Provide torrent creation feature via WebAPI

PR #20366.
Closes #5614.

Co-authored-by: Radu Carpa <radu.carpa@cern.ch>

src/base/bittorrent/torrentcreationmanager.cpp

@@ -0,0 +1,134 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2024  Vladimir Golovnev <glassez@yandex.ru>
+ * Copyright (C) 2024  Radu Carpa <radu.carpa@cern.ch>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ */
+
+#include "torrentcreationmanager.h"
+
+#include <utility>
+
+#include <boost/multi_index_container.hpp>
+#include <boost/multi_index/composite_key.hpp>
+#include <boost/multi_index/indexed_by.hpp>
+#include <boost/multi_index/mem_fun.hpp>
+#include <boost/multi_index/ordered_index.hpp>
+
+#include <QUuid>
+
+#define SETTINGS_KEY(name) u"TorrentCreator/Manager/" name
+
+namespace BitTorrent
+{
+    using namespace boost::multi_index;
+
+    class TorrentCreationManager::TaskSet final : public boost::multi_index_container<
+            std::shared_ptr<TorrentCreationTask>,
+            indexed_by<
+                    ordered_unique<tag<struct ByID>, const_mem_fun<TorrentCreationTask, QString, &TorrentCreationTask::id>>,
+                    ordered_non_unique<tag<struct ByCompletion>, composite_key<
+                            TorrentCreationTask,
+                            const_mem_fun<TorrentCreationTask, bool, &TorrentCreationTask::isFinished>,
+                            const_mem_fun<TorrentCreationTask, QDateTime, &TorrentCreationTask::timeAdded>>>>>
+    {
+    };
+}
+
+BitTorrent::TorrentCreationManager::TorrentCreationManager(IApplication *app, QObject *parent)
+    : ApplicationComponent(app, parent)
+    , m_maxTasks {SETTINGS_KEY(u"MaxTasks"_s), 256}
+    , m_numThreads {SETTINGS_KEY(u"NumThreads"_s), 1}
+    , m_tasks {std::make_unique<TaskSet>()}
+{
+    if (m_numThreads > 0)
+        m_threadPool.setMaxThreadCount(m_numThreads);
+}
+
+BitTorrent::TorrentCreationManager::~TorrentCreationManager() = default;
+
+std::shared_ptr<BitTorrent::TorrentCreationTask> BitTorrent::TorrentCreationManager::createTask(const TorrentCreatorParams &params, bool startSeeding)
+{
+    if (std::cmp_greater_equal(m_tasks->size(), m_maxTasks.get()))
+    {
+        // Try to delete old finished tasks to stay under target
+        auto &tasksByCompletion = m_tasks->get<ByCompletion>();
+        auto [iter, endIter] = tasksByCompletion.equal_range(std::make_tuple(true));
+        while ((iter != endIter) && std::cmp_greater_equal(m_tasks->size(), m_maxTasks.get()))
+        {
+            iter = tasksByCompletion.erase(iter);
+        }
+    }
+    if (std::cmp_greater_equal(m_tasks->size(), m_maxTasks.get()))
+        return {};
+
+    const QString taskID = generateTaskID();
+
+    auto *torrentCreator = new TorrentCreator(params, this);
+    auto creationTask = std::make_shared<TorrentCreationTask>(app(), taskID, torrentCreator, startSeeding);
+    connect(creationTask.get(), &QObject::destroyed, torrentCreator, &BitTorrent::TorrentCreator::requestInterruption);
+
+    m_tasks->get<ByID>().insert(creationTask);
+    m_threadPool.start(torrentCreator);
+
+    return creationTask;
+}
+
+QString BitTorrent::TorrentCreationManager::generateTaskID() const
+{
+    const auto &tasksByID = m_tasks->get<ByID>();
+    QString taskID = QUuid::createUuid().toString(QUuid::WithoutBraces);
+    while (tasksByID.find(taskID) != tasksByID.end())
+        taskID = QUuid::createUuid().toString(QUuid::WithoutBraces);
+
+    return taskID;
+}
+
+std::shared_ptr<BitTorrent::TorrentCreationTask> BitTorrent::TorrentCreationManager::getTask(const QString &id) const
+{
+    const auto &tasksByID = m_tasks->get<ByID>();
+    const auto iter = tasksByID.find(id);
+    if (iter == tasksByID.end())
+        return nullptr;
+
+    return *iter;
+}
+
+QList<std::shared_ptr<BitTorrent::TorrentCreationTask>> BitTorrent::TorrentCreationManager::tasks() const
+{
+    const auto &tasksByCompletion = m_tasks->get<ByCompletion>();
+    return {tasksByCompletion.cbegin(), tasksByCompletion.cend()};
+}
+
+bool BitTorrent::TorrentCreationManager::deleteTask(const QString &id)
+{
+    auto &tasksByID = m_tasks->get<ByID>();
+    const auto iter = tasksByID.find(id);
+    if (iter == tasksByID.end())
+        return false;
+
+    tasksByID.erase(iter);
+    return true;
+}