/// <summary>
/// Constructs a <b>PofExtractor</b> based on a POF navigator
/// and the entry extraction target.
/// </summary>
/// <param name="type">
/// The required type of the extracted value or <c>null</c> if the
/// type is to be inferred from the serialized state.
/// </param>
/// <param name="navigator">
/// POF navigator.
/// </param>
/// <param name="target">
/// One of the <see cref="AbstractExtractor.VALUE"/>
/// or <see cref="AbstractExtractor.KEY"/> values.
/// </param>
public PofExtractor(Type type, IPofNavigator navigator, int target)
{
if (navigator == null)
{
throw new ArgumentNullException("navigator");
}
m_type = type;
m_navigator = navigator;
m_target = target;
if (type == null)
{
m_typeId = PofConstants.T_UNKNOWN;
}
}
/// <summary>
/// Save the contents of a POF user type instance by writing its
/// state using the specified <see cref="IPofWriter"/> object.
/// </summary>
/// <param name="writer">
/// The <b>IPofWriter</b> to which to write the object's state.
/// </param>
/// <exception cref="IOException">
/// If an I/O error occurs.
/// </exception>
public void WriteExternal(IPofWriter writer)
{
IPofNavigator navigator = m_navigator;
if (navigator == null)
{
throw new SerializationException(
"PofExtractor was constructed without a navigator");
}
writer.WriteInt32(0, m_target);
writer.WriteObject(1, navigator);
// see note in readExternal regarding T_UNKNOWN offset
writer.WriteInt64(2, (long)GetPofTypeId(writer.PofContext) -
(long)PofConstants.T_UNKNOWN);
}
/// <summary>
/// Constructs a <b>PofUpdater</b> based on a POF navigator.
/// </summary>
/// <param name="navigator">
/// POF navigator.
/// </param>
public PofUpdater(IPofNavigator navigator)
{
m_navigator = navigator;
}
/// <summary>
/// Constructs a <b>PofExtractor</b> based on a POF navigator.
/// </summary>
/// <param name="type">
/// The required type of the extracted value or <c>null</c> if the
/// type is to be inferred from the serialized state.
/// </param>
/// <param name="navigator">
/// POF navigator.
/// </param>
public PofExtractor(Type type, IPofNavigator navigator)
: this(type, navigator, VALUE)
{
}