Overview

template<typename ErrorHandler>
class pw::allocator::internal::BaseFramingAllocator< ErrorHandler >

Provides generic framing logic for type-erased prefixes and suffixes.

Template Parameters

ErrorHandler Invoked when a frame error is encountered.

Inheritance diagram for pw::allocator::internal::BaseFramingAllocator< ErrorHandler >:

Protected Member Functions
constexpr	BaseFramingAllocator (Allocator &allocator)

ByteSpan	AllocateFrame (Layout prefix, Layout data, Layout suffix)

bool	ResizeFrame (void data, size_t new_size, Layout suffix, void tmp_suffix)

Result< Layout >	GetFrameInfo (InfoType info_type, const void *data, Layout suffix) const

Result< size_t >	GetFrameSize (const void *frame) const

Protected Member Functions inherited from pw::allocator::ForwardingAllocator
constexpr	ForwardingAllocator (const Capabilities &capabilities) noexcept

constexpr	ForwardingAllocator (pw::Allocator &allocator) noexcept

constexpr void	Init (pw::Allocator &allocator)

constexpr pw::Allocator &	allocator ()

constexpr const pw::Allocator &	allocator () const

void *	DoAllocate (Layout layout) override

void	DoDeallocate (void *ptr) override

bool	DoResize (void *ptr, size_t new_size) override

bool	DoBeforeReallocate (void *ptr, Layout new_layout) override

void	DoAfterReallocateCopy (void ptr, Layout new_layout, void new_ptr) override

void	DoAfterReallocateDone (Layout new_layout, void *new_ptr) override

size_t	DoGetAllocated () const override

std::optional< Fragmentation >	DoMeasureFragmentation () const override
	Returns fragmentation information for the allocator's memory region.

Result< Layout >	DoGetInfo (InfoType info_type, const void *ptr) const override

Protected Member Functions inherited from pw::Allocator
constexpr	Allocator () noexcept=default
	TODO(b/326509341): Remove when downstream consumers migrate.

constexpr	Allocator (const Capabilities &capabilities) noexcept

virtual void *	DoAllocate (Layout layout)=0

virtual bool	DoResize (void *ptr, size_t new_size)

virtual void *	DoReallocate (void *ptr, Layout new_layout)

virtual bool	DoBeforeReallocate (void *ptr, Layout new_layout)

virtual void	DoAfterReallocateCopy (void ptr, Layout new_layout, void new_ptr)

virtual void	DoAfterReallocateDone (Layout new_layout, void *new_ptr)

virtual size_t	DoGetAllocated () const

virtual std::optional< Fragmentation >	DoMeasureFragmentation () const
	Returns fragmentation information for the allocator's memory region.

Protected Member Functions inherited from pw::Deallocator
constexpr	Deallocator ()=default
	TODO(b/326509341): Remove when downstream consumers migrate.

constexpr	Deallocator (const Capabilities &capabilities)

Result< Layout >	GetInfo (InfoType info_type, const void *ptr) const

Result< Layout >	GetRequestedLayout (const void *ptr) const

Result< Layout >	GetUsableLayout (const void *ptr) const

Result< Layout >	GetAllocatedLayout (const void *ptr) const

bool	Recognizes (const void *ptr) const

virtual void	DoDeallocate (void *ptr)=0

virtual Result< Layout >	DoGetInfo (InfoType, const void *) const

Static Protected Member Functions
static constexpr size_t	Distance (const void start, const void end)
	Returns the distance between two pointers in bytes.

static void	UpdateOffsets (void frame, void data, void *suffix)


static void *	GetFrame (void *data, bool has_suffix, bool checked=true)

static const void *	GetFrame (const void *data, bool has_suffix, bool checked=true)


static void *	GetData (void *frame, Result< size_t > frame_size, Layout prefix)

static const void *	GetData (const void *frame, Result< size_t > frame_size, Layout prefix)


static void *	GetSuffix (void *data, size_t data_size, Layout suffix)

static const void *	GetSuffix (const void *data, size_t data_size, Layout suffix)

Static Protected Member Functions inherited from pw::Allocator
static bool	BeforeReallocate (Allocator &allocator, void *ptr, Layout new_layout)

static void	AfterReallocateCopy (Allocator &allocator, void ptr, Layout new_layout, void new_ptr)

static void	AfterReallocateDone (Allocator &allocator, Layout new_layout, void *new_ptr)

