1 files changed, 118 insertions, 0 deletions
diff --git a/sax/source/tools/CachedOutputStream.hxx b/sax/source/tools/CachedOutputStream.hxx
new file mode 100644
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+++ b/sax/source/tools/CachedOutputStream.hxx
@@ -0,0 +1,118 @@
+/* -*- 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/.
+ */
+
+#ifndef INCLUDED_SAX_SOURCE_TOOLS_CACHEDOUTPUTSTREAM_HXX
+#define INCLUDED_SAX_SOURCE_TOOLS_CACHEDOUTPUTSTREAM_HXX
+
+#include <sal/types.h>
+
+#include <com/sun/star/io/XOutputStream.hpp>
+#include <com/sun/star/uno/Sequence.hxx>
+
+#include <cstring>
+#include <memory>
+
+namespace sax_fastparser {
+
+class ForMergeBase
+{
+public:
+    virtual ~ForMergeBase() {}
+    virtual void append( const css::uno::Sequence<sal_Int8>& rWhat ) = 0;
+};
+
+class CachedOutputStream
+{
+    /// When buffer hits this size, it's written to mxOutputStream
+    static const sal_Int32 mnMaximumSize = 0x100000; // 1Mbyte
+
+    /// ForMerge structure is used for sorting elements in Writer
+    std::shared_ptr< ForMergeBase > mpForMerge;
+    const css::uno::Sequence<sal_Int8> mpCache;
+    /// Output stream, usually writing data into files.
+    css::uno::Reference< css::io::XOutputStream > mxOutputStream;
+    uno_Sequence *pSeq;
+    sal_Int32 mnCacheWrittenSize;
+    bool mbWriteToOutStream;
+
+public:
+    CachedOutputStream() : mpCache(mnMaximumSize)
+                         , pSeq(mpCache.get())
+                         , mnCacheWrittenSize(0)
+                         , mbWriteToOutStream(true)
+    {}
+
+    const css::uno::Reference< css::io::XOutputStream >& getOutputStream() const
+    {
+        return mxOutputStream;
+    }
+
+    void setOutputStream( const css::uno::Reference< css::io::XOutputStream >& xOutputStream )
+    {
+        mxOutputStream = xOutputStream;
+    }
+
+    void setOutput( std::shared_ptr< ForMergeBase > pForMerge )
+    {
+        flush();
+        mbWriteToOutStream = false;
+        mpForMerge = pForMerge;
+    }
+
+    void resetOutputToStream()
+    {
+        flush();
+        mbWriteToOutStream = true;
+        mpForMerge.reset();
+    }
+
+    /// cache string and if limit is hit, flush
+    void writeBytes( const sal_Int8* pStr, sal_Int32 nLen )
+    {
+        // Write when the buffer gets big enough
+        if (mnCacheWrittenSize + nLen > mnMaximumSize)
+        {
+            flush();
+
+            // Writer does some elements sorting, so it can accumulate
+            // pretty big strings in FastSaxSerializer::ForMerge.
+            // In that case, just flush data and write immediately.
+            if (nLen > mnMaximumSize)
+            {
+                if (mbWriteToOutStream)
+                    mxOutputStream->writeBytes( css::uno::Sequence<sal_Int8>(pStr, nLen) );
+                else
+                    mpForMerge->append( css::uno::Sequence<sal_Int8>(pStr, nLen) );
+                return;
+            }
+        }
+
+        memcpy(pSeq->elements + mnCacheWrittenSize, pStr, nLen);
+        mnCacheWrittenSize += nLen;
+    }
+
+    /// immediately write buffer into mxOutputStream and clear
+    void flush()
+    {
+        // resize the Sequence to written size
+        pSeq->nElements = mnCacheWrittenSize;
+        if (mbWriteToOutStream)
+            mxOutputStream->writeBytes( mpCache );
+        else
+            mpForMerge->append( mpCache );
+        // and next time write to the beginning
+        mnCacheWrittenSize = 0;
+    }
+};
+
+}
+
+#endif
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */