1 files changed, 420 insertions, 0 deletions
diff --git a/sd/source/ui/slidesorter/cache/SlsPageCacheManager.cxx b/sd/source/ui/slidesorter/cache/SlsPageCacheManager.cxx
new file mode 100644
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+++ b/sd/source/ui/slidesorter/cache/SlsPageCacheManager.cxx
@@ -0,0 +1,420 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include <cache/SlsPageCacheManager.hxx>
+
+#include "SlsBitmapCache.hxx"
+
+#include <deque>
+#include <map>
+#include <memory>
+#include <unordered_map>
+
+namespace {
+
+/** Collection of data that is stored for all active preview caches.
+*/
+class CacheDescriptor
+{
+public:
+    ::sd::slidesorter::cache::PageCacheManager::DocumentKey mpDocument;
+    Size maPreviewSize;
+
+    CacheDescriptor(
+        ::sd::slidesorter::cache::PageCacheManager::DocumentKey const & pDocument,
+        const Size& rPreviewSize)
+        :mpDocument(pDocument),maPreviewSize(rPreviewSize)
+    {}
+    /// Test for equality with respect to all members.
+    class Equal {public: bool operator() (
+        const CacheDescriptor& rDescriptor1, const CacheDescriptor& rDescriptor2) const {
+        return rDescriptor1.mpDocument==rDescriptor2.mpDocument
+            && rDescriptor1.maPreviewSize==rDescriptor2.maPreviewSize;
+    } };
+    /// Hash function that takes all members into account.
+    class Hash {public: size_t operator() (const CacheDescriptor& rDescriptor) const {
+        return reinterpret_cast<size_t>(rDescriptor.mpDocument.get()) + rDescriptor.maPreviewSize.Width();
+    } };
+};
+
+/** Collection of data that is stored for the inactive, recently used
+    caches.
+*/
+class RecentlyUsedCacheDescriptor
+{
+public:
+    Size maPreviewSize;
+    std::shared_ptr< ::sd::slidesorter::cache::BitmapCache> mpCache;
+
+    RecentlyUsedCacheDescriptor(
+        const Size& rPreviewSize,
+        const std::shared_ptr< ::sd::slidesorter::cache::BitmapCache>& rpCache)
+        :maPreviewSize(rPreviewSize),mpCache(rpCache)
+    {}
+};
+
+/** The list of recently used caches is organized as queue.  When elements
+    are added the list is shortened to the maximally allowed number of
+    elements by removing the least recently used elements.
+*/
+typedef ::std::deque<RecentlyUsedCacheDescriptor> RecentlyUsedQueue;
+
+/** Compare the caches by preview size.  Those that match the given size
+    come first, then, regardless of the given size, the largest ones before
+    the smaller ones.
+*/
+class BestFittingCacheComparer
+{
+public:
+    explicit BestFittingCacheComparer (const Size& rPreferredSize)
+        : maPreferredSize(rPreferredSize)
+    {}
+    bool operator()(const ::sd::slidesorter::cache::PageCacheManager::BestFittingPageCaches::value_type& rElement1,
+        const ::sd::slidesorter::cache::PageCacheManager::BestFittingPageCaches::value_type& rElement2)
+    {
+        if (rElement2.first == maPreferredSize)
+            return false;
+        else if (rElement1.first == maPreferredSize)
+            return true;
+        else
+            return (rElement1.first.Width()*rElement1.first.Height()
+                > rElement2.first.Width()*rElement2.first.Height());
+    }
+
+private:
+    Size maPreferredSize;
+};
+
+} // end of anonymous namespace
+
+namespace sd::slidesorter::cache {
+
+/** Container for the active caches.
+*/
+class PageCacheManager::PageCacheContainer
+    : public std::unordered_map<CacheDescriptor,
+                             std::shared_ptr<BitmapCache>,
+                             CacheDescriptor::Hash,
+                             CacheDescriptor::Equal>
+{
+public:
+    PageCacheContainer() {}
+
+    /** Compare entries in the cache container with respect to the cache
+        address only.
+    */
+    class CompareWithCache { public:
+        explicit CompareWithCache(const std::shared_ptr<BitmapCache>& rpCache)
+            : mpCache(rpCache) {}
+        bool operator () (const PageCacheContainer::value_type& rValue) const
+        { return rValue.second == mpCache; }
+    private:
+        std::shared_ptr<BitmapCache> mpCache;
+    };
+};
+
+/** The recently used caches are stored in one queue for each document.
