/* 
 * COM1317 Project
 * Transaction.java
 * Copyright (C) Jing Shan 2003
 */

import java.io.*;
import java.util.*;

class Transaction extends Thread{
    private int id;
    private LockManager lockmnger;
    private LinkedList lockList;

    Transaction (int i, LockManager l){
	id = i;
	lockmnger = l;
	lockList = new LinkedList();
    }

    public void addLock(LCB l){
	lockList.addLast(l);
    }

    public void printLockList(){
	System.out.println("Transaction "+ id+" has "+lockList.size()+" locks in lock list");
    }

    public LinkedList getLockList(){
	return lockList;
    }

    public void run(){
	System.out.println("Transaction "+id+" is started");
	System.out.println();
	try{
	    File myFile = new File(id+".txt");
	    FileReader in =new FileReader(myFile);
	    BufferedReader tmpBufReader = new BufferedReader(in);
	    String oneLine = tmpBufReader.readLine();
	    while (oneLine != null){
		StringTokenizer s = new StringTokenizer(oneLine);
		if(s.countTokens() != 2){
		    System.out.println("illegal command in "+id+".txt:: "+ oneLine);
		    return;
		}
     
		try{
		    lockmnger.lock(this,s.nextToken(), s.nextToken());
		}catch (DeadLockException e){
		    System.out.println(e);
		    System.out.println("transaction "+ id+" aborts");
		    lockmnger.unlockAll(this);
		    return;
		}

		oneLine = tmpBufReader.readLine();
	    }
	}catch (IOException e){
	    System.out.println("illegal file operations: "+e);
	}

    }

    public int id(){
	return id;
    }
}