c@75: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
c@75: 
c@75: /*
c@75:     Piper C++
c@75: 
c@75:     Centre for Digital Music, Queen Mary, University of London.
c@75:     Copyright 2006-2016 Chris Cannam and QMUL.
c@75:   
c@75:     Permission is hereby granted, free of charge, to any person
c@75:     obtaining a copy of this software and associated documentation
c@75:     files (the "Software"), to deal in the Software without
c@75:     restriction, including without limitation the rights to use, copy,
c@75:     modify, merge, publish, distribute, sublicense, and/or sell copies
c@75:     of the Software, and to permit persons to whom the Software is
c@75:     furnished to do so, subject to the following conditions:
c@75: 
c@75:     The above copyright notice and this permission notice shall be
c@75:     included in all copies or substantial portions of the Software.
c@75: 
c@75:     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
c@75:     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
c@75:     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
c@75:     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
c@75:     ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
c@75:     CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
c@75:     WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
c@75: 
c@75:     Except as contained in this notice, the names of the Centre for
c@75:     Digital Music; Queen Mary, University of London; and Chris Cannam
c@75:     shall not be used in advertising or otherwise to promote the sale,
c@75:     use or other dealings in this Software without prior written
c@75:     authorization.
c@75: */
c@75: 
c@75: #ifndef PIPER_PRESERVING_PLUGIN_HANDLE_MAPPER_H
c@75: #define PIPER_PRESERVING_PLUGIN_HANDLE_MAPPER_H
c@75: 
c@75: #include "PluginHandleMapper.h"
c@75: #include "PreservingPluginOutputIdMapper.h"
c@75: 
c@75: #include <iostream>
c@75: 
c@97: namespace piper_vamp {
c@75: 
cannam@265: /**
cannam@265:  * A PluginHandleMapper that accepts a handle in the handleToPlugin
cannam@265:  * method, storing it for later, and returns the same handle from
cannam@265:  * pluginToHandle when given the same plugin pointer as it had earlier
cannam@265:  * returned from handleToPlugin. It can only remember one handle, and
cannam@265:  * knows nothing about actual plugins - the plugin pointer it returns
cannam@265:  * is nominal and must never be dereferenced.
cannam@265:  */
c@75: class PreservingPluginHandleMapper : public PluginHandleMapper
c@75: {
cannam@265:     class NotAPlugin : public Vamp::Plugin
cannam@265:     {
cannam@265:         #define STR(x) std::string get##x() const { return "not-a-plugin"; }
cannam@265:     public:
cannam@265:         STR(Identifier) STR(Name) STR(Description) STR(Maker) STR(Copyright)
cannam@265:         int getPluginVersion() const { return 1; }
cannam@265:         bool initialise(size_t, size_t, size_t) { return false; }
cannam@265:         void reset() { }
cannam@265:         InputDomain getInputDomain() const { return TimeDomain; }
cannam@265:         OutputList getOutputDescriptors() const { return {}; }
cannam@265:         FeatureSet process(const float *const *, Vamp::RealTime) { return {}; }
cannam@265:         FeatureSet getRemainingFeatures() { return {}; }
cannam@265:         NotAPlugin() : Plugin(1) { }
cannam@265:     };
cannam@265:     
c@75: public:
c@75:     PreservingPluginHandleMapper() :
cannam@265:         m_handle(INVALID_HANDLE),
cannam@265:         m_plugin(nullptr),
c@75:         m_omapper(std::make_shared<PreservingPluginOutputIdMapper>()) { }
c@75: 
cannam@265:     virtual ~PreservingPluginHandleMapper() {
cannam@265:         delete m_plugin;
cannam@265:     }
cannam@265: 
c@75:     virtual Handle pluginToHandle(Vamp::Plugin *p) const noexcept {
c@75:         if (!p) return INVALID_HANDLE;
c@75: 	if (p == m_plugin) return m_handle;
c@75: 	else {
c@75: 	    std::cerr << "PreservingPluginHandleMapper: p = " << p
c@75: 		      << " differs from saved m_plugin " << m_plugin
c@75: 		      << " (not returning saved handle " << m_handle << ")"
c@75: 		      << std::endl;
c@75:             return INVALID_HANDLE;
c@75: 	}
c@75:     }
c@75: 
c@75:     virtual Vamp::Plugin *handleToPlugin(Handle h) const noexcept {
c@75:         if (h == INVALID_HANDLE) return nullptr;
cannam@265:         if (h == m_handle) return m_plugin;
cannam@265:         if (m_handle != INVALID_HANDLE) {
cannam@265:             std::cerr << "PreservingPluginHandleMapper: m_handle " << m_handle
cannam@277:                       << " is non-null when a new handle (" << h
cannam@277:                       << ") is provided, but "
cannam@265:                       << "this stupid stub class can only handle one handle"
cannam@265:                       << std::endl;
cannam@265:             return nullptr;
cannam@265:         }
c@75: 	m_handle = h;
cannam@265:         // We allocate something here, just so that we can
cannam@265:         // sanity-check in the pluginToHandle call that the thing
cannam@265:         // passed in is likely to be the pointer we returned from
cannam@265:         // handleToPlugin earlier. Allocating an actual plugin allows
cannam@265:         // us to return it without running afoul of strict-aliasing
cannam@265:         // rules or the C++ object memory model.
cannam@265:         m_plugin = new NotAPlugin();
cannam@265:         return m_plugin;
c@75:     }
c@75: 
c@75:     virtual const std::shared_ptr<PluginOutputIdMapper> pluginToOutputIdMapper
c@75:     (Vamp::Plugin *p) const noexcept {
c@75:         if (!p) return {};
c@75:         return m_omapper;
c@75:     }
c@75:         
c@75:     virtual const std::shared_ptr<PluginOutputIdMapper> handleToOutputIdMapper
c@75:     (Handle h) const noexcept {
c@75:         if (h == INVALID_HANDLE) return {};
c@75:         return m_omapper;
c@75:     }
c@75:     
c@75: private:
c@75:     mutable Handle m_handle;
cannam@265:     mutable NotAPlugin *m_plugin;
c@75:     std::shared_ptr<PreservingPluginOutputIdMapper> m_omapper;
c@75: };
c@75: 
c@75: }
c@75: 
c@75: #endif