1 files changed, 85 insertions, 0 deletions
diff --git a/io/source/stm/streamhelper.hxx b/io/source/stm/streamhelper.hxx
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+++ b/io/source/stm/streamhelper.hxx
@@ -0,0 +1,85 @@
+/* -*- 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 .
+ */
+
+#pragma once
+
+#include <com/sun/star/uno/Sequence.hxx>
+
+#include <assert.h>
+
+using namespace com::sun::star::uno;
+
+namespace io_stm
+{
+
+class MemRingBuffer
+{
+public:
+    MemRingBuffer();
+    virtual ~MemRingBuffer();
+
+    /***
+    * overwrites data at given position. Size is automatically extended, when
+    * data is written beyond end.
+    ***/
+    /// @throws css::io::BufferSizeExceededException
+    void    writeAt( sal_Int32 nPos, const Sequence<sal_Int8> &);
+    /// @throws css::io::BufferSizeExceededException
+    void    readAt( sal_Int32 nPos, Sequence<sal_Int8> & , sal_Int32 nBytesToRead ) const;
+    sal_Int32   getSize() const noexcept;
+    /// @throws css::io::BufferSizeExceededException
+    void    forgetFromStart(sal_Int32 nBytesToForget);
+
+private:
+    /// @throws css::io::BufferSizeExceededException
+    void resizeBuffer(sal_Int32 nMinSize);
+    void checkInvariants() const {
+        assert( m_nBufferLen >= 0 );
+        assert( m_nOccupiedBuffer >= 0 );
+        assert( m_nOccupiedBuffer <= m_nBufferLen );
+        assert( m_nStart >= 0 );
+        assert( 0 == m_nStart || m_nStart < m_nBufferLen );
+        (void) this; // avoid loplugin:staticmethods
+    }
+
+    sal_Int8    *m_p;
+    sal_Int32   m_nBufferLen;
+    sal_Int32   m_nStart;
+    sal_Int32   m_nOccupiedBuffer;
+};
+
+
+class MemFIFO :
+    private MemRingBuffer
+{
+public:
+    /// @throws css::io::BufferSizeExceededException
+    void          write( const Sequence<sal_Int8> &);
+    /// @throws css::io::BufferSizeExceededException
+    void          read( Sequence<sal_Int8> & , sal_Int32 nBytesToRead );
+    /// @throws css::io::BufferSizeExceededException
+    void          skip( sal_Int32 nBytesToSkip );
+    sal_Int32     getSize() const noexcept
+                  { return MemRingBuffer::getSize(); }
+
+};
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */