annotate vamp-client/PiperVampPlugin.h @ 217:d06300b789ea

Name, defensive comment

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
/*
  Piper C++

  An API for audio analysis and feature extraction plugins.

  Centre for Digital Music, Queen Mary, University of London.
  Copyright 2006-2017 Chris Cannam and QMUL.
  
  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.
*/

#ifndef PIPER_VAMP_PLUGIN_H
#define PIPER_VAMP_PLUGIN_H

#include <vamp-hostsdk/Plugin.h>
#include <vamp-hostsdk/PluginLoader.h>

#include "vamp-support/PluginStaticData.h"
#include "vamp-support/PluginConfiguration.h"

#include "PluginClient.h"

#include <cstdint>
#include <iostream>

namespace piper_vamp {
namespace client {

/**
 * PiperVampPlugin presents a Piper feature extractor in the form of a
 * Vamp plugin.
 */
class PiperVampPlugin : public Vamp::Plugin
{
    enum State {
        /**
         * The plugin's corresponding Piper feature extractor has been
         * loaded but no subsequent state change has happened. This is
         * the initial state of PiperVampPlugin on construction, since
         * it is associated with a pre-loaded handle.
         */
        Loaded,
        
        /**
         * The plugin has been configured, and the step and block size
         * received from the host in its last call to initialise()
         * match those that were returned in the configuration
         * response (i.e. the server's desired step and block
         * size). Our m_config record reflects these correct
         * values. The plugin is ready to process.
         */
        Configured,

        /**
         * The plugin has been configured, but the step and block size
         * received from the host in its last call to initialise()
         * differ from those returned by the server in the
         * configuration response. Our initialise() call therefore
         * returned false, and the plugin cannot be used until the
         * host calls initialise() again with the "correct" step and
         * block size. Our m_config record reflects these correct
         * values, so the host can retrieve them through
         * getPreferredStepSize and getPreferredBlockSize.
         */
        Misconfigured,

        /**
         * The finish() function has been called and the plugin
         * unloaded. No further plugin activity is possible.
         */
        Finished,

        /** 
         * A call has failed unrecoverably. No further plugin activity
         * is possible.
         */
        Failed
    };
    
public:
    PiperVampPlugin(PluginClient *client,
                    std::string pluginKey,
                    float inputSampleRate,
                    int adapterFlags,
                    PluginStaticData psd,
                    PluginConfiguration defaultConfig) :
        Plugin(inputSampleRate),
        m_client(client),
        m_key(pluginKey),
        m_adapterFlags(adapterFlags),
        m_state(Loaded),
        m_psd(psd),
        m_defaultConfig(defaultConfig),
        m_config(defaultConfig)
    { }

    virtual ~PiperVampPlugin() {
        if (m_state != Finished && m_state != Failed) {
            try {
                (void)m_client->finish(this);
            } catch (const std::exception &e) {
                // Finish can throw, but our destructor must not
                std::cerr << "WARNING: PiperVampPlugin::~PiperVampPlugin: caught exception from finish(): " << e.what() << std::endl;
            }
        }
    }
    
    virtual std::string getIdentifier() const {
        return m_psd.basic.identifier;
    }

    virtual std::string getName() const {
        return m_psd.basic.name;
    }

    virtual std::string getDescription() const {
        return m_psd.basic.description;
    }

    virtual std::string getMaker() const {
        return m_psd.maker;
    }

    virtual std::string getCopyright() const {
        return m_psd.copyright;
    }

    virtual int getPluginVersion() const {
        return m_psd.pluginVersion;
    }

    virtual ParameterList getParameterDescriptors() const {
        return m_psd.parameters;
    }

    virtual float getParameter(std::string name) const {
        if (m_config.parameterValues.find(name) != m_config.parameterValues.end()) {
            return m_config.parameterValues.at(name);
        } else {
            return 0.f;
        }
    }

    virtual void setParameter(std::string name, float value) {
        if (m_state == Failed) {
            throw std::logic_error("Plugin is in failed state");
        }
        if (m_state != Loaded) {
            m_state = Failed;
            throw std::logic_error("Can't set parameter after plugin initialised");
        }
        m_config.parameterValues[name] = value;
    }

    virtual ProgramList getPrograms() const {
        return m_psd.programs;
    }

    virtual std::string getCurrentProgram() const {
        return m_config.currentProgram;
    }
    
    virtual void selectProgram(std::string program) {
        if (m_state == Failed) {
            throw std::logic_error("Plugin is in failed state");
        }
        if (m_state != Loaded) {
            m_state = Failed;
            throw std::logic_error("Can't select program after plugin initialised");
        }
        m_config.currentProgram = program;
    }

    virtual bool initialise(size_t inputChannels,
                            size_t stepSize,
                            size_t blockSize) {

        if (m_state == Failed) {
            throw std::logic_error("Plugin is in failed state");
        }

        if (m_state == Misconfigured) {
            if (int(stepSize) == m_config.framing.stepSize &&
                int(blockSize) == m_config.framing.blockSize) {
                m_state = Configured;
                return true;
            } else {
                return false;
            }
        }
        
        if (m_state != Loaded) {
            m_state = Failed;
            throw std::logic_error("Plugin has already been initialised");
        }
        
        m_config.channelCount = int(inputChannels);
        m_config.framing.stepSize = int(stepSize);
        m_config.framing.blockSize = int(blockSize);

        try {
            auto response = m_client->configure(this, m_config);
            m_outputs = response.outputs;
            
            // Update with the new preferred step and block size now
            // that the plugin has taken into account its parameter
            // settings. If the values passed in to initialise()
            // weren't suitable, then this ensures that a subsequent
            // call to getPreferredStepSize/BlockSize on this plugin
            // object will at least get acceptable values from now on
            m_config.framing = response.framing;

            // And if they didn't match up with the passed-in ones,
            // lodge ourselves in Misconfigured state and report
            // failure so as to provoke the host to call initialise()
            // again before any processing.
            if (m_config.framing.stepSize != int(stepSize) ||
                m_config.framing.blockSize != int(blockSize)) {
                m_state = Misconfigured;
                return false;
            }
            
        } catch (const std::exception &e) {
            m_state = Failed;
            throw;
        }

        if (!m_outputs.empty()) {
            m_state = Configured;
            return true;
        } else {
            return false;
        }
    }

    virtual void reset() {
        
        if (m_state == Failed) {
            throw std::logic_error("Plugin is in failed state");
        }
        if (m_state == Loaded || m_state == Misconfigured) {
            // reset is a no-op if the plugin hasn't been initialised yet
            return;
        }

        try {
            m_client->reset(this, m_config);
        } catch (const std::exception &e) {
            m_state = Failed;
            throw;
        }

        m_state = Configured;
    }

    virtual InputDomain getInputDomain() const {
        return m_psd.inputDomain;
    }

    virtual size_t getPreferredBlockSize() const {
        // Return this from m_config instead of m_defaultConfig, so
        // that it gets updated in the event of an initialise() call
        // that fails for the wrong value
        return m_config.framing.blockSize;
    }

    virtual size_t getPreferredStepSize() const {
        // Return this from m_config instead of m_defaultConfig, so
        // that it gets updated in the event of an initialise() call
        // that fails for the wrong value
        return m_config.framing.stepSize;
    }

    virtual size_t getMinChannelCount() const {
        return m_psd.minChannelCount;
    }

    virtual size_t getMaxChannelCount() const {
        return m_psd.maxChannelCount;
    }

    virtual OutputList getOutputDescriptors() const {

        if (m_state == Failed) {
            throw std::logic_error("Plugin is in failed state");
        }
        if (m_state == Configured) {
            return m_outputs;
        }

        //!!! todo: figure out for which hosts (and adapters?) it may
        //!!! be a problem that the output descriptors are incomplete
        //!!! here. Any such hosts/adapters are broken, but I bet they
        //!!! exist
        
        OutputList staticOutputs;
        for (const auto &o: m_psd.basicOutputInfo) {
            OutputDescriptor od;
            od.identifier = o.identifier;
            od.name = o.name;
            od.description = o.description;
            staticOutputs.push_back(od);
        }
        return staticOutputs;
    }

    virtual FeatureSet process(const float *const *inputBuffers,
                               Vamp::RealTime timestamp) {

        if (m_state == Failed) {
            throw std::logic_error("Plugin is in failed state");
        }
        if (m_state == Loaded || m_state == Misconfigured) {
            m_state = Failed;
            throw std::logic_error("Plugin has not been initialised");
        }
        if (m_state == Finished) {
            m_state = Failed;
            throw std::logic_error("Plugin has already been disposed of");
        }

        std::vector<std::vector<float> > vecbuf;
        for (int c = 0; c < m_config.channelCount; ++c) {
            vecbuf.push_back(std::vector<float>
                             (inputBuffers[c],
                              inputBuffers[c] + m_config.framing.blockSize));
        }

        try {
            return m_client->process(this, vecbuf, timestamp);
        } catch (const std::exception &e) {
            m_state = Failed;
            throw;
        }
    }

    virtual FeatureSet getRemainingFeatures() {

        if (m_state == Failed) {
            throw std::logic_error("Plugin is in failed state");
        }
        if (m_state == Loaded || m_state == Misconfigured) {
            m_state = Failed;
            throw std::logic_error("Plugin has not been configured");
        }
        if (m_state == Finished) {
            m_state = Failed;
            throw std::logic_error("Plugin has already been disposed of");
        }

        m_state = Finished;

        try {
            return m_client->finish(this);
        } catch (const std::exception &e) {
            m_state = Failed;
            throw;
        }
    }

    // Not Plugin methods, but needed by the PluginClient to support reloads:
    
    virtual float getInputSampleRate() const {
        return m_inputSampleRate;
    }

    virtual std::string getPluginKey() const {
        return m_key;
    }

    virtual int getAdapterFlags() const {
        return m_adapterFlags;
    }
    
private:
    PluginClient *m_client;
    std::string m_key;
    int m_adapterFlags;
    State m_state;
    PluginStaticData m_psd;
    OutputList m_outputs;
    PluginConfiguration m_defaultConfig;
    PluginConfiguration m_config;
};

}
}

#endif