etc: Move the responsibility of type checking to properties

This commit is contained in:
Joshua Scott 2018-11-27 15:36:57 +00:00
parent 3a22c992b5
commit 34bc3d30bc
7 changed files with 172 additions and 81 deletions

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@ -24,6 +24,7 @@ namespace pclass
PropertyBase(PropertyClass &object,
const PropertyBase &that);
const PropertyClass &get_instance() const;
std::string get_name() const;
hash_t get_name_hash() const;
hash_t get_full_hash() const;
@ -40,6 +41,7 @@ namespace pclass
virtual void read_value_from(BitStream &stream) = 0;
private:
const PropertyClass *m_instance;
std::string m_name;
hash_t m_name_hash;
hash_t m_full_hash;

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@ -12,8 +12,8 @@ namespace pclass
/// @cond DOXYGEN_SKIP
/**
* A helper utility that provides the right implementation of construct()
* and get_object() based on characteristics of type: ValueT.
* A helper utility that provides the right implementation of construct(),
* copy(), get_object() and set_object(), based on characteristics of type: ValueT.
*/
template <
typename ValueT,
@ -61,8 +61,9 @@ namespace pclass
* - does not derive from PropertyClass
*
* This should:
* - Construct to a nullptr; and
* - Throw an exception when get_object() is called.
* - Construct to a nullptr;
* - Copy construct to the same pointer as the original; and
* - Throw an exception when get_object() or set_object() is called.
*/
template <typename ValueT>
struct value_object_helper<
@ -87,7 +88,7 @@ namespace pclass
static ValueT copy(const StaticProperty<ValueT> &prop)
{
// The copy constructor for all pointers is to copy the pointer
// without creating a new copy of the object it's pointing too.
// without creating a new copy of the object it's pointing to.
return prop.m_value;
}
@ -116,9 +117,12 @@ namespace pclass
* - does derive from PropertyClass
*
* This should:
* - Construct to a nullptr; and
* - Construct to a nullptr;
* - Copy construct to the same pointer as the original;
* - Return a pointer to a ValueT instance (as a PropertyClass *)
* when get_object() is called.
* when get_object() is called; and
* - Throw an exception when the object supplied to set_object()
* does not inherit from the property's type, but set m_value otherwise.
*/
template <typename ValueT>
struct value_object_helper<
@ -143,7 +147,7 @@ namespace pclass
static ValueT copy(const StaticProperty<ValueT> &prop)
{
// The copy constructor for all pointers is to copy the pointer
// without creating a new copy of the object it's pointing too.
// without creating a new copy of the object it's pointing to.
return prop.m_value;
}
@ -156,6 +160,10 @@ namespace pclass
static void set_object(StaticProperty<ValueT> &prop, PropertyClass *object)
{
// Ensure that object inherits the type of the property
if (object)
assert_type_match(prop.get_type(), object->get_type(), true);
// ValueT does derive from PropertyClass, and we have a pointer to an instance
// of PropertyClass, so cast the pointer up to a ValueT.
prop.m_value = dynamic_cast<ValueT>(object);
@ -198,7 +206,7 @@ namespace pclass
static ValueT copy(const StaticProperty<ValueT> &prop)
{
// Derivitives of PropertyClass implement a clone method that returns
// a clone as a pointer.
// a pointer to a copy.
ValueT *value_ptr = dynamic_cast<ValueT *>(prop.m_value.clone());
ValueT value = *value_ptr;
delete value_ptr;
@ -214,9 +222,17 @@ namespace pclass
static void set_object(StaticProperty<ValueT> &prop, PropertyClass *object)
{
// Ensure that object is not nullptr
if (!object)
throw runtime_error("Value cannot be null.");
// Ensure that object is exactly the type of the property.
assert_type_match(prop.get_type(), object->get_type());
// ValueT does derive from PropertyClass, but we don't store a pointer,
// so we need to copy the value in.
prop.m_value = *object;
delete object;
}
};

