First cut at new layout

1 files changed, 200 insertions, 0 deletions

diff --git a/src/ProtocolBuffers/ExtendableMessage.cs b/src/ProtocolBuffers/ExtendableMessage.cs
new file mode 100644
index 00000000..a4a6e17e
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+++ b/src/ProtocolBuffers/ExtendableMessage.cs
@@ -0,0 +1,200 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.
+// http://code.google.com/p/protobuf/
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+using System;
+using System.Collections.Generic;
+using Google.ProtocolBuffers.Collections;
+using Google.ProtocolBuffers.Descriptors;
+
+namespace Google.ProtocolBuffers {
+  public abstract class ExtendableMessage<TMessage, TBuilder> : GeneratedMessage<TMessage, TBuilder>
+    where TMessage : GeneratedMessage<TMessage, TBuilder>
+    where TBuilder : GeneratedBuilder<TMessage, TBuilder> {
+
+    protected ExtendableMessage() {}
+    private readonly FieldSet extensions = FieldSet.CreateInstance();
+
+    /// <summary>
+    /// Access for the builder.
+    /// </summary>
+    internal FieldSet Extensions {
+      get { return extensions; }
+    }
+
+    /// <summary>
+    /// Checks if a singular extension is present.
+    /// </summary>
+    public bool HasExtension<TExtension>(GeneratedExtensionBase<TExtension> extension) {
+      return extensions.HasField(extension.Descriptor);
+    }
+
+    /// <summary>
+    /// Returns the number of elements in a repeated extension.
+    /// </summary>
+    public int GetExtensionCount<TExtension>(GeneratedExtensionBase<IList<TExtension>> extension) {
+      return extensions.GetRepeatedFieldCount(extension.Descriptor);
+    }
+
+    /// <summary>
+    /// Returns the value of an extension.
+    /// </summary>
+    public TExtension GetExtension<TExtension>(GeneratedExtensionBase<TExtension> extension) {
+      object value = extensions[extension.Descriptor];
+      if (value == null) {
+        return (TExtension) extension.MessageDefaultInstance;
+      } else {
+        return (TExtension) extension.FromReflectionType(value);
+      }
+    }
+
+    /// <summary>
+    /// Returns one element of a repeated extension.
+    /// </summary>
+    public TExtension GetExtension<TExtension>(GeneratedExtensionBase<IList<TExtension>> extension, int index) {
+      return (TExtension) extension.SingularFromReflectionType(extensions[extension.Descriptor, index]);
+    }
+
+    /// <summary>
+    /// Called to check if all extensions are initialized.
+    /// </summary>
+    protected bool ExtensionsAreInitialized {
+      get { return extensions.IsInitialized; }      
+    }
+
+    public override bool IsInitialized {
+      get {
+        return base.IsInitialized && ExtensionsAreInitialized;
+      }
+    }
+
+    #region Reflection
+    public override IDictionary<FieldDescriptor, object> AllFields {
+      get {
+        IDictionary<FieldDescriptor, object> result = GetMutableFieldMap();
+        foreach(KeyValuePair<FieldDescriptor, object> entry in extensions.AllFields) {
+          result[entry.Key] = entry.Value;
+        }
+        return Dictionaries.AsReadOnly(result);
+      }
+    }
+
+    public override bool HasField(FieldDescriptor field) {
+      if (field.IsExtension) {
+        VerifyContainingType(field);
+        return extensions.HasField(field);
+      } else {
+        return base.HasField(field);
+      }
+    }
+
+    public override object this[FieldDescriptor field] {
+      get {
+        if (field.IsExtension) {
+          VerifyContainingType(field);
+          object value = extensions[field];
+          if (value == null) {
+            // Lacking an ExtensionRegistry, we have no way to determine the
+            // extension's real type, so we return a DynamicMessage.
+            // TODO(jonskeet): Work out what this means
+            return DynamicMessage.GetDefaultInstance(field.MessageType);
+          } else {
+            return value;
+          }
+        } else {
+          return base[field];
+        }
+      }
+    }
+
+    public override int GetRepeatedFieldCount(FieldDescriptor field) {
+      if (field.IsExtension) {
+        VerifyContainingType(field);
+        return extensions.GetRepeatedFieldCount(field);
+      } else {
+        return base.GetRepeatedFieldCount(field);
+      }
+    }
+
+    public override object this[FieldDescriptor field, int index] {
+      get {
+        if (field.IsExtension) {
+          VerifyContainingType(field);
+          return extensions[field, index];
+        } else {
+          return base[field, index];
+        }
+      }
+    }
+  
+    internal void VerifyContainingType(FieldDescriptor field) {
+      if (field.ContainingType != DescriptorForType) {
+        throw new ArgumentException("FieldDescriptor does not match message type.");
+      }
+    }
+    #endregion
+
+    /// <summary>
+    /// Used by subclasses to serialize extensions. Extension ranges may be
+    /// interleaves with field numbers, but we must write them in canonical
+    /// (sorted by field number) order. This class helps us to write individual
+    /// ranges of extensions at once.
+    /// 
+    /// TODO(jonskeet): See if we can improve this in terms of readability.
+    /// </summary>
+    protected class ExtensionWriter {
+      readonly IEnumerator<KeyValuePair<FieldDescriptor, object>> iterator;
+      readonly FieldSet extensions;
+      KeyValuePair<FieldDescriptor, object>? next = null;
+
+      internal ExtensionWriter(ExtendableMessage<TMessage, TBuilder> message) {
+        extensions = message.extensions;
+        iterator = message.extensions.GetEnumerator();
+        if (iterator.MoveNext()) {
+          next = iterator.Current;
+        }
+      }
+
+      public void WriteUntil(int end, CodedOutputStream output) {
+        while (next != null && next.Value.Key.FieldNumber < end) {
+          extensions.WriteField(next.Value.Key, next.Value.Value, output);
+          if (iterator.MoveNext()) {
+            next = iterator.Current;
+          } else {
+            next = null;
+          }
+        }
+      }
+    }
+
+    protected ExtensionWriter CreateExtensionWriter(ExtendableMessage<TMessage, TBuilder> message) {
+      return new ExtensionWriter(message);
+    }
+
+    /// <summary>
+    /// Called by subclasses to compute the size of extensions.
+    /// </summary>
+    protected int ExtensionsSerializedSize {
+      get { return extensions.SerializedSize; }
+    }
+
+    internal void VerifyExtensionContainingType<TExtension>(GeneratedExtensionBase<TExtension> extension) {
+      if (extension.Descriptor.ContainingType != DescriptorForType) {
+        // This can only happen if someone uses unchecked operations.
+        throw new ArgumentException("Extension is for type \"" + extension.Descriptor.ContainingType.FullName
+          + "\" which does not match message type \"" + DescriptorForType.FullName + "\".");
+      }
+    }
+  }
+}