1 files changed, 152 insertions, 0 deletions
diff --git a/canvas/source/tools/pagemanager.cxx b/canvas/source/tools/pagemanager.cxx
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+++ b/canvas/source/tools/pagemanager.cxx
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+/* -*- 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 <sal/config.h>
+
+#include "pagemanager.hxx"
+
+namespace canvas
+{
+    FragmentSharedPtr PageManager::allocateSpace( const ::basegfx::B2ISize& rSize )
+    {
+        // we are asked to find a location for the requested size.
+        // first we try to satisfy the request from the
+        // remaining space in the existing pages.
+        for( const auto& pPage : maPages )
+        {
+            FragmentSharedPtr pFragment( pPage->allocateSpace(rSize) );
+            if(pFragment)
+            {
+                // the page created a new fragment, since we maybe want
+                // to consolidate sparse pages we keep a reference to
+                // the fragment.
+                maFragments.push_back(pFragment);
+                return pFragment;
+            }
+        }
+
+        // otherwise try to create a new page and allocate space there...
+        PageSharedPtr pPage = std::make_shared<Page>(mpRenderModule);
+        if(pPage->isValid())
+        {
+            maPages.push_back(pPage);
+            FragmentSharedPtr pFragment(pPage->allocateSpace(rSize));
+            if (pFragment)
+                maFragments.push_back(pFragment);
+            return pFragment;
+        }
+
+        // the rendermodule failed to create a new page [maybe out
+        // of videomemory], and all other pages could not take
+        // the new request. we decide to create a 'naked' fragment
+        // which will receive its location later.
+        FragmentSharedPtr pFragment = std::make_shared<PageFragment>(rSize);
+        maFragments.push_back(pFragment);
+        return pFragment;
+    }
+
+    void PageManager::free( const FragmentSharedPtr& pFragment )
+    {
+        // erase the reference to the given fragment from our
+        // internal container.
+        FragmentContainer_t::iterator it(
+            std::remove(
+                maFragments.begin(),maFragments.end(),pFragment));
+        maFragments.erase(it,maFragments.end());
+
+        // let the fragment itself know about it...
+        // we need to pass 'this' as argument since the fragment
+        // needs to pass this to the page and can't create
+        // shared_ptr from itself...
+        pFragment->free(pFragment);
+    }
+
+    void PageManager::nakedFragment( const FragmentSharedPtr& pFragment )
+    {
+        if(maPages.empty())
+            return;
+
+        // okay, one last chance is left, we try all available
+        // pages again. maybe some other fragment was deleted
+        // and we can exploit the space.
+        while( !( relocate( pFragment ) ) )
+        {
+            // no way, we need to free up some space...
+            // TODO(F1): this is a heuristic, could
+            // be designed as a policy.
+            auto       aEnd( maFragments.cend() );
+            auto       aCurrMax( aEnd );
+            sal_uInt32 nCurrMaxArea = 0;
+            for( auto aCurr = maFragments.begin(); aCurr != aEnd; ++aCurr )
+            {
+                if( *aCurr && !( ( *aCurr )->isNaked() ) )
+                {
+                    const ::basegfx::B2ISize& rSize( ( *aCurr )->getSize() );
+                    sal_uInt32                nArea( rSize.getX() * rSize.getY() );
+
+                    if( nCurrMaxArea < nArea )
+                    {
+                        aCurrMax = aCurr;
+                        nCurrMaxArea = nArea;
+                    }
+                }
+            }
+            // this does not erase the candidate,
+            // but makes it 'naked'...
+            if( aCurrMax != aEnd )
+                ( *aCurrMax )->free( *aCurrMax );
+            else
+                break;
+        }
+    }
+
+    bool PageManager::relocate( const FragmentSharedPtr& pFragment )
+    {
+        // the fragment passed as argument is assumed to
+        // be naked, that is it is not located on any page.
+        // we try all available pages again, maybe some
+        // other fragment was deleted and we can exploit the space.
+        for( const auto& pPage : maPages )
+        {
+            // if the page at hand takes the fragment, we immediately
+            // call select() to pull the information from the associated
+            // image to the hardware surface.
+            if( pPage->nakedFragment( pFragment ) )
+            {
+                // dirty, since newly allocated.
+                pFragment->select(true);
+                return true;
+            }
+        }
+        return false;
+    }
+
+    void PageManager::validatePages()
+    {
+        for( const auto& rPagePtr : maPages )
+            rPagePtr->validate();
+    }
+
+    ::basegfx::B2ISize PageManager::getPageSize() const
+    {
+        return mpRenderModule->getPageSize();
+    }
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */