#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;
}
}
}
}