Update //third_party/protobuf to version 3.

third_party/protobuf/csharp/src/Google.Protobuf/Reflection/DescriptorPool.cs

Index: third_party/protobuf/csharp/src/Google.Protobuf/Reflection/DescriptorPool.cs
diff --git a/third_party/protobuf/csharp/src/Google.Protobuf/Reflection/DescriptorPool.cs b/third_party/protobuf/csharp/src/Google.Protobuf/Reflection/DescriptorPool.cs
new file mode 100644
index 0000000000000000000000000000000000000000..99ca4bf34f1418fc241aa734ba9d75d4fcae4a8d
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+++ b/third_party/protobuf/csharp/src/Google.Protobuf/Reflection/DescriptorPool.cs
@@ -0,0 +1,368 @@
+#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.Text;
+using System.Text.RegularExpressions;
+
+namespace Google.Protobuf.Reflection
+{
+    /// <summary>
+    /// Contains lookup tables containing all the descriptors defined in a particular file.
+    /// </summary>
+    internal sealed class DescriptorPool
+    {
+        private readonly IDictionary<string, IDescriptor> descriptorsByName =
+            new Dictionary<string, IDescriptor>();
+
+        private readonly IDictionary<DescriptorIntPair, FieldDescriptor> fieldsByNumber =
+            new Dictionary<DescriptorIntPair, FieldDescriptor>();
+
+        private readonly IDictionary<DescriptorIntPair, EnumValueDescriptor> enumValuesByNumber =
+            new Dictionary<DescriptorIntPair, EnumValueDescriptor>();
+
+        private readonly HashSet<FileDescriptor> dependencies;
+
+        internal DescriptorPool(FileDescriptor[] dependencyFiles)
+        {
+            dependencies = new HashSet<FileDescriptor>();
+            for (int i = 0; i < dependencyFiles.Length; i++)
+            {
+                dependencies.Add(dependencyFiles[i]);
+                ImportPublicDependencies(dependencyFiles[i]);
+            }
+
+            foreach (FileDescriptor dependency in dependencyFiles)
+            {
+                AddPackage(dependency.Package, dependency);
+            }
+        }
+
+        private void ImportPublicDependencies(FileDescriptor file)
+        {
+            foreach (FileDescriptor dependency in file.PublicDependencies)
+            {
+                if (dependencies.Add(dependency))
+                {
+                    ImportPublicDependencies(dependency);
+                }
+            }
+        }
+
+        /// <summary>
+        /// Finds a symbol of the given name within the pool.
+        /// </summary>
+        /// <typeparam name="T">The type of symbol to look for</typeparam>
+        /// <param name="fullName">Fully-qualified name to look up</param>
+        /// <returns>The symbol with the given name and type,
+        /// or null if the symbol doesn't exist or has the wrong type</returns>
+        internal T FindSymbol<T>(string fullName) where T : class
+        {
+            IDescriptor result;
+            descriptorsByName.TryGetValue(fullName, out result);
+            T descriptor = result as T;
+            if (descriptor != null)
+            {
+                return descriptor;
+            }
+
+            // dependencies contains direct dependencies and any *public* dependencies
+            // of those dependencies (transitively)... so we don't need to recurse here.
+            foreach (FileDescriptor dependency in dependencies)
+            {
+                dependency.DescriptorPool.descriptorsByName.TryGetValue(fullName, out result);
+                descriptor = result as T;
+                if (descriptor != null)
+                {
+                    return descriptor;
+                }
+            }
+
+            return null;
+        }
+
+        /// <summary>
+        /// Adds a package to the symbol tables. If a package by the same name
+        /// already exists, that is fine, but if some other kind of symbol
+        /// exists under the same name, an exception is thrown. If the package
+        /// has multiple components, this also adds the parent package(s).