+*/
+class PageCacheManager::RecentlyUsedPageCaches
+{
+public:
+    typedef DocumentKey                                 key_type;
+    typedef RecentlyUsedQueue                           mapped_type;
+    typedef std::map<key_type,mapped_type>::iterator    iterator;
+private:
+    std::map<key_type,mapped_type> maMap;
+public:
+    RecentlyUsedPageCaches () {};
+
+    iterator end() { return maMap.end(); }
+    void clear() { maMap.clear(); }
+    iterator find(const key_type& key) { return maMap.find(key); }
+    template<class... Args>
+    std::pair<iterator,bool> emplace(Args&&... args) { return maMap.emplace(std::forward<Args>(args)...); }
+};
+
+class PageCacheManager::Deleter
+{
+public:
+    void operator() (PageCacheManager* pObject) { delete pObject; }
+};
+
+//===== PageCacheManager ====================================================
+
+std::weak_ptr<PageCacheManager> PageCacheManager::mpInstance;
+
+std::shared_ptr<PageCacheManager> PageCacheManager::Instance()
+{
+    std::shared_ptr<PageCacheManager> pInstance;
+
+    ::osl::MutexGuard aGuard (::osl::Mutex::getGlobalMutex());
+
+    pInstance = mpInstance.lock();
+    if (pInstance == nullptr)
+    {
+        pInstance = std::shared_ptr<PageCacheManager>(
+            new PageCacheManager(),
+            PageCacheManager::Deleter());
+        mpInstance = pInstance;
+    }
+
+    return pInstance;
+}
+
+PageCacheManager::PageCacheManager()
+    : mpPageCaches(new PageCacheContainer()),
+      mpRecentlyUsedPageCaches(new RecentlyUsedPageCaches())
+{
+}
+
+PageCacheManager::~PageCacheManager()
+{
+}
+
+std::shared_ptr<BitmapCache> PageCacheManager::GetCache (
+    const DocumentKey& pDocument,
+    const Size& rPreviewSize)
+{
+    std::shared_ptr<BitmapCache> pResult;
+
+    // Look for the cache in the list of active caches.
+    CacheDescriptor aKey (pDocument, rPreviewSize);
+    PageCacheContainer::iterator iCache (mpPageCaches->find(aKey));
+    if (iCache != mpPageCaches->end())
+        pResult = iCache->second;
+
+    // Look for the cache in the list of recently used caches.
+    if (pResult == nullptr)
+        pResult = GetRecentlyUsedCache(pDocument, rPreviewSize);
+
+    // Create the cache when no suitable one does exist.
+    if (pResult == nullptr)
+        pResult = std::make_shared<BitmapCache>();
+
+    // The cache may be newly created and thus empty or is old and may
+    // contain previews that are not up-to-date.  Recycle previews from
+    // other caches to fill in the holes.
+    Recycle(pResult, pDocument,rPreviewSize);
+
+    // Put the new (or old) cache into the container.
+    mpPageCaches->emplace(aKey, pResult);
+
+    return pResult;
+}
+
+void PageCacheManager::Recycle (
+    const std::shared_ptr<BitmapCache>& rpCache,
+    const DocumentKey& pDocument,
+    const Size& rPreviewSize)
+{
+    BestFittingPageCaches aCaches;
+
+    // Add bitmap caches from active caches.
+    for (auto& rActiveCache : *mpPageCaches)
+    {
+        if (rActiveCache.first.mpDocument == pDocument)
+            aCaches.emplace_back(
+                rActiveCache.first.maPreviewSize, rActiveCache.second);
+    }
+
+    // Add bitmap caches from recently used caches.
+    RecentlyUsedPageCaches::iterator iQueue (mpRecentlyUsedPageCaches->find(pDocument));
+    if (iQueue != mpRecentlyUsedPageCaches->end())
+    {
+        for (const auto& rRecentCache : iQueue->second)
+            aCaches.emplace_back(
+                rRecentCache.maPreviewSize, rRecentCache.mpCache);
+    }
+
+    ::std::sort(aCaches.begin(), aCaches.end(), BestFittingCacheComparer(rPreviewSize));
+
+    for (const auto& rBestCache : aCaches)
+    {
+        rpCache->Recycle(*rBestCache.second);
+    }
+}
+
+void PageCacheManager::ReleaseCache (const std::shared_ptr<BitmapCache>& rpCache)
+{
+    PageCacheContainer::iterator iCache (::std::find_if(
+        mpPageCaches->begin(),
+        mpPageCaches->end(),
+        PageCacheContainer::CompareWithCache(rpCache)));
+
+    if (iCache != mpPageCaches->end())
+    {
+        assert(iCache->second == rpCache);
+
+        PutRecentlyUsedCache(iCache->first.mpDocument,iCache->first.maPreviewSize,rpCache);
+
+        mpPageCaches->erase(iCache);
+    }
+}
+
+std::shared_ptr<BitmapCache> PageCacheManager::ChangeSize (
+    const std::shared_ptr<BitmapCache>& rpCache,
+    const Size&,
+    const Size& rNewPreviewSize)
+{
+    std::shared_ptr<BitmapCache> pResult;
+
+    if (rpCache != nullptr)
+    {
+        // Look up the given cache in the list of active caches.
+        PageCacheContainer::iterator iCacheToChange (::std::find_if(
+            mpPageCaches->begin(),
+            mpPageCaches->end(),
+            PageCacheContainer::CompareWithCache(rpCache)));
+        if (iCacheToChange != mpPageCaches->end())
+        {
+            assert(iCacheToChange->second == rpCache);
+
+            // Now, we can change the preview size of the existing one by
+            // removing the cache from the list and re-insert it with the
+            // updated size.
