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Diffstat (limited to 'csharp/src/Google.Protobuf/Reflection/FileDescriptor.cs')
| -rw-r--r-- | csharp/src/Google.Protobuf/Reflection/FileDescriptor.cs | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/csharp/src/Google.Protobuf/Reflection/FileDescriptor.cs b/csharp/src/Google.Protobuf/Reflection/FileDescriptor.cs new file mode 100644 index 00000000..ab7cd922 --- /dev/null +++ b/csharp/src/Google.Protobuf/Reflection/FileDescriptor.cs @@ -0,0 +1,344 @@ +#region Copyright notice and license +// Protocol Buffers - Google's data interchange format +// Copyright 2008 Google Inc. All rights reserved. +// https://developers.google.com/protocol-buffers/ +// +// 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 System.Collections.ObjectModel; + +namespace Google.Protobuf.Reflection +{ + /// <summary> + /// Describes a .proto file, including everything defined within. + /// IDescriptor is implemented such that the File property returns this descriptor, + /// and the FullName is the same as the Name. + /// </summary> + public sealed class FileDescriptor : IDescriptor + { + private FileDescriptor(ByteString descriptorData, FileDescriptorProto proto, FileDescriptor[] dependencies, DescriptorPool pool, bool allowUnknownDependencies, GeneratedClrTypeInfo generatedCodeInfo) + { + SerializedData = descriptorData; + DescriptorPool = pool; + Proto = proto; + Dependencies = new ReadOnlyCollection<FileDescriptor>((FileDescriptor[]) dependencies.Clone()); + + PublicDependencies = DeterminePublicDependencies(this, proto, dependencies, allowUnknownDependencies); + + pool.AddPackage(Package, this); + + MessageTypes = DescriptorUtil.ConvertAndMakeReadOnly(proto.MessageType, + (message, index) => + new MessageDescriptor(message, this, null, index, generatedCodeInfo.NestedTypes[index])); + + EnumTypes = DescriptorUtil.ConvertAndMakeReadOnly(proto.EnumType, + (enumType, index) => + new EnumDescriptor(enumType, this, null, index, generatedCodeInfo.NestedEnums[index])); + + Services = DescriptorUtil.ConvertAndMakeReadOnly(proto.Service, + (service, index) => + new ServiceDescriptor(service, this, index)); + } + + /// <summary> + /// Computes the full name of a descriptor within this file, with an optional parent message. + /// </summary> + internal string ComputeFullName(MessageDescriptor parent, string name) + { + if (parent != null) + { + return parent.FullName + "." + name; + } + if (Package.Length > 0) + { + return Package + "." + name; + } + return name; + } + + /// <summary> + /// Extracts public dependencies from direct dependencies. This is a static method despite its + /// first parameter, as the value we're in the middle of constructing is only used for exceptions. + /// </summary> + private static IList<FileDescriptor> DeterminePublicDependencies(FileDescriptor @this, FileDescriptorProto proto, FileDescriptor[] dependencies, bool allowUnknownDependencies) + { + var nameToFileMap = new Dictionary<string, FileDescriptor>(); + foreach (var file in dependencies) + { + nameToFileMap[file.Name] = file; + } + var publicDependencies = new List<FileDescriptor>(); + for (int i = 0; i < proto.PublicDependency.Count; i++) + { + int index = proto.PublicDependency[i]; + if (index < 0 || index >= proto.Dependency.Count) + { + throw new DescriptorValidationException(@this, "Invalid public dependency index."); + } + string name = proto.Dependency[index]; + FileDescriptor file = nameToFileMap[name]; + if (file == null) + { + if (!allowUnknownDependencies) + { + throw new DescriptorValidationException(@this, "Invalid public dependency: " + name); + } + // Ignore unknown dependencies. + } + else + { + publicDependencies.Add(file); + } + } + return new ReadOnlyCollection<FileDescriptor>(publicDependencies); + } + + /// <value> + /// The descriptor in its protocol message representation. + /// </value> + internal FileDescriptorProto Proto { get; } + + /// <value> + /// The file name. + /// </value> + public string Name => Proto.Name; + + /// <summary> + /// The package as declared in the .proto file. This may or may not + /// be equivalent to the .NET namespace of the generated classes. + /// </summary> + public string Package => Proto.Package; + + /// <value> + /// Unmodifiable list of top-level message types declared in this file. + /// </value> + public IList<MessageDescriptor> MessageTypes { get; } + + /// <value> + /// Unmodifiable list of top-level enum types declared in this file. + /// </value> + public IList<EnumDescriptor> EnumTypes { get; } + + /// <value> + /// Unmodifiable list of top-level services declared in this file. + /// </value> + public IList<ServiceDescriptor> Services { get; } + + /// <value> + /// Unmodifiable list of this file's dependencies (imports). + /// </value> + public IList<FileDescriptor> Dependencies { get; } + + /// <value> + /// Unmodifiable list of this file's public dependencies (public imports). + /// </value> + public IList<FileDescriptor> PublicDependencies { get; } + + /// <value> + /// The original serialized binary form of this descriptor. + /// </value> + public ByteString SerializedData { get; } + + /// <value> + /// Implementation of IDescriptor.FullName - just returns the same as Name. + /// </value> + string IDescriptor.FullName => Name; + + /// <value> + /// Implementation of IDescriptor.File - just returns this descriptor. + /// </value> + FileDescriptor IDescriptor.File => this; + + /// <value> + /// Pool containing symbol descriptors. + /// </value> + internal DescriptorPool DescriptorPool { get; } + + /// <summary> + /// Finds a type (message, enum, service or extension) in the file by name. Does not find nested types. + /// </summary> + /// <param name="name">The unqualified type name to look for.</param> + /// <typeparam name="T">The type of descriptor to look for</typeparam> + /// <returns>The type's descriptor, or null if not found.