annotate vamp-client/CapnpRRClient.h @ 146:c4f841ccb208

Allow the completeness checker to report failure (invalid message) as well as incompleteness

/* -*- 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 2006-2016 Chris Cannam and QMUL.
  
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  obtaining a copy of this software and associated documentation
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  of the Software, and to permit persons to whom the Software is
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  shall not be used in advertising or otherwise to promote the sale,
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*/

#ifndef PIPER_CAPNP_CLIENT_H
#define PIPER_CAPNP_CLIENT_H

#include "Loader.h"
#include "PluginClient.h"
#include "PluginStub.h"
#include "SynchronousTransport.h"

#include "vamp-support/AssignedPluginHandleMapper.h"
#include "vamp-capnp/VampnProto.h"

#include <sstream>

#include <capnp/serialize.h>

//#define LOG_ENTRYPOINTS 1

#ifdef LOG_ENTRYPOINTS
#define LOG_E(x) log(x)
#else
#define LOG_E(x)
#endif

namespace piper_vamp {
namespace client {

/**
 * Client for a request-response Piper server, i.e. using the
 * RpcRequest/RpcResponse structures with a single process call rather
 * than having individual RPC methods, with a synchronous transport
 * such as a subprocess pipe arrangement. Only one request can be
 * handled at a time. This class is thread-safe if and only if it is
 * constructed with a thread-safe SynchronousTransport implementation.
 */
class CapnpRRClient : public PluginClient,
                      public Loader
{
    // unsigned to avoid undefined behaviour on possible wrap
    typedef uint32_t ReqId;

    class CompletenessChecker : public MessageCompletenessChecker {
    public:
        State check(const std::vector<char> &message) const override {

            auto karr = toKJArray(message);
            size_t words = karr.size();
            size_t expected = capnp::expectedSizeInWordsFromPrefix(karr);

            // Lacking a way to definitively check whether a message
            // is valid or not, we would still like to trap obvious
            // cases where a programming mistake results in garbage
            // being returned from the server. We impose a limit on
            // message size and, if a prefix is projected to exceed
            // that limit, call it invalid. If an extractor wants to
            // return a feature set greater than a gigaword in size,
            // it'll just have to do it across multiple process calls.
            size_t limit = size_t(1) << 30;
            
//            cerr << "CompletenessChecker: message.size() = " << message.size()
//                 << ", words = " << words << ", limit = " << limit << ", expected = " << expected << endl;

            if (words > expected) {
                std::cerr << "WARNING: obtained more data than expected ("
                          << words << " " << sizeof(capnp::word)
                          << "-byte words, expected "
                          << expected << ")" << std::endl;
                return Complete;
            } else if (words == expected) {
                return Complete;
            } else if (expected > limit) {
                return Invalid;
            } else {
                return Incomplete;
            }
        }
    };
    
public:
    CapnpRRClient(SynchronousTransport *transport, //!!! ownership? shared ptr?
                  LogCallback *logger) : // logger may be nullptr for cerr
        m_logger(logger),
        m_transport(transport),
        m_completenessChecker(new CompletenessChecker) {
        transport->setCompletenessChecker(m_completenessChecker);
    }

    ~CapnpRRClient() {
        delete m_completenessChecker;
    }

    //!!! obviously, factor out all repetitive guff

    //!!! list and load are supposed to be called by application code,
    //!!! but the rest are only supposed to be called by the plugin --
    //!!! sort out the api here

    // Loader methods:

    ListResponse
    listPluginData(const ListRequest &req) override {

        LOG_E("CapnpRRClient::listPluginData called");
        
        if (!m_transport->isOK()) {
            log("Piper server crashed or failed to start (caller should have checked this)");
            throw std::runtime_error("Piper server crashed or failed to start");
        }

        capnp::MallocMessageBuilder message;
        piper::RpcRequest::Builder builder = message.initRoot<piper::RpcRequest>();
        VampnProto::buildRpcRequest_List(builder, req);
        ReqId id = getId();
        builder.getId().setNumber(id);

        auto karr = call(message, "list", true);

        capnp::FlatArrayMessageReader responseMessage(karr);
        piper::RpcResponse::Reader reader = responseMessage.getRoot<piper::RpcResponse>();

        checkResponseType(reader, piper::RpcResponse::Response::Which::LIST, id);

        ListResponse lr;
        VampnProto::readListResponse(lr, reader.getResponse().getList());

        LOG_E("CapnpRRClient::listPluginData returning");
        
        return lr;
    }
    
    LoadResponse
    loadPlugin(const LoadRequest &req) override {

        LOG_E("CapnpRRClient::loadPlugin called");
        
        if (!m_transport->isOK()) {
            log("Piper server crashed or failed to start (caller should have checked this)");
            throw std::runtime_error("Piper server crashed or failed to start");
        }

