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Diffstat (limited to 'csharp/src/ProtocolBuffers/ExtensionRegistryLite.cs')
| -rw-r--r-- | csharp/src/ProtocolBuffers/ExtensionRegistryLite.cs | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/csharp/src/ProtocolBuffers/ExtensionRegistryLite.cs b/csharp/src/ProtocolBuffers/ExtensionRegistryLite.cs new file mode 100644 index 00000000..cc4a50bb --- /dev/null +++ b/csharp/src/ProtocolBuffers/ExtensionRegistryLite.cs @@ -0,0 +1,232 @@ +#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(new ExtensionIntPairEqualityComparer()),
+ 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(new ExtensionIntPairEqualityComparer()), 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;
+ }
+ }
+
+ internal class ExtensionIntPairEqualityComparer : IEqualityComparer<ExtensionIntPair>
+ {
+ public bool Equals(ExtensionIntPair x, ExtensionIntPair y)
+ {
+ return x.Equals(y);
+ }
+ public int GetHashCode(ExtensionIntPair obj)
+ {
+ return obj.GetHashCode();
+ }
+ }
+ }
+}
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