using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Globalization;
using System.Runtime.InteropServices;
using System.Security;
namespace Python.Runtime
{
///
/// Performs data conversions between managed types and Python types.
///
[SuppressUnmanagedCodeSecurity]
internal class Converter
{
private Converter()
{
}
private static NumberFormatInfo nfi;
private static Type objectType;
private static Type stringType;
private static Type singleType;
private static Type doubleType;
private static Type decimalType;
private static Type int16Type;
private static Type int32Type;
private static Type int64Type;
private static Type flagsType;
private static Type boolType;
private static Type typeType;
static Converter()
{
nfi = NumberFormatInfo.InvariantInfo;
objectType = typeof(Object);
stringType = typeof(String);
int16Type = typeof(Int16);
int32Type = typeof(Int32);
int64Type = typeof(Int64);
singleType = typeof(Single);
doubleType = typeof(Double);
decimalType = typeof(Decimal);
flagsType = typeof(FlagsAttribute);
boolType = typeof(Boolean);
typeType = typeof(Type);
}
///
/// Given a builtin Python type, return the corresponding CLR type.
///
internal static Type GetTypeByAlias(IntPtr op)
{
if (op == Runtime.PyStringType)
return stringType;
if (op == Runtime.PyUnicodeType)
return stringType;
if (op == Runtime.PyIntType)
return int32Type;
if (op == Runtime.PyLongType)
return int64Type;
if (op == Runtime.PyFloatType)
return doubleType;
if (op == Runtime.PyBoolType)
return boolType;
return null;
}
internal static IntPtr GetPythonTypeByAlias(Type op)
{
if (op == stringType)
return Runtime.PyUnicodeType;
if (op == int16Type)
return Runtime.PyIntType;
if (op == int32Type)
return Runtime.PyIntType;
if (op == int64Type)
return Runtime.PyIntType;
if (op == doubleType)
return Runtime.PyFloatType;
if (op == singleType)
return Runtime.PyFloatType;
if (op == boolType)
return Runtime.PyBoolType;
return IntPtr.Zero;
}
///
/// Return a Python object for the given native object, converting
/// basic types (string, int, etc.) into equivalent Python objects.
/// This always returns a new reference. Note that the System.Decimal
/// type has no Python equivalent and converts to a managed instance.
///
internal static IntPtr ToPython(T value)
{
return ToPython(value, typeof(T));
}
private static readonly Func IsTransparentProxy = GetIsTransparentProxy();
private static bool Never(object _) => false;
private static Func GetIsTransparentProxy()
{
var remoting = typeof(int).Assembly.GetType("System.Runtime.Remoting.RemotingServices");
if (remoting is null) return Never;
var isProxy = remoting.GetMethod("IsTransparentProxy", new[] { typeof(object) });
if (isProxy is null) return Never;
return (Func)Delegate.CreateDelegate(
typeof(Func), isProxy,
throwOnBindFailure: true);
}
internal static IntPtr ToPython(object value, Type type)
{
if (value is PyObject)
{
IntPtr handle = ((PyObject)value).Handle;
Runtime.XIncref(handle);
return handle;
}
IntPtr result = IntPtr.Zero;
// Null always converts to None in Python.
if (value == null)
{
result = Runtime.PyNone;
Runtime.XIncref(result);
return result;
}
if (Type.GetTypeCode(type) == TypeCode.Object && value.GetType() != typeof(object)) {
var encoded = PyObjectConversions.TryEncode(value, type);
if (encoded != null) {
result = encoded.Handle;
Runtime.XIncref(result);
return result;
}
}
if (value is IList && !(value is INotifyPropertyChanged) && value.GetType().IsGenericType)
{
using (var resultlist = new PyList())
{
foreach (object o in (IEnumerable)value)
{
using (var p = new PyObject(ToPython(o, o?.GetType())))
{
resultlist.Append(p);
}
}
Runtime.XIncref(resultlist.Handle);
return resultlist.Handle;
}
}
if (type.IsInterface)
{
var ifaceObj = (InterfaceObject)ClassManager.GetClass(type);
return ifaceObj.WrapObject(value);
}
// We need to special case interface array handling to ensure we
// produce the correct type. Value may be an array of some concrete
// type (FooImpl[]), but we want access to go via the interface type
// (IFoo[]).