+            const ::sd::slidesorter::cache::PageCacheManager::DocumentKey aKey (
+                iCacheToChange->first.mpDocument);
+            mpPageCaches->erase(iCacheToChange);
+            mpPageCaches->emplace(
+                CacheDescriptor(aKey,rNewPreviewSize),
+                rpCache);
+
+            pResult = rpCache;
+        }
+        else
+        {
+            assert(iCacheToChange != mpPageCaches->end());
+        }
+    }
+
+    return pResult;
+}
+
+bool PageCacheManager::InvalidatePreviewBitmap (
+    const  DocumentKey& pDocument,
+    const SdrPage* pKey)
+{
+    bool bHasChanged (false);
+
+    if (pDocument!=nullptr)
+    {
+        // Iterate over all caches that are currently in use and invalidate
+        // the previews in those that belong to the document.
+        for (auto& rCache : *mpPageCaches)
+            if (rCache.first.mpDocument == pDocument)
+                bHasChanged |= rCache.second->InvalidateBitmap(pKey);
+
+        // Invalidate the previews in the recently used caches belonging to
+        // the given document.
+        RecentlyUsedPageCaches::iterator iQueue (mpRecentlyUsedPageCaches->find(pDocument));
+        if (iQueue != mpRecentlyUsedPageCaches->end())
+        {
+            for (const auto& rCache2 : iQueue->second)
+                bHasChanged |= rCache2.mpCache->InvalidateBitmap(pKey);
+        }
+    }
+
+    return bHasChanged;
+}
+
+void PageCacheManager::InvalidateAllPreviewBitmaps (const DocumentKey& pDocument)
+{
+    if (pDocument == nullptr)
+        return;
+
+    // Iterate over all caches that are currently in use and invalidate the
+    // previews in those that belong to the document.
+    for (auto& rCache : *mpPageCaches)
+        if (rCache.first.mpDocument == pDocument)
+            rCache.second->InvalidateCache();
+
+    // Invalidate the previews in the recently used caches belonging to the
+    // given document.
+    RecentlyUsedPageCaches::iterator iQueue (mpRecentlyUsedPageCaches->find(pDocument));
+    if (iQueue != mpRecentlyUsedPageCaches->end())
+    {
+        for (const auto& rCache2 : iQueue->second)
+            rCache2.mpCache->InvalidateCache();
+    }
+}
+
+void PageCacheManager::InvalidateAllCaches()
+{
+    // Iterate over all caches that are currently in use and invalidate
+    // them.
+    for (auto& rCache : *mpPageCaches)
+        rCache.second->InvalidateCache();
+
+    // Remove all recently used caches, there is not much sense in storing
+    // invalidated and unused caches.
+    mpRecentlyUsedPageCaches->clear();
+}
+
+void PageCacheManager::ReleasePreviewBitmap (const SdrPage* pPage)
+{
+    for (auto& rCache : *mpPageCaches)
+        rCache.second->ReleaseBitmap(pPage);
+}
+
+std::shared_ptr<BitmapCache> PageCacheManager::GetRecentlyUsedCache (
+    const DocumentKey& pDocument,
+    const Size& rPreviewSize)
+{
+    std::shared_ptr<BitmapCache> pCache;
+
+    // Look for the cache in the list of recently used caches.
+    RecentlyUsedPageCaches::iterator iQueue (mpRecentlyUsedPageCaches->find(pDocument));
+    if (iQueue != mpRecentlyUsedPageCaches->end())
+    {
+        RecentlyUsedQueue::iterator iCache = std::find_if(iQueue->second.begin(), iQueue->second.end(),
+            [&rPreviewSize](const RecentlyUsedCacheDescriptor& rCache) { return rCache.maPreviewSize == rPreviewSize; });
+        if (iCache != iQueue->second.end())
+        {
+            pCache = iCache->mpCache;
+            iQueue->second.erase(iCache);
+        }
+    }
+
+    return pCache;
+}
+
+void PageCacheManager::PutRecentlyUsedCache(
+    DocumentKey const & pDocument,
+    const Size& rPreviewSize,
+    const std::shared_ptr<BitmapCache>& rpCache)
+{
+    // Look up the list of recently used caches for the given document.
+    RecentlyUsedPageCaches::iterator iQueue (mpRecentlyUsedPageCaches->find(pDocument));
+    if (iQueue == mpRecentlyUsedPageCaches->end())
+        iQueue = mpRecentlyUsedPageCaches->emplace(
+            pDocument, RecentlyUsedQueue()
+            ).first;
+
+    if (iQueue != mpRecentlyUsedPageCaches->end())
+    {
+        iQueue->second.push_front(RecentlyUsedCacheDescriptor(rPreviewSize,rpCache));
+        // Shorten the list of recently used caches to the allowed maximal length.
+        while (iQueue->second.size() > mnMaximalRecentlyCacheCount)
+            iQueue->second.pop_back();
+    }
+}
+
+} // end of namespace ::sd::slidesorter::cache
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */