/// <summary>
/// Gets either cached value or gets value and caches for future.
/// </summary>
/// <param name="objType">use object.GetType()</param>
/// <returns>version number</returns>
/// <exception cref="ArgumentException">if object does not have version attribute</exception>
public static VersionNumbers GetVersion(Type objType)
{
VersionNumbers versionNo;
if (TypeVersionCache.TryGetValue(objType, out versionNo))
{
return(versionNo);
}
versionNo = BuildVersionCache(objType);
return(versionNo);
}
/// <summary>
/// Builds type wise version number cache.
/// </summary>
/// <param name="objType"></param>
/// <returns></returns>
private static VersionNumbers BuildVersionCache(Type objType)
{
var versionTypeAttribute = Attribute.GetCustomAttribute(objType, typeof(VersionTypeAttribute))
as VersionTypeAttribute;
if (versionTypeAttribute == null)
{
throw new ArgumentException("No version type attribute specified for the type");
}
var versionNo = versionTypeAttribute.Version;
TypeVersionCache.TryAdd(objType, versionNo);
return(versionNo);
}