public MapStrategy(IRecord record)
{
if (record.ContainsOnlyPrimitives())
{
var loader = DictionaryLoad.DirectlyFromRecord();
_mapMethod = BuildMappingMethod(
from p in typeof(TReturn).GetProperties(ObjectToDictionary.BindingFlagsForDTO)
let neoName = Config.DotnetToNeoPropNames(p.Name)
where p.CanWrite
select new PropertyMap {
Loader = loader, Property = p, RecordKey = neoName
});
}
else if (record.ContainsOnlySingleNode())
{
var nodeKey = record.Keys.First();
var loader = DictionaryLoad.FromEmbeddedNode(nodeKey);
_mapMethod = BuildMappingMethod(
from p in typeof(TReturn).GetProperties(ObjectToDictionary.BindingFlagsForDTO)
let neoName = Config.DotnetToNeoPropNames(p.Name)
where p.CanWrite
select new PropertyMap {
Loader = loader, Property = p, RecordKey = neoName
});
}
}
private Func <IRecord, TReturn> BuildMappingMethod(IEnumerable <PropertyMap> propertyMaps)
{
var emit = Emit <Func <IRecord, TReturn> > .NewDynamicMethod($"MapTo_{typeof(TReturn).Name}_{Guid.NewGuid().ToBase64Guid()}");
var ret = emit.DeclareLocal(typeof(TReturn));
var v = emit.DeclareLocal(typeof(object));
var check = emit.DeclareLocal(typeof(bool));
var valueDict = emit.DeclareLocal(typeof(IReadOnlyDictionary <string, object>));
emit.NewObject(typeof(TReturn));
emit.StoreLocal(ret);
int labelCounter = 0;
DictionaryLoad currentLoader = null;
foreach (var pm in propertyMaps)
{
if (!ReferenceEquals(currentLoader, pm.Loader))
{
// valueDict = record.Values || ((INode)record["v"]).Properties || ...
currentLoader = pm.Loader;
currentLoader.EmitLoad(emit, valueDict);
}
// check = dict.TryGetValue(recordKey, out v)
// if (check)
// ret.Property = (cast)v;
var lbl = emit.DefineLabel("lbl_" + labelCounter);
emit.LoadLocal(valueDict);
emit.LoadConstant(pm.RecordKey);
emit.LoadLocalAddress(v);
emit.CallVirtual(TryGetValue);
emit.AsShorthand().Ldc(0); // <-- Copied from looking at IL
emit.AsShorthand().Ceq(); // it seems to turn around the true val
emit.StoreLocal(check); // and jump to the label
emit.LoadLocal(check);
emit.BranchIfTrue(lbl);
emit.LoadLocal(ret);
emit.LoadLocal(v);
if (pm.Property.PropertyType.GetTypeInfo().IsValueType)
{
emit.UnboxAny(pm.Property.PropertyType);
}
else
{
emit.CastClass(pm.Property.PropertyType);
}
emit.CallVirtual(pm.Property.SetMethod);
emit.MarkLabel(lbl);
labelCounter++;
}
emit.LoadLocal(ret);
emit.Return();
return(emit.CreateDelegate());
}
