XmlSerializer constructor with XmlTypeMapping and XmlRootAttribute arguments
I'd like to prefetch in C#, the XmlTypeMapping of a known set of class types to speed up XML deserialization of them while instantiating a new XmlSerializer as XmlReflectionImporter.ImportTypeMapping (happening during XmlSerializer contruction on a class type) is quite time consuming and seem to happen at each XmlSerializer construction.
In addition the xml content I am parsing forces me to use XmlRootAttribute argument to set the xml root element name to parse as it is not always the same. To achieve that, I can use the XmlSerializer(Type, XmlRootAttribute) constructor to deserialize my object.
However I would also like to benefit from the prefetch XmlTypeMapping and I can't see any XmlSerializer constructor like : XmlSerializer( XmlTypeMapping, XmlRootAttribute ) or something close. How could I achieve that?
Any help would be greatly appreciated! Thanks.
The built-in cache is not used on any of the constructors that accept an XmlRootAttribute. Your best bet is to use the constructor that accepts a single XmlTypeMapping parameter:
public XmlSerializer(XmlTypeMapping xmlTypeMapping)
And to wrap it in your own constructor that accepts a XmlRootAttribute, and constructs the XmlTypeMapping from it using XmlReflectionImporter:
public class CachedRootXmlSerializer : XmlSerializer
{
private static Dictionary<int, XmlTypeMapping> rootMapCache = new Dictionary<int,XmlTypeMapping>();
private static XmlTypeMapping GetXmlTypeMappingFromRoot(Type type, XmlRootAttribute xmlRootAttribute)
{
XmlTypeMapping result = null;
int hash = 17;
unchecked
{
hash = hash * 31 + type.GUID.GetHashCode();
hash = hash * 31 + xmlRootAttribute.GetHashCode();
}
lock (rootMapCache)
{
if (!rootMapCache.ContainsKey(hash))
{
XmlReflectionImporter importer = new XmlReflectionImporter(null, null);
rootMapCache[hash] = importer.ImportTypeMapping(type, xmlRootAttribute, null);
}
result = rootMapCache[hash];
}
return result;
}
CachedRootXmlSerializer(Type type, XmlRootAttribute xmlRootAttribute)
: base(GetXmlTypeMappingFromRoot(type, xmlRootAttribute))
{
}
}
Enjoy!
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