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#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;
using System.Linq;
namespace Google.Protobuf.Reflection
{
/// <summary>
/// Describes a message type.
/// </summary>
public sealed class MessageDescriptor : DescriptorBase
{
private static readonly HashSet<string> WellKnownTypeNames = new HashSet<string>
{
"google/protobuf/any.proto",
"google/protobuf/api.proto",
"google/protobuf/duration.proto",
"google/protobuf/empty.proto",
"google/protobuf/wrappers.proto",
"google/protobuf/timestamp.proto",
"google/protobuf/field_mask.proto",
"google/protobuf/source_context.proto",
"google/protobuf/struct.proto",
"google/protobuf/type.proto",
};
private readonly IList<FieldDescriptor> fieldsInDeclarationOrder;
private readonly IList<FieldDescriptor> fieldsInNumberOrder;
private readonly IDictionary<string, FieldDescriptor> jsonFieldMap;
internal MessageDescriptor(DescriptorProto proto, FileDescriptor file, MessageDescriptor parent, int typeIndex, GeneratedClrTypeInfo generatedCodeInfo)
: base(file, file.ComputeFullName(parent, proto.Name), typeIndex)
{
Proto = proto;
Parser = generatedCodeInfo?.Parser;
ClrType = generatedCodeInfo?.ClrType;
ContainingType = parent;
// Note use of generatedCodeInfo. rather than generatedCodeInfo?. here... we don't expect
// to see any nested oneofs, types or enums in "not actually generated" code... we do
// expect fields though (for map entry messages).
Oneofs = DescriptorUtil.ConvertAndMakeReadOnly(
proto.OneofDecl,
(oneof, index) =>
new OneofDescriptor(oneof, file, this, index, generatedCodeInfo.OneofNames[index]));
NestedTypes = DescriptorUtil.ConvertAndMakeReadOnly(
proto.NestedType,
(type, index) =>
new MessageDescriptor(type, file, this, index, generatedCodeInfo.NestedTypes[index]));
EnumTypes = DescriptorUtil.ConvertAndMakeReadOnly(
proto.EnumType,
(type, index) =>
new EnumDescriptor(type, file, this, index, generatedCodeInfo.NestedEnums[index]));
fieldsInDeclarationOrder = DescriptorUtil.ConvertAndMakeReadOnly(
proto.Field,
(field, index) =>
new FieldDescriptor(field, file, this, index, generatedCodeInfo?.PropertyNames[index]));
fieldsInNumberOrder = new ReadOnlyCollection<FieldDescriptor>(fieldsInDeclarationOrder.OrderBy(field => field.FieldNumber).ToArray());
// TODO: Use field => field.Proto.JsonName when we're confident it's appropriate. (And then use it in the formatter, too.)
jsonFieldMap = CreateJsonFieldMap(fieldsInNumberOrder);
file.DescriptorPool.AddSymbol(this);
Fields = new FieldCollection(this);
}
private static ReadOnlyDictionary<string, FieldDescriptor> CreateJsonFieldMap(IList<FieldDescriptor> fields)
{
var map = new Dictionary<string, FieldDescriptor>();
foreach (var field in fields)
{
map[field.Name] = field;
map[field.JsonName] = field;
}
return new ReadOnlyDictionary<string, FieldDescriptor>(map);
}
/// <summary>
/// The brief name of the descriptor's target.
/// </summary>
public override string Name => Proto.Name;
internal DescriptorProto Proto { get; }
/// <summary>
/// The CLR type used to represent message instances from this descriptor.
/// </summary>
/// <remarks>
/// <para>
/// The value returned by this property will be non-null for all regular fields. However,
/// if a message containing a map field is introspected, the list of nested messages will include
/// an auto-generated nested key/value pair message for the field. This is not represented in any
/// generated type, so this property will return null in such cases.
/// </para>
/// <para>
/// For wrapper types (<see cref="Google.Protobuf.WellKnownTypes.StringValue"/> and the like), the type returned here
/// will be the generated message type, not the native type used by reflection for fields of those types. Code
/// using reflection should call <see cref="IsWrapperType"/> to determine whether a message descriptor represents
/// a wrapper type, and handle the result appropriately.
/// </para>
/// </remarks>
public Type ClrType { get; }
/// <summary>
/// A parser for this message type.
/// </summary>
/// <remarks>
/// <para>
/// As <see cref="MessageDescriptor"/> is not generic, this cannot be statically
/// typed to the relevant type, but it should produce objects of a type compatible with <see cref="ClrType"/>.
/// </para>
/// <para>
/// The value returned by this property will be non-null for all regular fields. However,
/// if a message containing a map field is introspected, the list of nested messages will include
/// an auto-generated nested key/value pair message for the field. No message parser object is created for
/// such messages, so this property will return null in such cases.
/// </para>
/// <para>
/// For wrapper types (<see cref="Google.Protobuf.WellKnownTypes.StringValue"/> and the like), the parser returned here
/// will be the generated message type, not the native type used by reflection for fields of those types. Code
/// using reflection should call <see cref="IsWrapperType"/> to determine whether a message descriptor represents
/// a wrapper type, and handle the result appropriately.
/// </para>
/// </remarks>
public MessageParser Parser { get; }
/// <summary>
/// Returns whether this message is one of the "well known types" which may have runtime/protoc support.
