/// <summary>
/// Appends the fields and values defined by the given object of the given Class.
/// </summary>
/// <param name="builder">the builder to Append to</param>
/// <param name="clazz">the class to Append details of</param>
/// <param name="obj">the object to Append details of</param>
/// <param name="useTransients">whether to use transient fields</param>
private static void ReflectionAppend(object obj, Type clazz, HashCodeBuilder builder, bool useTransients)
{
//TODO: atrosin what does it mean? f.Name.IndexOf('$')
//TODO: atrosin //AccessibleObject.setAccessible(fields, true);
FieldInfo[] fields =
clazz.GetFields(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic
| BindingFlags.GetField);
//AccessibleObject.setAccessible(fields, true);
for (int i = 0; i < fields.Length; i++)
{
FieldInfo f = fields[i];
if ((f.Name.IndexOf('$') == -1) &&
(useTransients || !IsTransient(f)) &&
!f.IsStatic)
{
try
{
builder.Append(f.GetValue(obj));
}
catch (Exception)
{
throw new Exception("Unexpected IllegalAccessException");
}
}
}
}
/// <summary>
/// This method uses reflection to build a valid hash code.
///
/// It uses AccessibleObject.setAccessible to gain access to private
/// fields. This means that it will throw a security exception if run under
/// a security manager, if the permissions are not set up correctly. It is also
/// not as efficient as testing explicitly.
///
/// If the TestTransients parameter is set to true, transient
/// members will be tested, otherwise they are ignored, as they are likely
/// derived fields, and not part of the value of the Object.
///
/// Static fields will not be included. Superclass fields will be included
/// up to and including the specified superclass. A null superclass is treated
/// as java.lang.Object.
///
/// Two randomly chosen, non-zero, odd numbers must be passed in. Ideally
/// these should be different for each class, however this is not vital.
/// Prime numbers are preferred, especially for the multiplier.
/// Throws IllegalArgumentException if the Object is null
/// Throws IllegalArgumentException if the number is zero or even since 2.0
/// </summary>
/// <param name="initialNonZeroOddNumber">a non-zero, odd number used as the initial value</param>
/// <param name="multiplierNonZeroOddNumber">a non-zero, odd number used as the multiplier</param>
/// <param name="obj">the Object to create a hashCode for</param>
/// <param name="reflectUpToClass">whether to include transient fields</param>
/// <param name="testTransients">the superclass to reflect up to (inclusive),may be null</param>
/// <returns>hash code</returns>
public static int ReflectionHashCode(
int initialNonZeroOddNumber,
int multiplierNonZeroOddNumber,
object obj,
bool testTransients,
Type reflectUpToClass)
{
if (obj == null)
{
throw new ArgumentException("The object to build a hash code for must not be null");
}
HashCodeBuilder builder = new HashCodeBuilder(initialNonZeroOddNumber, multiplierNonZeroOddNumber);
Type clazz = obj.GetType();
ReflectionAppend(obj, clazz, builder, testTransients);
while (clazz.BaseType != null && clazz != reflectUpToClass)
{
clazz = clazz.BaseType;
ReflectionAppend(obj, clazz, builder, testTransients);
}
return(builder.ToHashCode());
}
