using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Reflection;
namespace Python.Runtime
{
static partial class InternString
{
private static readonly Dictionary _string2interns = new();
private static readonly Dictionary _intern2strings = new();
const BindingFlags PyIdentifierFieldFlags = BindingFlags.Static | BindingFlags.NonPublic;
static InternString()
{
var identifierNames = typeof(PyIdentifier).GetFields(PyIdentifierFieldFlags)
.Select(fi => fi.Name.Substring(1));
var validNames = new HashSet(identifierNames);
if (validNames.Count != _builtinNames.Length)
{
throw new InvalidOperationException("Identifiers args not matching");
}
foreach (var name in _builtinNames)
{
if (!validNames.Contains(name))
{
throw new InvalidOperationException($"{name} is not declared");
}
}
}
public static void Initialize()
{
Debug.Assert(_string2interns.Count == 0);
Type type = typeof(PyIdentifier);
foreach (string name in _builtinNames)
{
NewReference pyStr = Runtime.PyUnicode_InternFromString(name);
var op = new PyString(pyStr.StealOrThrow());
Debug.Assert(name == op.As());
SetIntern(name, op);
var field = type.GetField("f" + name, PyIdentifierFieldFlags)!;
field.SetValue(null, op.DangerousGetAddressOrNull());
}
}
public static void Shutdown()
{
foreach (var entry in _string2interns)
{
var field = typeof(PyIdentifier).GetField("f" + entry.Value, PyIdentifierFieldFlags)!;
entry.Value.Dispose();
field.SetValue(null, IntPtr.Zero);
}
_string2interns.Clear();
_intern2strings.Clear();
}
public static string? GetManagedString(BorrowedReference op)
{
if (TryGetInterned(op, out string s))
{
return s;
}
return Runtime.GetManagedString(op);
}
public static bool TryGetInterned(BorrowedReference op, out string s)
{
return _intern2strings.TryGetValue(op.DangerousGetAddress(), out s);
}
private static void SetIntern(string s, PyString op)
{
_string2interns.Add(s, op);
_intern2strings.Add(op.Reference.DangerousGetAddress(), s);
}
}
}