Added IDisposable support for several classes

src/Microsoft.ML.Data/DataLoadSave/CompositeDataLoader.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System;
 using Microsoft.ML;
 using Microsoft.ML.Data;
 using Microsoft.ML.Runtime;
@@ -15,7 +16,7 @@ namespace Microsoft.ML.Data
     /// This class represents a data loader that applies a transformer chain after loading.
     /// It also has methods to save itself to a repository.
     /// </summary>
-    public sealed class CompositeDataLoader<TSource, TLastTransformer> : IDataLoader<TSource>
+    public sealed class CompositeDataLoader<TSource, TLastTransformer> : IDataLoader<TSource>, IDisposable
         where TLastTransformer : class, ITransformer
     {
         internal const string TransformerDirectory = TransformerChain.LoaderSignature;
@@ -38,13 +39,15 @@ public CompositeDataLoader(IDataLoader<TSource> loader, TransformerChain<TLastTr
 
             Loader = loader;
             Transformer = transformerChain ?? new TransformerChain<TLastTransformer>();
+            _disposed = false;
         }
 
         private CompositeDataLoader(IHost host, ModelLoadContext ctx)
         {
             if (!ctx.LoadModelOrNull<IDataLoader<TSource>, SignatureLoadModel>(host, out Loader, LegacyLoaderDirectory))
                 ctx.LoadModel<IDataLoader<TSource>, SignatureLoadModel>(host, out Loader, LoaderDirectory);
             ctx.LoadModel<TransformerChain<TLastTransformer>, SignatureLoadModel>(host, out Transformer, TransformerDirectory);
+            _disposed = false;
         }
 
         private static CompositeDataLoader<TSource, TLastTransformer> Create(IHostEnvironment env, ModelLoadContext ctx)
@@ -110,5 +113,25 @@ private static VersionInfo GetVersionInfo()
                 loaderSignature: LoaderSignature,
                 loaderAssemblyName: typeof(CompositeDataLoader<,>).Assembly.FullName);
         }
+
+        #region IDisposable Support
+        private bool _disposed;
+
+        private void Dispose(bool disposing)
+        {
+            if (_disposed)
+                return;
+
+            if (disposing)
+                Transformer.Dispose();
+
+            _disposed = true;
+        }
+
+        void IDisposable.Dispose()
+        {
+            Dispose(true);
+        }
+        #endregion
     }
 }

src/Microsoft.ML.Data/DataLoadSave/TransformerChain.cs

@@ -50,7 +50,7 @@ internal interface ITransformerChainAccessor
     /// A chain of transformers (possibly empty) that end with a <typeparamref name="TLastTransformer"/>.
     /// For an empty chain, <typeparamref name="TLastTransformer"/> is always <see cref="ITransformer"/>.
     /// </summary>
-    public sealed class TransformerChain<TLastTransformer> : ITransformer, IEnumerable<ITransformer>, ITransformerChainAccessor
+    public sealed class TransformerChain<TLastTransformer> : ITransformer, IEnumerable<ITransformer>, ITransformerChainAccessor, IDisposable
     where TLastTransformer : class, ITransformer
     {
         private readonly ITransformer[] _transformers;
@@ -92,6 +92,7 @@ public TransformerChain(IEnumerable<ITransformer> transformers, IEnumerable<Tran
 
             Contracts.Check((_transformers.Length > 0) == (LastTransformer != null));
             Contracts.Check(_transformers.Length == _scopes.Length);
+            _disposed = false;
         }
 
         /// <summary>
@@ -116,6 +117,7 @@ public TransformerChain(params ITransformer[] transformers)
                 LastTransformer = transformers.Last() as TLastTransformer;
                 Contracts.Check(LastTransformer != null);
             }
+            _disposed = false;
         }
 
         public DataViewSchema GetOutputSchema(DataViewSchema inputSchema)
@@ -232,6 +234,31 @@ IRowToRowMapper ITransformer.GetRowToRowMapper(DataViewSchema inputSchema)
             }
             return new CompositeRowToRowMapper(inputSchema, mappers);
         }
+
+        #region IDisposable Support
+        private bool _disposed;
+
+        private void Dispose(bool disposing)
+        {
+            if (_disposed)
+                return;
+
+            if (disposing)
+            {
+                foreach (var transformer in _transformers)
+                    (transformer as IDisposable)?.Dispose();
+
+                (LastTransformer as IDisposable)?.Dispose();
+            }
+
+            _disposed = true;
+        }
+
+        public void Dispose()
+        {
+            Dispose(true);
+        }
+        #endregion
     }
 