/// </summary>
internal bool IsWellKnownType => File.Package == "google.protobuf" && WellKnownTypeNames.Contains(File.Name);
/// <summary>
/// Returns whether this message is one of the "wrapper types" used for fields which represent primitive values
/// with the addition of presence.
/// </summary>
internal bool IsWrapperType => File.Package == "google.protobuf" && File.Name == "google/protobuf/wrappers.proto";
/// <value>
/// If this is a nested type, get the outer descriptor, otherwise null.
/// </value>
public MessageDescriptor ContainingType { get; }
/// <value>
/// A collection of fields, which can be retrieved by name or field number.
/// </value>
public FieldCollection Fields { get; }
/// <value>
/// An unmodifiable list of this message type's nested types.
/// </value>
public IList<MessageDescriptor> NestedTypes { get; }
/// <value>
/// An unmodifiable list of this message type's enum types.
/// </value>
public IList<EnumDescriptor> EnumTypes { get; }
/// <value>
/// An unmodifiable list of the "oneof" field collections in this message type.
/// </value>
public IList<OneofDescriptor> Oneofs { get; }
/// <summary>
/// Finds a field by field name.
/// </summary>
/// <param name="name">The unqualified name of the field (e.g. "foo").</param>
/// <returns>The field's descriptor, or null if not found.</returns>
public FieldDescriptor FindFieldByName(String name) => File.DescriptorPool.FindSymbol<FieldDescriptor>(FullName + "." + name);
/// <summary>
/// Finds a field by field number.
/// </summary>
/// <param name="number">The field number within this message type.</param>
/// <returns>The field's descriptor, or null if not found.</returns>
public FieldDescriptor FindFieldByNumber(int number) => File.DescriptorPool.FindFieldByNumber(this, number);
/// <summary>
/// Finds a nested descriptor by name. The is valid for fields, nested
/// message types, oneofs and enums.
/// </summary>
/// <param name="name">The unqualified name of the descriptor, e.g. "Foo"</param>
/// <returns>The descriptor, or null if not found.</returns>
public T FindDescriptor<T>(string name) where T : class, IDescriptor =>
File.DescriptorPool.FindSymbol<T>(FullName + "." + name);
/// <summary>
/// Looks up and cross-links all fields and nested types.
/// </summary>
internal void CrossLink()
{
foreach (MessageDescriptor message in NestedTypes)
{
message.CrossLink();
}
foreach (FieldDescriptor field in fieldsInDeclarationOrder)
{
field.CrossLink();
}
foreach (OneofDescriptor oneof in Oneofs)
{
oneof.CrossLink();
}
}
/// <summary>
/// A collection to simplify retrieving the field accessor for a particular field.
/// </summary>
public sealed class FieldCollection
{
private readonly MessageDescriptor messageDescriptor;
internal FieldCollection(MessageDescriptor messageDescriptor)
{
this.messageDescriptor = messageDescriptor;
}
/// <value>
/// Returns the fields in the message as an immutable list, in the order in which they
/// are declared in the source .proto file.
/// </value>
public IList<FieldDescriptor> InDeclarationOrder() => messageDescriptor.fieldsInDeclarationOrder;
/// <value>
/// Returns the fields in the message as an immutable list, in ascending field number
/// order. Field numbers need not be contiguous, so there is no direct mapping from the
/// index in the list to the field number; to retrieve a field by field number, it is better
/// to use the <see cref="FieldCollection"/> indexer.
/// </value>
public IList<FieldDescriptor> InFieldNumberOrder() => messageDescriptor.fieldsInNumberOrder;
// TODO: consider making this public in the future. (Being conservative for now...)
/// <value>
/// Returns a read-only dictionary mapping the field names in this message as they're available
/// in the JSON representation to the field descriptors. For example, a field <c>foo_bar</c>
/// in the message would result two entries, one with a key <c>fooBar</c> and one with a key
/// <c>foo_bar</c>, both referring to the same field.
/// </value>
internal IDictionary<string, FieldDescriptor> ByJsonName() => messageDescriptor.jsonFieldMap;
/// <summary>
/// Retrieves the descriptor for the field with the given number.
/// </summary>
/// <param name="number">Number of the field to retrieve the descriptor for</param>
/// <returns>The accessor for the given field</returns>
/// <exception cref="KeyNotFoundException">The message descriptor does not contain a field
/// with the given number</exception>
public FieldDescriptor this[int number]
{
get
{
var fieldDescriptor = messageDescriptor.FindFieldByNumber(number);
if (fieldDescriptor == null)
{
throw new KeyNotFoundException("No such field number");
}
return fieldDescriptor;
}
}
/// <summary>
/// Retrieves the descriptor for the field with the given name.
/// </summary>
/// <param name="name">Name of the field to retrieve the descriptor for</param>
/// <returns>The descriptor for the given field</returns>
/// <exception cref="KeyNotFoundException">The message descriptor does not contain a field
/// with the given name</exception>
public FieldDescriptor this[string name]
{
get
{
var fieldDescriptor = messageDescriptor.FindFieldByName(name);
if (fieldDescriptor == null)
{
throw new KeyNotFoundException("No such field name");
}
return fieldDescriptor;
}
}
}
}
}