Files
test/source/blender/depsgraph/intern/node/deg_node_id.cc
Hans Goudey 81a63153d0 Despgraph: Rename "copy-on-write" to "copy-on-evaluation"
The depsgraph CoW mechanism is a bit of a misnomer. It creates an
evaluated copy for data-blocks regardless of whether the copy will
actually be written to. The point is to have physical separation between
original and evaluated data. This is in contrast to the commonly used
performance improvement of keeping a user count and copying data
implicitly when it needs to be changed. In Blender code we call this
"implicit sharing" instead. Importantly, the dependency graph has no
idea about the _actual_ CoW behavior in Blender.

Renaming this functionality in the despgraph removes some of the
confusion that comes up when talking about this, and will hopefully
make the depsgraph less confusing to understand initially too. Wording
like "the evaluated copy" (as opposed to the original data-block) has
also become common anyway.

Pull Request: https://projects.blender.org/blender/blender/pulls/118338
2024-02-19 15:54:08 +01:00

203 lines
5.4 KiB
C++

/* SPDX-FileCopyrightText: 2013 Blender Authors
*
* SPDX-License-Identifier: GPL-2.0-or-later */
/** \file
* \ingroup depsgraph
*/
#include "intern/node/deg_node_id.hh"
#include <cstdio>
#include <cstring> /* required for STREQ later on. */
#include "BLI_string.h"
#include "BLI_utildefines.h"
#include "DNA_ID.h"
#include "DNA_anim_types.h"
#include "BKE_lib_id.hh"
#include "DEG_depsgraph.hh"
#include "intern/eval/deg_eval_copy_on_write.h"
#include "intern/node/deg_node_component.hh"
#include "intern/node/deg_node_factory.hh"
#include "intern/node/deg_node_time.hh"
namespace blender::deg {
const char *linkedStateAsString(eDepsNode_LinkedState_Type linked_state)
{
switch (linked_state) {
case DEG_ID_LINKED_INDIRECTLY:
return "INDIRECTLY";
case DEG_ID_LINKED_VIA_SET:
return "VIA_SET";
case DEG_ID_LINKED_DIRECTLY:
return "DIRECTLY";
}
BLI_assert_msg(0, "Unhandled linked state, should never happen.");
return "UNKNOWN";
}
IDNode::ComponentIDKey::ComponentIDKey(NodeType type, const char *name) : type(type), name(name) {}
bool IDNode::ComponentIDKey::operator==(const ComponentIDKey &other) const
{
return type == other.type && STREQ(name, other.name);
}
uint64_t IDNode::ComponentIDKey::hash() const
{
const int type_as_int = int(type);
return BLI_ghashutil_combine_hash(BLI_ghashutil_uinthash(type_as_int),
BLI_ghashutil_strhash_p(name));
}
void IDNode::init(const ID *id, const char * /*subdata*/)
{
BLI_assert(id != nullptr);
/* Store ID-pointer. */
id_type = GS(id->name);
id_orig = (ID *)id;
id_orig_session_uid = id->session_uid;
eval_flags = 0;
previous_eval_flags = 0;
customdata_masks = DEGCustomDataMeshMasks();
previous_customdata_masks = DEGCustomDataMeshMasks();
linked_state = DEG_ID_LINKED_INDIRECTLY;
is_visible_on_build = true;
is_enabled_on_eval = true;
is_collection_fully_expanded = false;
has_base = false;
is_user_modified = false;
id_cow_recalc_backup = 0;
visible_components_mask = 0;
previously_visible_components_mask = 0;
}
void IDNode::init_copy_on_write(ID *id_cow_hint)
{
/* Create pointer as early as possible, so we can use it for function
* bindings. Rest of data we'll be copying to the new datablock when
* it is actually needed. */
if (id_cow_hint != nullptr) {
// BLI_assert(deg_eval_copy_is_needed(id_orig));
if (deg_eval_copy_is_needed(id_orig)) {
id_cow = id_cow_hint;
}
else {
id_cow = id_orig;
}
}
else if (deg_eval_copy_is_needed(id_orig)) {
id_cow = (ID *)BKE_libblock_alloc_notest(GS(id_orig->name));
DEG_COW_PRINT(
"Create shallow copy for %s: id_orig=%p id_cow=%p\n", id_orig->name, id_orig, id_cow);
deg_tag_eval_copy_id(id_cow, id_orig);
}
else {
id_cow = id_orig;
}
}
/* Free 'id' node. */
IDNode::~IDNode()
{
destroy();
}
void IDNode::destroy()
{
if (id_orig == nullptr) {
return;
}
for (ComponentNode *comp_node : components.values()) {
delete comp_node;
}
/* Free memory used by this evaluated ID. */
if (!ELEM(id_cow, id_orig, nullptr)) {
deg_free_eval_copy_datablock(id_cow);
MEM_freeN(id_cow);
id_cow = nullptr;
DEG_COW_PRINT(
"Destroy evaluated ID for %s: id_orig=%p id_cow=%p\n", id_orig->name, id_orig, id_cow);
}
/* Tag that the node is freed. */
id_orig = nullptr;
}
string IDNode::identifier() const
{
char orig_ptr[24], cow_ptr[24];
SNPRINTF(orig_ptr, "%p", id_orig);
SNPRINTF(cow_ptr, "%p", id_cow);
return string(nodeTypeAsString(type)) + " : " + name + " (orig: " + orig_ptr +
", eval: " + cow_ptr + ", is_visible_on_build " +
(is_visible_on_build ? "true" : "false") + ")";
}
ComponentNode *IDNode::find_component(NodeType type, const char *name) const
{
ComponentIDKey key(type, name);
return components.lookup_default(key, nullptr);
}
ComponentNode *IDNode::add_component(NodeType type, const char *name)
{
ComponentNode *comp_node = find_component(type, name);
if (!comp_node) {
DepsNodeFactory *factory = type_get_factory(type);
BLI_assert(factory);
comp_node = (ComponentNode *)factory->create_node(this->id_orig, "", name);
/* Register. */
ComponentIDKey key(type, comp_node->name.c_str());
components.add_new(key, comp_node);
comp_node->owner = this;
}
return comp_node;
}
void IDNode::tag_update(Depsgraph *graph, eUpdateSource source)
{
for (ComponentNode *comp_node : components.values()) {
/* Relations update does explicit animation update when needed. Here we ignore animation
* component to avoid loss of possible unkeyed changes. */
if (comp_node->type == NodeType::ANIMATION && source == DEG_UPDATE_SOURCE_RELATIONS) {
continue;
}
comp_node->tag_update(graph, source);
}
}
void IDNode::finalize_build(Depsgraph *graph)
{
/* Finalize build of all components. */
for (ComponentNode *comp_node : components.values()) {
comp_node->finalize_build(graph);
}
visible_components_mask = get_visible_components_mask();
}
IDComponentsMask IDNode::get_visible_components_mask() const
{
IDComponentsMask result = 0;
for (ComponentNode *comp_node : components.values()) {
if (comp_node->possibly_affects_visible_id) {
const int component_type_as_int = int(comp_node->type);
BLI_assert(component_type_as_int < 64);
result |= (1ULL << component_type_as_int);
}
}
return result;
}
} // namespace blender::deg