#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 ExtensionByNameMap = System.Collections.Generic.Dictionary<object, System.Collections.Generic.Dictionary<string, Google.ProtocolBuffers.IGeneratedExtensionLite>>; | |
using ExtensionByIdMap = System.Collections.Generic.Dictionary<Google.ProtocolBuffers.ExtensionRegistry.ExtensionIntPair, Google.ProtocolBuffers.IGeneratedExtensionLite>; | |
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 | |
{ | |
private static readonly ExtensionRegistry empty = new ExtensionRegistry( | |
new ExtensionByNameMap(), | |
new ExtensionByIdMap(), | |
true); | |
private readonly ExtensionByNameMap extensionsByName; | |
private readonly ExtensionByIdMap extensionsByNumber; | |
private readonly bool readOnly; | |
private ExtensionRegistry(ExtensionByNameMap byName, ExtensionByIdMap byNumber, bool readOnly) | |
{ | |
this.extensionsByName = byName; | |
this.extensionsByNumber = byNumber; | |
this.readOnly = readOnly; | |
} | |
/// <summary> | |
/// Construct a new, empty instance. | |
/// </summary> | |
public static ExtensionRegistry CreateInstance() | |
{ | |
return new ExtensionRegistry(new ExtensionByNameMap(), new ExtensionByIdMap(), false); | |
} | |
public ExtensionRegistry AsReadOnly() | |
{ | |
return new ExtensionRegistry(extensionsByName, extensionsByNumber, true); | |
} | |
/// <summary> | |
/// Get the unmodifiable singleton empty instance. | |
/// </summary> | |
public static ExtensionRegistry Empty | |
{ | |
get { return empty; } | |
} | |
/// <summary> | |
/// Finds an extension by containing type and field number. | |
/// A null reference is returned if the extension can't be found. | |
/// </summary> | |
public IGeneratedExtensionLite this[IMessageLite containingType, int fieldNumber] | |
{ | |
get | |
{ | |
IGeneratedExtensionLite ret; | |
extensionsByNumber.TryGetValue(new ExtensionIntPair(containingType, fieldNumber), out ret); | |
return ret; | |
} | |
} | |
public IGeneratedExtensionLite FindByName(IMessageLite defaultInstanceOfType, string fieldName) | |
{ | |
return FindExtensionByName(defaultInstanceOfType, fieldName); | |
} | |
private IGeneratedExtensionLite FindExtensionByName(object forwhat, string fieldName) | |
{ | |
IGeneratedExtensionLite extension = null; | |
Dictionary<string, IGeneratedExtensionLite> map; | |
if (extensionsByName.TryGetValue(forwhat, out map) && map.TryGetValue(fieldName, out extension)) | |
{ | |
return extension; | |
} | |
return null; | |
} | |
/// <summary> | |
/// Add an extension from a generated file to the registry. | |
/// </summary> | |
public void Add(IGeneratedExtensionLite extension) | |
{ | |
if (readOnly) | |
{ | |
throw new InvalidOperationException("Cannot add entries to a read-only extension registry"); | |
} | |
extensionsByNumber.Add(new ExtensionIntPair(extension.ContainingType, extension.Number), extension); | |
Dictionary<string, IGeneratedExtensionLite> map; | |
if (!extensionsByName.TryGetValue(extension.ContainingType, out map)) | |
{ | |
extensionsByName.Add(extension.ContainingType, map = new Dictionary<string, IGeneratedExtensionLite>()); | |
} | |
map[extension.Descriptor.Name] = extension; | |
map[extension.Descriptor.FullName] = extension; | |
} | |
/// <summary> | |
/// Nested type just used to represent a pair of MessageDescriptor and int, as | |
/// the key into the "by number" map. | |
/// </summary> | |
internal struct ExtensionIntPair : IEquatable<ExtensionIntPair> | |
{ | |
private readonly object msgType; | |
private readonly int number; | |
internal ExtensionIntPair(object msgType, int number) | |
{ | |
this.msgType = msgType; | |
this.number = number; | |
} | |
public override int GetHashCode() | |
{ | |
return msgType.GetHashCode()*((1 << 16) - 1) + number; | |
} | |
public override bool Equals(object obj) | |
{ | |
if (!(obj is ExtensionIntPair)) | |
{ | |
return false; | |
} | |
return Equals((ExtensionIntPair) obj); | |
} | |
public bool Equals(ExtensionIntPair other) | |
{ | |
return msgType.Equals(other.msgType) && number == other.number; | |
} | |
} | |
} | |
} |