package js.tinyvm;

import java.io.*;
import java.util.*;
import js.classfile.*;

public class InstanceFieldRecord implements WritableData, Constants
{
  JField iField;
  int iType;

  public InstanceFieldRecord (JField aEntry)
  {
    iField = aEntry;
    iType = descriptorToType (iField.getDescriptor().toString());
  }

  public String getName()
  {
    return iField.getName();
  }

  public static int descriptorToType (String aDesc)
  {
    switch (aDesc.charAt (0))
    {
      case 'B':
        return T_BYTE;
      case 'C':
        return T_CHAR;
      case 'D':
        return T_DOUBLE;
      case 'F':
        return T_FLOAT;
      case 'I':
        return T_INT;
      case 'J':
        return T_LONG;
      case 'S':
        return T_SHORT;
      case 'Z':
        return T_BOOLEAN;
      case 'L':
      case '[':
        return T_REFERENCE;
      default:
        Assertion.fatal ("Bug IFR-2: " + aDesc);  
    }
    return 0;
  }

  public int getLength()
  {
    return 1;
  }

  public void dump (ByteWriter aOut) throws Exception
  {
    aOut.writeU1 ((int) iType);
  }

  public static int getTypeSize (int aType)
  {
    switch (aType)
    {
      case T_BYTE:
      case T_BOOLEAN:
        return 1;
      case T_SHORT:
      case T_CHAR:
        return 2;
      case T_INT:
      case T_REFERENCE:
      case T_FLOAT:
        return 4;
      case T_LONG:
      case T_DOUBLE:
        return 8;
      default:
        Assertion.fatal ("Bug SV-1: " + aType);
    }
    return 0;
  }

  public int getFieldSize()
  {
    return getTypeSize (iType);
  }

  public boolean equals (Object aOther)
  {
    if (!(aOther instanceof InstanceFieldRecord))
      return false;
    return ((InstanceFieldRecord) aOther).iField.equals (iField);    
  }  

  public int hashCode()
  {
    return iField.hashCode();
  }
}