if (type.IsArray && type.GetElementType().IsInterface)
{
return CLRObject.GetInstHandle(value, type);
}
// it the type is a python subclass of a managed type then return the
// underlying python object rather than construct a new wrapper object.
var pyderived = value as IPythonDerivedType;
if (null != pyderived)
{
if (!IsTransparentProxy(pyderived))
return ClassDerivedObject.ToPython(pyderived);
}
// hmm - from Python, we almost never care what the declared
// type is. we'd rather have the object bound to the actual
// implementing class.
type = value.GetType();
TypeCode tc = Type.GetTypeCode(type);
switch (tc)
{
case TypeCode.Object:
return CLRObject.GetInstHandle(value, type);
case TypeCode.String:
return Runtime.PyUnicode_FromString((string)value);
case TypeCode.Int32:
return Runtime.PyInt_FromInt32((int)value);
case TypeCode.Boolean:
if ((bool)value)
{
Runtime.XIncref(Runtime.PyTrue);
return Runtime.PyTrue;
}
Runtime.XIncref(Runtime.PyFalse);
return Runtime.PyFalse;
case TypeCode.Byte:
return Runtime.PyInt_FromInt32((int)((byte)value));
case TypeCode.Char:
return Runtime.PyUnicode_FromOrdinal((int)((char)value));
case TypeCode.Int16:
return Runtime.PyInt_FromInt32((int)((short)value));
case TypeCode.Int64:
return Runtime.PyLong_FromLongLong((long)value);
case TypeCode.Single:
// return Runtime.PyFloat_FromDouble((double)((float)value));
string ss = ((float)value).ToString(nfi);
IntPtr ps = Runtime.PyString_FromString(ss);
IntPtr op = Runtime.PyFloat_FromString(ps, IntPtr.Zero);
Runtime.XDecref(ps);
return op;
case TypeCode.Double:
return Runtime.PyFloat_FromDouble((double)value);
case TypeCode.SByte:
return Runtime.PyInt_FromInt32((int)((sbyte)value));
case TypeCode.UInt16:
return Runtime.PyInt_FromInt32((int)((ushort)value));
case TypeCode.UInt32:
return Runtime.PyLong_FromUnsignedLong((uint)value);
case TypeCode.UInt64:
return Runtime.PyLong_FromUnsignedLongLong((ulong)value);
default:
if (value is IEnumerable)
{
using (var resultlist = new PyList())
{
foreach (object o in (IEnumerable)value)
{
using (var p = new PyObject(ToPython(o, o?.GetType())))
{
resultlist.Append(p);
}
}
Runtime.XIncref(resultlist.Handle);
return resultlist.Handle;
}
}
result = CLRObject.GetInstHandle(value, type);
return result;
}
}
///
/// In a few situations, we don't have any advisory type information
/// when we want to convert an object to Python.
///
internal static IntPtr ToPythonImplicit(object value)
{
if (value == null)
{
IntPtr result = Runtime.PyNone;
Runtime.XIncref(result);
return result;
}
return ToPython(value, objectType);
}
///
/// Return a managed object for the given Python object, taking funny
/// byref types into account.
///
internal static bool ToManaged(IntPtr value, Type type,
out object result, bool setError)
{
if (type.IsByRef)
{
type = type.GetElementType();
}
return Converter.ToManagedValue(value, type, out result, setError);
}
internal static bool ToManagedValue(BorrowedReference value, Type obType,
out object result, bool setError)
=> ToManagedValue(value.DangerousGetAddress(), obType, out result, setError);
internal static bool ToManagedValue(IntPtr value, Type obType,
out object result, bool setError)
{
if (obType == typeof(PyObject))
{
Runtime.XIncref(value); // PyObject() assumes ownership
result = new PyObject(value);
return true;
}
// Common case: if the Python value is a wrapped managed object
// instance, just return the wrapped object.
