com.github.ambry.commons.BlobId.java Source code

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Here is the source code for com.github.ambry.commons.BlobId.java

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/**
 * Copyright 2016 LinkedIn Corp. All rights reserved.
 *
 * Licensed 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.
 */
package com.github.ambry.commons;

import com.github.ambry.clustermap.ClusterMap;
import com.github.ambry.clustermap.PartitionId;
import com.github.ambry.store.StoreKey;
import com.github.ambry.utils.ByteBufferInputStream;
import com.github.ambry.utils.Utils;

import java.io.DataInputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.UUID;
import org.apache.commons.codec.binary.Base64;

/**
 * BlobId uniquely identifies a stored blob as well as the Partition in which the blob is stored.
 */
public class BlobId extends StoreKey {
    private Short version = 1;
    private static short Version_Size_In_Bytes = 2;
    private PartitionId partitionId;
    private String uuid;
    private static int UUID_Size_In_Bytes = 4;

    /**
     * Constructs a new unique BlobId for the specified partition.
     *
     * @param partitionId of Partition in which blob is to be stored.
     */
    public BlobId(PartitionId partitionId) {
        this.partitionId = partitionId;
        this.uuid = UUID.randomUUID().toString();
    }

    /**
     * Re-constructs existing blobId by deserializing from BlobId "string"
     *
     * @param id of Blob as output by BlobId.getID()
     * @param clusterMap of the cluster that the blob id belongs to
     * @throws IOException
     */
    public BlobId(String id, ClusterMap clusterMap) throws IOException {
        this(new DataInputStream(new ByteBufferInputStream(ByteBuffer.wrap(Base64.decodeBase64(id)))), clusterMap);
    }

    /**
     * Re-constructs existing blobId by deserializing from data input stream
     *
     * @param stream from which to deserialize the blobid
     * @param clusterMap of the cluster that the blob id belongs to
     * @throws IOException
     */
    public BlobId(DataInputStream stream, ClusterMap clusterMap) throws IOException {
        this.version = stream.readShort();
        if (version == 1) {
            this.partitionId = clusterMap.getPartitionIdFromStream(stream);
            uuid = Utils.readIntString(stream);
        } else {
            throw new IllegalArgumentException("version " + version + " not supported for blob id");
        }
    }

    public short sizeInBytes() {
        return (short) (Version_Size_In_Bytes + partitionId.getBytes().length + UUID_Size_In_Bytes + uuid.length());
    }

    public PartitionId getPartition() {
        return partitionId;
    }

    @Override
    public byte[] toBytes() {
        ByteBuffer idBuf = ByteBuffer.allocate(sizeInBytes());
        idBuf.putShort(version);
        idBuf.put(partitionId.getBytes());
        idBuf.putInt(uuid.getBytes().length);
        idBuf.put(uuid.getBytes());
        return idBuf.array();
    }

    @Override
    public String getID() {
        return Base64.encodeBase64URLSafeString(toBytes());
    }

    @Override
    public String getLongForm() {
        StringBuilder sb = new StringBuilder();
        sb.append("[").append(getID());
        sb.append(":").append(version);
        sb.append(":").append(partitionId);
        sb.append(":").append(uuid).append("]");
        return sb.toString();
    }

    @Override
    public String toString() {
        return getID();
    }

    @Override
    public int compareTo(StoreKey o) {
        BlobId other = (BlobId) o;

        int result = version.compareTo(other.version);
        if (result == 0) {
            result = partitionId.compareTo(other.partitionId);
            if (result == 0) {
                result = uuid.compareTo(other.uuid);
            }
        }
        return result;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        BlobId blobId = (BlobId) o;

        if (!version.equals(blobId.version)) {
            return false;
        }
        if (!partitionId.equals(blobId.partitionId)) {
            return false;
        }
        if (!uuid.equals(blobId.uuid)) {
            return false;
        }

        return true;
    }

    @Override
    public int hashCode() {
        return Utils.hashcode(new Object[] { version, partitionId, uuid });
    }
}