001// Licensed under the Apache License, Version 2.0 (the "License");
002// you may not use this file except in compliance with the License.
003// You may obtain a copy of the License at
004//
005// http://www.apache.org/licenses/LICENSE-2.0
006//
007// Unless required by applicable law or agreed to in writing, software
008// distributed under the License is distributed on an "AS IS" BASIS,
009// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
010// See the License for the specific language governing permissions and
011// limitations under the License.
012
013package org.apache.tapestry5.internal.services.assets;
014
015import org.apache.tapestry5.ContentType;
016import org.apache.tapestry5.internal.TapestryInternalUtils;
017import org.apache.tapestry5.ioc.Resource;
018import org.apache.tapestry5.ioc.internal.util.CollectionFactory;
019import org.apache.tapestry5.services.assets.*;
020
021import java.io.ByteArrayOutputStream;
022import java.io.IOException;
023import java.io.InputStream;
024import java.util.Map;
025import java.util.Set;
026
027public class StreamableResourceSourceImpl implements StreamableResourceSource
028{
029    private final Map<String, ResourceTransformer> configuration;
030
031    private final ContentTypeAnalyzer contentTypeAnalyzer;
032
033    private final CompressionAnalyzer compressionAnalyzer;
034
035    private final ResourceChangeTracker resourceChangeTracker;
036
037    private final AssetChecksumGenerator checksumGenerator;
038
039    public StreamableResourceSourceImpl(Map<String, ResourceTransformer> configuration,
040                                        ContentTypeAnalyzer contentTypeAnalyzer, CompressionAnalyzer compressionAnalyzer,
041                                        ResourceChangeTracker resourceChangeTracker, AssetChecksumGenerator checksumGenerator)
042    {
043        this.configuration = configuration;
044        this.contentTypeAnalyzer = contentTypeAnalyzer;
045        this.compressionAnalyzer = compressionAnalyzer;
046        this.resourceChangeTracker = resourceChangeTracker;
047        this.checksumGenerator = checksumGenerator;
048    }
049
050    public Set<String> fileExtensionsForContentType(ContentType contentType)
051    {
052        Set<String> result = CollectionFactory.newSet();
053
054        for (Map.Entry<String, ResourceTransformer> me : configuration.entrySet())
055        {
056            if (me.getValue().getTransformedContentType().equals(contentType))
057            {
058                result.add(me.getKey());
059            }
060        }
061
062        return result;
063    }
064
065    public StreamableResource getStreamableResource(Resource baseResource, StreamableResourceProcessing processing, ResourceDependencies dependencies)
066            throws IOException
067    {
068        assert baseResource != null;
069
070        if (!baseResource.exists())
071        {
072            throw new IOException(String.format("Resource %s does not exist.", baseResource));
073        }
074
075        String fileSuffix = TapestryInternalUtils.toFileSuffix(baseResource.getFile());
076
077        // Optionally, transform the resource. The main driver for this is to allow
078        // for libraries like LessJS (http://lesscss.org/) or
079        // http://jashkenas.github.com/coffee-script/
080        ResourceTransformer rt = configuration.get(fileSuffix);
081
082        InputStream transformed = rt == null ? baseResource.openStream() : rt.transform(baseResource, dependencies);
083
084        assert transformed != null;
085
086        BytestreamCache bytestreamCache = readStream(transformed);
087
088        transformed.close();
089
090        ContentType contentType = rt == null
091                ? new ContentType(contentTypeAnalyzer.getContentType(baseResource))
092                : rt.getTransformedContentType();
093
094        boolean compressable = compressionAnalyzer.isCompressable(contentType.getMimeType());
095
096        long lastModified = resourceChangeTracker.trackResource(baseResource);
097
098        return new StreamableResourceImpl(baseResource.toString(), contentType, compressable ? CompressionStatus.COMPRESSABLE
099                : CompressionStatus.NOT_COMPRESSABLE, lastModified, bytestreamCache, checksumGenerator, null);
100    }
101
102    private BytestreamCache readStream(InputStream stream) throws IOException
103    {
104        ByteArrayOutputStream bos = new ByteArrayOutputStream();
105
106        TapestryInternalUtils.copy(stream, bos);
107
108        stream.close();
109
110        return new BytestreamCache(bos);
111    }
112
113}