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@ -13,7 +13,8 @@ namespace pclass
/// @cond DOXYGEN_SKIP
/**
*
* A helper utility that provides the right implementation of copy(),
* get_object() and set_object(), based on characteristics of type: ValueT.
*/
template <
typename ValueT,
@ -24,6 +25,12 @@ namespace pclass
{
static ValueT copy(VectorProperty<ValueT> &prop, const int index)
{
// Ensure index is within bounds
if (index < 0 || index >= prop.size())
throw runtime_error("Index out of bounds.");
// In cases where ValueT is not a pointer, and does not derive from PropertyClass,
// just call the copy constructor.
return ValueT(prop.at(index));
}
@ -65,6 +72,12 @@ namespace pclass
{
static ValueT copy(VectorProperty<ValueT> &prop, const int index)
{
// Ensure index is within bounds
if (index < 0 || index >= prop.size())
throw runtime_error("Index out of bounds.");
// The copy constructor for all pointers is to copy the pointer
// without creating a new copy of the object it's pointing to.
return prop.at(index);
}
@ -87,47 +100,6 @@ namespace pclass
}
};
/**
*
*/
template <typename ValueT>
struct vector_value_object_helper<
ValueT,
typename std::enable_if<
!std::is_pointer<ValueT>::value
>::type,
typename std::enable_if<
std::is_base_of<
PropertyClass,
typename std::remove_pointer<ValueT>::type
>::value
>::type
>
{
static ValueT copy(VectorProperty<ValueT> &prop, const int index)
{
ValueT *value_ptr = dynamic_cast<ValueT *>(prop.at(index).copy());
ValueT value = *value_ptr;
delete value_ptr;
return value;
}
static const PropertyClass *get_object(const VectorProperty<ValueT> &prop, const int index)
{
if (index < 0 || index >= prop.size())
throw runtime_error("Index out of bounds.");
return dynamic_cast<PropertyClass *>(&prop.at(index));
}
static void set_object(VectorProperty<ValueT> &prop, PropertyClass *object, const int index)
{
if (index < 0 || index >= prop.size())
throw runtime_error("Index out of bounds.");
prop.at(index) = dynamic_cast<ValueT>(*object);
delete object;
}
};
/**
*
*/
@ -147,24 +119,100 @@ namespace pclass
{
static ValueT copy(VectorProperty<ValueT> &prop, const int index)
{
// The copy constructor for all pointers is to copy the pointer
// without creating a new copy of the object it's pointing to.
return prop.at(index);
}
static const PropertyClass *get_object(const VectorProperty<ValueT> &prop, const int index)
{
// Ensure index is within bounds
if (index < 0 || index >= prop.size())
throw runtime_error("Index out of bounds.");
// ValueT does derive from PropertyClass, and we have a pointer to an instance
// of ValueT, so we can cast down to a PropertyClass pointer.
return dynamic_cast<PropertyClass *>(prop.at(index));
}
static void set_object(VectorProperty<ValueT> &prop, PropertyClass *object, const int index)
{
// Ensure index is within bounds
if (index < 0 || index >= prop.size())
throw runtime_error("Index out of bounds.");
// Ensure that object inherits the type of the property
if (object)
assert_type_match(prop.get_type(), object->get_type(), true);
// ValueT does derive from PropertyClass, and we have a pointer to an instance
// of PropertyClass, so cast the pointer up to a ValueT.
prop.at(index) = dynamic_cast<ValueT>(object);
}
};
/**
*
*/
template <typename ValueT>
struct vector_value_object_helper<
ValueT,
typename std::enable_if<
!std::is_pointer<ValueT>::value
>::type,
typename std::enable_if<
std::is_base_of<
PropertyClass,
typename std::remove_pointer<ValueT>::type
>::value
>::type
>
{
static ValueT copy(VectorProperty<ValueT> &prop, const int index)
{
// Ensure index is within bounds
if (index < 0 || index >= prop.size())
throw runtime_error("Index out of bounds.");
// Derivitives of PropertyClass implement a clone method that returns
// a pointer to a copy.
ValueT *value_ptr = dynamic_cast<ValueT *>(prop.at(index).copy());
ValueT value = *value_ptr;
delete value_ptr;
return value;
}
static const PropertyClass *get_object(const VectorProperty<ValueT> &prop, const int index)
{
// Ensure index is within bounds
if (index < 0 || index >= prop.size())
throw runtime_error("Index out of bounds.");
// ValueT does derive from PropertyClass, and we have an instance of ValueT,
// so we can cast down to a PropertyClass pointer.
return dynamic_cast<PropertyClass *>(&prop.at(index));
}
static void set_object(VectorProperty<ValueT> &prop, PropertyClass *object, const int index)
{
// Ensure index is within bounds
if (index < 0 || index >= prop.size())
throw runtime_error("Index out of bounds.");
// Ensure that object is not nullptr
if (!object)
throw runtime_error("Value cannot be null.");
// Ensure that object is exactly the type of the property
assert_type_match(prop.get_type(), object->get_type());
// ValueT does derive from PropertyClass, but we don't store a pointer,
// so we need to copy the value in.
prop.at(index) = dynamic_cast<ValueT>(*object);
delete object;
}
};
/**
*
*/
@ -176,6 +224,7 @@ namespace pclass
{
static void write_value_to(const VectorProperty<ValueT> &prop, BitStream &stream, const int index)
{
// Ensure index is within bounds
if (index < 0 || index >= prop.size())
throw runtime_error("Index out of bounds.");
prop.get_type().write_to(stream, prop.at(index));
@ -183,6 +232,7 @@ namespace pclass
static void read_value_from(VectorProperty<ValueT> &prop, BitStream &stream, const int index)
{
// Ensure index is within bounds
if (index < 0 || index >= prop.size())
throw runtime_error("Index out of bounds.");
prop.get_type().read_from(stream, Value(prop.at(index)));
@ -200,15 +250,19 @@ namespace pclass
{
static void write_value_to(const VectorProperty<ValueT> &prop, BitStream &stream, const int index)
{
// Ensure index is within bounds
if (index < 0 || index >= prop.size())
throw runtime_error("Index out of bounds.");
prop.get_type().write_to(stream, *prop.at(index));
}
static void read_value_from(VectorProperty<ValueT> &prop, BitStream &stream, const int index)
{
// Ensure index is within bounds
if (index < 0 || index >= prop.size())
throw runtime_error("Index out of bounds.");
prop.get_type().read_from(stream, Value(*prop.at(index)));
}
};