Static Protected Member Functions inherited from pw::Deallocator
static Result< Layout >	GetInfo (const Deallocator &deallocator, InfoType info_type, const void *ptr)

static Result< Layout >	GetRequestedLayout (const Deallocator &deallocator, const void *ptr)

static Result< Layout >	GetUsableLayout (const Deallocator &deallocator, const void *ptr)

static Result< Layout >	GetAllocatedLayout (const Deallocator &deallocator, const void *ptr)

static bool	Recognizes (const Deallocator &deallocator, const void *ptr)

Additional Inherited Members
Public Types inherited from pw::Allocator
using	Fragmentation = allocator::Fragmentation

Public Types inherited from pw::Deallocator
using	Capabilities = allocator::Capabilities

using	Capability = allocator::Capability

using	Layout = allocator::Layout

Public Member Functions inherited from pw::Allocator
void *	Allocate (Layout layout)

template<typename T , int &... kExplicitGuard, std::enable_if_t<!std::is_array_v< T >, int > = 0, typename... Args>
T *	New (Args &&... args)

template<typename T , int &... kExplicitGuard, typename ElementType = std::remove_extent_t<T>, std::enable_if_t< is_bounded_array_v< T >, int > = 0>
ElementType *	New ()

template<typename T , int &... kExplicitGuard, typename ElementType = std::remove_extent_t<T>, std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
ElementType *	New (size_t count)

template<typename T , int &... kExplicitGuard, typename ElementType = std::remove_extent_t<T>, std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
ElementType *	New (size_t count, size_t alignment)
	Constructs an `alignment`-byte aligned array of `count` objects.

template<typename T , int &... kExplicitGuard, std::enable_if_t<!std::is_array_v< T >, int > = 0, typename... Args>
UniquePtr< T >	MakeUnique (Args &&... args)

template<typename T , std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
UniquePtr< T >	MakeUnique (size_t size)

template<typename T , std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
UniquePtr< T >	MakeUnique (size_t size, size_t alignment)

template<typename T , std::enable_if_t< is_bounded_array_v< T >, int > = 0>
UniquePtr< T >	MakeUnique ()

template<typename T , int &... kExplicitGuard, std::enable_if_t<!std::is_array_v< T >, int > = 0, typename... Args>
SharedPtr< T >	MakeShared (Args &&... args)

template<typename T , std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
SharedPtr< T >	MakeShared (size_t size)

template<typename T , std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
SharedPtr< T >	MakeShared (size_t size, size_t alignment)

template<typename T , std::enable_if_t< is_bounded_array_v< T >, int > = 0>
SharedPtr< T >	MakeShared ()

bool	Resize (void *ptr, size_t new_size)

void *	Reallocate (void *ptr, Layout new_layout)

size_t	GetAllocated () const

std::optional< Fragmentation >	MeasureFragmentation () const
	Returns fragmentation information for the allocator's memory region.

Public Member Functions inherited from pw::Deallocator
constexpr const Capabilities &	capabilities () const

constexpr bool	HasCapability (Capability capability) const
	Returns whether a given capability is enabled for this object.

void	Deallocate (void *ptr)

template<typename ElementType >
void	DeleteArray (ElementType *ptr, size_t count)

template<typename ElementType >
void	Destroy (ElementType *ptr, size_t count)

StatusWithSize	GetCapacity () const

bool	IsEqual (const Deallocator &other) const

template<typename T , int &... kExplicitGuard, std::enable_if_t<!std::is_array_v< T >, int > = 0>
void	Delete (T *ptr)

template<typename T , int &... kExplicitGuard, typename ElementType = std::remove_extent_t<T>, std::enable_if_t< is_bounded_array_v< T >, int > = 0>
void	Delete (ElementType *ptr)

template<typename T , int &... kExplicitGuard, typename ElementType = std::remove_extent_t<T>, std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
void	Delete (ElementType *ptr, size_t count)

Protected Types inherited from pw::Deallocator
enum class	InfoType { kRequestedLayoutOf , kUsableLayoutOf , kAllocatedLayoutOf , kCapacity , kRecognizes }

Static Protected Attributes inherited from pw::Deallocator
template<typename T >
static constexpr bool	is_bounded_array_v = ::pw::is_bounded_array_v<T>

template<typename T >
static constexpr bool	is_unbounded_array_v = ::pw::is_unbounded_array_v<T>

Member Function Documentation

◆ AllocateFrame()

template<typename ErrorHandler >

ByteSpan pw::allocator::internal::BaseFramingAllocator< ErrorHandler >::AllocateFrame	(	Layout	prefix,
		Layout	data,
		Layout	suffix
	)

protected

Allocates a frame that can hold the requested data framed by a prefix and/or suffix, and returns it as a span of bytes.

Parameters

prefix	Layout of the type-erased prefix.
data	Requested layout.
suffix	Layout of the type-erased suffix.

◆ GetData()

template<typename ErrorHandler >

void * pw::allocator::internal::BaseFramingAllocator< ErrorHandler >::GetData	(	void *	frame,
		Result< size_t >	frame_size,
		Layout	prefix
	)

staticprotected

Returns a data pointer from a frame pointer.

Parameters

frame	Pointer to an underlying allocation.
frame_size	Size of the frame.
prefix	Layout of the type-erased prefix, or a default layout.

◆ GetFrame()

template<typename ErrorHandler >

void * pw::allocator::internal::BaseFramingAllocator< ErrorHandler >::GetFrame	(	void *	data,
		bool	has_suffix,
		bool	checked = `true`
	)

staticprotected

Returns a frame pointer from a data pointer.

Unlike many of the other pointer conversion methods, this method includes a checked parameter that can be set to false to avoid calling the error handler. This is useful when the returned frame pointer is intended to be passed to a method that accepts any pointer, e.g. a Deallocator method that returns pw::Status::NotFound() for invalid pointers.

Parameters

data	Pointer to usable memory.
has_suffix	Used to locate the data-relative prefix offset.
checked	If false, the ErrorHandler is never called.

◆ GetFrameInfo()

template<typename ErrorHandler >

Result< Layout > pw::allocator::internal::BaseFramingAllocator< ErrorHandler >::GetFrameInfo	(	InfoType	info_type,
		const void *	data,
		Layout	suffix
	)		const

protected

Returns info like Deallocator::GetInfo.

Parameters

info_type	See `Deallocator::InfoType`.
data	Pointer to usable memory.
suffix	Layout of the type-erased suffix, or a default layout.

◆ GetFrameSize()

template<typename ErrorHandler >

Result< size_t > pw::allocator::internal::BaseFramingAllocator< ErrorHandler >::GetFrameSize ( const void * frame ) const

protected

Returns the usable size of an underlying allocation.

Returns

A Result containing size of the frame on success or one of the following error codes on failure:

OK: Returns the size of the frame in bytes.
NOT_FOUND: Frame is not recognized by the underlying allocator.
UNIMPLEMENTED: The underlying allocator cannot get usable sizes.

◆ GetSuffix()

template<typename ErrorHandler >

void * pw::allocator::internal::BaseFramingAllocator< ErrorHandler >::GetSuffix	(	void *	data,
		size_t	data_size,
		Layout	suffix
	)

staticprotected

Returns a frame pointer from a data pointer.

Parameters

data	Pointer to usable memory.
data_size	Size of the memory from `data` to the end of the frame, including the suffix.
suffix	Layout of the type-erased suffix, or a default layout.

◆ ResizeFrame()

template<typename ErrorHandler >

bool pw::allocator::internal::BaseFramingAllocator< ErrorHandler >::ResizeFrame	(	void *	data,
		size_t	new_size,
		Layout	suffix,
		void *	tmp_suffix
	)

protected

Resizes a frame that holds the provided data to be at least the new size while keeping the (type-erased) prefix and/or suffix.

Returns: Whether the frame was successfully resized.

Parameters

data	Pointer to usable memory.
new_size	Requested new size of the usable memory.
suffix	Layout of the type-erased suffix, or a default layout.
tmp_suffix	Pointer to a temporary suffix, or null.

◆ UpdateOffsets()

template<typename ErrorHandler >

void pw::allocator::internal::BaseFramingAllocator< ErrorHandler >::UpdateOffsets	(	void *	frame,
		void *	data,
		void *	suffix
	)

staticprotected

Updates the frame-relative and data-relative prefix offsets, and the suffix offset as needed for the given pointers to locations in the frame.

Parameters

frame	Pointer to the underlying allocation.
data	Pointer to the usable memory.
suffix	Pointer to the type-erased suffix, or null.

The documentation for this class was generated from the following file:

pw_allocator/public/pw_allocator/framing_allocator.h

Overview

Protected Member Functions

Static Protected Member Functions

Additional Inherited Members

Member Function Documentation

◆ AllocateFrame()

◆ GetData()

◆ GetFrame()

◆ GetFrameInfo()

◆ GetFrameSize()

◆ GetSuffix()

◆ ResizeFrame()

◆ UpdateOffsets()