/// <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.");
}
result.CrossLink();
return(result);
}
private FileDescriptor(ByteString descriptorData, FileDescriptorProto proto, IEnumerable <FileDescriptor> dependencies, DescriptorPool pool, bool allowUnknownDependencies, GeneratedClrTypeInfo generatedCodeInfo)
{
SerializedData = descriptorData;
DescriptorPool = pool;
Proto = proto;
Dependencies = new ReadOnlyCollection <FileDescriptor>(dependencies.ToList());
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));
Extensions = new ExtensionCollection(this, generatedCodeInfo?.Extensions);
declarations = new Lazy <Dictionary <IDescriptor, DescriptorDeclaration> >(CreateDeclarationMap, LazyThreadSafetyMode.ExecutionAndPublication);
if (!proto.HasSyntax || proto.Syntax == "proto2")
{
Syntax = Syntax.Proto2;
}
else if (proto.Syntax == "proto3")
{
Syntax = Syntax.Proto3;
}
else
{
Syntax = Syntax.Unknown;
}
}
/// <summary>
/// Converts the given descriptor binary data into FileDescriptor objects.
/// Note: reflection using the returned FileDescriptors is not currently supported.
/// </summary>
/// <param name="descriptorData">The binary file descriptor proto data. Must not be null, and any
/// dependencies must come before the descriptor which depends on them. (If A depends on B, and B
/// depends on C, then the descriptors must be presented in the order C, B, A.) This is compatible
/// with the order in which protoc provides descriptors to plugins.</param>
/// <returns>The file descriptors corresponding to <paramref name="descriptorData"/>.</returns>
public static IReadOnlyList <FileDescriptor> BuildFromByteStrings(IEnumerable <ByteString> descriptorData)
{
ProtoPreconditions.CheckNotNull(descriptorData, nameof(descriptorData));
// TODO: See if we can build a single DescriptorPool instead of building lots of them.
// This will all behave correctly, but it's less efficient than we'd like.
var descriptors = new List <FileDescriptor>();
var descriptorsByName = new Dictionary <string, FileDescriptor>();
foreach (var data in descriptorData)
{
var proto = FileDescriptorProto.Parser.ParseFrom(data);
var dependencies = new List <FileDescriptor>();
foreach (var dependencyName in proto.Dependency)
{
FileDescriptor dependency;
if (!descriptorsByName.TryGetValue(dependencyName, out dependency))
{
throw new ArgumentException($"Dependency missing: {dependencyName}");
}
dependencies.Add(dependency);
}
var pool = new DescriptorPool(dependencies);
FileDescriptor descriptor = new FileDescriptor(
data, proto, dependencies, pool,
allowUnknownDependencies: false, generatedCodeInfo: null);
descriptor.CrossLink();
descriptors.Add(descriptor);
if (descriptorsByName.ContainsKey(descriptor.Name))
{
throw new ArgumentException($"Duplicate descriptor name: {descriptor.Name}");
}
descriptorsByName.Add(descriptor.Name, descriptor);
}
return(new ReadOnlyCollection <FileDescriptor>(descriptors));
}
