org.pentaho.di.core.vfs.ConcurrentFileSystemManager.java Source code

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Here is the source code for org.pentaho.di.core.vfs.ConcurrentFileSystemManager.java

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/*! ******************************************************************************
 *
 * Pentaho Data Integration
 *
 * Copyright (C) 2002-2018 by Hitachi Vantara : http://www.pentaho.com
 *
 *******************************************************************************
 *
 * 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.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 ******************************************************************************/

package org.pentaho.di.core.vfs;

import org.apache.commons.vfs2.Capability;
import org.apache.commons.vfs2.FileName;
import org.apache.commons.vfs2.FileObject;
import org.apache.commons.vfs2.FileSystem;
import org.apache.commons.vfs2.FileSystemConfigBuilder;
import org.apache.commons.vfs2.FileSystemException;
import org.apache.commons.vfs2.FileSystemOptions;
import org.apache.commons.vfs2.NameScope;
import org.apache.commons.vfs2.impl.StandardFileSystemManager;
import org.apache.commons.vfs2.provider.FileProvider;
import org.pentaho.di.core.osgi.api.VfsEmbeddedFileSystemCloser;

import java.util.Collection;
import java.util.Map;
import java.util.concurrent.locks.ReentrantReadWriteLock;

/**
 * This class is aimed to be a thread-safe version of
 * {@link org.apache.commons.vfs2.impl.StandardFileSystemManager StandardFileSystemManager}.
 * It locks methods that accessing or mutating the providers Map in
 * {@link org.apache.commons.vfs2.impl.DefaultFileSystemManager DefaultFileSystemManager}.
 */
public class ConcurrentFileSystemManager extends StandardFileSystemManager {

    private static final String CONFIG_RESOURCE = "providers.xml";

    private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();

    public ConcurrentFileSystemManager() {
        setConfiguration(this.getClass().getResource(CONFIG_RESOURCE));
    }

    @Override
    public void addProvider(String[] urlSchemes, FileProvider provider) throws FileSystemException {
        lock.writeLock().lock();
        try {
            super.addProvider(urlSchemes, provider);
        } finally {
            lock.writeLock().unlock();
        }
    }

    @Override
    public String[] getSchemes() {
        lock.readLock().lock();
        try {
            return super.getSchemes();
        } finally {
            lock.readLock().unlock();
        }
    }

    @Override
    public boolean hasProvider(String scheme) {
        lock.readLock().lock();
        try {
            return super.hasProvider(scheme);
        } finally {
            lock.readLock().unlock();
        }
    }

    @Override
    public FileObject resolveFile(FileObject baseFile, String uri, FileSystemOptions fileSystemOptions)
            throws FileSystemException {
        lock.readLock().lock();
        try {
            return super.resolveFile(baseFile, uri, fileSystemOptions);
        } finally {
            lock.readLock().unlock();
        }
    }

    @Override
    public FileName resolveName(FileName base, String name, NameScope scope) throws FileSystemException {
        lock.readLock().lock();
        try {
            return super.resolveName(base, name, scope);
        } finally {
            lock.readLock().unlock();
        }
    }

    @Override
    public FileName resolveURI(String uri) throws FileSystemException {
        lock.readLock().lock();
        try {
            return super.resolveURI(uri);
        } finally {
            lock.readLock().unlock();
        }
    }

    @Override
    public FileObject createFileSystem(String scheme, FileObject file) throws FileSystemException {
        lock.readLock().lock();
        try {
            return super.createFileSystem(scheme, file);
        } finally {
            lock.readLock().unlock();
        }
    }

    @Override
    public void _closeFileSystem(FileSystem filesystem) {
        lock.readLock().lock();
        try {
            super._closeFileSystem(filesystem);
        } finally {
            lock.readLock().unlock();
        }
    }

    @Override
    public Collection<Capability> getProviderCapabilities(String scheme) throws FileSystemException {
        lock.readLock().lock();
        try {
            return super.getProviderCapabilities(scheme);
        } finally {
            lock.readLock().unlock();
        }
    }

    @Override
    public FileSystemConfigBuilder getFileSystemConfigBuilder(String scheme) throws FileSystemException {
        lock.readLock().lock();
        try {
            return super.getFileSystemConfigBuilder(scheme);
        } finally {
            lock.readLock().unlock();
        }
    }

    @Override
    public void close() {
        lock.writeLock().lock();
        try {
            super.close();
        } finally {
            lock.writeLock().unlock();
        }
    }

    @Override
    public void freeUnusedResources() {
        lock.readLock().lock();
        try {
            super.freeUnusedResources();
        } finally {
            lock.readLock().unlock();
        }
    }

    public void closeEmbeddedFileSystem(String embeddedMetastoreKey) {
        lock.readLock().lock();
        Map<String, FileProvider> providers;
        try {
            // Close the file system
            java.lang.reflect.Field field = null;
            try {
                field = this.getClass().getSuperclass().getSuperclass().getDeclaredField("providers");
                field.setAccessible(true);
            } catch (NoSuchFieldException e) {
                e.printStackTrace();
            }
            providers = (Map<String, FileProvider>) field.get(this);
            FileProvider provider = providers.get("hc");
            if (provider != null) {
                ((VfsEmbeddedFileSystemCloser) provider).closeFileSystem(embeddedMetastoreKey);
            }
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } finally {
            lock.readLock().unlock();
        }
    }
}