tornavis/source/blender/functions/FN_lazy_function_graph_exec...

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C++

/* SPDX-FileCopyrightText: 2023 Blender Authors
*
* SPDX-License-Identifier: GPL-2.0-or-later */
#pragma once
/** \file
* \ingroup fn
*
* This file provides means to create a #LazyFunction from #Graph (which could then e.g. be used in
* another #Graph again).
*/
#include "BLI_vector.hh"
#include "BLI_vector_set.hh"
#include "FN_lazy_function_graph.hh"
namespace blender::fn::lazy_function {
/**
* Can be implemented to log values produced during graph evaluation.
*/
class GraphExecutorLogger {
public:
virtual ~GraphExecutorLogger() = default;
virtual void log_socket_value(const Socket &socket,
GPointer value,
const Context &context) const;
virtual void log_before_node_execute(const FunctionNode &node,
const Params &params,
const Context &context) const;
virtual void log_after_node_execute(const FunctionNode &node,
const Params &params,
const Context &context) const;
virtual void dump_when_outputs_are_missing(const FunctionNode &node,
Span<const OutputSocket *> missing_sockets,
const Context &context) const;
virtual void dump_when_input_is_set_twice(const InputSocket &target_socket,
const OutputSocket &from_socket,
const Context &context) const;
};
/**
* Has to be implemented when some of the nodes in the graph may have side effects. The
* #GraphExecutor has to know about that to make sure that these nodes will be executed even though
* their outputs are not needed.
*/
class GraphExecutorSideEffectProvider {
public:
virtual ~GraphExecutorSideEffectProvider() = default;
virtual Vector<const FunctionNode *> get_nodes_with_side_effects(const Context &context) const;
};
/**
* Can be used to pass extra context into the execution of a function. The main alternative to this
* is to create a wrapper `LazyFunction` for the `FunctionNode`s. Using this light weight wrapper
* is preferable if possible.
*/
class GraphExecutorNodeExecuteWrapper {
public:
virtual ~GraphExecutorNodeExecuteWrapper() = default;
/**
* Is expected to run `node.function().execute(params, context)` but might do some extra work,
* like adjusting the context.
*/
virtual void execute_node(const FunctionNode &node,
Params &params,
const Context &context) const = 0;
};
class GraphExecutor : public LazyFunction {
public:
using Logger = GraphExecutorLogger;
using SideEffectProvider = GraphExecutorSideEffectProvider;
using NodeExecuteWrapper = GraphExecutorNodeExecuteWrapper;
private:
/**
* The graph that is evaluated.
*/
const Graph &graph_;
/**
* Input and output sockets of the entire graph.
*/
Vector<const GraphInputSocket *> graph_inputs_;
Vector<const GraphOutputSocket *> graph_outputs_;
Array<int> graph_input_index_by_socket_index_;
Array<int> graph_output_index_by_socket_index_;
/**
* Optional logger for events that happen during execution.
*/
const Logger *logger_;
/**
* Optional side effect provider. It knows which nodes have side effects based on the context
* during evaluation.
*/
const SideEffectProvider *side_effect_provider_;
/**
* Optional wrapper for node execution functions.
*/
const NodeExecuteWrapper *node_execute_wrapper_;
/**
* When a graph is executed, various things have to be allocated (e.g. the state of all nodes).
* Instead of doing many small allocations, a single bigger allocation is done. This struct
* contains the preprocessed offsets into that bigger buffer.
*/
struct {
int node_states_array_offset;
int loaded_inputs_array_offset;
Array<int> node_states_offsets;
int total_size;
} init_buffer_info_;
friend class Executor;
public:
GraphExecutor(const Graph &graph,
Vector<const GraphInputSocket *> graph_inputs,
Vector<const GraphOutputSocket *> graph_outputs,
const Logger *logger,
const SideEffectProvider *side_effect_provider,
const NodeExecuteWrapper *node_execute_wrapper);
void *init_storage(LinearAllocator<> &allocator) const override;
void destruct_storage(void *storage) const override;
std::string input_name(int index) const override;
std::string output_name(int index) const override;
private:
void execute_impl(Params &params, const Context &context) const override;
};
} // namespace blender::fn::lazy_function