void ICanSaveModel.Save(ModelSaveContext ctx)
{
Host.CheckValue(ctx, nameof(ctx));
Host.Check(CanSave(), "Cannot save this transform as it was not specified as being savable");
ctx.CheckAtModel();
ctx.SetVersionInfo(SerializableLambdaTransform.GetVersionInfo());
// *** Binary format ***
// int: Number of bytes the load method was serialized to
// byte[n]: The serialized load method info
// <arbitrary>: Arbitrary bytes saved by the save action
Host.AssertNonEmpty(_loadFuncBytes);
ctx.Writer.WriteByteArray(_loadFuncBytes);
using (var ms = new MemoryStream())
{
using (var writer = new BinaryWriter(ms, Encoding.UTF8, leaveOpen: true))
_saveAction(writer);
ctx.Writer.WriteByteArray(ms.ToArray());
}
}
protected LambdaTransformBase(IHostEnvironment env, string name, Action <BinaryWriter> saveAction, LambdaTransform.LoadDelegate loadFunc)
{
Contracts.AssertValue(env);
env.AssertNonWhiteSpace(name);
Host = env.Register(name);
Host.Assert((saveAction == null) == (loadFunc == null));
if (saveAction != null)
{
_saveAction = saveAction;
// First, verify as best we can, that we can recover the function, by attempting to do it once.
_loadFuncBytes = SerializableLambdaTransform.GetSerializedStaticDelegate(loadFunc);
Exception error;
var recoveredLoadFunc = SerializableLambdaTransform.DeserializeStaticDelegateOrNull(Host, _loadFuncBytes, out error);
if (recoveredLoadFunc == null)
{
Host.AssertValue(error);
throw Host.Except(error, "Load function does not appear recoverable");
}
}
AssertConsistentSerializable();
}