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Diffstat (limited to 'src/libs/installer/genericdatacache.cpp')
| -rw-r--r-- | src/libs/installer/genericdatacache.cpp | 695 |
1 files changed, 695 insertions, 0 deletions
diff --git a/src/libs/installer/genericdatacache.cpp b/src/libs/installer/genericdatacache.cpp new file mode 100644 index 000000000..a1e31ccfe --- /dev/null +++ b/src/libs/installer/genericdatacache.cpp @@ -0,0 +1,695 @@ +/************************************************************************** +** +** Copyright (C) 2023 The Qt Company Ltd. +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the Qt Installer Framework. +** +** $QT_BEGIN_LICENSE:GPL-EXCEPT$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3 as published by the Free Software +** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT +** included in the packaging of this file. Please review the following +** information to ensure the GNU General Public License requirements will +** be met: https://www.gnu.org/licenses/gpl-3.0.html. +** +** $QT_END_LICENSE$ +** +**************************************************************************/ + +#include "genericdatacache.h" + +#include "errors.h" +#include "fileutils.h" +#include "globals.h" +#include "metadata.h" +#include "updater.h" + +#include <QDir> +#include <QDirIterator> +#include <QtConcurrent> + +namespace QInstaller { + +static const QLatin1String scManifestFile("manifest.json"); + +/*! + \inmodule QtInstallerFramework + \class QInstaller::CacheableItem + \brief The CacheableItem is a pure virtual class that defines an interface for + a type suited for storage with the \l{GenericDataCache} class. +*/ + +/*! + \fn QInstaller::CacheableItem::path() const + + Returns the path of this item. A subclass may override this method. +*/ + +/*! + \fn QInstaller::CacheableItem::setPath(const QString &path) + + Sets the path of the item to \a path. A subclass may override this method. +*/ + +/*! + \fn QInstaller::CacheableItem::checksum() const + + Returns the checksum of this item. A subclass must implement this method. +*/ + +/*! + \fn QInstaller::CacheableItem::isValid() const + + Returns \c true if this item is valid, \c false otherwise. + A subclass must implement this method. +*/ + +/*! + \fn QInstaller::CacheableItem::isActive() const + + Returns \c true if this item is an actively used cache item, \c false otherwise. + This information is used as a hint for filtering obsolete entries, an active item + can never be obsolete. + + A subclass must implement this method. +*/ + +/*! + \fn QInstaller::CacheableItem::obsoletes(CacheableItem *other) + + Returns \c true if the calling item obsoletes \a other item, \c false otherwise. + This method is used for filtering obsolete entries from the cache. + + A subclass must implement this method. +*/ + +/*! + Virtual destructor for \c CacheableItem. +*/ +CacheableItem::~CacheableItem() +{ +} + + +/*! + \inmodule QtInstallerFramework + \class QInstaller::GenericDataCache + \brief The GenericDataCache is a template class for a checksum based storage + of items on disk. + + GenericDataCache\<T\> manages a cache storage for a set \l{path()}, which contains + a subdirectory for each registered item. An item of type \c T should implement + methods declared in the \l{CacheableItem} interface. The GenericDataCache\<T\> class can + still be explicitly specialized to use the derived type as a template argument, to + allow retrieving items as the derived type without casting. + + Each cache has a manifest file in its root directory, which lists the version + and wrapped type of the cache, and all its items. The file is updated automatically + when the cache object is destructed, or it can be updated periodically by + calling \l{sync()}. +*/ + +/*! + \enum GenericDataCache::RegisterMode + This enum holds the possible values for modes of registering items to cache. + + \value Copy + The contents of the item are copied to the cache. + \value Move + The contents of the item are move to the cache. +*/ + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::GenericDataCache() + + Constructs a new empty cache. The cache is invalid until set with a + path and initialized. +*/ +template <typename T> +GenericDataCache<T>::GenericDataCache() + : m_version(QLatin1String("1.0.0")) + , m_invalidated(true) +{ +} + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::GenericDataCache(const QString &path, const QString &type, const QString &version) + + Constructs a cache to \a path with the given \a type and \a version. + The cache is initialized automatically. +*/ +template <typename T> +GenericDataCache<T>::GenericDataCache(const QString &path, const QString &type, + const QString &version) + : m_path(path) + , m_type(type) + , m_version(version) + , m_invalidated(true) +{ + initialize(); +} + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::~GenericDataCache() + + Deletes the cache object. Item contents on disk are kept. +*/ +template <typename T> +GenericDataCache<T>::~GenericDataCache() +{ + if (m_invalidated) + return; + + toDisk(); + invalidate(); +} + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::setType(const QString &type) + + Sets the name of the wrapped type to \a type. This is used for determining if an + existing cache holds items of the same type. Trying to load cached items with mismatching + type results in discarding the old items. Optional. +*/ +template<typename T> +void GenericDataCache<T>::setType(const QString &type) +{ + QMutexLocker _(&m_mutex); + m_type = type; +} + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::setVersion(const QString &version) + + Sets the version of the cache to \a version. Loading from a cache with different + expected version discards the old items. The version property defaults to \c{1.0.0}. +*/ +template<typename T> +void GenericDataCache<T>::setVersion(const QString &version) +{ + QMutexLocker _(&m_mutex); + m_version = version; +} + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::initialize() + + Initializes a cache. Creates a new directory for the path configured for + this cache if it does not exist, and loads any previously cached items from + the directory. The cache directory is locked for access by this process only. + Returns \c true on success, \c false otherwise. +*/ +template <typename T> +bool GenericDataCache<T>::initialize() +{ + QMutexLocker _(&m_mutex); + Q_ASSERT(m_items.isEmpty()); + + if (m_path.isEmpty()) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot initialize cache with empty path.")); + return false; + } + + QDir directory(m_path); + if (!directory.exists() && !directory.mkpath(m_path)) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot create directory \"%1\" for cache.").arg(m_path)); + return false; + } + + if (m_lock && !m_lock->unlock()) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot initialize cache: %1").arg(m_lock->errorString())); + return false; + } + + m_lock.reset(new KDUpdater::LockFile(m_path + QLatin1String("/cache.lock"))); + if (!m_lock->lock()) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot initialize cache: %1").arg(m_lock->errorString())); + return false; + } + + if (!fromDisk()) + return false; + + m_invalidated = false; + return true; +} + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::clear() + + Removes all items from the cache and deletes their contents on disk. If + the cache directory becomes empty, it is also deleted. The cache becomes + invalid after this action, even in case of error while clearing. In that + case already deleted items will be lost. Returns \c true on success, + \c false otherwise. +*/ +template <typename T> +bool GenericDataCache<T>::clear() +{ + QMutexLocker _(&m_mutex); + if (m_invalidated) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot clear invalidated cache.")); + return false; + } + + QFile manifestFile(m_path + QDir::separator() + scManifestFile); + if (manifestFile.exists() && !manifestFile.remove()) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot remove manifest file: %1").arg(manifestFile.errorString())); + invalidate(); + return false; + } + + bool success = true; + for (T *item : qAsConst(m_items)) { + try { + QInstaller::removeDirectory(item->path()); + } catch (const Error &e) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Error while clearing cache: %1").arg(e.message())); + success = false; + } + } + + invalidate(); + QDir().rmdir(m_path); + return success; +} + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::sync() + + Synchronizes the contents of the cache to its manifest file. Returns \c true + if the manifest file was updates successfully, \c false otherwise. +*/ +template<typename T> +bool GenericDataCache<T>::sync() +{ + QMutexLocker _(&m_mutex); + if (m_invalidated) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot synchronize invalidated cache.")); + return false; + } + return toDisk(); +} + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::isValid() const + + Returns \c true if the cache is valid, \c false otherwise. A cache is considered + valid when it is initialized to a set path. +*/ +template<typename T> +bool GenericDataCache<T>::isValid() const +{ + QMutexLocker _(&m_mutex); + return !m_invalidated; +} + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::errorString() const + + Returns a string representing the last error with the cache. +*/ +template<typename T> +QString GenericDataCache<T>::errorString() const +{ + QMutexLocker _(&m_mutex); + return m_error; +} + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::path() const + + Returns the path of the cache on disk. +*/ +template <typename T> +QString GenericDataCache<T>::path() const +{ + QMutexLocker _(&m_mutex); + return m_path; +} + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::setPath(const QString &path) + + Sets a new \a path for the cache and invalidates current items. Saves the information + of the old cache to its manifest file. +*/ +template <typename T> +void GenericDataCache<T>::setPath(const QString &path) +{ + QMutexLocker _(&m_mutex); + if (!m_invalidated) + toDisk(); + + m_path = path; + invalidate(); +} + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::items() const + + Returns a list of cached items. +*/ +template <typename T> +QList<T *> GenericDataCache<T>::items() const +{ + QMutexLocker _(&m_mutex); + if (m_invalidated) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot retrieve items from invalidated cache.")); + return QList<T *>(); + } + return m_items.values(); +} + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::itemByChecksum(const QByteArray &checksum) const + + Returns an item that matches the \a checksum or \c nullptr in case + no such item is cached. +*/ +template <typename T> +T *GenericDataCache<T>::itemByChecksum(const QByteArray &checksum) const +{ + QMutexLocker _(&m_mutex); + if (m_invalidated) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot retrieve item from invalidated cache.")); + return nullptr; + } + return m_items.value(checksum); +} + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::itemByPath(const QString &path) const + + Returns an item from the \a path or \c nullptr in case no such item + is cached. Depending on the size of the cache, this can be much + slower than retrieving an item with \l{itemByChecksum()}. +*/ +template <typename T> +T *GenericDataCache<T>::itemByPath(const QString &path) const +{ + QMutexLocker _(&m_mutex); + auto it = std::find_if(m_items.constBegin(), m_items.constEnd(), + [&](T *item) { + return (QDir::fromNativeSeparators(path) == QDir::fromNativeSeparators(item->path())); + } + ); + if (it != m_items.constEnd()) + return it.value(); + + return nullptr; +} + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::registerItem(T *item, bool replace, RegisterMode mode) + + Registers the \a item to the cache. If \a replace is set to \c true, + the new \a item replaces a previous item with the same checksum. + + The cache takes ownership of the object pointed by \a item. The contents of the + item are copied or moved to the cache with a subdirectory name that matches the checksum + of the item. The \a mode decides how the contents of the item are registered, either by + copying or moving. + + Returns \c true on success or \c false if the item could not be registered. +*/ +template <typename T> +bool GenericDataCache<T>::registerItem(T *item, bool replace, RegisterMode mode) +{ + QMutexLocker _(&m_mutex); + if (m_invalidated) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot register item to invalidated cache.")); + return false; + } + if (!item) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot register null item.")); + return false; + } + if (!item->isValid()) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot register invalid item with checksum %1").arg(QLatin1String(item->checksum()))); + return false; + } + if (m_items.contains(item->checksum())) { + if (replace) {// replace existing item including contents on disk + remove(item->checksum()); + } else { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot register item with checksum %1. An item with the same checksum " + "already exists in cache.").arg(QLatin1String(item->checksum()))); + return false; + } + } + + const QString newPath = m_path + QDir::separator() + QString::fromLatin1(item->checksum()); + try { + // A directory is in the way but it isn't registered to the current cache, remove. + QDir dir; + if (dir.exists(newPath)) + QInstaller::removeDirectory(newPath); + + switch (mode) { + case Copy: + QInstaller::copyDirectoryContents(item->path(), newPath); + break; + case Move: + // First, try moving the top level directory + if (!dir.rename(item->path(), newPath)) { + qCDebug(lcDeveloperBuild) << "Failed to rename directory" << item->path() + << "to" << newPath << ". Trying again."; + // If that does not work, fallback to moving the contents one by one + QInstaller::moveDirectoryContents(item->path(), newPath); + } + break; + default: + throw Error(QCoreApplication::translate("GenericDataCache", + "Unknown register mode selected!")); + } + } catch (const Error &e) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Error while copying item to path \"%1\": %2").arg(newPath, e.message())); + return false; + } + + item->setPath(newPath); + if (item->isValid()) { + m_items.insert(item->checksum(), item); + return true; + } + return false; +} + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::removeItem(const QByteArray &checksum) + + Removes the item specified by \a checksum from the cache and deletes the + contents of the item from disk. Returns \c true if the item + was removed successfully, \c false otherwise. +*/ +template <typename T> +bool GenericDataCache<T>::removeItem(const QByteArray &checksum) +{ + QMutexLocker _(&m_mutex); + return remove(checksum); +} + +/*! + \fn template <typename T> QInstaller::GenericDataCache<T>::obsoleteItems() const + + Returns items considered obsolete from the cache. +*/ +template<typename T> +QList<T *> GenericDataCache<T>::obsoleteItems() const +{ + QMutexLocker _(&m_mutex); + const QList<T *> obsoletes = QtConcurrent::blockingFiltered(m_items.values(), + [&](T *item1) { + if (item1->isActive()) // We can skip the iteration for active entries + return false; + + for (T *item2 : qAsConst(m_items)) { + if (item2->obsoletes(item1)) + return true; + } + return false; + } + ); + return obsoletes; +} + +/*! + \internal + + Marks the cache invalid and clears all items. The contents + on disk are not deleted. Releases the lock file of the cache. +*/ +template <typename T> +void GenericDataCache<T>::invalidate() +{ + if (!m_items.isEmpty()) { + qDeleteAll(m_items); + m_items.clear(); + } + if (m_lock && !m_lock->unlock()) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Error while invalidating cache: %1").arg(m_lock->errorString())); + } + m_invalidated = true; +} + +/*! + \internal + + Sets the current error string to \a error and prints it as a warning to the console. +*/ +template <typename T> +void GenericDataCache<T>::setErrorString(const QString &error) const +{ + m_error = error; + qCWarning(QInstaller::lcInstallerInstallLog) << error; +} + +/*! + \internal + + Reads the manifest file of the cache if one exists, and populates the internal + hash from the file contents. Returns \c true if the manifests was read successfully + or if the reading was omitted. This is the case if the file does not exist yet, or + the type or version of the manifest does not match the current cache object. In case + of mismatch the old items are not restored. Returns \c false otherwise. +*/ +template<typename T> +bool GenericDataCache<T>::fromDisk() +{ + QFile manifestFile(m_path + QDir::separator() + scManifestFile); + if (!manifestFile.exists()) // Not yet created + return true; + + if (!manifestFile.open(QIODevice::ReadOnly)) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot open manifest file: %1").arg(manifestFile.errorString())); + return false; + } + + const QByteArray manifestData = manifestFile.readAll(); + const QJsonDocument manifestJsonDoc(QJsonDocument::fromJson(manifestData)); + const QJsonObject docJsonObject = manifestJsonDoc.object(); + + const QJsonValue type = docJsonObject.value(QLatin1String("type")); + if (type.toString() != m_type) { + qCDebug(QInstaller::lcInstallerInstallLog) << "Discarding existing items from cache of type:" + << type.toString() << ". New type:" << m_type; + return true; + } + + const QJsonValue version = docJsonObject.value(QLatin1String("version")); + if (KDUpdater::compareVersion(version.toString(), m_version) != 0) { + qCDebug(QInstaller::lcInstallerInstallLog) << "Discarding existing items from cache with version:" + << version.toString() << ". New version:" << m_version; + return true; + } + + const QJsonArray itemsJsonArray = docJsonObject.value(QLatin1String("items")).toArray(); + for (const auto &itemJsonValue : itemsJsonArray) { + const QString checksum = itemJsonValue.toString(); + + std::unique_ptr<T> item(new T(m_path + QDir::separator() + checksum)); + m_items.insert(checksum.toLatin1(), item.release()); + + // The cache directory may contain other entries (unrelated directories or + // invalid old cache items) which we don't care about, unless registering + // a new entry requires overwriting them. + } + return true; +} + +/*! + \internal + + Writes the manifest file with the contents of the internal item hash. + Returns \c true on success, \c false otherwise. +*/ +template<typename T> +bool GenericDataCache<T>::toDisk() +{ + QFile manifestFile(m_path + QDir::separator() + scManifestFile); + if (!manifestFile.open(QIODevice::WriteOnly)) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot open manifest file: %1").arg(manifestFile.errorString())); + return false; + } + + QJsonArray itemsJsonArray; + const QList<QByteArray> keys = m_items.keys(); + for (const QByteArray &key : keys) + itemsJsonArray.append(QJsonValue(QLatin1String(key))); + + QJsonObject docJsonObject; + docJsonObject.insert(QLatin1String("items"), itemsJsonArray); + docJsonObject.insert(QLatin1String("version"), m_version); + if (!m_type.isEmpty()) + docJsonObject.insert(QLatin1String("type"), m_type); + + QJsonDocument manifestJsonDoc; + manifestJsonDoc.setObject(docJsonObject); + if (manifestFile.write(manifestJsonDoc.toJson()) == -1) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot write contents for manifest file: %1").arg(manifestFile.errorString())); + return false; + } + return true; +} + +/*! + \internal +*/ +template<typename T> +bool GenericDataCache<T>::remove(const QByteArray &checksum) +{ + if (m_invalidated) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot remove item from invalidated cache.")); + return false; + } + QScopedPointer<T> item(m_items.take(checksum)); + if (!item) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Cannot remove item specified by checksum %1: no such item exists.").arg(QLatin1String(checksum))); + return false; + } + + try { + QInstaller::removeDirectory(item->path()); + } catch (const Error &e) { + setErrorString(QCoreApplication::translate("GenericDataCache", + "Error while removing directory \"%1\": %2").arg(item->path(), e.message())); + return false; + } + return true; +} + +template class GenericDataCache<Metadata>; + +} // namespace QInstaller |