org.apache.hudi.common.model.HoodieConsistentHashingMetadata Maven / Gradle / Ivy
The newest version!
/*
* 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.hudi.common.model;
import org.apache.hudi.common.table.timeline.HoodieTimeline;
import org.apache.hudi.common.util.JsonUtils;
import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.fasterxml.jackson.annotation.JsonProperty;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.io.Serializable;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;
import static org.apache.hudi.common.util.StringUtils.fromUTF8Bytes;
import static org.apache.hudi.common.util.StringUtils.getUTF8Bytes;
/**
* All the metadata that is used for consistent hashing bucket index
*/
@JsonIgnoreProperties(ignoreUnknown = true)
public class HoodieConsistentHashingMetadata implements Serializable {
private static final Logger LOG = LoggerFactory.getLogger(HoodieConsistentHashingMetadata.class);
/**
* Upper-bound of the hash value
*/
public static final int HASH_VALUE_MASK = Integer.MAX_VALUE;
public static final String HASHING_METADATA_FILE_SUFFIX = ".hashing_meta";
public static final String HASHING_METADATA_COMMIT_FILE_SUFFIX = ".commit";
private final short version;
private final String partitionPath;
private final String instant;
private final int numBuckets;
private final int seqNo;
private final List nodes;
@JsonIgnore
protected List childrenNodes = new ArrayList<>();
/**
* Used to indicate if the metadata is newly created, rather than read from the storage.
*/
@JsonIgnore
private boolean firstCreated;
@JsonCreator
public HoodieConsistentHashingMetadata(@JsonProperty("version") short version, @JsonProperty("partitionPath") String partitionPath,
@JsonProperty("instant") String instant, @JsonProperty("numBuckets") int numBuckets,
@JsonProperty("seqNo") int seqNo, @JsonProperty("nodes") List nodes) {
this.version = version;
this.partitionPath = partitionPath;
this.instant = instant;
this.numBuckets = numBuckets;
this.seqNo = seqNo;
this.nodes = nodes;
this.firstCreated = false;
}
/**
* Only used for creating new hashing metadata.
* Construct default metadata with all bucket's file group uuid initialized
*/
public HoodieConsistentHashingMetadata(String partitionPath, int numBuckets) {
this((short) 0, partitionPath, HoodieTimeline.INIT_INSTANT_TS, numBuckets, 0, constructDefaultHashingNodes(partitionPath, numBuckets));
this.firstCreated = true;
}
private static List constructDefaultHashingNodes(String partitionPath, int numBuckets) {
long step = ((long) HASH_VALUE_MASK + numBuckets - 1) / numBuckets;
long bucketStart = 0;
List nodes = new ArrayList<>(numBuckets);
for (int idx = 1; idx < numBuckets + 1; idx++) {
long bucketEnd = Math.min(step * idx, HASH_VALUE_MASK);
String fileId = generateUUID(partitionPath, bucketStart, bucketEnd);
nodes.add(new ConsistentHashingNode((int) bucketEnd, fileId));
bucketStart = bucketEnd;
}
return nodes;
}
private static String generateUUID(String partitionPath, long bucketStart, long bucketEnd) {
ByteBuffer byteBuffer = ByteBuffer.allocate(16);
byteBuffer.putLong(bucketStart);
byteBuffer.putLong(bucketEnd);
byte[] longBytes = byteBuffer.array();
byte[] partitionPathBytes = getUTF8Bytes(partitionPath);
byte[] combinedBytes = new byte[longBytes.length + partitionPathBytes.length];
System.arraycopy(longBytes, 0, combinedBytes, 0, longBytes.length);
System.arraycopy(partitionPathBytes, 0, combinedBytes, longBytes.length, partitionPathBytes.length);
return UUID.nameUUIDFromBytes(combinedBytes).toString();
}
public short getVersion() {
return version;
}
public String getPartitionPath() {
return partitionPath;
}
public String getInstant() {
return instant;
}
public int getNumBuckets() {
return numBuckets;
}
public int getSeqNo() {
return seqNo;
}
public boolean isFirstCreated() {
return firstCreated;
}
public List getNodes() {
return nodes;
}
public List getChildrenNodes() {
return childrenNodes;
}
public void setChildrenNodes(List childrenNodes) {
this.childrenNodes = childrenNodes;
}
public String getFilename() {
return instant + HASHING_METADATA_FILE_SUFFIX;
}
public byte[] toBytes() throws IOException {
return getUTF8Bytes(toJsonString());
}
public static HoodieConsistentHashingMetadata fromBytes(byte[] bytes) throws IOException {
try {
return fromJsonString(fromUTF8Bytes(bytes), HoodieConsistentHashingMetadata.class);
} catch (Exception e) {
throw new IOException("unable to read hashing metadata", e);
}
}
private String toJsonString() throws IOException {
return JsonUtils.getObjectMapper().writerWithDefaultPrettyPrinter().writeValueAsString(this);
}
protected static T fromJsonString(String jsonStr, Class clazz) throws Exception {
if (jsonStr == null || jsonStr.isEmpty()) {
// For empty commit file (no data or something bad happen).
return clazz.newInstance();
}
return JsonUtils.getObjectMapper().readValue(jsonStr, clazz);
}
/**
* Get instant time from the hashing metadata filename
* Pattern of the filename: .HASHING_METADATA_FILE_SUFFIX
*/
public static String getTimestampFromFile(String filename) {
return filename.split("\\.")[0];
}
}