io.hops.resolvingcache.OptimalMemcache.java Source code

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Here is the source code for io.hops.resolvingcache.OptimalMemcache.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 io.hops.resolvingcache;

import net.spy.memcached.MemcachedClient;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.server.namenode.INode;

import java.io.IOException;
import java.util.Arrays;
import java.util.List;

public class OptimalMemcache extends PathMemcache {
    @Override
    protected void setInternal(MemcachedClient mc, String path, List<INode> inodes) {
        if (INode.getPathNames(path).length != inodes.size())
            return;

        int lastIndex = path.lastIndexOf(Path.SEPARATOR);
        if (lastIndex <= 0)
            return;

        INode file = inodes.get(inodes.size() - 1);
        if (file.isDirectory()) {
            super.setInternal(mc, path, inodes);
            return;
        }

        String parentPath = path.substring(0, lastIndex);
        super.setInternal(mc, parentPath, inodes.subList(0, inodes.size() - 1));
        setInternal(mc, file);
    }

    @Override
    protected int[] getInternal(MemcachedClient mc, String path) throws IOException {
        int lastIndex = path.lastIndexOf(Path.SEPARATOR);
        if (lastIndex <= 0)
            return null;

        String parentPath = path.substring(0, lastIndex);
        int[] inodeIds = super.getInternal(mc, parentPath);
        if (inodeIds == null)
            return null;

        String file = path.substring(lastIndex + 1, path.length());
        int fileParentId = inodeIds[inodeIds.length - 1];
        Integer fileInodeId = INodeMemcache.getInternal(mc, keyPrefix, file, fileParentId);
        if (fileInodeId != null) {
            inodeIds = Arrays.copyOf(inodeIds, inodeIds.length + 1);
            inodeIds[inodeIds.length - 1] = fileInodeId;
        }
        return inodeIds;
    }

    @Override
    protected void setInternal(MemcachedClient mc, INode inode) {
        INodeMemcache.setInternal(mc, keyPrefix, keyExpiry, inode);
    }

    @Override
    protected void deleteInternal(MemcachedClient mc, String path) {
        int lastIndex = path.lastIndexOf(Path.SEPARATOR);
        if (lastIndex == -1)
            return;
        String parentPath = path.substring(0, lastIndex);
        super.deleteInternal(mc, parentPath);
    }

    @Override
    protected void deleteInternal(MemcachedClient mc, INode inode) {
        INodeMemcache.deleteInternal(mc, keyPrefix, inode);
    }

    @Override
    protected int getRoundTrips(String path) {
        return 2;
    }

    @Override
    protected int getRoundTrips(List<INode> inodes) {
        return 2;
    }
}