LUMIERA.clone/src/proc/engine/buffer-local-key.hpp

131 lines
3.1 KiB
C++

/*
BUFFER-LOCAL-KEY.hpp - opaque data for BufferProvider implementation
Copyright (C) Lumiera.org
2011, Hermann Vosseler <Ichthyostega@web.de>
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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/** @file buffer-local-key.hpp
** A marker data type used in metadata / buffer management of the render engine.
*/
#ifndef PROC_ENGINE_BUFFR_LOCAL_KEY_H
#define PROC_ENGINE_BUFFR_LOCAL_KEY_H
#include "lib/error.hpp"
#include "lib/hash-value.h"
#include <boost/functional/hash.hpp>
namespace proc {
namespace engine {
namespace metadata {
class Key;
class Entry;
}
class BufferMetadata;
using lib::HashVal;
/**
* an opaque ID to be used by the BufferProvider implementation.
* Typically this will be used, to set apart some pre-registered
* kinds of buffers. It is treated as being part of the buffer type.
* LocalKey objects may be copied but not re-assigned or changed.
*/
class LocalKey
{
union OpaqueData
{
uint64_t _as_number;
void* _as_pointer;
};
OpaqueData privateID_;
public:
explicit
LocalKey (uint64_t opaqueValue=0)
{
privateID_._as_number = opaqueValue;
}
LocalKey (void* impl_related_ptr)
{
privateID_._as_number = 0;
privateID_._as_pointer = impl_related_ptr;
}
operator uint64_t() const
{
return privateID_._as_number;
}
operator void*() const
{
return privateID_._as_pointer;
}
bool
isDefined() const
{
return bool(privateID_._as_number);
}
friend size_t
hash_value (LocalKey const& lkey)
{
boost::hash<uint64_t> hashFunction;
return hashFunction(lkey.privateID_._as_number);
}
friend bool
operator== (LocalKey const& left, LocalKey const& right)
{
return uint64_t(left) == uint64_t(right);
}
friend bool
operator!= (LocalKey const& left, LocalKey const& right)
{
return uint64_t(left) != uint64_t(right);
}
private:
/** assignment usually prohibited */
LocalKey& operator= (LocalKey const& o)
{
privateID_ = o.privateID_;
return *this;
}
/** but Key assignments are acceptable */
friend class metadata::Key;
};
}} // namespace proc::engine
#endif