diff pyvamp-main.cpp @ 24:7d28bed0864e

* Rearrange Python plugin construction.

  Formerly, the PyPluginAdapter has retained a single plugin instance pointer
  for each plugin found, and its createPlugin method has simply returned a new
  PyPlugin object wrapping the same instance pointer.  This has a couple of
  negative consequences:
   - Because construction of the actual Python instance occurred before the
     wrapper was constructed, it was not possible to pass arguments (i.e.
     the sample rate) from the wrapper constructor to the Python plugin
     instance constructor -- they had to be passed later, to initialise,
     disadvantaging those plugins that would like to use the sample rate
     for parameter & step/block size calculations etc
   - Because there was only a single Python plugin instance, it was not
     possible to run more than one instance at once with any isolation

  This rework instead stores the Python class pointer (rather than instance
  pointer) in the PyPluginAdapter, and each PyPlugin wrapper instance creates
  its own Python plugin instance.  What could possibly go wrong?

--- a/pyvamp-main.cpp	Thu Jul 16 13:19:20 2009 +0000
+++ b/pyvamp-main.cpp	Mon Aug 17 15:22:06 2009 +0000
@@ -1,44 +1,10 @@
 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
 
-/*
-    Vamp
-
-    An API for audio analysis and feature extraction plugins.
-
-    Centre for Digital Music, Queen Mary, University of London.
-    Copyright 2006 Chris Cannam.
-  
-    Permission is hereby granted, free of charge, to any person
-    obtaining a copy of this software and associated documentation
-    files (the "Software"), to deal in the Software without
-    restriction, including without limitation the rights to use, copy,
-    modify, merge, publish, distribute, sublicense, and/or sell copies
-    of the Software, and to permit persons to whom the Software is
-    furnished to do so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be
-    included in all copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
-    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
-    ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
-    CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
-    WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-
-    Except as contained in this notice, the names of the Centre for
-    Digital Music; Queen Mary, University of London; and Chris Cannam
-    shall not be used in advertising or otherwise to promote the sale,
-    use or other dealings in this Software without prior written
-    authorization.
-*/
-
 /**
  * This Vamp plugin is a wrapper for Python Scripts. (VamPy)
  * Centre for Digital Music, Queen Mary, University of London.
  * Copyright 2008, George Fazekas.
-*/
+ */
 
 #include <Python.h>
 #include "vamp/vamp.h"
@@ -67,37 +33,37 @@
 class PyPluginAdapter : public Vamp::PluginAdapterBase
 {
 public: 
-	PyPluginAdapter(std::string pyPlugId, PyObject* pyInstance) :
-		PluginAdapterBase(),
-		m_plug(pyPlugId),		
-		m_pyInstance(pyInstance)
-		{ 
-			cerr << "PyPluginAdapter:ctor:"<< adinstcount << ": " << m_plug << endl; 
-			adinstcount++;
-			m_instanceCount = 0;
-		}
-	
-	~PyPluginAdapter() 
-	{
-	}
-
+    PyPluginAdapter(std::string pyPlugId, PyObject* pyClass) :
+        PluginAdapterBase(),
+        m_plug(pyPlugId),		
+        m_pyClass(pyClass)
+    { 
+        cerr << "PyPluginAdapter:ctor:"<< adinstcount << ": " << m_plug << endl; 
+        adinstcount++;
+        m_instanceCount = 0;
+    }
+    
+    ~PyPluginAdapter() 
+    {
+    }
+    
 protected:
-	Vamp::Plugin *createPlugin(float inputSampleRate) {
-        
-		std::string pclass = m_plug.substr(m_plug.rfind(':')+1,m_plug.size()-1);
-		std::string ppath = m_plug.substr(0,m_plug.rfind(pathsep));
-		PyPlugin *plugin = new PyPlugin(m_plug,inputSampleRate,m_pyInstance);
-		m_instanceCount++;
-		cerr << "PyPluginAdapter::createPlugin:" << pclass << " (instance: " << m_instanceCount << ")" << endl;
-		return plugin;
-
-		}
-
-	std::string m_plug;
-	bool m_haveInitialized;
-	PyObject *m_pyInstance;
-	int m_instanceCount;
-
+    Vamp::Plugin *createPlugin(float inputSampleRate)
+    {
+        try {
+            PyPlugin *plugin = new PyPlugin(m_plug, inputSampleRate, m_pyClass);
+            m_instanceCount++;
+            return plugin;
+        } catch (...) {
+            cerr << "PyPluginAdapter::createPlugin: Failed to construct PyPlugin" << endl;
+            return 0;
+        }
+    }
+    
+    std::string m_plug;
+    bool m_haveInitialized;
+    PyObject *m_pyClass;
+    int m_instanceCount;
 };
 
 
@@ -183,8 +149,8 @@
     if (version < 1) return 0;
 
 	int isPythonInitialized = Py_IsInitialized();
-	//cerr << "# isPythonInitialized: " << isPythonInitialized << endl;
-	//cerr << "# haveScannedPlugins: " << haveScannedPlugins << endl;
+	cerr << "# isPythonInitialized: " << isPythonInitialized << endl;
+	cerr << "# haveScannedPlugins: " << haveScannedPlugins << endl;
 
 	if (!haveScannedPlugins) {
 
@@ -210,6 +176,7 @@
 						<< " Dynamic loading in scripts will fail." << endl;
 */
 			Py_Initialize();
+                        cerr << "# isPythonInitialized after initialize: " << Py_IsInitialized() << endl;
 	 		PyEval_InitThreads();			
 		} else {
 			//Py_InitializeEx(1);
@@ -217,7 +184,7 @@
 
 		vector<string> pyPlugs;
 		vector<string> pyPath;
-		vector<PyObject *> pyInstances;
+		vector<PyObject *> pyClasses;
 		static PyPlugScanner *scanner;
 		
 		//Scanning Plugins
@@ -230,11 +197,11 @@
 		pyPlugs = scanner->getPyPlugs();
 		cerr << "Found " << pyPlugs.size() << " Scripts ...OK" << endl;
 		//TODO: this will support multiple classes per script
-		pyInstances = scanner->getPyInstances();
-		cerr << "Found " << pyInstances.size() << " Instances ...OK" << endl;
+		pyClasses = scanner->getPyClasses();
+		cerr << "Found " << pyClasses.size() << " Classes ...OK" << endl;
 
 		for (size_t i = 0; i < pyPlugs.size(); ++i) {
-			adapters.push_back( new PyPluginAdapter(pyPlugs[i],pyInstances[i]));
+			adapters.push_back( new PyPluginAdapter(pyPlugs[i],pyClasses[i]));
 		} 
 		haveScannedPlugins=true;