ObservableLocalPluginAdapter.cpp

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/******************************************************************************
 * Copyright (c) 2025 Calypso Networks Association https://calypsonet.org/    *
 *                                                                            *
 * See the NOTICE file(s) distributed with this work for additional           *
 * information regarding copyright ownership.                                 *
 *                                                                            *
 * This program and the accompanying materials are made available under the   *
 * terms of the Eclipse Public License 2.0 which is available at              *
 * http://www.eclipse.org/legal/epl-2.0                                       *
 *                                                                            *
 * SPDX-License-Identifier: EPL-2.0                                           *
 ******************************************************************************/
 
#include "keyple/core/service/ObservableLocalPluginAdapter.hpp"
 
#include <memory>
#include <string>
#include <utility>
#include <vector>
 
#include "keyple/core/plugin/PluginIOException.hpp"
#include "keyple/core/service/KeyplePluginException.hpp"
#include "keyple/core/service/PluginEventAdapter.hpp"
#include "keyple/core/util/cpp/Arrays.hpp"
#include "keyple/core/util/cpp/exception/InterruptedException.hpp"
 
namespace keyple {
namespace core {
namespace service {
 
using keyple::core::plugin::PluginIOException;
using keyple::core::util::cpp::Arrays;
using keyple::core::util::cpp::exception::InterruptedException;
 
/* OBSERVABLE LOCAL PLUGIN ADAPTER JOB
 * ---------------------------------------------------------- */
 
/* OBSERVABLE LOCAL PLUGIN ADAPTER
 * -------------------------------------------------------------- */
 
ObservableLocalPluginAdapter::ObservableLocalPluginAdapter(
    std::shared_ptr<ObservablePluginSpi> observablePluginSpi)
: AbstractObservableLocalPluginAdapter(observablePluginSpi)
, mObservablePluginSpi(observablePluginSpi)
{
}
 
ObservableLocalPluginAdapter::~ObservableLocalPluginAdapter()
{
    if (mThread) {
        mThread->end();
        while (mThread->mRunning || !mThread->mTerminated) {
        }
    }
}
 
bool
ObservableLocalPluginAdapter::isMonitoring() const
{
    return mThread != nullptr && mThread->isAlive() && mThread->isMonitoring();
}
 
void
ObservableLocalPluginAdapter::addObserver(
    std::shared_ptr<PluginObserverSpi> observer)
{
    AbstractObservableLocalPluginAdapter::addObserver(observer);
 
    if (countObservers() == 1) {
        mLogger->info("Start monitoring the plugin [%]\n", getName());
        mThread = std::make_shared<EventThread>(getName(), this);
        mThread->setName("PluginEventMonitoringThread");
        mThread->setUncaughtExceptionHandler(
            std::make_shared<UncaughtExceptionHandler>(this));
        mThread->start();
        while (!mThread->mStarted) {
        }
    }
}
 
void
ObservableLocalPluginAdapter::removeObserver(
    const std::shared_ptr<PluginObserverSpi> observer)
{
    Assert::getInstance().notNull(observer, "observer");
 
    if (Arrays::contains(getObservationManager()->getObservers(), observer)) {
        AbstractObservableLocalPluginAdapter::removeObserver(observer);
 
        if (countObservers() == 0) {
            if (mThread != nullptr) {
                mThread->end();
                mLogger->info("Plugin monitoring stopped\n");
            }
        }
    }
}
 
void
ObservableLocalPluginAdapter::clearObservers()
{
    AbstractObservableLocalPluginAdapter::clearObservers();
 
    if (mThread != nullptr) {
        mThread->end();
        mLogger->info("Plugin monitoring stopped\n");
    }
}
 
/* UNCAUGHT EXCEPTION HANDLER
 * ------------------------------------------------------------------- */
 
ObservableLocalPluginAdapter::UncaughtExceptionHandler::
    UncaughtExceptionHandler(ObservableLocalPluginAdapter* parent)
: mParent(parent)
{
}
 
void
ObservableLocalPluginAdapter::UncaughtExceptionHandler::uncaughtException(
    std::shared_ptr<Thread> /*t*/, std::unique_ptr<Exception> e)
{
    mParent->getObservationManager()
        ->getObservationExceptionHandler()
        ->onPluginObservationError(mParent->mThread->mPluginName, std::move(e));
}
 
/* EVENT THREAD
 * ---------------------------------------------------------------------------------
 */
 
ObservableLocalPluginAdapter::EventThread::EventThread(
    const std::string& pluginName, ObservableLocalPluginAdapter* parent)
: Thread(std::string("ObservableLocalPluginAdapter-") + pluginName)
, mPluginName(pluginName)
, mMonitoringCycleDuration(
      parent->mObservablePluginSpi->getMonitoringCycleDuration())
, mRunning(true)
, mStarted(false)
, mTerminated(false)
, mParent(parent)
{
}
 
void
ObservableLocalPluginAdapter::EventThread::end()
{
    mRunning = false;
    interrupt();
}
 
bool
ObservableLocalPluginAdapter::EventThread::isMonitoring() const
{
    return mRunning;
}
 
void
ObservableLocalPluginAdapter::EventThread::addReader(
    const std::string& readerName)
{
    std::shared_ptr<ReaderSpi> readerSpi
        = mParent->mObservablePluginSpi->searchReader(readerName);
    std::shared_ptr<LocalReaderAdapter> reader
        = mParent->buildLocalReaderAdapter(readerSpi);
 
