A data log background writer that periodically flushes the data log on a background thread. More...

#include <wpi/DataLogBackgroundWriter.h>

Inheritance diagram for wpi::log::DataLogBackgroundWriter:

Public Member Functions
	DataLogBackgroundWriter (std::string_view dir="", std::string_view filename="", double period=0.25, std::string_view extraHeader="")
	Construct a new Data Log.

	DataLogBackgroundWriter (wpi::Logger &msglog, std::string_view dir="", std::string_view filename="", double period=0.25, std::string_view extraHeader="")
	Construct a new Data Log.

	DataLogBackgroundWriter (std::function< void(std::span< const uint8_t > data)> write, double period=0.25, std::string_view extraHeader="")
	Construct a new Data Log that passes its output to the provided function rather than a file.

	DataLogBackgroundWriter (wpi::Logger &msglog, std::function< void(std::span< const uint8_t > data)> write, double period=0.25, std::string_view extraHeader="")
	Construct a new Data Log that passes its output to the provided function rather than a file.

	~DataLogBackgroundWriter () final

	DataLogBackgroundWriter (const DataLogBackgroundWriter &)=delete

DataLogBackgroundWriter &	operator= (const DataLogBackgroundWriter &)=delete

	DataLogBackgroundWriter (DataLogBackgroundWriter &&)=delete

DataLogBackgroundWriter &	operator= (const DataLogBackgroundWriter &&)=delete

void	SetFilename (std::string_view filename)
	Change log filename.

void	Flush () final
	Explicitly flushes the log data to disk.

void	Pause () final
	Pauses appending of data records to the log.

void	Resume () final
	Resumes appending of data records to the log.

void	Stop () final
	Stops appending all records to the log, and closes the log file.

Public Member Functions inherited from wpi::log::DataLog
virtual	~DataLog ()=default

	DataLog (const DataLog &)=delete

DataLog &	operator= (const DataLog &)=delete

	DataLog (DataLog &&)=delete

DataLog &	operator= (const DataLog &&)=delete

bool	HasSchema (std::string_view name) const
	Returns whether there is a data schema already registered with the given name.

void	AddSchema (std::string_view name, std::string_view type, std::span< const uint8_t > schema, int64_t timestamp=0)
	Registers a data schema.

void	AddSchema (std::string_view name, std::string_view type, std::string_view schema, int64_t timestamp=0)
	Registers a data schema.

template<ProtobufSerializable T>
void	AddProtobufSchema (ProtobufMessage< T > &msg, int64_t timestamp=0)
	Registers a protobuf schema.

template<typename T , typename... I> requires StructSerializable<T, I...>
void	AddStructSchema (const I &... info, int64_t timestamp=0)
	Registers a struct schema.

int	Start (std::string_view name, std::string_view type, std::string_view metadata={}, int64_t timestamp=0)
	Start an entry.

void	Finish (int entry, int64_t timestamp=0)
	Finish an entry.

void	SetMetadata (int entry, std::string_view metadata, int64_t timestamp=0)
	Updates the metadata for an entry.

void	AppendRaw (int entry, std::span< const uint8_t > data, int64_t timestamp)
	Appends a raw record to the log.

void	AppendRaw2 (int entry, std::span< const std::span< const uint8_t > > data, int64_t timestamp)
	Appends a raw record to the log.

void	AppendBoolean (int entry, bool value, int64_t timestamp)
	Appends a boolean record to the log.

void	AppendInteger (int entry, int64_t value, int64_t timestamp)
	Appends an integer record to the log.

void	AppendFloat (int entry, float value, int64_t timestamp)
	Appends a float record to the log.

void	AppendDouble (int entry, double value, int64_t timestamp)
	Appends a double record to the log.

void	AppendString (int entry, std::string_view value, int64_t timestamp)
	Appends a string record to the log.

void	AppendBooleanArray (int entry, std::span< const bool > arr, int64_t timestamp)
	Appends a boolean array record to the log.

void	AppendBooleanArray (int entry, std::span< const int > arr, int64_t timestamp)
	Appends a boolean array record to the log.

void	AppendBooleanArray (int entry, std::span< const uint8_t > arr, int64_t timestamp)
	Appends a boolean array record to the log.

void	AppendIntegerArray (int entry, std::span< const int64_t > arr, int64_t timestamp)
	Appends an integer array record to the log.

void	AppendFloatArray (int entry, std::span< const float > arr, int64_t timestamp)
	Appends a float array record to the log.

void	AppendDoubleArray (int entry, std::span< const double > arr, int64_t timestamp)
	Appends a double array record to the log.

void	AppendStringArray (int entry, std::span< const std::string > arr, int64_t timestamp)
	Appends a string array record to the log.

void	AppendStringArray (int entry, std::span< const std::string_view > arr, int64_t timestamp)
	Appends a string array record to the log.

void	AppendStringArray (int entry, std::span< const struct WPI_String > arr, int64_t timestamp)
	Appends a string array record to the log.

