Ichthyostega
9484ea0b71
The ''design exercise'' started yesterday ran into a total rodadblock. And this is a good thing, as this unveils inconsistencies in our memory handling protocols * Buffer Provider Protocol * Output Slot Protocol The latter exposes a `BuffHandle`, which should be usable from within the Render Node code like any other regular buffer handle — which especially would require to ''delegate the lifecycle calls...'' So while this topic does not hinder us right now to proceed with a Node invocation in test setup, it must be addressed before we're able to deliver data into an actual OutputSlot. Created #1387 to track this topic...
129 lines
4.1 KiB
C++
129 lines
4.1 KiB
C++
/*
|
||
BUFFER-PROXY-PROVIDER.hpp - Adapter to access existing allocation via buffer handling protocol
|
||
|
||
Copyright (C)
|
||
2024, Hermann Vosseler <Ichthyostega@web.de>
|
||
|
||
**Lumiera** 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. See the file COPYING for further details.
|
||
|
||
*/
|
||
|
||
/** @file buffer-proxy-provider.hpp
|
||
** Adapter to expose a given memory block through a BuffHandle.
|
||
** This allows to integrate a specific data access (e.g. related to input / output)
|
||
** with the buffer lifecycle protocol as defined by BufferProvider.
|
||
** @todo BROKEN as of 12/2024 //////////////////////////////////////////////////////////////////////////////TICKET #1387 : can not properly compose BufferProvider
|
||
** @see output-slot.hpp
|
||
*/
|
||
|
||
#ifndef STEAM_ENGINE_BUFFER_PROXY_PROVIDER_H
|
||
#define STEAM_ENGINE_BUFFER_PROXY_PROVIDER_H
|
||
|
||
|
||
#include "lib/error.hpp"
|
||
#include "lib/symbol.hpp"
|
||
#include "lib/meta/util.hpp"
|
||
//#include "lib/hash-value.h"
|
||
#include "steam/engine/buffer-provider.hpp"
|
||
#include "steam/engine/buffer-metadata.hpp"
|
||
//#include "steam/engine/engine-ctx.hpp"
|
||
//#include "steam/engine/type-handler.hpp"
|
||
//#include "steam/engine/buffer-local-tag.hpp"
|
||
#include "lib/nocopy.hpp"
|
||
|
||
#include <functional>
|
||
#include <utility>
|
||
//#include <memory>
|
||
|
||
|
||
namespace steam {
|
||
namespace engine {
|
||
|
||
using lib::Literal;
|
||
// using std::unique_ptr;
|
||
// using std::forward;
|
||
|
||
|
||
|
||
|
||
/**
|
||
* Adapter to expose access to data blocks via BuffHandle and the BufferProvider protocol.
|
||
* @todo WIP-WIP 12/2024 this is a design sketch to explore extension capabilities of BufferProvider
|
||
*/
|
||
class BufferProxyProvider
|
||
: util::NonCopyable
|
||
{
|
||
|
||
using Listener = std::function<void(size_t,BufferState)>;
|
||
|
||
class ForwardingBufferProvider
|
||
: public BufferProvider
|
||
{
|
||
Listener listener_;
|
||
|
||
/* === BufferProvider API === */
|
||
|
||
uint
|
||
prepareBuffers (uint, HashVal) override
|
||
{
|
||
NOTREACHED ("this part of the API should not be used");
|
||
return 1; // can not sensibly do anything for "pre-allocation",
|
||
} // other than telling the caller that we only "have one buffer to provide"
|
||
|
||
BuffHandle
|
||
provideLockedBuffer (HashVal typeID) override
|
||
{
|
||
/////////////////////////////////////////////////////////////////////////////////////TICKET #1387 : BufferProvider default impl. is lacking means to compose and delegate
|
||
// return buildHandle (typeID, asBuffer(newBlock.accessMemory()), &newBlock);
|
||
}
|
||
|
||
void
|
||
mark_emitted (HashVal, LocalTag const&) override
|
||
{
|
||
|
||
}
|
||
|
||
void
|
||
detachBuffer (HashVal, LocalTag const&, Buff&) override
|
||
{
|
||
|
||
}
|
||
public:
|
||
ForwardingBufferProvider (Listener listener)
|
||
: BufferProvider{"BufferProxyProvider"}
|
||
, listener_{std::move (listener)}
|
||
{ }
|
||
};
|
||
|
||
ForwardingBufferProvider passThroughProvider_;
|
||
|
||
|
||
public:
|
||
template<class LIS, typename = lib::meta::disable_if_self<BufferProxyProvider, LIS>>
|
||
BufferProxyProvider (LIS&& listener)
|
||
: passThroughProvider_{std::forward<LIS> (listener)}
|
||
{ }
|
||
|
||
template<typename TAR>
|
||
BuffHandle
|
||
lockBuffer (TAR& dataBlock)
|
||
{
|
||
//////////////////////////////////////////////////////////////////////////////////////////////////TICKET #1387 : impossible due to inner contradictions in BufferProvider and OutputSlot
|
||
UNIMPLEMENTED ("setup type handler and then create a locked BuffHandle");
|
||
}
|
||
|
||
};
|
||
|
||
|
||
|
||
|
||
/* === Implementation === */
|
||
|
||
/** convenience shortcut: */
|
||
|
||
|
||
}} // namespace steam::engine
|
||
#endif /*STEAM_ENGINE_BUFFER_PROXY_PROVIDER_H*/
|