org.apache.hadoop.hdfs.server.namenode.INodeSymlink.java Source code

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Here is the source code for org.apache.hadoop.hdfs.server.namenode.INodeSymlink.java

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/**
 * 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.hadoop.hdfs.server.namenode;

import java.io.PrintWriter;

import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.fs.permission.PermissionStatus;
import org.apache.hadoop.hdfs.DFSUtil;
import org.apache.hadoop.hdfs.server.blockmanagement.BlockStoragePolicySuite;
import org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot;

/**
 * An {@link INode} representing a symbolic link.
 */
@InterfaceAudience.Private
public class INodeSymlink extends INodeWithAdditionalFields {
    private final byte[] symlink; // The target URI

    INodeSymlink(long id, byte[] name, PermissionStatus permissions, long mtime, long atime, String symlink) {
        super(id, name, permissions, mtime, atime);
        this.symlink = DFSUtil.string2Bytes(symlink);
    }

    INodeSymlink(INodeSymlink that) {
        super(that);
        this.symlink = that.symlink;
    }

    @Override
    void recordModification(int latestSnapshotId) {
        if (isInLatestSnapshot(latestSnapshotId)) {
            INodeDirectory parent = getParent();
            parent.saveChild2Snapshot(this, latestSnapshotId, new INodeSymlink(this));
        }
    }

    /** @return true unconditionally. */
    @Override
    public boolean isSymlink() {
        return true;
    }

    /** @return this object. */
    @Override
    public INodeSymlink asSymlink() {
        return this;
    }

    public String getSymlinkString() {
        return DFSUtil.bytes2String(symlink);
    }

    public byte[] getSymlink() {
        return symlink;
    }

    @Override
    public void cleanSubtree(ReclaimContext reclaimContext, final int snapshotId, int priorSnapshotId) {
        if (snapshotId == Snapshot.CURRENT_STATE_ID && priorSnapshotId == Snapshot.NO_SNAPSHOT_ID) {
            destroyAndCollectBlocks(reclaimContext);
        }
    }

    @Override
    public void destroyAndCollectBlocks(ReclaimContext reclaimContext) {
        reclaimContext.removedINodes.add(this);
        reclaimContext.quotaDelta().add(new QuotaCounts.Builder().nameSpace(1).build());
    }

    @Override
    public QuotaCounts computeQuotaUsage(BlockStoragePolicySuite bsps, byte blockStoragePolicyId, boolean useCache,
            int lastSnapshotId) {
        return new QuotaCounts.Builder().nameSpace(1).build();
    }

    @Override
    public ContentSummaryComputationContext computeContentSummary(int snapshotId,
            final ContentSummaryComputationContext summary) {
        summary.getCounts().addContent(Content.SYMLINK, 1);
        return summary;
    }

    @Override
    public void dumpTreeRecursively(PrintWriter out, StringBuilder prefix, final int snapshot) {
        super.dumpTreeRecursively(out, prefix, snapshot);
        out.println();
    }

    @Override
    public void removeAclFeature() {
        throw new UnsupportedOperationException("ACLs are not supported on symlinks");
    }

    @Override
    public void addAclFeature(AclFeature f) {
        throw new UnsupportedOperationException("ACLs are not supported on symlinks");
    }

    @Override
    final XAttrFeature getXAttrFeature(int snapshotId) {
        throw new UnsupportedOperationException("XAttrs are not supported on symlinks");
    }

    @Override
    public void removeXAttrFeature() {
        throw new UnsupportedOperationException("XAttrs are not supported on symlinks");
    }

    @Override
    public void addXAttrFeature(XAttrFeature f) {
        throw new UnsupportedOperationException("XAttrs are not supported on symlinks");
    }

    @Override
    public byte getStoragePolicyID() {
        throw new UnsupportedOperationException("Storage policy are not supported on symlinks");
    }

    @Override
    public byte getLocalStoragePolicyID() {
        throw new UnsupportedOperationException("Storage policy are not supported on symlinks");
    }
}