1 files changed, 189 insertions, 0 deletions
diff --git a/sd/source/ui/slidesorter/cache/SlsCacheCompactor.cxx b/sd/source/ui/slidesorter/cache/SlsCacheCompactor.cxx
new file mode 100644
index 000000000..79ab9fab2
--- /dev/null
+++ b/sd/source/ui/slidesorter/cache/SlsCacheCompactor.cxx
@@ -0,0 +1,189 @@
+/* -*- 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 <memory>
+#include "SlsCacheCompactor.hxx"
+
+#include "SlsBitmapCompressor.hxx"
+#include "SlsBitmapCache.hxx"
+#include "SlsCacheConfiguration.hxx"
+
+#include <rtl/ustring.hxx>
+#include <sal/log.hxx>
+#include <com/sun/star/uno/Any.hxx>
+
+using namespace ::com::sun::star::uno;
+
+namespace {
+
+/** This is a trivial implementation of the CacheCompactor interface class.
+    It ignores calls to RequestCompaction() and thus will never decrease the
+    total size of off-screen preview bitmaps.
+*/
+class NoCacheCompaction
+    : public ::sd::slidesorter::cache::CacheCompactor
+{
+public:
+    NoCacheCompaction (
+        ::sd::slidesorter::cache::BitmapCache& rCache,
+        sal_Int32 nMaximalCacheSize)
+        : CacheCompactor(rCache, nMaximalCacheSize)
+    {}
+
+    virtual void RequestCompaction() override { /* Ignored */ };
+
+protected:
+    virtual void Run() override { /* Do nothing */ };
+};
+
+/** This implementation of the CacheCompactor interface class uses one of
+    several bitmap compression algorithms to reduce the number of the bytes
+    of the off-screen previews in the bitmap cache.  See the documentation
+    of CacheCompactor::Create() for more details on configuration properties
+    that control the choice of compression algorithm.
+*/
+class CacheCompactionByCompression
+    : public ::sd::slidesorter::cache::CacheCompactor
+{
+public:
+    CacheCompactionByCompression (
+        ::sd::slidesorter::cache::BitmapCache& rCache,
+        sal_Int32 nMaximalCacheSize,
+        const std::shared_ptr< ::sd::slidesorter::cache::BitmapCompressor>& rpCompressor);
+
+protected:
+    virtual void Run() override;
+
+private:
+    std::shared_ptr< ::sd::slidesorter::cache::BitmapCompressor>  mpCompressor;
+};
+
+} // end of anonymous namespace
+
+namespace sd::slidesorter::cache {
+
+::std::unique_ptr<CacheCompactor> CacheCompactor::Create (
+    BitmapCache& rCache,
+    sal_Int32 nMaximalCacheSize)
+{
+    static const char sNone[] = "None";
+
+    std::shared_ptr<BitmapCompressor> pCompressor;
+    OUString sCompressionPolicy("PNGCompression");
+    Any aCompressionPolicy (CacheConfiguration::Instance()->GetValue("CompressionPolicy"));
+    if (aCompressionPolicy.has<OUString>())
+        aCompressionPolicy >>= sCompressionPolicy;
+    if (sCompressionPolicy == sNone)
+        pCompressor = std::make_shared<NoBitmapCompression>();
+    else if (sCompressionPolicy == "Erase")
+        pCompressor = std::make_shared<CompressionByDeletion>();
+    else if (sCompressionPolicy == "ResolutionReduction")
+        pCompressor = std::make_shared<ResolutionReduction>();
+    else
+        pCompressor = std::make_shared<PngCompression>();
+
+    ::std::unique_ptr<CacheCompactor> pCompactor;
+    OUString sCompactionPolicy("Compress");
+    Any aCompactionPolicy (CacheConfiguration::Instance()->GetValue("CompactionPolicy"));
+    if (aCompactionPolicy.has<OUString>())
+        aCompactionPolicy >>= sCompactionPolicy;
+    if (sCompactionPolicy == sNone)
+        pCompactor.reset(new NoCacheCompaction(rCache,nMaximalCacheSize));
+    else
+        pCompactor.reset(new CacheCompactionByCompression(rCache,nMaximalCacheSize,pCompressor));
+
+    return pCompactor;
+}
+
+void CacheCompactor::RequestCompaction()
+{
+    if ( ! mbIsCompactionRunning && ! maCompactionTimer.IsActive())
+        maCompactionTimer.Start();
+}
+
+CacheCompactor::CacheCompactor(
+    BitmapCache& rCache,
+    sal_Int32 nMaximalCacheSize)
+    : mrCache(rCache),
+      mnMaximalCacheSize(nMaximalCacheSize),
+      maCompactionTimer("sd CacheCompactor maCompactionTimer"),
+      mbIsCompactionRunning(false)
+{
+    maCompactionTimer.SetTimeout(100);
+    maCompactionTimer.SetInvokeHandler(LINK(this,CacheCompactor,CompactionCallback));
+}
+
+IMPL_LINK_NOARG(CacheCompactor, CompactionCallback, Timer *, void)
+{
+    mbIsCompactionRunning = true;
+
+    try
+    {
+        Run();
+    }
+    catch (const css::uno::RuntimeException&)
+    {
+    }
+    catch (const css::uno::Exception&)
+    {
+    }
+
+    mbIsCompactionRunning = false;
+}
+
+} // end of namespace ::sd::slidesorter::cache
+
+namespace {
+
+//===== CacheCompactionByCompression ==========================================
+
+CacheCompactionByCompression::CacheCompactionByCompression (
+    ::sd::slidesorter::cache::BitmapCache& rCache,
+    sal_Int32 nMaximalCacheSize,
+    const std::shared_ptr< ::sd::slidesorter::cache::BitmapCompressor>& rpCompressor)
+    : CacheCompactor(rCache,nMaximalCacheSize),
+      mpCompressor(rpCompressor)
+{
+}
+
+void CacheCompactionByCompression::Run()
+{
+    if (mrCache.GetSize() <= mnMaximalCacheSize)
+        return;
+
+    SAL_INFO("sd.sls", __func__ << ": bitmap cache uses too much space: " << mrCache.GetSize() << " > " << mnMaximalCacheSize);
+
+    ::sd::slidesorter::cache::BitmapCache::CacheIndex aIndex (
+        mrCache.GetCacheIndex());
+    for (const auto& rpIndex : aIndex)
+    {
+        if (rpIndex == nullptr)
+            continue;
+
+        mrCache.Compress(rpIndex, mpCompressor);
+        if (mrCache.GetSize() < mnMaximalCacheSize)
+            break;
+    }
+    mrCache.ReCalculateTotalCacheSize();
+    SAL_INFO("sd.sls", __func__ << ":    there are now " << mrCache.GetSize() << " bytes occupied");
+}
+
+} // end of anonymous namespace
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */