Deferred.java

/*
 * Copyright 2014 The Codehaus Foundation.
 *
 * 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.codehaus.plexus.components.io.resources;

import org.apache.commons.io.IOUtils;
import org.apache.commons.io.output.DeferredFileOutputStream;
import org.codehaus.plexus.components.io.functions.ContentSupplier;
import org.codehaus.plexus.components.io.functions.NameSupplier;
import org.codehaus.plexus.components.io.functions.SizeSupplier;
import org.codehaus.plexus.components.io.resources.proxy.ProxyFactory;

import javax.annotation.Nonnull;
import java.io.ByteArrayInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

class Deferred implements ContentSupplier, NameSupplier, SizeSupplier
{
    final DeferredFileOutputStream dfos;

    final PlexusIoResource resource;

    final PlexusIoResourceCollection owner;

    public Deferred( final PlexusIoResource resource, PlexusIoResourceCollection owner, boolean hasTransformer )
        throws IOException
    {
        this.resource = resource;
        this.owner = owner;
        dfos = hasTransformer ? new DeferredFileOutputStream( 5000000, "p-archiver", null, null ) : null;
        if ( dfos != null )
        {
            InputStream inputStream = owner.getInputStream( resource );
            IOUtils.copy( inputStream, dfos );
            IOUtils.closeQuietly( inputStream );
        }

    }

    @Nonnull
    public InputStream getContents()
        throws IOException
    {
        if ( dfos == null )
        {
            return resource.getContents();
        }
        if ( dfos.isInMemory() )
        {
            return new ByteArrayInputStream( dfos.getData() );
        }
        else
        {
            return new FileInputStream( dfos.getFile() ){
                @Override
                public void close()
                    throws IOException
                {
                    super.close();
                    dfos.getFile().delete();
                }
            };
        }
    }

    public long getSize()
    {
        if ( dfos == null )
        {
            return resource.getSize();
        }
        if ( dfos.isInMemory() )
        {
            return dfos.getByteCount();
        }
        else
        {
            return dfos.getFile().length();
        }
    }

    public String getName()
    {
        return owner.getName( resource );
    }


    public PlexusIoResource asResource()
    {
        return ProxyFactory.createProxy( resource,  Deferred.this);
    }

}