An Annotation which wraps a LengthDelimitedRingBuffer of up to Capacity bytes in length. More...

#include "client/ring_buffer_annotation.h"

Inheritance diagram for crashpad::RingBufferAnnotation< Capacity >:

Collaboration diagram for crashpad::RingBufferAnnotation< Capacity >:

Public Member Functions
constexpr	RingBufferAnnotation (Annotation::Type type, const char name[])
	Constructs a `RingBufferAnnotation`.

	RingBufferAnnotation (const RingBufferAnnotation &)=delete

RingBufferAnnotation &	operator= (const RingBufferAnnotation &)=delete

	RingBufferAnnotation (RingBufferAnnotation &&)=default

RingBufferAnnotation &	operator= (RingBufferAnnotation &&)=default

bool	Push (const void *const buffer, RingBufferAnnotationCapacity buffer_length)
	Pushes data onto this annotation's ring buffer.

void	ResetForTesting ()
	Reset the annotation (e.g., for testing). This method is not thread-safe.

Public Member Functions inherited from crashpad::Annotation
constexpr	Annotation (Type type, const char name[], void *value_ptr)
	Constructs a new annotation.

	Annotation (const Annotation &)=delete

Annotation &	operator= (const Annotation &)=delete

void	SetSize (ValueSizeType size)
	Specifies the number of bytes in value_ptr_ to include when generating a crash report.

void	Clear ()
	Marks the annotation as cleared, indicating the value_ptr_ should not be included in a crash report.

bool	is_set () const
	Tests whether the annotation has been set.

Type	type () const

ValueSizeType	size () const

const char *	name () const

const void *	value () const

ConcurrentAccessGuardMode	concurrent_access_guard_mode () const

std::optional< ScopedSpinGuard >	TryCreateScopedSpinGuard (uint64_t timeout_ns)
	If this Annotation guards concurrent access using ScopedSpinGuard, tries to obtain the spin guard and returns the result.

Additional Inherited Members
Public Types inherited from crashpad::Annotation
enum class	Type : uint16_t
	The type of data stored in the annotation. More...

enum class	ConcurrentAccessGuardMode : bool
	Mode used to guard concurrent reads from writes. More...

using	ValueSizeType = uint32_t
	The type used for SetSize().

Static Public Member Functions inherited from crashpad::Annotation
static constexpr Type	UserDefinedType (uint16_t value)
	Creates a user-defined Annotation::Type.

Static Public Attributes inherited from crashpad::Annotation
static constexpr size_t	kNameMaxLength = 256
	The maximum length of an annotation’s name, in bytes. Matches the behavior of Breakpad's SimpleStringDictionary.

static constexpr size_t	kValueMaxSize = 5 * 4096
	The maximum size of an annotation’s value, in bytes.

Protected Member Functions inherited from crashpad::Annotation
constexpr	Annotation (Type type, const char name[], void *value_ptr, ConcurrentAccessGuardMode concurrent_access_guard_mode)
	Constructs a new annotation.

std::atomic< Annotation * > &	link_node ()

Annotation *	GetLinkNode (std::memory_order order=std::memory_order_seq_cst)

const Annotation *	GetLinkNode (std::memory_order order=std::memory_order_seq_cst) const

Detailed Description

template<RingBufferAnnotationCapacity Capacity = internal::kDefaultRingBufferAnnotationCapacity>
class crashpad::RingBufferAnnotation< Capacity >

An Annotation which wraps a LengthDelimitedRingBuffer of up to Capacity bytes in length.

Supports writing variable-length data via Push(). When the ring buffer is full, it will drop old data items in FIFO order until enough space is available for the write.

Supports guarding concurrent reads from writes via ScopedSpinGuard, so writing to this object is thread-safe.

Clients which read this Annotation's memory can optionally invoke TryCreateScopedSpinGuard() on this object to ensure any pending write finishes before the memory is read.

Each item in this ring buffer is delimited by its length encoded in little-endian Base 128 varint encoding.

RingBufferAnnotation uses varint-encoded delimiters to enable zero-copy deserialization of the ringbuffer's contents when storing protobufs inside the ringbuffer, e.g. via google::protobuf::util::ParseDelimitedFromZeroCopyStream() or similar.

See also: https://github.com/protocolbuffers/protobuf/blob/3202b9da88ceb75b65bbabaf4033c95e872f828d/src/google/protobuf/util/delimited_message_util.h#L85; https://github.com/protocolbuffers/protobuf/blob/8bd49dea5e167a389d94b71d24c981d8f9fa0c99/src/google/protobuf/io/zero_copy_stream_impl_lite.h#L68; https://github.com/protocolbuffers/protobuf/blob/8bd49dea5e167a389d94b71d24c981d8f9fa0c99/src/google/protobuf/io/coded_stream.h#L171

To deserialize the items stored in this annotation, use LengthDelimitedRingBufferReader.

Constructor & Destructor Documentation

◆ RingBufferAnnotation()

template<RingBufferAnnotationCapacity Capacity = internal::kDefaultRingBufferAnnotationCapacity>

crashpad::RingBufferAnnotation< Capacity >::RingBufferAnnotation	(	Annotation::Type	type,
		const char	name[] )

inlineconstexpr

Constructs a RingBufferAnnotation.

Parameters

[in]	type	A unique identifier for the type of data in the ring buffer.
[in]	name	The name of the annotation.

Member Function Documentation

◆ Push()

template<RingBufferAnnotationCapacity Capacity = internal::kDefaultRingBufferAnnotationCapacity>

bool crashpad::RingBufferAnnotation< Capacity >::Push	(	const void *const	buffer,
		RingBufferAnnotationCapacity	buffer_length )

inline

Pushes data onto this annotation's ring buffer.

If the ring buffer does not have enough space to store buffer_length bytes of data, old data items are dropped in FIFO order until enough space is available to store the new data.

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

client/ring_buffer_annotation.h

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ RingBufferAnnotation()

Member Function Documentation

◆ Push()