CSHARP-5348: Cache Bson*Context.PushContext

Author: obligaron

benchmarks/MongoDB.Driver.Benchmarks/README.md

@@ -1,6 +1,6 @@
 # C# Driver Benchmark Suite
 
-This suite implements the benchmarks described in this [spec](https://github.com/mongodb/specifications/blob/master/source/benchmarking/benchmarking.rst).
+This suite implements the benchmarks described in this [spec](https://github.com/mongodb/specifications/blob/master/source/benchmarking/benchmarking.md).
 
 ## Running the Driver Benchmarks
 

src/MongoDB.Bson/IO/BsonBinaryReaderContext.cs

@@ -21,9 +21,10 @@ internal class BsonBinaryReaderContext
     {
         // private fields
         private readonly BsonBinaryReaderContext _parentContext;
-        private readonly ContextType _contextType;
-        private readonly long _startPosition;
-        private readonly long _size;
+        private BsonBinaryReaderContext _cachedPushContext;
+        private ContextType _contextType;
+        private long _startPosition;
+        private long _size;
         private string _currentElementName;
         private int _currentArrayIndex = -1;
 
@@ -86,7 +87,17 @@ public BsonBinaryReaderContext PopContext(long position)
 
         internal BsonBinaryReaderContext PushContext(ContextType contextType, long startPosition, long size)
         {
-            return new BsonBinaryReaderContext(this, contextType, startPosition, size);
+            if (_cachedPushContext == null)
+                _cachedPushContext = new BsonBinaryReaderContext(this, contextType, startPosition, size);
+            else
+            {
+                _cachedPushContext._contextType = contextType;
+                _cachedPushContext._startPosition = startPosition;
+                _cachedPushContext._size = size;
+                _cachedPushContext._currentArrayIndex = -1;
+                _cachedPushContext._currentElementName = null;
+            }
+            return _cachedPushContext;
         }
     }
 }

src/MongoDB.Bson/IO/BsonBinaryWriterContext.cs

@@ -18,7 +18,8 @@ namespace MongoDB.Bson.IO
     internal class BsonBinaryWriterContext
     {
         // private fields
-        private BsonBinaryWriterContext _parentContext;
+        private readonly BsonBinaryWriterContext _parentContext;
+        private BsonBinaryWriterContext _cachedPushContext;
         private ContextType _contextType;
         private long _startPosition;
         private int _index; // used when contextType is Array
@@ -63,7 +64,15 @@ internal BsonBinaryWriterContext PopContext()
 
         internal BsonBinaryWriterContext PushContext(ContextType contextType, long startPosition)
         {
-            return new BsonBinaryWriterContext(this, contextType, startPosition);
+            if (_cachedPushContext == null)
+                _cachedPushContext = new BsonBinaryWriterContext(this, contextType, startPosition);
+            else
+            {
+                _cachedPushContext._contextType = contextType;
+                _cachedPushContext._startPosition = startPosition;
+                _cachedPushContext._index = 0;
+            }
+            return _cachedPushContext;
         }
     }
 }

src/MongoDB.Bson/IO/BsonDocumentReaderContext.cs

@@ -18,20 +18,23 @@ namespace MongoDB.Bson.IO
     internal class BsonDocumentReaderContext
     {
         // private fields
-        private BsonDocumentReaderContext _parentContext;
+        private readonly BsonDocumentReaderContext _parentContext;
+        private BsonDocumentReaderContext _cachedPushContext;
         private ContextType _contextType;
         private BsonDocument _document;
         private BsonArray _array;
         private int _index;
 
         // constructors
-        internal BsonDocumentReaderContext(
+        private BsonDocumentReaderContext(
             BsonDocumentReaderContext parentContext,
             ContextType contextType,
+            BsonDocument document,
             BsonArray array)
         {
             _parentContext = parentContext;
             _contextType = contextType;
+            _document = document;
             _array = array;
         }
 
@@ -127,12 +130,26 @@ public BsonDocumentReaderContext PopContext()
 
         internal BsonDocumentReaderContext PushContext(ContextType contextType, BsonArray array)
         {
-            return new BsonDocumentReaderContext(this, contextType, array);
+            return PushContext(contextType, null, array);
         }
 
         internal BsonDocumentReaderContext PushContext(ContextType contextType, BsonDocument document)
         {
-            return new BsonDocumentReaderContext(this, contextType, document);
+            return PushContext(contextType, document, null);
+        }
+
+        private BsonDocumentReaderContext PushContext(ContextType contextType, BsonDocument document, BsonArray array)
+        {
+            if (_cachedPushContext == null)
+                _cachedPushContext = new BsonDocumentReaderContext(this, contextType, document, array);
+            else
+            {
+                _cachedPushContext._contextType = contextType;
+                _cachedPushContext._document = document;
+                _cachedPushContext._array = array;
+                _cachedPushContext._index = 0;
+            }
+            return _cachedPushContext;
         }
     }
 }

src/MongoDB.Bson/IO/BsonDocumentWriterContext.cs

@@ -18,7 +18,8 @@ namespace MongoDB.Bson.IO
     internal class BsonDocumentWriterContext
     {
         // private fields
-        private BsonDocumentWriterContext _parentContext;
+        private readonly BsonDocumentWriterContext _parentContext;
+        private BsonDocumentWriterContext _cachedPushContext;
         private ContextType _contextType;
         private BsonDocument _document;
         private BsonArray _array;
@@ -39,20 +40,14 @@ internal BsonDocumentWriterContext(
         private BsonDocumentWriterContext(
             BsonDocumentWriterContext parentContext,
             ContextType contextType,
-            BsonArray array)
-        {
-            _parentContext = parentContext;
-            _contextType = contextType;
-            _array = array;
-        }
-
-        private BsonDocumentWriterContext(
-            BsonDocumentWriterContext parentContext,
-            ContextType contextType,
+            BsonDocument document,
+            BsonArray array,
             string code)
         {
             _parentContext = parentContext;
             _contextType = contextType;
+            _document = document;
+            _array = array;
             _code = code;
         }
 
@@ -95,17 +90,32 @@ internal BsonDocumentWriterContext PopContext()
 
         internal BsonDocumentWriterContext PushContext(ContextType contextType, BsonDocument document)
         {
-            return new BsonDocumentWriterContext(this, contextType, document);
+            return PushContext(contextType, document, null, null);
         }
 
         internal BsonDocumentWriterContext PushContext(ContextType contextType, BsonArray array)
         {
-            return new BsonDocumentWriterContext(this, contextType, array);
+            return PushContext(contextType, null, array, null);
         }
 
         internal BsonDocumentWriterContext PushContext(ContextType contextType, string code)
         {
-            return new BsonDocumentWriterContext(this, contextType, code);
+            return PushContext(contextType, null, null, code);
+        }
+
+        private BsonDocumentWriterContext PushContext(ContextType contextType, BsonDocument document, BsonArray array, string code)
+        {
+            if (_cachedPushContext == null)
+                _cachedPushContext = new BsonDocumentWriterContext(this, contextType, document, array, code);
+            else
+            {
+                _cachedPushContext._contextType = contextType;
+                _cachedPushContext._document = document;
+                _cachedPushContext._array = array;
+                _cachedPushContext._code = code;
+                _cachedPushContext._name = null;
+            }
+            return _cachedPushContext;
         }
     }
 }

src/MongoDB.Bson/IO/JsonReaderContext.cs

@@ -18,7 +18,8 @@ namespace MongoDB.Bson.IO
     internal class JsonReaderContext
     {
         // private fields
-        private JsonReaderContext _parentContext;
+        private readonly JsonReaderContext _parentContext;
+        private JsonReaderContext _cachedPushContext;
         private ContextType _contextType;
 
         // constructors
@@ -56,7 +57,11 @@ public JsonReaderContext PopContext()
 
         internal JsonReaderContext PushContext(ContextType contextType)
         {
-            return new JsonReaderContext(this, contextType);
+            if (_cachedPushContext == null)
+                _cachedPushContext = new JsonReaderContext(this, contextType);
+            else
+                _cachedPushContext._contextType = contextType;
+            return _cachedPushContext;
         }
     }
 }

src/MongoDB.Bson/IO/JsonWriterContext.cs

@@ -18,7 +18,8 @@ namespace MongoDB.Bson.IO
     internal class JsonWriterContext
     {
         // private fields
-        private JsonWriterContext _parentContext;
+        private readonly JsonWriterContext _parentContext;
+        private JsonWriterContext _cachedPushContext;
         private ContextType _contextType;
         private string _indentation;
         private bool _hasElements = false;
@@ -60,7 +61,14 @@ internal JsonWriterContext PopContext()
 
         internal JsonWriterContext PushContext(ContextType contextType, string indentChars)
         {
-            return new JsonWriterContext(this, contextType, indentChars);
+            if (_cachedPushContext == null)
+                _cachedPushContext = new JsonWriterContext(this, contextType, indentChars);
+            else
+            {
+                _cachedPushContext._contextType = contextType;
+                _cachedPushContext._hasElements = false;
+            }
+            return _cachedPushContext;
         }
     }
 }