annotate PyExtensionManager.cpp @ 92:a6718f9fe942

If a module appears to redefine one of our own types, refuse to load it. Also clear out the class dict for all refused modules now, so that we don't get stale names on the next scan due to not having cleared the module on unload

/* -*- 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.)

*/

#include <Python.h>
#include "vamp/vamp.h"
#include "PyExtensionModule.h"
#include "PyExtensionManager.h"
#include <algorithm>
#include "Debug.h"

using std::cerr;
using std::endl;
using std::string;
using std::vector;
using std::find;

//static
const char* PyExtensionManager::m_exposedNames[] = {
	
		"ParameterDescriptor",
		"OutputDescriptor",
		"FeatureSet",
		"Feature",
		"RealTime",
		"frame2RealTime",

/* 		// using builtin objects:
		"ParameterList",
		"OutputList",
		"FeatureList",
		"OneSamplePerStep",
		"FixedSampleRate",
		"VariableSampleRate",
		"TimeDomain",
		"FrequencyDomain",
*/
		
		NULL
};

PyExtensionManager::PyExtensionManager()
{
	DSTREAM << "Creating extension manager." << endl;
}

bool 
PyExtensionManager::initExtension() 
{
	DSTREAM << "Initialising extension module." << endl; 

	/// call the module initialiser first
	initvampy();

	/// these references are all borrowed
	m_pyGlobalNamespace = PyImport_GetModuleDict();
	if (!m_pyGlobalNamespace) 
		{cerr << "Vampy::PyExtensionManager::initExtension: GlobalNamespace failed." << endl; return false;}
	PyObject *pyVampyModule = PyDict_GetItemString(m_pyGlobalNamespace,"vampy");
	if (!pyVampyModule) 
		{cerr << "Vampy::PyExtensionManager::initExtension: VampyModule failed." << endl; return false;}
	m_pyVampyNamespace = PyModule_GetDict(pyVampyModule);
	if (!m_pyVampyNamespace) 
		{cerr << "Vampy::PyExtensionManager::initExtension: VampyNamespace failed." << endl; return false;}
    
	/// initialise local namespaces
	updateAllLocals();

	DSTREAM << "Vampy: Extension namespaces updated." << endl; 

	return true;
}


PyExtensionManager::~PyExtensionManager()
{
	DSTREAM << "Cleaning locals..." << endl;

	cleanAllLocals(); 

	DSTREAM << "Cleaning module..." << endl;

	if (!cleanModule()) 
		cerr << "Vampy::~PyExtensionManager: failed to clean extension module." << endl;
	DSTREAM << "Vampy::~PyExtensionManager: Extension module cleaned." << endl;
}



void
PyExtensionManager::setPlugModuleNames(vector<string> pyPlugs)
{
	for (size_t i = 0; i < pyPlugs.size(); ++i) {
		string modName = pyPlugs[i];
		string tmp = modName.substr(modName.rfind(':')+1,modName.size()-1);
		m_plugModuleNames.push_back(tmp);

		DSTREAM << "Inserted module name: " << tmp << endl;
	}
}

void
PyExtensionManager::deleteModuleName(string plugKey)
{
	string name = plugKey.substr(plugKey.rfind(':')+1,plugKey.size()-1);
	vector<string>::iterator it = 
		find (m_plugModuleNames.begin(), m_plugModuleNames.end(), name);
	if (it != m_plugModuleNames.end()) m_plugModuleNames.erase(it);

	DSTREAM << "PyExtensionManager::deleteModuleName: Deleted module name: " << name << endl;
}


void 
PyExtensionManager::cleanAllLocals() const
{
	for (size_t i = 0; i < m_plugModuleNames.size(); ++i) {
	    cleanLocalNamespace(m_plugModuleNames[i].c_str());
	}
}

void 
PyExtensionManager::updateAllLocals() const
{
	for (size_t i = 0; i < m_plugModuleNames.size(); ++i) {
		updateLocalNamespace(m_plugModuleNames[i].c_str());
	}
}

void 
PyExtensionManager::cleanLocalNamespace(const char* plugModuleName) const
{
	DSTREAM << "Cleaning local namespace: " << plugModuleName << endl;