        LoadResponse resp;
        PluginHandleMapper::Handle handle = serverLoad(req.pluginKey,
                                                       req.inputSampleRate,
                                                       req.adapterFlags,
                                                       resp.staticData,
                                                       resp.defaultConfiguration);

        Vamp::Plugin *plugin = new PluginStub(this,
                                              req.pluginKey,
                                              req.inputSampleRate,
                                              req.adapterFlags,
                                              resp.staticData,
                                              resp.defaultConfiguration);

        m_mapper.addPlugin(handle, plugin);

        resp.plugin = plugin;

        LOG_E("CapnpRRClient::loadPlugin returning");
        
        return resp;
    }

    // PluginClient methods:
    
    virtual
    Vamp::Plugin::OutputList
    configure(PluginStub *plugin,
              PluginConfiguration config) override {

        LOG_E("CapnpRRClient::configure called");
        
        if (!m_transport->isOK()) {
            log("Piper server crashed or failed to start (caller should have checked this)");
            throw std::runtime_error("Piper server crashed or failed to start");
        }

        ConfigurationRequest request;
        request.plugin = plugin;
        request.configuration = config;

        capnp::MallocMessageBuilder message;
        piper::RpcRequest::Builder builder = message.initRoot<piper::RpcRequest>();

        VampnProto::buildRpcRequest_Configure(builder, request, m_mapper);
        ReqId id = getId();
        builder.getId().setNumber(id);

        auto karr = call(message, "configure", true);

        capnp::FlatArrayMessageReader responseMessage(karr);
        piper::RpcResponse::Reader reader = responseMessage.getRoot<piper::RpcResponse>();

        //!!! handle (explicit) error case

        checkResponseType(reader, piper::RpcResponse::Response::Which::CONFIGURE, id);

        ConfigurationResponse cr;
        VampnProto::readConfigurationResponse(cr,
                                              reader.getResponse().getConfigure(),
                                              m_mapper);

        LOG_E("CapnpRRClient::configure returning");
        
        return cr.outputs;
    };
    
    virtual
    Vamp::Plugin::FeatureSet
    process(PluginStub *plugin,
            std::vector<std::vector<float> > inputBuffers,
            Vamp::RealTime timestamp) override {

        LOG_E("CapnpRRClient::process called");
        
        if (!m_transport->isOK()) {
            log("Piper server crashed or failed to start (caller should have checked this)");
            throw std::runtime_error("Piper server crashed or failed to start");
        }

        ProcessRequest request;
        request.plugin = plugin;
        request.inputBuffers = inputBuffers;
        request.timestamp = timestamp;
        
        capnp::MallocMessageBuilder message;
        piper::RpcRequest::Builder builder = message.initRoot<piper::RpcRequest>();
        VampnProto::buildRpcRequest_Process(builder, request, m_mapper);
        ReqId id = getId();
        builder.getId().setNumber(id);

        auto karr = call(message, "process", false);

        capnp::FlatArrayMessageReader responseMessage(karr);
        piper::RpcResponse::Reader reader = responseMessage.getRoot<piper::RpcResponse>();

        //!!! handle (explicit) error case

        checkResponseType(reader, piper::RpcResponse::Response::Which::PROCESS, id);

        ProcessResponse pr;
        VampnProto::readProcessResponse(pr,
                                        reader.getResponse().getProcess(),
                                        m_mapper);

        LOG_E("CapnpRRClient::process returning");
        
        return pr.features;
    }

    virtual Vamp::Plugin::FeatureSet
    finish(PluginStub *plugin) override {

        LOG_E("CapnpRRClient::finish called");
        
        if (!m_transport->isOK()) {
            log("Piper server crashed or failed to start (caller should have checked this)");
            throw std::runtime_error("Piper server crashed or failed to start");
        }

        FinishRequest request;
        request.plugin = plugin;
        
        capnp::MallocMessageBuilder message;
        piper::RpcRequest::Builder builder = message.initRoot<piper::RpcRequest>();

        VampnProto::buildRpcRequest_Finish(builder, request, m_mapper);
        ReqId id = getId();
        builder.getId().setNumber(id);
        
        auto karr = call(message, "finish", true);

        capnp::FlatArrayMessageReader responseMessage(karr);
        piper::RpcResponse::Reader reader = responseMessage.getRoot<piper::RpcResponse>();

        //!!! handle (explicit) error case

        checkResponseType(reader, piper::RpcResponse::Response::Which::FINISH, id);

