io.hops.resolvingcache.INodeMemcache.java Source code

Introduction

Here is the source code for io.hops.resolvingcache.INodeMemcache.java

Source

/**
 * 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.hdfs.server.namenode.INode;
import org.apache.hadoop.hdfs.server.namenode.INodeDirectory;

import java.io.IOException;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;

public class INodeMemcache extends Memcache {

    @Override
    protected void setInternal(MemcachedClient mc, String path, List<INode> inodes) {
        for (INode inode : inodes) {
            setInternal(mc, inode);
        }
    }

    @Override
    protected int[] getInternal(MemcachedClient mc, String path) throws IOException {
        String[] pathComponents = INode.getPathNames(path);
        int[] inodeIds = new int[pathComponents.length];
        int parentId = INodeDirectory.ROOT_PARENT_ID;
        int index = 0;
        while (index < pathComponents.length) {
            String cmp = pathComponents[index];
            Integer inodeId = getInternal(mc, cmp, parentId);
            if (inodeId != null) {
                parentId = inodeId;
                inodeIds[index] = inodeId;
            } else {
                break;
            }
            index++;
        }

        //only the root was found
        if (index <= 1)
            return null;

        return Arrays.copyOf(inodeIds, index);
    }

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

    @Override
    protected void deleteInternal(MemcachedClient mc, String path) {
        throw new UnsupportedOperationException();
    }

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

    private String getKey(INode inode) {
        return getKey(keyPrefix, inode);
    }

    private Integer getInternal(MemcachedClient mc, String name, Integer parentId) {
        return getInternal(mc, keyPrefix, name, parentId);
    }

    private static String getKey(String KEY_PREFIX, INode inode) {
        return KEY_PREFIX + inode.nameParentKey();
    }

    private static String getKey(String KEY_PREFIX, String name, Integer parentId) {
        return KEY_PREFIX + INode.nameParentKey(parentId, name);
    }

    static Integer getInternal(MemcachedClient mc, String KEY_PREFIX, String name, Integer parentId) {
        Integer inodeId = null;
        Future<Object> f = mc.asyncGet(getKey(KEY_PREFIX, name, parentId));
        try {
            Object res = f.get(1, TimeUnit.SECONDS);
            if (res instanceof Integer) {
                inodeId = (Integer) res;
            }
        } catch (Exception ex) {
            LOG.error(ex);
            f.cancel(true);
        }
        return inodeId;
    }

    static void setInternal(MemcachedClient mc, String KEY_PREFIX, int KEY_EXPIRY, INode inode) {
        mc.set(getKey(KEY_PREFIX, inode), KEY_EXPIRY, inode.getId());
    }

    static void deleteInternal(MemcachedClient mc, String KEY_PREFIX, INode inode) {
        mc.delete(getKey(KEY_PREFIX, inode));
    }

    @Override
    protected int getRoundTrips(String path) {
        return INode.getPathNames(path).length;
    }

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