+        /// </summary>
+        internal void AddPackage(string fullName, FileDescriptor file)
+        {
+            int dotpos = fullName.LastIndexOf('.');
+            String name;
+            if (dotpos != -1)
+            {
+                AddPackage(fullName.Substring(0, dotpos), file);
+                name = fullName.Substring(dotpos + 1);
+            }
+            else
+            {
+                name = fullName;
+            }
+
+            IDescriptor old;
+            if (descriptorsByName.TryGetValue(fullName, out old))
+            {
+                if (!(old is PackageDescriptor))
+                {
+                    throw new DescriptorValidationException(file,
+                                                            "\"" + name +
+                                                            "\" is already defined (as something other than a " +
+                                                            "package) in file \"" + old.File.Name + "\".");
+                }
+            }
+            descriptorsByName[fullName] = new PackageDescriptor(name, fullName, file);
+        }
+
+        /// <summary>
+        /// Adds a symbol to the symbol table.
+        /// </summary>
+        /// <exception cref="DescriptorValidationException">The symbol already existed
+        /// in the symbol table.</exception>
+        internal void AddSymbol(IDescriptor descriptor)
+        {
+            ValidateSymbolName(descriptor);
+            String fullName = descriptor.FullName;
+
+            IDescriptor old;
+            if (descriptorsByName.TryGetValue(fullName, out old))
+            {
+                int dotPos = fullName.LastIndexOf('.');
+                string message;
+                if (descriptor.File == old.File)
+                {
+                    if (dotPos == -1)
+                    {
+                        message = "\"" + fullName + "\" is already defined.";
+                    }
+                    else
+                    {
+                        message = "\"" + fullName.Substring(dotPos + 1) + "\" is already defined in \"" +
+                                  fullName.Substring(0, dotPos) + "\".";
+                    }
+                }
+                else
+                {
+                    message = "\"" + fullName + "\" is already defined in file \"" + old.File.Name + "\".";
+                }
+                throw new DescriptorValidationException(descriptor, message);
+            }
+            descriptorsByName[fullName] = descriptor;
+        }
+
+        private static readonly Regex ValidationRegex = new Regex("^[_A-Za-z][_A-Za-z0-9]*$",
+                                                                  FrameworkPortability.CompiledRegexWhereAvailable);
+
+        /// <summary>
+        /// Verifies that the descriptor's name is valid (i.e. it contains
+        /// only letters, digits and underscores, and does not start with a digit).
+        /// </summary>
+        /// <param name="descriptor"></param>
+        private static void ValidateSymbolName(IDescriptor descriptor)
+        {
+            if (descriptor.Name == "")
+            {
+                throw new DescriptorValidationException(descriptor, "Missing name.");
+            }
+            if (!ValidationRegex.IsMatch(descriptor.Name))
+            {
+                throw new DescriptorValidationException(descriptor,
+                                                        "\"" + descriptor.Name + "\" is not a valid identifier.");
+            }
+        }
+
+        /// <summary>
+        /// Returns the field with the given number in the given descriptor,
+        /// or null if it can't be found.
+        /// </summary>
+        internal FieldDescriptor FindFieldByNumber(MessageDescriptor messageDescriptor, int number)
+        {
+            FieldDescriptor ret;
+            fieldsByNumber.TryGetValue(new DescriptorIntPair(messageDescriptor, number), out ret);
+            return ret;
+        }
+
+        internal EnumValueDescriptor FindEnumValueByNumber(EnumDescriptor enumDescriptor, int number)
+        {
+            EnumValueDescriptor ret;
+            enumValuesByNumber.TryGetValue(new DescriptorIntPair(enumDescriptor, number), out ret);
+            return ret;
+        }
+
+        /// <summary>
+        /// Adds a field to the fieldsByNumber table.
+        /// </summary>
+        /// <exception cref="DescriptorValidationException">A field with the same
+        /// containing type and number already exists.</exception>
+        internal void AddFieldByNumber(FieldDescriptor field)
+        {
+            DescriptorIntPair key = new DescriptorIntPair(field.ContainingType, field.FieldNumber);
+            FieldDescriptor old;
+            if (fieldsByNumber.TryGetValue(key, out old))
+            {
+                throw new DescriptorValidationException(field, "Field number " + field.FieldNumber +
+                                                               "has already been used in \"" +
+                                                               field.ContainingType.FullName +
+                                                               "\" by field \"" + old.Name + "\".");
+            }
+            fieldsByNumber[key] = field;
+        }
+
+        /// <summary>
+        /// Adds an enum value to the enumValuesByNumber table. If an enum value
+        /// with the same type and number already exists, this method does nothing.
