Imported protobuf-csharp-port into csharp/ tree

1 files changed, 215 insertions, 0 deletions

diff --git a/csharp/src/ProtocolBuffers/ExtensionRegistry.cs b/csharp/src/ProtocolBuffers/ExtensionRegistry.cs
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+++ b/csharp/src/ProtocolBuffers/ExtensionRegistry.cs
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+#region Copyright notice and license

+

+// Protocol Buffers - Google's data interchange format

+// Copyright 2008 Google Inc.  All rights reserved.

+// http://github.com/jskeet/dotnet-protobufs/

+// Original C++/Java/Python code:

+// http://code.google.com/p/protobuf/

+//

+// Redistribution and use in source and binary forms, with or without

+// modification, are permitted provided that the following conditions are

+// met:

+//

+//     * Redistributions of source code must retain the above copyright

+// notice, this list of conditions and the following disclaimer.

+//     * Redistributions in binary form must reproduce the above

+// copyright notice, this list of conditions and the following disclaimer

+// in the documentation and/or other materials provided with the

+// distribution.

+//     * Neither the name of Google Inc. nor the names of its

+// contributors may be used to endorse or promote products derived from

+// this software without specific prior written permission.

+//

+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

+

+#endregion

+

+using System;

+using System.Collections.Generic;

+using Google.ProtocolBuffers.Descriptors;

+

+namespace Google.ProtocolBuffers

+{

+    /// <summary>

+    /// A table of known extensions, searchable by name or field number.  When

+    /// parsing a protocol message that might have extensions, you must provide

+    /// an <see cref="ExtensionRegistry"/> in which you have registered any extensions

+    /// that you want to be able to parse.  Otherwise, those extensions will just

+    /// be treated like unknown fields.

+    /// </summary>

+    /// <example>

+    /// For example, if you had the <c>.proto</c> file:

+    /// <code>

+    /// option java_class = "MyProto";

+    ///

+    /// message Foo {

+    ///   extensions 1000 to max;

+    /// }

+    ///

+    /// extend Foo {

+    ///   optional int32 bar;

+    /// }

+    /// </code>

+    ///

+    /// Then you might write code like:

+    ///

+    /// <code>

+    /// ExtensionRegistry registry = ExtensionRegistry.CreateInstance();

+    /// registry.Add(MyProto.Bar);

+    /// MyProto.Foo message = MyProto.Foo.ParseFrom(input, registry);

+    /// </code>

+    /// </example>

+    ///

+    /// <remarks>

+    /// <para>You might wonder why this is necessary. Two alternatives might come to

+    /// mind. First, you might imagine a system where generated extensions are

+    /// automatically registered when their containing classes are loaded. This

+    /// is a popular technique, but is bad design; among other things, it creates a

+    /// situation where behavior can change depending on what classes happen to be

+    /// loaded. It also introduces a security vulnerability, because an

+    /// unprivileged class could cause its code to be called unexpectedly from a

+    /// privileged class by registering itself as an extension of the right type.

+    /// </para>

+    /// <para>Another option you might consider is lazy parsing: do not parse an

+    /// extension until it is first requested, at which point the caller must

+    /// provide a type to use. This introduces a different set of problems. First,

+    /// it would require a mutex lock any time an extension was accessed, which

+    /// would be slow. Second, corrupt data would not be detected until first

+    /// access, at which point it would be much harder to deal with it. Third, it

+    /// could violate the expectation that message objects are immutable, since the

+    /// type provided could be any arbitrary message class. An unprivileged user

+    /// could take advantage of this to inject a mutable object into a message

+    /// belonging to privileged code and create mischief.</para>

+    /// </remarks>

+    public sealed partial class ExtensionRegistry

+    {

+        /// <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>

+        [Obsolete("Please use the FindByName method instead.", true)]

+        public ExtensionInfo this[string fullName]

+        {

+            get

+            {

+                foreach (IGeneratedExtensionLite ext in extensionsByNumber.Values)

+                {

+                    if (StringComparer.Ordinal.Equals(ext.Descriptor.FullName, fullName))

+                    {

+                        return ext as ExtensionInfo;

+                    }

+                }

+                return null;

+            }

+        }

+

+#if !LITE

+        /// <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

+            {

+                IGeneratedExtensionLite ret;

+                extensionsByNumber.TryGetValue(new ExtensionIntPair(containingType, fieldNumber), out ret);

+                return ret as ExtensionInfo;

+            }

+        }

+

+        public ExtensionInfo FindByName(MessageDescriptor containingType, string fieldName)

+        {

+            return FindExtensionByName(containingType, fieldName) as ExtensionInfo;

+        }

+#endif

+

+        /// <summary>

+        /// Add an extension from a generated file to the registry.

+        /// </summary>

+        public void Add<TExtension>(GeneratedExtensionBase<TExtension> extension)

+        {

+            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.");

+            }

+

+            IGeneratedExtensionLite liteExtension = extension;

+            Add(liteExtension);

+

+            FieldDescriptor field = extension.Descriptor;

+            if (field.ContainingType.Options.MessageSetWireFormat

+                && 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.

+                Dictionary<string, IGeneratedExtensionLite> map;

+                if (extensionsByName.TryGetValue(liteExtension.ContainingType, out map))

+                {

+                    map[field.MessageType.FullName] = extension;

+                }

+            }

+        }

+    }

+}
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