    reader->doRegister();
    mParent->getReadersMap().insert({reader->getName(), reader});
 
    mParent->mLogger->info(
        "Plugin [%] adds plugged reader [%] to readers list\n",
        mPluginName,
        readerName);
}
 
void
ObservableLocalPluginAdapter::EventThread::removeReader(
    const std::shared_ptr<CardReader> reader)
{
    std::dynamic_pointer_cast<LocalReaderAdapter>(reader)->doUnregister();
    mParent->getReadersMap().erase(reader->getName());
 
    mParent->mLogger->info(
        "Plugin [%] removes unplugged reader [%] from readers list\n",
        mPluginName,
        reader->getName());
}
 
void
ObservableLocalPluginAdapter::EventThread::notifyChanges(
    const PluginEvent::Type type,
    const std::vector<std::string>& changedReaderNames)
{
    /* Grouped notification */
    mParent->mLogger->trace(
        "Notify reader %(s): %\n",
        type == PluginEvent::Type::READER_CONNECTED ? "connection"
                                                    : "disconnection",
        changedReaderNames);
 
    mParent->notifyObservers(
        std::make_shared<PluginEventAdapter>(
            mPluginName, changedReaderNames, type));
}
 
void
ObservableLocalPluginAdapter::EventThread::processChanges(
    const std::vector<std::string>& actualNativeReaderNames)
{
    std::vector<std::string> changedReaderNames;
 
    /* Parse the current readers list, notify for disappeared readers, update
     * readers list */
    const std::vector<std::shared_ptr<CardReader>> readers
        = mParent->getReaders();
    for (const auto& reader : readers) {
        if (!std::count(
                actualNativeReaderNames.begin(),
                actualNativeReaderNames.end(),
                reader->getName())) {
            changedReaderNames.push_back(reader->getName());
        }
    }
 
    /* Notify disconnections if any and update the reader list */
    if (!changedReaderNames.empty()) {
        /* List update */
        for (const auto& reader : readers) {
            if (!std::count(
                    actualNativeReaderNames.begin(),
                    actualNativeReaderNames.end(),
                    reader->getName())) {
                removeReader(reader);
            }
        }
 
        notifyChanges(
            PluginEvent::Type::READER_DISCONNECTED, changedReaderNames);
 
        /* Clean the list for a possible connection notification */
        changedReaderNames.clear();
    }
 
    /* Parse the new readers list, notify for readers appearance, update readers
     * list */
    for (const auto& readerName : actualNativeReaderNames) {
        const std::vector<std::string>& readerNames = mParent->getReaderNames();
        if (!std::count(readerNames.begin(), readerNames.end(), readerName)) {
            addReader(readerName);
 
            /* Add to the notification list */
            changedReaderNames.push_back(readerName);
        }
    }
 
    /* Notify connections if any */
    if (!changedReaderNames.empty()) {
        notifyChanges(PluginEvent::Type::READER_CONNECTED, changedReaderNames);
    }
}
 
void
ObservableLocalPluginAdapter::EventThread::execute()
{
    mStarted = true;
 
    /* True while a reader enumeration outage is in progress, see below. */
    bool isInError = false;
 
    try {
        while (mRunning) {
            try {
                /* Retrieves the current readers names list */
                const std::vector<std::string> actualNativeReaderNames
                    = mParent->mObservablePluginSpi
                          ->searchAvailableReaderNames();
 
                /* Checks if it has changed this algorithm favors cases where
                 * nothing change */
                const std::vector<std::string> currentlyRegisteredReaderNames
                    = mParent->getReaderNames();
                if (!Arrays::containsAll(
                        currentlyRegisteredReaderNames, actualNativeReaderNames)
                    || !Arrays::containsAll(
                        actualNativeReaderNames,
                        currentlyRegisteredReaderNames)) {
                    processChanges(actualNativeReaderNames);
                }
 
                isInError = false;
 
            } catch (const PluginIOException& e) {
                /*
                 * Deliberate divergence from the Java reference, where this
                 * catch sits outside the loop and the first such error ends
                 * monitoring for good. On Windows, unplugging the LAST reader
                 * stops the Smart Card service, so a terminal behaviour leaves
                 * the plugin deaf even after the readers come back. Report the
                 * outage once, then keep polling so reconnections are seen.
                 */
                if (!isInError) {
                    isInError = true;
                    auto kpe(std::unique_ptr<KeyplePluginException>(
                        new KeyplePluginException(
                            "An error occurred while monitoring the readers",
                            e)));
                    mParent->getObservationManager()
                        ->getObservationExceptionHandler()
                        ->onPluginObservationError(mPluginName, std::move(kpe));
                }
            }
 
            /* Sleep for a while, whether or not the cycle succeeded */
            Thread::sleep(mMonitoringCycleDuration);
        }
    } catch (const InterruptedException& e) {
        (void)e;
        mParent->mLogger->info(
            "Plugin monitoring stopped, possibly because there is no more "
            "registered observer");
 
        /* Restore interrupted state... */
        interrupt();
    }
 
    mTerminated = true;
}
 
} /* namespace service */
} /* namespace core */
} /* namespace keyple */