        FinishResponse pr;
        VampnProto::readFinishResponse(pr,
                                       reader.getResponse().getFinish(),
                                       m_mapper);

        m_mapper.removePlugin(m_mapper.pluginToHandle(plugin));

        // Don't delete the plugin. It's the plugin that is supposed
        // to be calling us here
        
        LOG_E("CapnpRRClient::finish returning");
        
        return pr.features;
    }

    virtual void
    reset(PluginStub *plugin,
          PluginConfiguration config) override {

        // Reload the plugin on the server side, and configure it as requested

        log("CapnpRRClient: reset() called, plugin will be closed and reloaded");
        
        if (!m_transport->isOK()) {
            log("Piper server crashed or failed to start (caller should have checked this)");
            throw std::runtime_error("Piper server crashed or failed to start");
        }

        if (m_mapper.havePlugin(plugin)) {
            (void)finish(plugin); // server-side unload
        }

        PluginStaticData psd;
        PluginConfiguration defaultConfig;
        PluginHandleMapper::Handle handle =
            serverLoad(plugin->getPluginKey(),
                       plugin->getInputSampleRate(),
                       plugin->getAdapterFlags(),
                       psd, defaultConfig);

        m_mapper.addPlugin(handle, plugin);

        (void)configure(plugin, config);
    }
    
private:
    AssignedPluginHandleMapper m_mapper;
    ReqId getId() {
        //!!! todo: mutex
        static ReqId m_nextId = 0;
        return m_nextId++;
    }

    static
    kj::Array<capnp::word>
    toKJArray(const std::vector<char> &buffer) {
        // We could do this whole thing with fewer copies, but let's
        // see whether it matters first
        size_t wordSize = sizeof(capnp::word);
        size_t words = buffer.size() / wordSize;
        kj::Array<capnp::word> karr(kj::heapArray<capnp::word>(words));
        memcpy(karr.begin(), buffer.data(), words * wordSize);
        return karr;
    }

    void
    checkResponseType(const piper::RpcResponse::Reader &r,
                      piper::RpcResponse::Response::Which type,
                      ReqId id) {
        
        if (r.getResponse().which() != type) {
            std::ostringstream s;
            s << "checkResponseType: wrong response type (received "
              << int(r.getResponse().which()) << ", expected " << int(type) << ")";
            log(s.str());
            throw std::runtime_error("Wrong response type");
        }
        if (ReqId(r.getId().getNumber()) != id) {
            std::ostringstream s;
            s << "checkResponseType: wrong response id (received "
              << r.getId().getNumber() << ", expected " << id << ")";
            log(s.str());
            throw std::runtime_error("Wrong response id");
        }
    }

    kj::Array<capnp::word>
    call(capnp::MallocMessageBuilder &message, std::string type, bool slow) {
        auto arr = capnp::messageToFlatArray(message);
        auto responseBuffer = m_transport->call(arr.asChars().begin(),
                                                arr.asChars().size(),
                                                type,
                                                slow);
        return toKJArray(responseBuffer);
    }
    
    PluginHandleMapper::Handle
    serverLoad(std::string key, float inputSampleRate, int adapterFlags,
               PluginStaticData &psd,
               PluginConfiguration &defaultConfig) {

        LoadRequest request;
        request.pluginKey = key;
        request.inputSampleRate = inputSampleRate;
        request.adapterFlags = adapterFlags;

        capnp::MallocMessageBuilder message;
        piper::RpcRequest::Builder builder = message.initRoot<piper::RpcRequest>();

        VampnProto::buildRpcRequest_Load(builder, request);
        ReqId id = getId();
        builder.getId().setNumber(id);

        auto karr = call(message, "load", false);

        //!!! ... --> will also need some way to kill this process
        //!!! (from another thread)

        capnp::FlatArrayMessageReader responseMessage(karr);
        piper::RpcResponse::Reader reader = responseMessage.getRoot<piper::RpcResponse>();

        //!!! handle (explicit) error case

        checkResponseType(reader, piper::RpcResponse::Response::Which::LOAD, id);
        
        const piper::LoadResponse::Reader &lr = reader.getResponse().getLoad();
        VampnProto::readExtractorStaticData(psd, lr.getStaticData());
        VampnProto::readConfiguration(defaultConfig, lr.getDefaultConfiguration());
        return lr.getHandle();
    };     

private:
    LogCallback *m_logger;
    SynchronousTransport *m_transport; //!!! I don't own this, but should I?
    CompletenessChecker *m_completenessChecker; // I own this
    
    void log(std::string message) const {
        if (m_logger) m_logger->log(message);
        else std::cerr << message << std::endl;
    }
};

}
}

#endif