ManagedType mt = ManagedType.GetManagedObject(value);
result = null;
if (mt != null)
{
if (mt is CLRObject)
{
object tmp = ((CLRObject)mt).inst;
if (obType.IsInstanceOfType(tmp))
{
result = tmp;
return true;
}
Exceptions.SetError(Exceptions.TypeError, $"value cannot be converted to {obType}");
return false;
}
if (mt is ClassBase)
{
var cb = (ClassBase)mt;
if (!cb.type.Valid)
{
Exceptions.SetError(Exceptions.TypeError, cb.type.DeletedMessage);
return false;
}
result = cb.type.Value;
return true;
}
// shouldn't happen
return false;
}
if (value == Runtime.PyNone && !obType.IsValueType)
{
result = null;
return true;
}
if (obType.IsGenericType && obType.GetGenericTypeDefinition() == typeof(Nullable))
{
if( value == Runtime.PyNone )
{
result = null;
return true;
}
// Set type to underlying type
obType = obType.GetGenericArguments()[0];
}
if (obType.IsArray)
{
return ToArray(value, obType, out result, setError);
}
if (obType.IsEnum)
{
return ToEnum(value, obType, out result, setError);
}
// Conversion to 'Object' is done based on some reasonable default
// conversions (Python string -> managed string, Python int -> Int32 etc.).
if (obType == objectType)
{
if (Runtime.IsStringType(value))
{
return ToPrimitive(value, stringType, out result, setError);
}
if (Runtime.PyBool_Check(value))
{
return ToPrimitive(value, boolType, out result, setError);
}
if (Runtime.PyInt_Check(value))
{
return ToPrimitive(value, int32Type, out result, setError);
}
if (Runtime.PyLong_Check(value))
{
return ToPrimitive(value, int64Type, out result, setError);
}
if (Runtime.PyFloat_Check(value))
{
return ToPrimitive(value, doubleType, out result, setError);
}
// give custom codecs a chance to take over conversion of sequences
IntPtr pyType = Runtime.PyObject_TYPE(value);
if (PyObjectConversions.TryDecode(value, pyType, obType, out result))
{
return true;
}
if (Runtime.PySequence_Check(value))
{
return ToArray(value, typeof(object[]), out result, setError);
}
Runtime.XIncref(value); // PyObject() assumes ownership
result = new PyObject(value);
return true;
}
// Conversion to 'Type' is done using the same mappings as above for objects.
if (obType == typeType)
{
if (value == Runtime.PyStringType)
{
result = stringType;
return true;
}
if (value == Runtime.PyBoolType)
{
result = boolType;
return true;
}
if (value == Runtime.PyIntType)
{
result = int32Type;
return true;
}
if (value == Runtime.PyLongType)
{
result = int64Type;
return true;
}
if (value == Runtime.PyFloatType)
{
result = doubleType;
return true;
}
if (value == Runtime.PyListType || value == Runtime.PyTupleType)
{
result = typeof(object[]);
return true;
}
if (setError)
{
Exceptions.SetError(Exceptions.TypeError, "value cannot be converted to Type");
}
return false;
}
TypeCode typeCode = Type.GetTypeCode(obType);
if (typeCode == TypeCode.Object)
{
IntPtr pyType = Runtime.PyObject_TYPE(value);
if (PyObjectConversions.TryDecode(value, pyType, obType, out result))
{
return true;
}
}
return ToPrimitive(value, obType, out result, setError);
}
internal delegate bool TryConvertFromPythonDelegate(IntPtr pyObj, out object result);
///
/// Convert a Python value to an instance of a primitive managed type.
///
private static bool ToPrimitive(IntPtr value, Type obType, out object result, bool setError)
{
TypeCode tc = Type.GetTypeCode(obType);
result = null;
IntPtr op = IntPtr.Zero;
switch (tc)
{
case TypeCode.String:
string st = Runtime.GetManagedString(value);
if (st == null)
{
goto type_error;
}
result = st;
return true;
case TypeCode.Int32:
{
// Python3 always use PyLong API
long num = Runtime.PyLong_AsLongLong(value);
if (num == -1 && Exceptions.ErrorOccurred())
{
goto convert_error;
}
if (num > Int32.MaxValue || num < Int32.MinValue)
{
goto overflow;
}
result = (int)num;
return true;
}
case TypeCode.Boolean:
result = Runtime.PyObject_IsTrue(value) != 0;
return true;
case TypeCode.Byte:
{
if (Runtime.PyObject_TypeCheck(value, Runtime.PyBytesType))
{
if (Runtime.PyBytes_Size(value) == 1)
{
op = Runtime.PyBytes_AS_STRING(value);
result = (byte)Marshal.ReadByte(op);
return true;
}
goto type_error;
}
int num = Runtime.PyLong_AsLong(value);
if (num == -1 && Exceptions.ErrorOccurred())
{
goto convert_error;
}
if (num > Byte.MaxValue || num < Byte.MinValue)
{
goto overflow;
}
result = (byte)num;
return true;
}
case TypeCode.SByte:
{
if (Runtime.PyObject_TypeCheck(value, Runtime.PyBytesType))
{
if (Runtime.PyBytes_Size(value) == 1)
{
op = Runtime.PyBytes_AS_STRING(value);
result = (byte)Marshal.ReadByte(op);
return true;
}
goto type_error;
}
int num = Runtime.PyLong_AsLong(value);
if (num == -1 && Exceptions.ErrorOccurred())
{
goto convert_error;
}
if (num > SByte.MaxValue || num < SByte.MinValue)
{
goto overflow;
}
result = (sbyte)num;
return true;
}
case TypeCode.Char:
{
if (Runtime.PyObject_TypeCheck(value, Runtime.PyBytesType))
{
if (Runtime.PyBytes_Size(value) == 1)
{
op = Runtime.PyBytes_AS_STRING(value);
result = (byte)Marshal.ReadByte(op);
return true;
}
goto type_error;
}
else if (Runtime.PyObject_TypeCheck(value, Runtime.PyUnicodeType))
{
if (Runtime.PyUnicode_GetSize(value) == 1)
{
op = Runtime.PyUnicode_AsUnicode(value);
Char[] buff = new Char[1];
Marshal.Copy(op, buff, 0, 1);
result = buff[0];
return true;
}
goto type_error;
}
int num = Runtime.PyLong_AsLong(value);
if (num == -1 && Exceptions.ErrorOccurred())
{
goto convert_error;
}
if (num > Char.MaxValue || num < Char.MinValue)
{
goto overflow;
}
result = (char)num;
return true;
}
case TypeCode.Int16:
{
int num = Runtime.PyLong_AsLong(value);
if (num == -1 && Exceptions.ErrorOccurred())
{
goto convert_error;
}
if (num > Int16.MaxValue || num < Int16.MinValue)
{
goto overflow;
}
result = (short)num;
return true;
}
case TypeCode.Int64:
{
long num = (long)Runtime.PyLong_AsLongLong(value);
if (num == -1 && Exceptions.ErrorOccurred())
{
goto convert_error;
}
result = num;
return true;
}
case TypeCode.UInt16:
{
long num = Runtime.PyLong_AsLong(value);
if (num == -1 && Exceptions.ErrorOccurred())
{
goto convert_error;
}
if (num > UInt16.MaxValue || num < UInt16.MinValue)
{
goto overflow;
}
result = (ushort)num;
return true;
}
case TypeCode.UInt32:
{
op = value;
if (Runtime.PyObject_TYPE(value) != Runtime.PyLongType)
{
op = Runtime.PyNumber_Long(value);
if (op == IntPtr.Zero)
{
goto convert_error;
}
}
if (Runtime.Is32Bit || Runtime.IsWindows)
{
uint num = Runtime.PyLong_AsUnsignedLong32(op);
if (num == uint.MaxValue && Exceptions.ErrorOccurred())
{
goto convert_error;
}
result = num;
}
else
{
ulong num = Runtime.PyLong_AsUnsignedLong64(op);
if (num == ulong.MaxValue && Exceptions.ErrorOccurred())
{
goto convert_error;
}
try
{
result = Convert.ToUInt32(num);
}
catch (OverflowException)
{
// Probably wasn't an overflow in python but was in C# (e.g. if cpython
// longs are 64 bit then 0xFFFFFFFF + 1 will not overflow in
// PyLong_AsUnsignedLong)
goto overflow;
}
}
return true;
}
case TypeCode.UInt64:
{
op = value;
if (Runtime.PyObject_TYPE(value) != Runtime.PyLongType)
{
op = Runtime.PyNumber_Long(value);
if (op == IntPtr.Zero)
{
goto convert_error;
}
}
ulong num = Runtime.PyLong_AsUnsignedLongLong(op);
if (num == ulong.MaxValue && Exceptions.ErrorOccurred())
{
goto overflow;
}
result = num;
return true;
}
case TypeCode.Single:
{
double num = Runtime.PyFloat_AsDouble(value);
if (num == -1.0 && Exceptions.ErrorOccurred())
{
goto convert_error;
}
if (num > Single.MaxValue || num < Single.MinValue)
{
if (!double.IsInfinity(num))
{
goto overflow;
}
}
result = (float)num;
return true;
}
case TypeCode.Double:
{
double num = Runtime.PyFloat_AsDouble(value);
if (num == -1.0 && Exceptions.ErrorOccurred())
{
goto convert_error;
}
result = num;
return true;
}
default:
goto type_error;
}
convert_error:
if (op != value)
{
Runtime.XDecref(op);
}
if (!setError)
{
Exceptions.Clear();
}
return false;
type_error:
if (setError)
{
string tpName = Runtime.PyObject_GetTypeName(value);
Exceptions.SetError(Exceptions.TypeError, $"'{tpName}' value cannot be converted to {obType}");
}
return false;
overflow:
// C# level overflow error
if (op != value)
{
Runtime.XDecref(op);
}
if (setError)
{
Exceptions.SetError(Exceptions.OverflowError, "value too large to convert");
}
return false;
}
private static void SetConversionError(IntPtr value, Type target)
{
IntPtr ob = Runtime.PyObject_Repr(value);
string src = Runtime.GetManagedString(ob);
Runtime.XDecref(ob);
Exceptions.SetError(Exceptions.TypeError, $"Cannot convert {src} to {target}");
}
///
/// Convert a Python value to a correctly typed managed array instance.
/// The Python value must support the Python iterator protocol or and the
/// items in the sequence must be convertible to the target array type.
///
private static bool ToArray(IntPtr value, Type obType, out object result, bool setError)
{
Type elementType = obType.GetElementType();
result = null;
bool IsSeqObj = Runtime.PySequence_Check(value);
var len = IsSeqObj ? Runtime.PySequence_Size(value) : -1;
IntPtr IterObject = Runtime.PyObject_GetIter(value);
if(IterObject==IntPtr.Zero) {
if (setError)
{
SetConversionError(value, obType);
}
return false;
}
Array items;
var listType = typeof(List);
var constructedListType = listType.MakeGenericType(elementType);
IList list = IsSeqObj ? (IList) Activator.CreateInstance(constructedListType, new Object[] {(int) len}) :
(IList) Activator.CreateInstance(constructedListType);
IntPtr item;
while ((item = Runtime.PyIter_Next(IterObject)) != IntPtr.Zero)
{
object obj = null;
if (!Converter.ToManaged(item, elementType, out obj, true))
{
Runtime.XDecref(item);
return false;
}
list.Add(obj);
Runtime.XDecref(item);
}
Runtime.XDecref(IterObject);
items = Array.CreateInstance(elementType, list.Count);
list.CopyTo(items, 0);
result = items;
return true;
}
///
/// Convert a Python value to a correctly typed managed enum instance.
///
private static bool ToEnum(IntPtr value, Type obType, out object result, bool setError)
{
Type etype = Enum.GetUnderlyingType(obType);
result = null;
if (!ToPrimitive(value, etype, out result, setError))
{
return false;
}
if (Enum.IsDefined(obType, result))
{
result = Enum.ToObject(obType, result);
return true;
}
if (obType.GetCustomAttributes(flagsType, true).Length > 0)
{
result = Enum.ToObject(obType, result);
return true;
}
if (setError)
{
Exceptions.SetError(Exceptions.ValueError, "invalid enumeration value");
}
return false;
}
}
public static class ConverterExtension
{
public static PyObject ToPython(this object o)
{
return new PyObject(Converter.ToPython(o, o?.GetType()));
}
}
}