+        /// (This is allowed; the first value defined with the number takes precedence.)
+        /// </summary>
+        internal void AddEnumValueByNumber(EnumValueDescriptor enumValue)
+        {
+            DescriptorIntPair key = new DescriptorIntPair(enumValue.EnumDescriptor, enumValue.Number);
+            if (!enumValuesByNumber.ContainsKey(key))
+            {
+                enumValuesByNumber[key] = enumValue;
+            }
+        }
+
+        /// <summary>
+        /// Looks up a descriptor by name, relative to some other descriptor.
+        /// The name may be fully-qualified (with a leading '.'), partially-qualified,
+        /// or unqualified. C++-like name lookup semantics are used to search for the
+        /// matching descriptor.
+        /// </summary>
+        /// <remarks>
+        /// This isn't heavily optimized, but it's only used during cross linking anyway.
+        /// If it starts being used more widely, we should look at performance more carefully.
+        /// </remarks>
+        internal IDescriptor LookupSymbol(string name, IDescriptor relativeTo)
+        {
+            IDescriptor result;
+            if (name.StartsWith("."))
+            {
+                // Fully-qualified name.
+                result = FindSymbol<IDescriptor>(name.Substring(1));
+            }
+            else
+            {
+                // If "name" is a compound identifier, we want to search for the
+                // first component of it, then search within it for the rest.
+                int firstPartLength = name.IndexOf('.');
+                string firstPart = firstPartLength == -1 ? name : name.Substring(0, firstPartLength);
+
+                // We will search each parent scope of "relativeTo" looking for the
+                // symbol.
+                StringBuilder scopeToTry = new StringBuilder(relativeTo.FullName);
+
+                while (true)
+                {
+                    // Chop off the last component of the scope.
+
+                    int dotpos = scopeToTry.ToString().LastIndexOf(".");
+                    if (dotpos == -1)
+                    {
+                        result = FindSymbol<IDescriptor>(name);
+                        break;
+                    }
+                    else
+                    {
+                        scopeToTry.Length = dotpos + 1;
+
+                        // Append firstPart and try to find.
+                        scopeToTry.Append(firstPart);
+                        result = FindSymbol<IDescriptor>(scopeToTry.ToString());
+
+                        if (result != null)
+                        {
+                            if (firstPartLength != -1)
+                            {
+                                // We only found the first part of the symbol.  Now look for
+                                // the whole thing.  If this fails, we *don't* want to keep
+                                // searching parent scopes.
+                                scopeToTry.Length = dotpos + 1;
+                                scopeToTry.Append(name);
+                                result = FindSymbol<IDescriptor>(scopeToTry.ToString());
+                            }
+                            break;
+                        }
+
+                        // Not found.  Remove the name so we can try again.
+                        scopeToTry.Length = dotpos;
+                    }
+                }
+            }
+
+            if (result == null)
+            {
+                throw new DescriptorValidationException(relativeTo, "\"" + name + "\" is not defined.");
+            }
+            else
+            {
+                return result;
+            }
+        }
+
+        /// <summary>
+        /// Struct used to hold the keys for the fieldByNumber table.
+        /// </summary>
+        private struct DescriptorIntPair : IEquatable<DescriptorIntPair>
+        {
+            private readonly int number;
+            private readonly IDescriptor descriptor;
+
+            internal DescriptorIntPair(IDescriptor descriptor, int number)
+            {
+                this.number = number;
+                this.descriptor = descriptor;
+            }
+
+            public bool Equals(DescriptorIntPair other)
+            {
+                return descriptor == other.descriptor
+                       && number == other.number;
+            }
+
+            public override bool Equals(object obj)
+            {
+                if (obj is DescriptorIntPair)
+                {
+                    return Equals((DescriptorIntPair) obj);
+                }
+                return false;
+            }
+
+            public override int GetHashCode()
+            {
+                return descriptor.GetHashCode()*((1 << 16) - 1) + number;
+            }
+        }
+    }
+}