comparison PyTypeConversions.h @ 71:40a01bb24209 vampyhost

Pull apart some type conversion classes for possible use in VamPy Host

+/* -*- c-basic-offset: 8 indent-tabs-mode: t -*- */
+/*
+
+ * Vampy : This plugin is a wrapper around the Vamp plugin API.
+ * It allows for writing Vamp plugins in Python.
+
+ * Centre for Digital Music, Queen Mary University of London.
+ * Copyright (C) 2008-2009 Gyorgy Fazekas, QMUL. (See Vamp sources 
+ * for licence information.)
+
+*/
+
+/*
+PyTypeConversions: Type safe conversion utilities between Python types 
+and basic C/C++ types.
+*/
+
+#ifndef _PY_TYPE_CONVERSIONS_H_
+#define _PY_TYPE_CONVERSIONS_H_
+#include <Python.h>
+#ifdef HAVE_NUMPY
+#define PY_ARRAY_UNIQUE_SYMBOL VAMPY_ARRAY_API
+#define NO_IMPORT_ARRAY
+#define NPY_NO_DEPRECATED_API NPY_1_7_API_VERSION
+#include "numpy/arrayobject.h"
+#endif
+
+#include <vector>
+#include <queue>
+#include <string>
+#include <sstream>
+#include <iostream>
+
+using std::cerr;
+using std::endl;
+
+#ifdef HAVE_NUMPY
+enum eArrayDataType {
+	dtype_float32 = (int) NPY_FLOAT,
+	dtype_complex64 = (int) NPY_CFLOAT 
+	};
+#endif 
+
+/* C++ mapping of PyNone Type */
+struct NoneType {};
+	
+// Data
+class ValueError
+{
+public:
+	ValueError() {}
+	ValueError(std::string m, bool s) : message(m),strict(s) {}
+	std::string location;
+	std::string message;
+	bool strict;
+	std::string str() const { 
+		return (location.empty()) ? message : message + "\nLocation: " + location;}
+	void print() const { cerr << str() << endl; }
+	template<typename V> ValueError &operator<< (const V& v)
+	{
+		std::ostringstream ss;
+		ss << v;
+		location += ss.str();
+		return *this;
+	}
+};
+
+class PyTypeConversions
+{
+public:
+	PyTypeConversions();
+	~PyTypeConversions();
+	
+	// Utilities
+	void setStrictTypingFlag(bool b) {m_strict = b;}
+	void setNumpyInstalled(bool b) {m_numpyInstalled = b;}
+	ValueError getError() const;
+	std::string PyValue_Get_TypeName(PyObject*) const;
+
+	// Basic type conversion: Python to C++ 
+	float 	PyValue_To_Float(PyObject*) const;
+	size_t 	PyValue_To_Size_t(PyObject*) const;
+	bool 	PyValue_To_Bool(PyObject*) const;
+	std::string PyValue_To_String(PyObject*) const;
+	long 	PyValue_To_Long(PyObject*) const;
+	// int 	PyValue_To_Int(PyObject* pyValue) const;
+	
+	// C++ to Python
+	PyObject *PyValue_From_CValue(const char*) const;
+	PyObject *PyValue_From_CValue(const std::string& x) const { return PyValue_From_CValue(x.c_str()); }
+	PyObject *PyValue_From_CValue(size_t) const;
+	PyObject *PyValue_From_CValue(double) const;
+	PyObject *PyValue_From_CValue(float x) const { return PyValue_From_CValue((double)x); }
+	PyObject *PyValue_From_CValue(bool) const;
+	
+	// Sequence types
+	std::vector<std::string> PyValue_To_StringVector (PyObject*) const;
+	std::vector<float> PyValue_To_FloatVector (PyObject*) const;
+	std::vector<float> PyList_To_FloatVector (PyObject*) const;
+
+	// Numpy types
+#ifdef HAVE_NUMPY
+	std::vector<float> PyArray_To_FloatVector (PyObject *pyValue) const;
+#endif
+
+	/// Convert DTYPE type 1D NumpyArray to std::vector<RET>
+	template<typename RET, typename DTYPE>
+	std::vector<RET> PyArray_Convert(void* raw_data_ptr, long length, size_t strides) const
+	{
+		std::vector<RET> rValue;
+		
+		/// check if the array is continuous, if not use strides info
+		if (sizeof(DTYPE)!=strides) {
+#ifdef _DEBUG_VALUES
+			cerr << "Warning: discontinuous numpy array. Strides: " << strides << " bytes. sizeof(dtype): " << sizeof(DTYPE) << endl;
+#endif
+			char* data = (char*) raw_data_ptr;
+			for (long i = 0; i<length; ++i){
+				rValue.push_back((RET)(*((DTYPE*)data)));
+#ifdef _DEBUG_VALUES
+				cerr << "value: " << (RET)(*((DTYPE*)data)) << endl;
+#endif				
+				data+=strides;
+			}
+			return rValue;
+		}
+
+		DTYPE* data = (DTYPE*) raw_data_ptr;
+		for (long i = 0; i<length; ++i){
+#ifdef _DEBUG_VALUES
+			cerr << "value: " << (RET)data[i] << endl;
+#endif
+			rValue.push_back((RET)data[i]);
+		}
+		return rValue;
+	}
+
+	/// this is a special case. numpy.float64 has an array conversions but no array descriptor
+	inline std::vector<float> PyArray0D_Convert(PyArrayInterface *ai) const
+	{
+		std::vector<float> rValue;
+		if ((ai->typekind) == *"f") 
+			rValue.push_back((float)*(double*)(ai->data));
+		else { 
+			setValueError("Unsupported NumPy data type.",m_strict); 
+			return rValue;
+		}
+#ifdef _DEBUG_VALUES
+		cerr << "value: " << rValue[0] << endl;
+#endif
+		return rValue;
+	}
+
+private:
+	bool m_strict;
+	mutable bool m_error;
+	mutable std::queue<ValueError> m_errorQueue;
+	bool m_numpyInstalled;
+	
+	void setValueError(std::string,bool) const;
+	ValueError& lastError() const;
+
+public:
+	const bool& error;
+
+};
+
+#endif