Sector.java

package com.osroyale.fs.cache;
 
import com.google.common.base.Preconditions;
import com.osroyale.fs.util.ByteBufferUtil;
 
import java.nio.ByteBuffer;

 
public final class Sector {

    private final int indexId;

    private final int chunk;

    private final int nextIndexId;

    private final int cacheId;

    private Sector(int indexId, int chunk, int nextIndexId, int cacheId) {
        this.indexId = indexId;
        this.chunk = chunk;
        this.nextIndexId = nextIndexId;
        this.cacheId = cacheId;
    }

    public static Sector decode(ByteBuffer buffer, byte[] data, int offset, int length) {
        int indexId = buffer.getShort() & 0xFFFF;
        int chunk = buffer.getShort() & 0xFFFF;
        int nextIndexId = ByteBufferUtil.getMedium(buffer);
        int cacheId = buffer.get() & 0xFF;
        buffer.get(data, offset, length);
        return new Sector(indexId, chunk, nextIndexId, cacheId);
    }

    public void check(int cacheId, int indexId, int chunk) {
        Preconditions.checkArgument(this.cacheId == cacheId);
        Preconditions.checkArgument(this.indexId == indexId);
        Preconditions.checkArgument(this.chunk == chunk);
    }

    public int getIndexId() {
        return indexId;
    }

    public int getChunk() {
        return chunk;
    }

    public int getNextIndexId() {
        return nextIndexId;
    }

    public int getCacheId() {
        return cacheId;
    }
 
}