org.glassfish.grizzly.utils.ChunkingFilter Maven / Gradle / Ivy

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package org.glassfish.grizzly.utils;

import org.glassfish.grizzly.AbstractTransformer;
import org.glassfish.grizzly.Buffer;
import org.glassfish.grizzly.Grizzly;
import org.glassfish.grizzly.TransformationException;
import org.glassfish.grizzly.TransformationResult;
import org.glassfish.grizzly.attributes.AttributeStorage;
import org.glassfish.grizzly.filterchain.AbstractCodecFilter;
import org.glassfish.grizzly.filterchain.FilterChain;
import org.glassfish.grizzly.memory.Buffers;
import java.util.logging.Logger;


/**
 * The Filter is responsible to break the incoming/outgoing data into chunks and
 * pass them down/up by the {@link FilterChain}.
 * This Filter could be useful for testing reasons to check if all Filters in
 * the {@link FilterChain} work properly with chunked data.
 * 
 * @author Alexey Stashok
 */
public class ChunkingFilter extends AbstractCodecFilter {
    private static final Logger LOGGER = Grizzly.logger(ChunkingFilter.class);

    private final int chunkSize;

    /**
     * Construct a ChunkFilter, which will break incoming/outgoing data
     * into chunks of the specified size.
     *
     * @param chunkSize the chunk size.
     */
    public ChunkingFilter(int chunkSize) {
        super(new ChunkingDecoder(chunkSize),
                new ChunkingEncoder(chunkSize));
        this.chunkSize = chunkSize;
    }

    public int getChunkSize() {
        return chunkSize;
    }

    public static final class ChunkingDecoder extends ChunkingTransformer {

        public ChunkingDecoder(int chunk) {
            super(chunk);
        }

    }

    public static final class ChunkingEncoder extends ChunkingTransformer {

        public ChunkingEncoder(int chunk) {
            super(chunk);
        }

    }

    public static abstract class ChunkingTransformer
            extends AbstractTransformer {
        private final int chunk;

        public ChunkingTransformer(int chunk) {
            this.chunk = chunk;
        }

        @Override
        public String getName() {
            return "ChunkingTransformer";
        }

        @Override
        protected TransformationResult transformImpl(
                AttributeStorage storage, Buffer input)
                throws TransformationException {

            if (!input.hasRemaining()) {
                return TransformationResult.createIncompletedResult(input);
            }

            final int chunkSize = Math.min(chunk, input.remaining());

            final int oldInputPos = input.position();
            final int oldInputLimit = input.limit();

            Buffers.setPositionLimit(input, oldInputPos, oldInputPos + chunkSize);
            
            final Buffer output = obtainMemoryManager(storage).allocate(chunkSize);
            output.put(input).flip();

            Buffers.setPositionLimit(input, oldInputPos + chunkSize, oldInputLimit);

            return TransformationResult.createCompletedResult(
                    output, input);
        }

        @Override
        public boolean hasInputRemaining(AttributeStorage storage, Buffer input) {
            return input != null && input.hasRemaining();
        }
    }
}