org.glassfish.grizzly.http.server.CompressionEncodingFilter Maven / Gradle / Ivy

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package org.glassfish.grizzly.http.server;

import org.glassfish.grizzly.http.CompressionConfig;
import org.glassfish.grizzly.http.CompressionConfig.CompressionMode;
import org.glassfish.grizzly.http.CompressionConfig.CompressionModeI;
import org.glassfish.grizzly.http.EncodingFilter;
import org.glassfish.grizzly.http.HttpHeader;
import org.glassfish.grizzly.http.HttpRequestPacket;
import org.glassfish.grizzly.http.HttpResponsePacket;
import org.glassfish.grizzly.http.util.DataChunk;
import org.glassfish.grizzly.http.util.Header;
import org.glassfish.grizzly.http.util.MimeHeaders;

import java.util.Arrays;


public class CompressionEncodingFilter implements EncodingFilter {
    private final CompressionConfig compressionConfig;
    private final String[] aliases;

    public CompressionEncodingFilter(final CompressionConfig compressionConfig,
            final String[] aliases) {
        this.compressionConfig = new CompressionConfig(compressionConfig);
        this.aliases = Arrays.copyOf(aliases, aliases.length);
    }
    
    /**
     * 
     * @param compressionMode
     * @param compressionMinSize
     * @param compressableMimeTypes
     * @param noCompressionUserAgents
     * @param aliases 
     */
    public CompressionEncodingFilter(CompressionModeI compressionMode,
            int compressionMinSize,
            String[] compressableMimeTypes,
            String[] noCompressionUserAgents,
            String[] aliases) {
        
        final CompressionMode mode;
        if (compressionMode instanceof CompressionMode) {
            mode = (CompressionMode) compressionMode;
        } else {
            // backwards compatibility
            assert (compressionMode instanceof CompressionLevel);
            mode = ((CompressionLevel) compressionMode).normalize();
        }

        compressionConfig = new CompressionConfig(mode, compressionMinSize,
                null, null);
        compressionConfig.setCompressableMimeTypes(compressableMimeTypes);
        compressionConfig.setNoCompressionUserAgents(noCompressionUserAgents);
        
        this.aliases = Arrays.copyOf(aliases, aliases.length);
    }

    @Override
    public boolean applyEncoding(final HttpHeader httpPacket) {
        if (httpPacket.isRequest()) {
            assert httpPacket instanceof HttpRequestPacket;
            return false;
        }
        
        assert httpPacket instanceof HttpResponsePacket;
        return canCompressHttpResponse((HttpResponsePacket) httpPacket,
                compressionConfig, aliases);
    }

    @Override
    public boolean applyDecoding(final HttpHeader httpPacket) {
        return false;
    }
    
    /**
     * Returns true if the {@link HttpResponsePacket} could be
     * compressed, or false otherwise.
     * The method checks if client supports compression and if the resource,
     * that we are about to send matches {@link CompressionConfig} configuration.
     */
    protected static boolean canCompressHttpResponse(
            final HttpResponsePacket response,
            final CompressionConfig compressionConfig,
            final String[] aliases) {
        
        // If at least one encoding has been already selected
        // skip this one
        if (!response.getContentEncodings().isEmpty()) {
            return false;
        }

        final MimeHeaders responseHeaders = response.getHeaders();
        // Check if content is already encoded (no matter which encoding)
        final DataChunk contentEncodingMB =
                responseHeaders.getValue(Header.ContentEncoding);
        if (contentEncodingMB != null && !contentEncodingMB.isNull()) {
            return false;
        }

        if (!CompressionConfig.isClientSupportCompression(compressionConfig,
                response.getRequest(), aliases)) {
            return false;
        }
        
        // If force mode, always compress (test purposes only)
        if (compressionConfig.getCompressionMode() == CompressionMode.FORCE) {
            response.setChunked(true);
            response.setContentLength(-1);
            return true;
        }
                
        // Check if sufficient len to trig the compression
        final long contentLength = response.getContentLength();
        if (contentLength == -1
                || contentLength >= compressionConfig.getCompressionMinSize()) {

            if (compressionConfig.checkMimeType(response.getContentType())) {
                response.setChunked(true);
                response.setContentLength(-1);
                return true;
            }
        }

        return false;
    }    
}