BitsSignatureTable.java

/**
 * 
 */
package ivory.lsh.data;

/**
 * @author Tamer
 *
 */

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.lang.reflect.Array;

import org.apache.hadoop.io.Writable;


public class BitsSignatureTable implements Writable{
  Signature[] signaturesArray = null;
  int[] docNosArray = null;

  int nSignatures = 0;

  public BitsSignatureTable (){
  }

  public void set(Signature[] signs, int[] nos, int nElements){
    if(signs.length == 0) throw new RuntimeException("invalid size of signatures: "+signs.length);
    if(nos.length == 0) throw new RuntimeException("invalid size of docnos: "+nos.length);
    if(signs.length != nos.length) 
      throw new RuntimeException("size mismatch: "+signs.length+"\t"+nos.length);
    if(nElements <= 0 || nElements > signs.length) throw new RuntimeException("invalid size: "+nElements);
    signaturesArray = signs;
    docNosArray = nos;	
    nSignatures = nElements;
  }

  public void add(SixtyFourBitSignature sign, int docno){
    throw new UnsupportedOperationException();
  }

  @SuppressWarnings("unchecked")
  public void readFields(DataInput in) throws IOException {

    String className = in.readUTF();
    try {
      Class c = Class.forName(className);
      nSignatures = in.readInt();
      if(signaturesArray== null || signaturesArray.length < nSignatures)
        signaturesArray = (Signature[]) Array.newInstance(c, nSignatures);
      for(int  i = 0; i < nSignatures; i++){
        signaturesArray[i] = (Signature) c.newInstance();
        signaturesArray[i].readFields(in);
      }
    } catch (Exception e) {
      e.printStackTrace();
      throw new RuntimeException("Signature class not found");
    }

    if(docNosArray== null || docNosArray.length < nSignatures)
      docNosArray = new int[nSignatures];
    for(int  i = 0; i < nSignatures; i++){
      docNosArray[i] = in.readInt();
    }
  }

  /*public void readFields(DataInput in) throws IOException {

		nSignatures = in.readInt();
		if(signaturesArray== null || signaturesArray.length < nSignatures)
			signaturesArray = new SixtyFourBitSignature[nSignatures];
		for(int  i = 0; i < nSignatures; i++){
			signaturesArray[i] = new SixtyFourBitSignature();
			signaturesArray[i].readFields(in);
		}
		if(docNosArray== null || docNosArray.length < nSignatures)
			docNosArray = new int[nSignatures];
		for(int  i = 0; i < nSignatures; i++){
			docNosArray[i] = in.readInt();
		}
	}*/

  public void clear(){
    nSignatures = 0;
  }

  public void free(){
    nSignatures = 0;
    signaturesArray = null;
    docNosArray = null;
  }

  public void write(DataOutput out) throws IOException {
    if(signaturesArray == null)
      throw new RuntimeException("invalid NULL signaturesArray!");
    if(docNosArray == null)
      throw new RuntimeException("invalid NULL docNosArray!");

    out.writeUTF(signaturesArray[0].getClass().getCanonicalName());

    out.writeInt(nSignatures);
    for(int i = 0; i < nSignatures; i++) signaturesArray[i].write(out);
    for(int i = 0; i < nSignatures; i++) out.writeInt(docNosArray[i]);
  }

  public Signature[] getSignatures(){
    return signaturesArray;
  }

  public int[] getDocNos(){
    return docNosArray;
  }

  public int getNumOfSignatures(){
    return nSignatures;
  }

  public String toString(){
    String s ="";
    for(int i=0;i<nSignatures;i++){
      s+="("+docNosArray[i]+","+signaturesArray[i]+");";
    }
    return s;
  }
}