	/// these references are all borrowed
	PyObject *pyPlugModule = PyDict_GetItemString(m_pyGlobalNamespace,plugModuleName);
	if (!pyPlugModule) return;
	PyObject *pyPlugDict = PyModule_GetDict(pyPlugModule);
	if (!pyPlugDict) return;
	
	int i = 0;
	while (PyExtensionManager::m_exposedNames[i]) {
		const char* name = PyExtensionManager::m_exposedNames[i];
		i++;
		PyObject *key = PyString_FromString(name);
		if (!key) break;
		if (PyDict_Contains(pyPlugDict,key)) {
			if (PyDict_SetItem(pyPlugDict,key,Py_None) != 0)
				cerr << "Vampy::PyExtensionManager::cleanLocalNamespace: Failed: " 
				<< name << " of "<< plugModuleName << endl;
			else DSTREAM << "Cleaned local name: " << name << endl;
		}
		Py_DECREF(key);
	}
}

void 
PyExtensionManager::updateLocalNamespace(const char* plugModuleName) const
{
	DSTREAM << "Updating local namespace: " << plugModuleName << endl;

	/// this allows the use of common syntax like:
	/// from vampy import * 
	/// even after several unload/reload cycles
		
	/// these references are all borrowed
	PyObject *pyPlugModule = PyDict_GetItemString(m_pyGlobalNamespace,plugModuleName);
	if (!pyPlugModule) return;
	PyObject *pyPlugDict = PyModule_GetDict(pyPlugModule);
	if (!pyPlugDict) return;
	
	int i = 0;
	while (PyExtensionManager::m_exposedNames[i]) {
		const char* name = PyExtensionManager::m_exposedNames[i];
		i++;
		PyObject *key = PyString_FromString(name);
		if (!key) break;
		if (PyDict_Contains(pyPlugDict,key)) {
			PyObject* item = PyDict_GetItem(m_pyVampyNamespace,key);
			if (PyDict_SetItem(pyPlugDict,key,item) != 0)
				cerr << "Vampy::PyExtensionManager::updateLocalNamespace: Failed: " 
				<< name << " of "<< plugModuleName << endl;
			else DSTREAM << "Updated local name: " << name << endl;
		} else {
			DSTREAM << "Local namespace does not contain name: " << name << endl;
		}
		Py_DECREF(key);
	}
}


bool 
PyExtensionManager::cleanModule(void) const
{
	PyObject *m = PyImport_AddModule("vampy");
	if (!m) {
		if (PyErr_Occurred()) {PyErr_Print(); PyErr_Clear();}
		cerr << "Vampy::PyExtensionManager::cleanModule: PyImport_AddModule returned NULL!" << endl;
		return false;
	} else {
		PyObject *dict = PyModule_GetDict(m);
#ifdef _DEBUG		
		Py_ssize_t ln = PyDict_Size(dict);
		DSTREAM << "Vampy::PyExtensionManager::cleanModule: Size of module dict = " << (int) ln << endl;
#endif		
		/// Clean the module dictionary.
		// printDict(dict);
		PyDict_Clear(dict);
		if (PyErr_Occurred()) 
			{ PyErr_Print(); PyErr_Clear(); return false; }
		PyObject *name = PyString_FromString("vampy");
		if (name) PyDict_SetItemString(dict,"__name__",name);
		Py_XDECREF(name);
#ifdef _DEBUG		
	    ln = PyDict_Size(dict);
		DSTREAM << "Vampy::PyExtensionManager::cleanModule: Size of module dict (cleaned) = " << (int) ln << endl;
#endif
		return true;
	}
}

void 
PyExtensionManager::printDict(PyObject* inDict) const
{
	Py_ssize_t pyPos = 0;
	PyObject *pyKey, *pyDictValue;
	cerr << endl << endl << "Module dictionary contents: " << endl;
	while (PyDict_Next(inDict, &pyPos, &pyKey, &pyDictValue))
	{ 
		char *key = PyString_AS_STRING(pyKey);
		char *val = PyString_AS_STRING(PyObject_Str(pyDictValue));
		cerr << "key: [ '" << key << "' ] value: " << val << endl;
	}
}