</returns> + public T FindTypeByName<T>(String name) + where T : class, IDescriptor + { + // Don't allow looking up nested types. This will make optimization + // easier later. + if (name.IndexOf('.') != -1) + { + return null; + } + if (Package.Length > 0) + { + name = Package + "." + name; + } + T result = DescriptorPool.FindSymbol<T>(name); + if (result != null && result.File == this) + { + return result; + } + return null; + } + + /// <summary> + /// Builds a FileDescriptor from its protocol buffer representation. + /// </summary> + /// <param name="descriptorData">The original serialized descriptor data. + /// We have only limited proto2 support, so serializing FileDescriptorProto + /// would not necessarily give us this.</param> + /// <param name="proto">The protocol message form of the FileDescriptor.</param> + /// <param name="dependencies">FileDescriptors corresponding to all of the + /// file's dependencies, in the exact order listed in the .proto file. May be null, + /// in which case it is treated as an empty array.</param> + /// <param name="allowUnknownDependencies">Whether unknown dependencies are ignored (true) or cause an exception to be thrown (false).</param> + /// <param name="generatedCodeInfo">Details about generated code, for the purposes of reflection.</param> + /// <exception cref="DescriptorValidationException">If <paramref name="proto"/> is not + /// a valid descriptor. This can occur for a number of reasons, such as a field + /// having an undefined type or because two messages were defined with the same name.</exception> + private static FileDescriptor BuildFrom(ByteString descriptorData, FileDescriptorProto proto, FileDescriptor[] dependencies, bool allowUnknownDependencies, GeneratedClrTypeInfo generatedCodeInfo) + { + // Building descriptors involves two steps: translating and linking. + // In the translation step (implemented by FileDescriptor's + // constructor), we build an object tree mirroring the + // FileDescriptorProto's tree and put all of the descriptors into the + // DescriptorPool's lookup tables. In the linking step, we look up all + // type references in the DescriptorPool, so that, for example, a + // FieldDescriptor for an embedded message contains a pointer directly + // to the Descriptor for that message's type. We also detect undefined + // types in the linking step. + if (dependencies == null) + { + dependencies = new FileDescriptor[0]; + } + + DescriptorPool pool = new DescriptorPool(dependencies); + FileDescriptor result = new FileDescriptor(descriptorData, proto, dependencies, pool, allowUnknownDependencies, generatedCodeInfo); + + // Validate that the dependencies we've been passed (as FileDescriptors) are actually the ones we + // need. + if (dependencies.Length != proto.Dependency.Count) + { + throw new DescriptorValidationException( + result, + "Dependencies passed to FileDescriptor.BuildFrom() don't match " + + "those listed in the FileDescriptorProto."); + } + for (int i = 0; i < proto.Dependency.Count; i++) + { + if (dependencies[i].Name != proto.Dependency[i]) + { + throw new DescriptorValidationException( + result, + "Dependencies passed to FileDescriptor.BuildFrom() don't match " + + "those listed in the FileDescriptorProto. Expected: " + + proto.Dependency[i] + " but was: " + dependencies[i].Name); + } + } + + result.CrossLink(); + return result; + } + + private void CrossLink() + { + foreach (MessageDescriptor message in MessageTypes) + { + message.CrossLink(); + } + + foreach (ServiceDescriptor service in Services) + { + service.CrossLink(); + } + } + + /// <summary> + /// Creates a descriptor for generated code. + /// </summary> + /// <remarks> + /// This method is only designed to be used by the results of generating code with protoc, + /// which creates the appropriate dependencies etc. It has to be public because the generated + /// code is "external", but should not be called directly by end users. + /// </remarks> + public static FileDescriptor FromGeneratedCode( + byte[] descriptorData, + FileDescriptor[] dependencies, + GeneratedClrTypeInfo generatedCodeInfo) + { + FileDescriptorProto proto; + try + { + proto = FileDescriptorProto.Parser.ParseFrom(descriptorData); + } + catch (InvalidProtocolBufferException e) + { + throw new ArgumentException("Failed to parse protocol buffer descriptor for generated code.", e); + } + + try + { + // When building descriptors for generated code, we allow unknown + // dependencies by default. + return BuildFrom(ByteString.CopyFrom(descriptorData), proto, dependencies, true, generatedCodeInfo); + } + catch (DescriptorValidationException e) + { + throw new ArgumentException($"Invalid embedded descriptor for \"{proto.Name}\".", e); + } + } + + /// <summary> + /// Returns a <see cref="System.String" /> that represents this instance. + /// </summary> + /// <returns> + /// A <see cref="System.String" /> that represents this instance. + /// </returns> + public override string ToString() + { + return $"FileDescriptor for {Name}"; + } + + /// <summary> + /// Returns the file descriptor for descriptor.proto. + /// </summary> + /// <remarks> + /// This is used for protos which take a direct dependency on <c>descriptor.proto</c>, typically for + /// annotations. While <c>descriptor.proto</c> is a proto2 file, it is built into the Google.Protobuf + /// runtime for reflection purposes. The messages are internal to the runtime as they would require + /// proto2 semantics for full support, but the file descriptor is available via this property. The + /// C# codegen in protoc automatically uses this property when it detects a dependency on <c>descriptor.proto</c>. + /// </remarks> + /// <value> + /// The file descriptor for <c>descriptor.proto</c>. + /// </value> + public static FileDescriptor DescriptorProtoFileDescriptor { get { return DescriptorReflection.Descriptor; } } + } +}
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