/*
* The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
* (the "License"). You may not use this work except in compliance with the License, which is
* available at www.apache.org/licenses/LICENSE-2.0
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
* either express or implied, as more fully set forth in the License.
*
* See the NOTICE file distributed with this work for information regarding copyright ownership.
*/
package alluxio.client.keyvalue;
import alluxio.AlluxioURI;
import alluxio.client.file.FileSystemContext;
import alluxio.exception.AlluxioException;
import alluxio.thrift.PartitionInfo;
import alluxio.util.io.BufferUtils;
import com.google.common.base.Preconditions;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.util.List;
import javax.annotation.concurrent.NotThreadSafe;
/**
* Default implementation of {@link KeyValueStoreReader} to access an Alluxio key-value store.
*/
@NotThreadSafe
class BaseKeyValueStoreReader implements KeyValueStoreReader {
private static final Logger LOG = LoggerFactory.getLogger(BaseKeyValueStoreReader.class);
private final InetSocketAddress mMasterAddress = FileSystemContext.INSTANCE.getMasterAddress();
private final KeyValueMasterClient mMasterClient;
/** A list of partitions of the store. */
private final List<PartitionInfo> mPartitions;
/**
* Constructs a {@link BaseKeyValueStoreReader} instance.
*
* @param uri URI of the key-value store
*/
BaseKeyValueStoreReader(AlluxioURI uri) throws IOException {
// TODO(binfan): use a thread pool to manage the client.
LOG.info("Create KeyValueStoreReader for {}", uri);
mMasterClient = new KeyValueMasterClient(mMasterAddress);
mPartitions = mMasterClient.getPartitionInfo(uri);
mMasterClient.close();
}
@Override
public void close() {
}
@Override
public byte[] get(byte[] key) throws IOException, AlluxioException {
ByteBuffer value = get(ByteBuffer.wrap(key));
if (value == null) {
return null;
}
return BufferUtils.newByteArrayFromByteBuffer(value);
}
@Override
public ByteBuffer get(ByteBuffer key) throws IOException, AlluxioException {
Preconditions.checkNotNull(key);
int left = 0;
int right = mPartitions.size();
while (left < right) {
int middle = (right + left) / 2;
PartitionInfo partition = mPartitions.get(middle);
// NOTE: keyStart and keyLimit are both inclusive
if (key.compareTo(partition.bufferForKeyStart()) < 0) {
right = middle;
} else if (key.compareTo(partition.bufferForKeyLimit()) > 0) {
left = middle + 1;
} else {
// The key is either in this partition or not in the key-value store
long blockId = partition.getBlockId();
try (KeyValuePartitionReader reader = KeyValuePartitionReader.Factory.create(blockId)) {
return reader.get(key);
}
}
}
return null;
}
@Override
public KeyValueIterator iterator() throws IOException, AlluxioException {
return new KeyValueStoreIterator(mPartitions);
}
@Override
public int size() throws IOException, AlluxioException {
int totalSize = 0;
for (PartitionInfo partition : mPartitions) {
totalSize += partition.getKeyCount();
}
return totalSize;
}
}