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Replace garbage-collection-like cleanup

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Entity IDs are now guaranteed to not change for a living entity.
Cleanup is replaced by using a std::unordered_set to store deleted
Entity IDs to be reclaimed on later calls to addEntity().
This commit is contained in:
Stephen Seo 2017-12-01 14:00:49 +09:00
parent 477580ad34
commit 6124a45453
2 changed files with 56 additions and 196 deletions
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164
src/EC/Manager.hpp
View file

@ -63,14 +63,15 @@ namespace EC
};
using ComponentsStorage =
typename EC::Meta::Morph<ComponentsList, Storage<> >::type;
// Entity: isAlive, dataIndex, ComponentsTags Info
using EntitiesTupleType = std::tuple<bool, std::size_t, BitsetType>;
// Entity: isAlive, ComponentsTags Info
using EntitiesTupleType = std::tuple<bool, BitsetType>;
using EntitiesType = std::vector<EntitiesTupleType>;
EntitiesType entities;
ComponentsStorage componentsStorage;
std::size_t currentCapacity = 0;
std::size_t currentSize = 0;
std::unordered_set<std::size_t> deletedSet;
public:
/*!
@ -100,7 +101,7 @@ namespace EC
entities.resize(newCapacity);
for(std::size_t i = currentCapacity; i < newCapacity; ++i)
{
entities[i] = std::make_tuple(false, i, BitsetType{});
entities[i] = std::make_tuple(false, BitsetType{});
}
currentCapacity = newCapacity;
@ -110,41 +111,58 @@ namespace EC
/*!
\brief Adds an entity to the system, returning the ID of the entity.
WARNING: The ID of an entity may change after calls to cleanup().
Usage of entity IDs should be safe during initialization.
Otherwise, only use the ID given during usage of
forMatchingSignature().
Note: The ID of an entity is guaranteed to not change.
*/
std::size_t addEntity()
{
if(currentSize == currentCapacity)
if(deletedSet.empty())
{
resize(currentCapacity + EC_GROW_SIZE_AMOUNT);
if(currentSize == currentCapacity)
{
resize(currentCapacity + EC_GROW_SIZE_AMOUNT);
}
std::get<bool>(entities[currentSize]) = true;
std::get<BitsetType>(entities[currentSize]).reset();
return currentSize++;
}
else
{
std::size_t id;
{
auto iter = deletedSet.begin();
id = *iter;
deletedSet.erase(iter);
}
std::get<bool>(entities[id]) = true;
std::get<BitsetType>(entities[id]).reset();
return id;
}
std::get<bool>(entities[currentSize]) = true;
return currentSize++;
}
/*!
\brief Marks an entity for deletion.
A deleted Entity is not actually deleted until cleanup() is called.
While an Entity is "deleted" but still in the system, calls to
forMatchingSignature() will ignore the Entity.
A deleted Entity's id is stored to be reclaimed later when
addEntity is called. Thus calling addEntity may return an id of
a previously deleted Entity.
*/
void deleteEntity(const std::size_t& index)
{
std::get<bool>(entities.at(index)) = false;
if(hasEntity(index))
{
std::get<bool>(entities.at(index)) = false;
deletedSet.insert(index);
}
}
/*!
\brief Checks if the Entity with the given ID is in the system.
Note that deleted Entities that haven't yet been cleaned up
(via cleanup()) are considered still in the system.
Note that deleted Entities are still considered in the system.
Consider using isAlive().
*/
bool hasEntity(const std::size_t& index) const
{
@ -166,12 +184,12 @@ namespace EC
/*!
\brief Returns the current size or number of entities in the system.
Note that this size includes entities that have been marked for
deletion but not yet cleaned up by the cleanup function.
Note this function will only count entities where isAlive() returns
true.
*/
std::size_t getCurrentSize() const
{
return currentSize;
return currentSize - deletedSet.size();
}
/*
@ -189,11 +207,10 @@ namespace EC
/*!
\brief Returns a const reference to an Entity's info.
An Entity's info is a std::tuple with a bool, std::size_t, and a
An Entity's info is a std::tuple with a bool, and a
bitset.
\n The bool determines if the Entity is alive.
