId, name));
  6.  } catch (RocksDBException e) {
  7.   throw new RuntimeException(e);
  8.  }
  9.  if (id == null) {
  10.   return Optional.empty();
  11.  }
  12.  return Optional.of(Longs.fromByteArray(id));
  13. }

代码示例来源：origin: apache/flink

  1. @Override
  2. public UV get(UK userKey) throws IOException, RocksDBException {
  3.   byte[] rawKeyBytes = serializeCurrentKeyWithGroupAndNamespacePlusUserKey(userKey, userKeySerializer);
  4.   byte[] rawValueBytes = backend.db.get(columnFamily, rawKeyBytes);
  5.   return (rawValueBytes == null ? null : deserializeUserValue(dataInputView, rawValueBytes, userValueSerializer));
  6. }

代码示例来源：origin: Alluxio/alluxio

  1. @Override
  2. public Optional<BlockMeta> getBlock(long id) {
  3.  byte[] meta;
  4.  try {
  5.   meta = mDb.get(mBlockMetaColumn, Longs.toByteArray(id));
  6.  } catch (RocksDBException e) {
  7.   throw new RuntimeException(e);
  8.  }
  9.  if (meta == null) {
  10.   return Optional.empty();
  11.  }
  12.  try {
  13.   return Optional.of(BlockMeta.parseFrom(meta));
  14.  } catch (Exception e) {
  15.   throw new RuntimeException(e);
  16.  }
  17. }

代码示例来源：origin: alibaba/jstorm

  1. @Override
  2. public V get(K key) throws IOException {
  3.   try {
  4.     V ret = null;
  5.     if (key != null) {
  6.       byte[] rawKey = serializer.serialize(key);
  7.       byte[] rawData = rocksDb.get(columnFamily, rawKey);
  8.       ret = rawData != null ? (V) serializer.deserialize(rawData) : null;
  9.     }
  10.     return ret;
  11.   } catch (RocksDBException e) {
  12.     throw new IOException(String.format("Failed to get value by key-%s", key), e);
  13.   }
  14. }

代码示例来源：origin: alibaba/jstorm

  1. @Override
  2. public Object get(String key) {
  3.   try {
  4.     byte[] data = db.get(key.getBytes());
  5.     if (data != null) {
  6.       try {
  7.         return deserialize(data);
  8.       } catch (Exception e) {
  9.         LOG.error("Failed to deserialize obj of " + key, e);
  10.         db.remove(key.getBytes());
  11.         return null;
  12.       }
  13.     }
  14.   } catch (Exception ignored) {
  15.   }
  16.   return null;
  17. }

代码示例来源：origin: ethereum/ethereumj

  1. @Override
  2. public byte[] get(byte[] key) {
  3.   resetDbLock.readLock().lock();
  4.   try {
  5.     if (logger.isTraceEnabled()) logger.trace("~> RocksDbDataSource.get(): " + name + ", key: " + toHexString(key));
  6.     byte[] ret = db.get(readOpts, key);
  7.     if (logger.isTraceEnabled()) logger.trace("<~ RocksDbDataSource.get(): " + name + ", key: " + toHexString(key) + ", " + (ret == null ? "null" : ret.length));
  8.     return ret;
  9.   } catch (RocksDBException e) {
  10.     logger.error("Failed to get from db '{}'", name, e);
  11.     hintOnTooManyOpenFiles(e);
  12.     throw new RuntimeException(e);
  13.   } finally {
  14.     resetDbLock.readLock().unlock();
  15.   }
  16. }

代码示例来源：origin: Alluxio/alluxio

  1. @Override
  2. public Optional<MutableInode<?>> getMutable(long id) {
  3.  byte[] inode;
  4.  try {
  5.   inode = mDb.get(mInodesColumn, Longs.toByteArray(id));
  6.  } catch (RocksDBException e) {
  7.   throw new RuntimeException(e);
  8.  }
  9.  if (inode == null) {
  10.   return Optional.empty();
  11.  }
  12.  try {
  13.   return Optional.of(MutableInode.fromProto(InodeMeta.Inode.parseFrom(inode)));
  14.  } catch (Exception e) {
  15.   throw new RuntimeException(e);
  16.  }
  17. }

代码示例来源：origin: apache/flink

  1. SV getInternal(byte[] key) {
  2.   try {
  3.     byte[] valueBytes = backend.db.get(columnFamily, key);
  4.     if (valueBytes == null) {
  5.       return null;
  6.     }
  7.     dataInputView.setBuffer(valueBytes);
  8.     return valueSerializer.deserialize(dataInputView);
  9.   } catch (IOException | RocksDBException e) {
  10.     throw new FlinkRuntimeException("Error while retrieving data from RocksDB", e);
  11.   }
  12. }