     /// <summary>

src/Microsoft.ML.Data/DataView/CompositeRowToRowMapper.cs

@@ -14,7 +14,7 @@ namespace Microsoft.ML.Data
     /// A row-to-row mapper that is the result of a chained application of multiple mappers.
     /// </summary>
     [BestFriend]
-    internal sealed class CompositeRowToRowMapper : IRowToRowMapper
+    internal sealed class CompositeRowToRowMapper : IRowToRowMapper, IDisposable
     {
         [BestFriend]
         internal IRowToRowMapper[] InnerMappers { get; }
@@ -36,6 +36,7 @@ public CompositeRowToRowMapper(DataViewSchema inputSchema, IRowToRowMapper[] map
             InnerMappers = Utils.Size(mappers) > 0 ? mappers : _empty;
             InputSchema = inputSchema;
             OutputSchema = Utils.Size(mappers) > 0 ? mappers[mappers.Length - 1].OutputSchema : inputSchema;
+            _disposed = false;
         }
 
         /// <summary>
@@ -118,5 +119,28 @@ public SubsetActive(DataViewRow row, Func<int, bool> pred)
             /// </summary>
             public override bool IsColumnActive(DataViewSchema.Column column) => _pred(column.Index);
         }
+
+        #region IDisposable Support
+        private bool _disposed;
+
+        private void Dispose(bool disposing)
+        {
+            if (_disposed)
+                return;
+
+            if (disposing)
+            {
+                foreach (var mapper in InnerMappers)
+                    (mapper as IDisposable)?.Dispose();
+            }
+
+            _disposed = true;
+        }
+
+        void IDisposable.Dispose()
+        {
+            Dispose(true);
+        }
+        #endregion
     }
 }

src/Microsoft.ML.Data/Prediction/PredictionEngine.cs

@@ -147,6 +147,7 @@ private protected virtual void PredictionEngineCore(IHostEnvironment env, DataVi
             var outputRowLocal = mapper.GetRow(inputRow, mapper.OutputSchema);
             outputRow = cursorable.GetRow(outputRowLocal);
             disposer = inputRow.Dispose;
+            //(mapper as IDisposable)?.Dispose();
         }
 
         private protected virtual Func<DataViewSchema, IRowToRowMapper> TransformerChecker(IExceptionContext ectx, ITransformer transformer)
@@ -168,7 +169,10 @@ private protected void Disposing(bool disposing)
             if (_disposed)
                 return;
             if (disposing)
+            {
                 _disposer?.Invoke();
+                (Transformer as IDisposable)?.Dispose();
+            }
             _disposed = true;
         }
 

src/Microsoft.ML.Data/Scorers/MulticlassClassificationScorer.cs

@@ -64,7 +64,8 @@ private static VersionInfo GetVersionInfo()
         /// </summary>
         // REVIEW: It seems like the attachment of metadata should be solvable in a manner
         // less ridiculously verbose than this.
-        public sealed class LabelNameBindableMapper : ISchemaBindableMapper, ICanSaveModel, IBindableCanSavePfa, IBindableCanSaveOnnx
+        public sealed class LabelNameBindableMapper : ISchemaBindableMapper, ICanSaveModel, IBindableCanSavePfa,
+            IBindableCanSaveOnnx, IDisposable
         {
             private static readonly FuncInstanceMethodInfo1<LabelNameBindableMapper, object, Delegate> _decodeInitMethodInfo
                 = FuncInstanceMethodInfo1<LabelNameBindableMapper, object, Delegate>.Create(target => target.DecodeInit<int>);
@@ -125,6 +126,7 @@ private LabelNameBindableMapper(IHostEnvironment env, ISchemaBindableMapper bind
                 _getter = getter;
                 _metadataKind = metadataKind;
                 _canWrap = canWrap;
+                _disposed = false;
             }
 
             private LabelNameBindableMapper(IHost host, ModelLoadContext ctx)
@@ -144,6 +146,7 @@ private LabelNameBindableMapper(IHost host, ModelLoadContext ctx)
                 _getter = Utils.MarshalInvoke(_decodeInitMethodInfo, this, _type.ItemType.RawType, value);
                 _metadataKind = ctx.Header.ModelVerReadable >= VersionAddedMetadataKind ?
                     ctx.LoadNonEmptyString() : AnnotationUtils.Kinds.SlotNames;
+                _disposed = false;
             }
 
             private Delegate DecodeInit<T>(object value)
@@ -379,6 +382,27 @@ public RowImpl(DataViewRow row, DataViewSchema schema)
                     public override ValueGetter<TValue> GetGetter<TValue>(DataViewSchema.Column column) => Input.GetGetter<TValue>(column);
                 }
             }
+
+            #region IDisposable Support
+            private bool _disposed;
+
+            private void Dispose(bool disposing)
+            {
+                // TODO: Is it necessary to call the base class Dispose()?
+                if (_disposed)
+                    return;
+
+                if (disposing)
+                    (_bindable as IDisposable)?.Dispose();
+
+                _disposed = true;
+            }
+
+            void IDisposable.Dispose()
+            {
+                Dispose(true);
+            }
+            #endregion
         }
 
