/// <summary>
/// Gets a PredictionEngine for a named model.
/// </summary>
/// <param name="modelName">
/// The name of the model which allows for uniquely identifying the model when
/// multiple models have the same <typeparamref name="TData"/> and
/// <typeparamref name="TPrediction"/> types.
/// </param>
public PredictionEngine <TData, TPrediction> GetPredictionEngine(string modelName)
{
if (_namedPools.TryGetValue(modelName, out var existingPool))
{
return(existingPool.PredictionEnginePool.Get());
}
//This is the case where someone has used string.Empty to get the default model.
//We can throw all the time, but it seems reasonable that we would just do what
//they are expecting if they know that an empty string means default.
if (string.IsNullOrEmpty(modelName))
{
if (_defaultEnginePool == null)
{
throw new ArgumentException("You need to configure a default, not named, model before you use this method.");
}
return(_defaultEnginePool.PredictionEnginePool.Get());
}
//Here we are in the world of named models where the model hasn't been built yet.
var options = _predictionEngineOptions.Create(modelName);
var pool = new PoolLoader <TData, TPrediction>(_serviceProvider, options);
pool = _namedPools.GetOrAdd(modelName, pool);
return(pool.PredictionEnginePool.Get());
}
private PoolLoader <TData, TPrediction> AddPool(string modelName)
{
//Here we are in the world of named models where the model hasn't been built yet.
var options = _predictionEngineOptions.Create(modelName);
var pool = new PoolLoader <TData, TPrediction>(_serviceProvider, options);
pool = _namedPools.GetOrAdd(modelName, pool);
return(pool);
}
public PredictionEnginePool(IServiceProvider serviceProvider,
IOptions <MLOptions> mlContextOptions,
IOptionsFactory <PredictionEnginePoolOptions <TData, TPrediction> > predictionEngineOptions)
{
_mlContextOptions = mlContextOptions.Value;
_predictionEngineOptions = predictionEngineOptions;
_serviceProvider = serviceProvider;
var defaultOptions = _predictionEngineOptions.Create(string.Empty);
if (defaultOptions.ModelLoader != null)
{
_defaultEnginePool = new PoolLoader <TData, TPrediction>(_serviceProvider, defaultOptions);
}
_namedPools = new ConcurrentDictionary <string, PoolLoader <TData, TPrediction> >();
}