\n The std::size_t is the ID to this Entity's data in the system.
\n The bitset shows what Components and Tags belong to the Entity.
*/
const EntitiesTupleType& getEntityInfo(const std::size_t& index) const
@ -215,7 +232,7 @@ namespace EC
Component& getEntityData(const std::size_t& index)
{
return std::get<std::vector<Component> >(componentsStorage).at(
std::get<std::size_t>(entities.at(index)));
index);
}
/*!
@ -250,7 +267,7 @@ namespace EC
const Component& getEntityData(const std::size_t& index) const
{
return std::get<std::vector<Component> >(componentsStorage).at(
std::get<std::size_t>(entities.at(index)));
index);
}
/*!
@ -302,90 +319,6 @@ namespace EC
entities.at(index)).template getTagBit<Tag>();
}
/*!
\brief Does garbage collection on Entities.
Does housekeeping on the vector containing Entities that will
result in entity IDs changing if some Entities were marked for
deletion.
<b>This function should be called periodically to correctly handle
deletion of entities.</b>
The vector returned by this function lists all entities that have
changed as a result of calling this function.
The first parameter in the tuple (bool) is true if the entity has
been relocated (entity id has changed) and is false if the entity
has been deleted.
The second parameter (size_t) is the original entity id of the
entity. If the previous parameter was false for deleted, then this
refers to the id of that deleted entity. If the previous parameter
was true for relocated, then this refers to the previous id of the
relocated entity
The third parameter (size_t) is the new entity id of the entity if
the entity was relocated. If the entity was deleted then this
parameter is undefined as it is not used in that case.
*/
using CleanupReturnType =
std::vector<std::tuple<bool, std::size_t, std::size_t> >;
CleanupReturnType cleanup()
{
CleanupReturnType changedVector;
if(currentSize == 0)
{
return changedVector;
}
std::size_t rhs = currentSize - 1;
std::size_t lhs = 0;
while(lhs < rhs)
{
while(!std::get<bool>(entities[rhs]))
{
if(rhs == 0)
{
currentSize = 0;
return changedVector;
}
changedVector.push_back(std::make_tuple(false, rhs, 0));
std::get<BitsetType>(entities[rhs]).reset();
--rhs;
}
if(lhs >= rhs)
{
break;
}
else if(!std::get<bool>(entities[lhs]))
{
// lhs is marked for deletion
// store deleted and changed id
changedVector.push_back(std::make_tuple(false, lhs, 0));
changedVector.push_back(std::make_tuple(true, rhs, lhs));
// swap lhs entity with rhs entity
std::swap(entities[lhs], entities.at(rhs));
// clear deleted bitset
std::get<BitsetType>(entities[rhs]).reset();
// inc/dec pointers
++lhs; --rhs;
}
else
{
++lhs;
}
}
currentSize = rhs + 1;
return changedVector;
}
/*!
\brief Adds a component to the given Entity.
@ -415,7 +348,7 @@ namespace EC
template <typename Component, typename... Args>
void addComponent(const std::size_t& entityID, Args&&... args)
{
if(!hasEntity(entityID) || !isAlive(entityID))
if(!isAlive(entityID))
{
return;
}
@ -428,7 +361,7 @@ namespace EC
std::get<std::vector<Component> >(
componentsStorage
)[std::get<std::size_t>(entities[entityID])] = std::move(component);
)[entityID] = std::move(component);
}
/*!
@ -445,7 +378,7 @@ namespace EC
template <typename Component>
void removeComponent(const std::size_t& entityID)
{
if(!hasEntity(entityID) || !isAlive(entityID))
if(!isAlive(entityID))
{
return;
}
@ -466,7 +399,7 @@ namespace EC
template <typename Tag>
void addTag(const std::size_t& entityID)
{
if(!hasEntity(entityID) || !isAlive(entityID))
if(!isAlive(entityID))
{
return;
}
@ -489,7 +422,7 @@ namespace EC
template <typename Tag>
void removeTag(const std::size_t& entityID)
{
if(!hasEntity(entityID) || !isAlive(entityID))
if(!isAlive(entityID))
{
return;
}
@ -1558,6 +1491,7 @@ namespace EC
currentSize = 0;
currentCapacity = 0;
deletedSet.clear();
resize(EC_INIT_ENTITIES_SIZE);
}
};

88
src/test/ECTest.cpp
View file

@ -132,10 +132,6 @@ TEST(EC, Manager)
}
manager.deleteEntity(e0);
manager.cleanup();
std::size_t edata = std::get<std::size_t>(manager.getEntityInfo(0));
EXPECT_EQ(edata, 1);
std::size_t e2 = manager.addEntity();
@ -154,7 +150,6 @@ TEST(EC, Manager)
manager.deleteEntity(e1);
manager.deleteEntity(e2);
manager.cleanup();
}
TEST(EC, MoveComponentWithUniquePtr)
@ -217,24 +212,13 @@ TEST(EC, DeletedEntities)
{
auto eid = manager.addEntity();
manager.addComponent<C0>(eid);
if(i >= 2)
{
manager.deleteEntity(eid);
}
}
manager.cleanup();
manager.deleteEntity(2);
manager.deleteEntity(3);
for(unsigned int i = 0; i < 4; ++i)
{
if(i < 2)
{
EXPECT_TRUE(manager.hasComponent<C0>(i));
}
else
{
EXPECT_FALSE(manager.hasComponent<C0>(i));
}
EXPECT_TRUE(manager.hasComponent<C0>(i));
}
for(unsigned int i = 0; i < 2; ++i)
@ -393,44 +377,6 @@ TEST(EC, FunctionStorage)
}
}
/*
This test demonstrates that while entity ids may change after cleanup,
pointers to their components do not.
*/
TEST(EC, DataPointers)
{
EC::Manager<ListComponentsAll, ListTagsAll> manager;
auto first = manager.addEntity();
auto second = manager.addEntity();
manager.addComponent<C0>(first, 5, 5);
manager.addComponent<C0>(second, 10, 10);
manager.addTag<T0>(second);
auto* cptr = &manager.getEntityData<C0>(second);
EXPECT_EQ(10, cptr->x);
EXPECT_EQ(10, cptr->y);
manager.deleteEntity(first);
manager.cleanup();
auto newSecond = second;
manager.forMatchingSignature<EC::Meta::TypeList<T0>>(
[&newSecond] (auto eid) {
newSecond = eid;
});
EXPECT_NE(newSecond, second);
auto* newcptr = &manager.getEntityData<C0>(newSecond);
EXPECT_EQ(newcptr, cptr);
EXPECT_EQ(10, newcptr->x);
EXPECT_EQ(10, newcptr->y);
}
TEST(EC, DeletedEntityID)
{
EC::Manager<ListComponentsAll, ListTagsAll> manager;
@ -443,28 +389,10 @@ TEST(EC, DeletedEntityID)
manager.deleteEntity(e0);
manager.deleteEntity(e1);
auto changedVector = manager.cleanup();
for(const auto& t : changedVector)
{
if(std::get<1>(t) == 0)
{
EXPECT_FALSE(std::get<0>(t));
}
else if(std::get<1>(t) == 1)
{
EXPECT_FALSE(std::get<0>(t));
}
else
{
EXPECT_TRUE(std::get<0>(t));
}
}
EXPECT_FALSE(manager.hasEntity(2));
EXPECT_FALSE(manager.hasEntity(3));
EXPECT_TRUE(manager.hasEntity(0));
EXPECT_TRUE(manager.hasEntity(1));
EXPECT_FALSE(manager.isAlive(e0));
EXPECT_FALSE(manager.isAlive(e1));
EXPECT_TRUE(manager.isAlive(e2));
EXPECT_TRUE(manager.isAlive(e3));
}
TEST(EC, MultiThreaded)
@ -497,7 +425,6 @@ TEST(EC, MultiThreaded)
{
manager.deleteEntity(i);
}
manager.cleanup();
for(unsigned int i = 0; i < 3; ++i)
{
@ -563,7 +490,6 @@ TEST(EC, MultiThreaded)
{
manager.deleteEntity(i);
}
manager.cleanup();
manager.callForMatchingFunction(f0, 8);