         /// <summary>

src/Microsoft.ML.Data/Scorers/PredictedLabelScorerBase.cs

@@ -17,7 +17,7 @@ namespace Microsoft.ML.Data
     /// Class for scorers that compute on additional "PredictedLabel" column from the score column.
     /// Currently, this scorer is used for binary classification, multi-class classification, and clustering.
     /// </summary>
-    internal abstract class PredictedLabelScorerBase : RowToRowScorerBase, ITransformCanSavePfa, ITransformCanSaveOnnx
+    internal abstract class PredictedLabelScorerBase : RowToRowScorerBase, ITransformCanSavePfa, ITransformCanSaveOnnx, IDisposable
     {
         public abstract class ThresholdArgumentsBase : ScorerArgumentsBase
         {
@@ -294,6 +294,7 @@ private protected PredictedLabelScorerBase(ScorerArgumentsBase args, IHostEnviro
 
             Bindings = BindingsImpl.Create(data.Schema, rowMapper, args.Suffix, scoreColKind, scoreColIndex, predColType, predictedLabelColumnName);
             OutputSchema = Bindings.AsSchema;
+            _disposed = false;
         }
 
         protected PredictedLabelScorerBase(IHostEnvironment env, PredictedLabelScorerBase transform,
@@ -302,6 +303,7 @@ protected PredictedLabelScorerBase(IHostEnvironment env, PredictedLabelScorerBas
         {
             Bindings = transform.Bindings.ApplyToSchema(newSource.Schema, Bindable, env);
             OutputSchema = Bindings.AsSchema;
+            _disposed = false;
         }
 
         [BestFriend]
@@ -316,6 +318,7 @@ private protected PredictedLabelScorerBase(IHost host, ModelLoadContext ctx, IDa
 
             Bindings = BindingsImpl.Create(ctx, input.Schema, host, Bindable, outputTypeMatches, getPredColType);
             OutputSchema = Bindings.AsSchema;
+            _disposed = false;
         }
 
         private protected override void SaveCore(ModelSaveContext ctx)
@@ -435,5 +438,28 @@ protected void EnsureCachedPosition<TScore>(ref long cachedPosition, ref TScore
                 cachedPosition = boundRow.Position;
             }
         }
+
+        #region IDisposable Support
+        private bool _disposed;
+
+        protected virtual void Dispose(bool disposing)
+        {
+            if (_disposed)
+                return;
+
+            if (disposing)
+            {
+                (Bindings.RowMapper as IDisposable)?.Dispose();
+                (Bindable as IDisposable)?.Dispose();
+            }
+
+            _disposed = true;
+        }
+
+        void IDisposable.Dispose()
+        {
+            Dispose(true);
+        }
+        #endregion
     }
 }

src/Microsoft.ML.Data/Scorers/PredictionTransformer.cs

@@ -40,7 +40,7 @@ internal static class PredictionTransformerBase
     /// Base class for transformers with no feature column, or more than one feature columns.
     /// </summary>
     /// <typeparam name="TModel">The type of the model parameters used by this prediction transformer.</typeparam>
-    public abstract class PredictionTransformerBase<TModel> : IPredictionTransformer<TModel>
+    public abstract class PredictionTransformerBase<TModel> : IPredictionTransformer<TModel>, IDisposable
         where TModel : class
     {
         /// <summary>
@@ -89,6 +89,7 @@ private protected PredictionTransformerBase(IHost host, TModel model, DataViewSc
 
             Host.CheckValue(trainSchema, nameof(trainSchema));
             TrainSchema = trainSchema;
+            _disposed = false;
         }
 
         [BestFriend]
@@ -103,6 +104,7 @@ private protected PredictionTransformerBase(IHost host, ModelLoadContext ctx)
             Model = model;
 
             InitializeLogic(host, ctx);
+            _disposed = false;
         }
 
         [BestFriend]
@@ -111,6 +113,7 @@ private protected PredictionTransformerBase(IHost host, ModelLoadContext ctx, TM
             Host = host;
             Model = model; // prediction model
             InitializeLogic(host, ctx);
+            _disposed = false;
         }
 
         private void InitializeLogic(IHost host, ModelLoadContext ctx)
@@ -181,6 +184,30 @@ private protected void SaveModelCore(ModelSaveContext ctx)
                 }
             });
         }
+
+        #region IDisposable Support
+        private bool _disposed;
+
+        protected virtual void Dispose(bool disposing)
+        {
+            if (_disposed)
+                return;
+
+            if (disposing)
+            {
+                (Model as IDisposable)?.Dispose();
+                (BindableMapper as IDisposable)?.Dispose();
+                (Scorer as IDisposable)?.Dispose();
+            }
+
+            _disposed = true;
+        }
+
+        void IDisposable.Dispose()
+        {
+            Dispose(true);
+        }
+        #endregion
     }
 
     /// <summary>