Some work on AbstractBuilder, and complete implementation of UnknownField and UnknownFieldSet

1 files changed, 161 insertions, 1 deletions

diff --git a/csharp/ProtocolBuffers/ExtensionRegistry.cs b/csharp/ProtocolBuffers/ExtensionRegistry.cs
index a8ed661d..6c36aff4 100644
--- a/csharp/ProtocolBuffers/ExtensionRegistry.cs
+++ b/csharp/ProtocolBuffers/ExtensionRegistry.cs
@@ -13,7 +13,167 @@
 // 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.Collections.Generic;
+using Google.ProtocolBuffers.Descriptors;
+using System;
+
 namespace Google.ProtocolBuffers {
-  public class ExtensionRegistry {
+  /// <summary>
+  /// TODO(jonskeet): Copy docs from Java
+  /// </summary>
+  public sealed class ExtensionRegistry {
+
+    private static readonly ExtensionRegistry empty = new ExtensionRegistry(
+        new Dictionary<string, ExtensionInfo>(),
+        new Dictionary<DescriptorIntPair, ExtensionInfo>(),
+        true);
+
+    private readonly IDictionary<string, ExtensionInfo> extensionsByName;
+    private readonly IDictionary<DescriptorIntPair, ExtensionInfo> extensionsByNumber;
+    private readonly bool readOnly;
+
+    private ExtensionRegistry(IDictionary<String, ExtensionInfo> extensionsByName,
+        IDictionary<DescriptorIntPair, ExtensionInfo> extensionsByNumber,
+        bool readOnly) {
+      this.extensionsByName = extensionsByName;
+      this.extensionsByNumber = extensionsByNumber;
+      this.readOnly = readOnly;
+    }
+
+    /// <summary>
+    /// Construct a new, empty instance.
+    /// </summary>
+    public static ExtensionRegistry CreateInstance() {
+      return new ExtensionRegistry(new Dictionary<string, ExtensionInfo>(),
+        new Dictionary<DescriptorIntPair, ExtensionInfo>(), false);
+    }
+
+    /// <summary>
+    /// Get the unmodifiable singleton empty instance.
+    /// </summary>
+    public static ExtensionRegistry Empty {
+      get { return empty; }
+    }
+
+    public ExtensionRegistry AsReadOnly() {
+      return new ExtensionRegistry(extensionsByName, extensionsByNumber, true);
+    }
+
+    /// <summary>
+    /// Finds an extension by fully-qualified field name, in the
+    /// proto namespace, i.e. result.Descriptor.FullName will match
+    /// <paramref name="fullName"/> if a match is found. A null
+    /// reference is returned if the extension can't be found.
+    /// </summary>
+    public ExtensionInfo this[string fullName] {
+      get {
+        ExtensionInfo ret;
+        extensionsByName.TryGetValue(fullName, out ret);
+        return ret;
+      }
+    }
+
+    /// <summary>
+    /// Finds an extension by containing type and field number.
+    /// A null reference is returned if the extension can't be found.
+    /// </summary>
+    public ExtensionInfo this[MessageDescriptor containingType, int fieldNumber] {
+      get {
+        ExtensionInfo ret;
+        extensionsByNumber.TryGetValue(new DescriptorIntPair(containingType, fieldNumber), out ret);
+        return ret;
+      }
+    }
+
+    /// <summary>
+    /// Add an extension from a generated file to the registry.
+    /// </summary>
+    public void Add<TContainer, TExtension> (GeneratedExtension<TContainer, TExtension> extension) 
+        where TContainer : IMessage<TContainer> {
+      if (extension.Descriptor.MappedType == MappedType.Message) {
+        Add(new ExtensionInfo(extension.Descriptor, extension.MessageDefaultInstance));
+      } else {
+        Add(new ExtensionInfo(extension.Descriptor, null));
+      }
+    }
+
+    /// <summary>
+    /// Adds a non-message-type extension to the registry by descriptor.
+    /// </summary>
+    /// <param name="type"></param>
+    public void Add(FieldDescriptor type) {
+      if (type.MappedType == MappedType.Message) {
+        throw new ArgumentException("ExtensionRegistry.Add() must be provided a default instance "
+            + "when adding an embedded message extension.");
+      }
+      Add(new ExtensionInfo(type, null));
+    }
+
+    /// <summary>
+    /// Adds a message-type-extension to the registry by descriptor.
+    /// </summary>
+    /// <param name="type"></param>
+    /// <param name="defaultInstance"></param>
+    public void Add(FieldDescriptor type, IMessage defaultInstance) {
+      if (type.MappedType != MappedType.Message) {
+        throw new ArgumentException("ExtensionRegistry.Add() provided a default instance for a "
+            + "non-message extension.");
+      }
+      Add(new ExtensionInfo(type, defaultInstance));
+    }
+
+    private void Add(ExtensionInfo extension) {
+      if (readOnly) {
+        throw new InvalidOperationException("Cannot add entries to a read-only extension registry");
+      }
+      if (!extension.Descriptor.IsExtension) {
+        throw new ArgumentException("ExtensionRegistry.add() was given a FieldDescriptor for a "
+            + "regular (non-extension) field.");
+      }
+
+      extensionsByName[extension.Descriptor.FullName] = extension;
+      extensionsByNumber[new DescriptorIntPair(extension.Descriptor.ContainingType,
+          extension.Descriptor.FieldNumber)] = extension;
+
+      FieldDescriptor field = extension.Descriptor;
+      if (field.ContainingType.Options.IsMessageSetWireFormat
+          && field.FieldType == FieldType.Message
+          && field.IsOptional
+          && field.ExtensionScope == field.MessageType) {
+        // This is an extension of a MessageSet type defined within the extension
+        // type's own scope.  For backwards-compatibility, allow it to be looked
+        // up by type name.
+        extensionsByName[field.MessageType.FullName] = extension;
+      }
+    }
+
+    /// <summary>
+    /// Nested type just used to represent a pair of MessageDescriptor and int, as
+    /// the key into the "by number" map.
+    /// </summary>
+    private struct DescriptorIntPair : IEquatable<DescriptorIntPair> {
+      readonly MessageDescriptor descriptor;
+      readonly int number;
+
+      internal DescriptorIntPair(MessageDescriptor descriptor, int number) {
+        this.descriptor = descriptor;
+        this.number = number;
+      }
+
+      public override int GetHashCode() {
+        return descriptor.GetHashCode() * ((1 << 16) - 1) + number;
+      }
+
+      public override bool Equals(object obj) {
+        if (!(obj is DescriptorIntPair)) {
+          return false;
+        }
+        return Equals((DescriptorIntPair)obj);
+      }
+
+      public bool Equals(DescriptorIntPair other) {
+        return descriptor == other.descriptor && number == other.number;
+      }
+    }
   }
 }