1 files changed, 102 insertions, 0 deletions
diff --git a/backend/genesys/buffer.cpp b/backend/genesys/buffer.cpp
new file mode 100644
index 0000000..f17e361
--- /dev/null
+++ b/backend/genesys/buffer.cpp
@@ -0,0 +1,102 @@
+/* sane - Scanner Access Now Easy.
+
+   Copyright (C) 2019 Povilas Kanapickas <povilas@radix.lt>
+
+   This file is part of the SANE package.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+   MA 02111-1307, USA.
+
+   As a special exception, the authors of SANE give permission for
+   additional uses of the libraries contained in this release of SANE.
+
+   The exception is that, if you link a SANE library with other files
+   to produce an executable, this does not by itself cause the
+   resulting executable to be covered by the GNU General Public
+   License.  Your use of that executable is in no way restricted on
+   account of linking the SANE library code into it.
+
+   This exception does not, however, invalidate any other reasons why
+   the executable file might be covered by the GNU General Public
+   License.
+
+   If you submit changes to SANE to the maintainers to be included in
+   a subsequent release, you agree by submitting the changes that
+   those changes may be distributed with this exception intact.
+
+   If you write modifications of your own for SANE, it is your choice
+   whether to permit this exception to apply to your modifications.
+   If you do not wish that, delete this exception notice.
+*/
+
+#include "buffer.h"
+#include <cstring>
+#include <stdexcept>
+
+namespace genesys {
+
+void Genesys_Buffer::alloc(std::size_t size)
+{
+    buffer_.resize(size);
+    avail_ = 0;
+    pos_ = 0;
+}
+
+void Genesys_Buffer::clear()
+{
+    buffer_.clear();
+    avail_ = 0;
+    pos_ = 0;
+}
+
+void Genesys_Buffer::reset()
+{
+    avail_ = 0;
+    pos_ = 0;
+}
+
+std::uint8_t* Genesys_Buffer::get_write_pos(std::size_t size)
+{
+    if (avail_ + size > buffer_.size())
+        return nullptr;
+    if (pos_ + avail_ + size > buffer_.size())
+    {
+        std::memmove(buffer_.data(), buffer_.data() + pos_, avail_);
+        pos_ = 0;
+    }
+    return buffer_.data() + pos_ + avail_;
+}
+
+std::uint8_t* Genesys_Buffer::get_read_pos()
+{
+    return buffer_.data() + pos_;
+}
+
+void Genesys_Buffer::produce(std::size_t size)
+{
+    if (size > buffer_.size() - avail_)
+        throw std::runtime_error("buffer size exceeded");
+    avail_ += size;
+}
+
+void Genesys_Buffer::consume(std::size_t size)
+{
+    if (size > avail_)
+        throw std::runtime_error("no more data in buffer");
+    avail_ -= size;
+    pos_ += size;
+}
+
+} // namespace genesys