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@ -71,5 +71,17 @@ namespace pclass
typedef std::vector<Type *> TypeList;
typedef std::map<std::string, Type *> TypeNameMap;
typedef std::map<hash_t, Type *> TypeHashMap;
/**
* @param[in] expected The Type that is expected to match with the actual Type.
* @param[in] actual The Type that is being checked for a match with the expected Type.
* @param[in] allow_inheritance If false, then the expected and actual types must match exactly.
* @throws ki::runtime_error If the expected and actual types do not match.
*/
void assert_type_match(
const Type &expected,
const Type &actual,
bool allow_inheritance = false
);
}
}

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@ -10,6 +10,7 @@ namespace pclass
PropertyBase::PropertyBase(PropertyClass &object,
const std::string &name, const Type &type)
{
m_instance = &object;
m_name = name;
m_name_hash = type
.get_type_system()
@ -25,6 +26,7 @@ namespace pclass
PropertyBase::PropertyBase(PropertyClass &object,
const PropertyBase &that)
{
m_instance = &object;
m_name = that.m_name;
m_name_hash = that.m_name_hash;
m_full_hash = that.m_full_hash;
@ -34,6 +36,11 @@ namespace pclass
object.add_property(*this);
}
const PropertyClass &PropertyBase::get_instance() const
{
return *m_instance;
}
std::string PropertyBase::get_name() const
{
return m_name;

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@ -1,4 +1,5 @@
#include "ki/pclass/types/Type.h"
#include "ki/pclass/types/ClassType.h"
#include "ki/pclass/TypeSystem.h"
#include "ki/util/exception.h"
#include <stdexcept>
@ -65,5 +66,34 @@ namespace pclass
.get_hash_calculator()
.calculate_type_hash(m_name);
}
void assert_type_match(
const Type &expected,
const Type &actual,
const bool allow_inheritance
)
{
// Do the types match via inheritance?
if (allow_inheritance &&
expected.get_kind() == Type::kind::CLASS)
{
const auto &actual_class = dynamic_cast<const ClassTypeBase &>(actual);
if (actual_class.inherits(expected))
return;
}
// Do the types match exactly?
if (&expected == &actual)
return;
// The types do not match
std::ostringstream oss;
oss << "Type mismatch. ("
<< "expected=" << expected.get_name() << ", "
<< "actual=" << actual.get_name() << ", "
<< "allow_inheritance=" << allow_inheritance
<< ")";
throw runtime_error(oss.str());
}
}
}

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@ -404,21 +404,6 @@ namespace serialization
// Read the object as a nested object
pclass::PropertyClass *object = nullptr;
load_object(object, stream);
if (object)
{
// Does the nested object inherit from the property's type?
const auto &object_type =
dynamic_cast<const pclass::ClassTypeBase &>(
object->get_type()
);
if (!object_type.inherits(dynamic_property.get_type()))
{
std::ostringstream oss;
oss << "Type '" << object_type.get_name() << "' does not derive from "
<< "property type '" << prop.get_type().get_name() << "'.";
throw runtime_error(oss.str());
}
}
dynamic_property.set_object(object, i);
}
else
@ -438,21 +423,6 @@ namespace serialization
// Read the object as a nested object
pclass::PropertyClass *object = nullptr;
load_object(object, stream);
if (object)
{
// Does the nested object inherit from the property's type?
const auto &object_type =
dynamic_cast<const pclass::ClassTypeBase &>(
object->get_type()
);
if (!object_type.inherits(prop.get_type()))
{
std::ostringstream oss;
oss << "Type '" << object_type.get_name() << "' does not derive from "
<< "property type '" << prop.get_type().get_name() << "'.";
throw runtime_error(oss.str());
}
}
prop.set_object(object);
}
else