代码示例来源：origin: apache/flink

  1. @Override
  2. public List<V> getInternal() {
  3.   try {
  4.     byte[] key = serializeCurrentKeyWithGroupAndNamespace();
  5.     byte[] valueBytes = backend.db.get(columnFamily, key);
  6.     return deserializeList(valueBytes);
  7.   } catch (RocksDBException e) {
  8.     throw new FlinkRuntimeException("Error while retrieving data from RocksDB", e);
  9.   }
  10. }

代码示例来源：origin: apache/kylin

  1. @Override
  2. public String[] getRow(Array<String> key) {
  3.   byte[] encodeKey = rowEncoder.encodeStringsWithLenPfx(key.data, false);
  4.   try {
  5.     byte[] value = rocksDB.get(encodeKey);
  6.     if (value == null) {
  7.       return null;
  8.     }
  9.     return rowEncoder.decode(new KV(encodeKey, value));
  10.   } catch (RocksDBException e) {
  11.     throw new IllegalStateException("error when get key from rocksdb", e);
  12.   }
  13. }

代码示例来源：origin: apache/storm

  1. boolean populateFromKey(RocksDbKey key, Metric metric) throws MetricException {
  2.   try {
  3.     byte[] value = db.get(key.getRaw());
  4.     if (value == null) {
  5.       return false;
  6.     }
  7.     RocksDbValue rdbValue = new RocksDbValue(value);
  8.     rdbValue.populateMetric(metric);
  9.   } catch (Exception e) {
  10.     String message = "Failed to populate metric";
  11.     LOG.error(message, e);
  12.     if (this.failureMeter != null) {
  13.       this.failureMeter.mark();
  14.     }
  15.     throw new MetricException(message, e);
  16.   }
  17.   return true;
  18. }

代码示例来源：origin: brianfrankcooper/YCSB

  1. @Override
  2. public Status read(final String table, final String key, final Set<String> fields,
  3.   final Map<String, ByteIterator> result) {
  4.  try {
  5.   if (!COLUMN_FAMILIES.containsKey(table)) {
  6.    createColumnFamily(table);
  7.   }
  8.   final ColumnFamilyHandle cf = COLUMN_FAMILIES.get(table).getHandle();
  9.   final byte[] values = rocksDb.get(cf, key.getBytes(UTF_8));
  10.   if(values == null) {
  11.    return Status.NOT_FOUND;
  12.   }
  13.   deserializeValues(values, fields, result);
  14.   return Status.OK;
  15.  } catch(final RocksDBException e) {
  16.   LOGGER.error(e.getMessage(), e);
  17.   return Status.ERROR;
  18.  }
  19. }

代码示例来源：origin: brianfrankcooper/YCSB

  1. @Override
  2. public Status update(final String table, final String key, final Map<String, ByteIterator> values) {
  3.  //TODO(AR) consider if this would be faster with merge operator
  4.  try {
  5.   if (!COLUMN_FAMILIES.containsKey(table)) {
  6.    createColumnFamily(table);
  7.   }
  8.   final ColumnFamilyHandle cf = COLUMN_FAMILIES.get(table).getHandle();
  9.   final Map<String, ByteIterator> result = new HashMap<>();
  10.   final byte[] currentValues = rocksDb.get(cf, key.getBytes(UTF_8));
  11.   if(currentValues == null) {
  12.    return Status.NOT_FOUND;
  13.   }
  14.   deserializeValues(currentValues, null, result);
  15.   //update
  16.   result.putAll(values);
  17.   //store
  18.   rocksDb.put(cf, key.getBytes(UTF_8), serializeValues(result));
  19.   return Status.OK;
  20.  } catch(final RocksDBException | IOException e) {
  21.   LOGGER.error(e.getMessage(), e);
  22.   return Status.ERROR;
  23.  }
  24. }

代码示例来源：origin: apache/flink

  1. @Override
  2. public V value() {
  3.   try {
  4.     byte[] valueBytes = backend.db.get(columnFamily,
  5.       serializeCurrentKeyWithGroupAndNamespace());
  6.     if (valueBytes == null) {
  7.       return getDefaultValue();
  8.     }
  9.     dataInputView.setBuffer(valueBytes);
  10.     return valueSerializer.deserialize(dataInputView);
  11.   } catch (IOException | RocksDBException e) {
  12.     throw new FlinkRuntimeException("Error while retrieving data from RocksDB.", e);
  13.   }
  14. }

代码示例来源：origin: apache/storm

  1. private String metadataIdToString(KeyType type, int id, Map<Integer, String> lookupCache) throws MetricException {
  2.   String s = readOnlyStringMetadataCache.getMetadataString(id);
  3.   if (s != null) {
  4.     return s;
  5.   }
  6.   s = lookupCache.get(id);
  7.   if (s != null) {
  8.     return s;
  9.   }
  10.   // get from DB and add to lookup cache
  11.   RocksDbKey key = new RocksDbKey(type, id);
  12.   try {
  13.     byte[] value = db.get(key.getRaw());
  14.     if (value == null) {
  15.       throw new MetricException("Failed to find metadata string for id " + id + " of type " + type);
  16.     }
  17.     RocksDbValue rdbValue = new RocksDbValue(value);
  18.     s = rdbValue.getMetdataString();
  19.     lookupCache.put(id, s);
  20.     return s;
  21.   } catch (RocksDBException e) {
  22.     if (this.failureMeter != null) {
  23.       this.failureMeter.mark();
  24.     }
  25.     throw new MetricException("Failed to get from RocksDb", e);
  26.   }
  27. }

代码示例来源：origin: apache/flink

  1. @Override
  2. public void mergeNamespaces(N target, Collection<N> sources) {
  3.   if (sources == null || sources.isEmpty()) {
  4.     return;
  5.   }
  6.   try {
  7.     // create the target full-binary-key
  8.     setCurrentNamespace(target);
  9.     final byte[] targetKey = serializeCurrentKeyWithGroupAndNamespace();
  10.     // merge the sources to the target
  11.     for (N source : sources) {
  12.       if (source != null) {
  13.         setCurrentNamespace(source);
  14.         final byte[] sourceKey = serializeCurrentKeyWithGroupAndNamespace();
  15.         byte[] valueBytes = backend.db.get(columnFamily, sourceKey);
  16.         backend.db.delete(columnFamily, writeOptions, sourceKey);
  17.         if (valueBytes != null) {
  18.           backend.db.merge(columnFamily, writeOptions, targetKey, valueBytes);
  19.         }
  20.       }
  21.     }
  22.   }
  23.   catch (Exception e) {
  24.     throw new FlinkRuntimeException("Error while merging state in RocksDB", e);
  25.   }
  26. }

代码示例来源：origin: apache/flink

  1. @Override
  2. public byte[] getSerializedValue(
  3.     final byte[] serializedKeyAndNamespace,
  4.     final TypeSerializer<K> safeKeySerializer,
  5.     final TypeSerializer<N> safeNamespaceSerializer,
  6.     final TypeSerializer<V> safeValueSerializer) throws Exception {
  7.   //TODO make KvStateSerializer key-group aware to save this round trip and key-group computation
  8.   Tuple2<K, N> keyAndNamespace = KvStateSerializer.deserializeKeyAndNamespace(
  9.       serializedKeyAndNamespace, safeKeySerializer, safeNamespaceSerializer);
  10.   int keyGroup = KeyGroupRangeAssignment.assignToKeyGroup(keyAndNamespace.f0, backend.getNumberOfKeyGroups());
  11.   RocksDBSerializedCompositeKeyBuilder<K> keyBuilder =
  12.           new RocksDBSerializedCompositeKeyBuilder<>(
  13.             safeKeySerializer,
  14.             backend.getKeyGroupPrefixBytes(),
  15.             32
  16.           );
  17.   keyBuilder.setKeyAndKeyGroup(keyAndNamespace.f0, keyGroup);
  18.   byte[] key = keyBuilder.buildCompositeKeyNamespace(keyAndNamespace.f1, namespaceSerializer);
  19.   return backend.db.get(columnFamily, key);
  20. }

代码示例来源：origin: apache/flink

  1. setCurrentNamespace(source);
  2.   final byte[] sourceKey = serializeCurrentKeyWithGroupAndNamespace();
  3.   final byte[] valueBytes = backend.db.get(columnFamily, sourceKey);
  4.   backend.db.delete(columnFamily, writeOptions, sourceKey);
  5. final byte[] targetValueBytes = backend.db.get(columnFamily, targetKey);

代码示例来源：origin: apache/flink

  1. setCurrentNamespace(source);
  2.   final byte[] sourceKey = serializeCurrentKeyWithGroupAndNamespace();
  3.   final byte[] valueBytes = backend.db.get(columnFamily, sourceKey);
  4.   backend.db.delete(columnFamily, writeOptions, sourceKey);
  5. final byte[] targetValueBytes = backend.db.get(columnFamily, targetKey);

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