protected DataViewBase(IHostEnvironment env, string name, InternalSchemaDefinition schemaDefn)
{
Contracts.AssertValue(env);
env.AssertNonWhiteSpace(name);
Host = env.Register(name);
Host.AssertValue(schemaDefn);
_schemaDefn = schemaDefn;
_schema = new Schema(GetSchemaColumns(schemaDefn));
int n = schemaDefn.Columns.Length;
_peeks = new Delegate[n];
for (var i = 0; i < n; i++)
{
var currentColumn = schemaDefn.Columns[i];
_peeks[i] = currentColumn.IsComputed
? currentColumn.Generator
: ApiUtils.GeneratePeek <DataViewBase <TRow>, TRow>(currentColumn);
}
}
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();
}