Additional Inherited Members
Protected Member Functions inherited from wpi::log::DataLog
	DataLog (wpi::Logger &msglog, std::string_view extraHeader="")
	Constructs the log.

void	StartFile ()
	Starts the log.

void	FlushBufs (std::vector< Buffer > *writeBufs)
	Provides complete set of all buffers that need to be written.

void	ReleaseBufs (std::vector< Buffer > *bufs)
	Releases memory for a set of buffers back to the internal buffer pool.

Protected Attributes inherited from wpi::log::DataLog
wpi::Logger &	m_msglog

Static Protected Attributes inherited from wpi::log::DataLog
static constexpr size_t	kBlockSize = 16 * 1024

static wpi::Logger	s_defaultMessageLog

Detailed Description

A data log background writer that periodically flushes the data log on a background thread.

The data log file is created immediately upon construction with a temporary filename. The file may be renamed at any time using the SetFilename() function.

The lifetime of this object must be longer than any data log entry objects that refer to it.

The data log is periodically flushed to disk. It can also be explicitly flushed to disk by using the Flush() function. This operation is, however, non-blocking.

Constructor & Destructor Documentation

◆ DataLogBackgroundWriter() [1/6]

wpi::log::DataLogBackgroundWriter::DataLogBackgroundWriter	(	std::string_view	dir = "",
		std::string_view	filename = "",
		double	period = 0.25,
		std::string_view	extraHeader = "" )

explicit

Construct a new Data Log.

The log will be initially created with a temporary filename.

Parameters

dir	directory to store the log
filename	filename to use; if none provided, a random filename is generated of the form "wpilog_{}.wpilog"
period	time between automatic flushes to disk, in seconds; this is a time/storage tradeoff
extraHeader	extra header data

◆ DataLogBackgroundWriter() [2/6]

wpi::log::DataLogBackgroundWriter::DataLogBackgroundWriter	(	wpi::Logger &	msglog,
		std::string_view	dir = "",
		std::string_view	filename = "",
		double	period = 0.25,
		std::string_view	extraHeader = "" )

explicit

Construct a new Data Log.

The log will be initially created with a temporary filename.

Parameters

msglog	message logger (will be called from separate thread)
dir	directory to store the log
filename	filename to use; if none provided, a random filename is generated of the form "wpilog_{}.wpilog"
period	time between automatic flushes to disk, in seconds; this is a time/storage tradeoff
extraHeader	extra header data

◆ DataLogBackgroundWriter() [3/6]

wpi::log::DataLogBackgroundWriter::DataLogBackgroundWriter	(	std::function< void(std::span< const uint8_t > data)>	write,
		double	period = 0.25,
		std::string_view	extraHeader = "" )

explicit

Construct a new Data Log that passes its output to the provided function rather than a file.

The write function will be called on a separate background thread and may block. The write function is called with an empty data array when the thread is terminating.

Parameters

write	write function
period	time between automatic calls to write, in seconds; this is a time/storage tradeoff
extraHeader	extra header data

◆ DataLogBackgroundWriter() [4/6]

wpi::log::DataLogBackgroundWriter::DataLogBackgroundWriter	(	wpi::Logger &	msglog,
		std::function< void(std::span< const uint8_t > data)>	write,
		double	period = 0.25,
		std::string_view	extraHeader = "" )

explicit

Construct a new Data Log that passes its output to the provided function rather than a file.

The write function will be called on a separate background thread and may block. The write function is called with an empty data array when the thread is terminating.

Parameters

msglog	message logger (will be called from separate thread)
write	write function
period	time between automatic calls to write, in seconds; this is a time/storage tradeoff
extraHeader	extra header data

◆ ~DataLogBackgroundWriter()

wpi::log::DataLogBackgroundWriter::~DataLogBackgroundWriter ( )

final

◆ DataLogBackgroundWriter() [5/6]

wpi::log::DataLogBackgroundWriter::DataLogBackgroundWriter ( const DataLogBackgroundWriter & )

delete

◆ DataLogBackgroundWriter() [6/6]

wpi::log::DataLogBackgroundWriter::DataLogBackgroundWriter ( DataLogBackgroundWriter && )

delete

Member Function Documentation

◆ Flush()

void wpi::log::DataLogBackgroundWriter::Flush ( )

finalvirtual

Explicitly flushes the log data to disk.

Implements wpi::log::DataLog.

◆ operator=() [1/2]

DataLogBackgroundWriter & wpi::log::DataLogBackgroundWriter::operator= ( const DataLogBackgroundWriter && )

delete

◆ operator=() [2/2]

DataLogBackgroundWriter & wpi::log::DataLogBackgroundWriter::operator= ( const DataLogBackgroundWriter & )

delete

◆ Pause()

void wpi::log::DataLogBackgroundWriter::Pause ( )

finalvirtual

Pauses appending of data records to the log.

While paused, no data records are saved (e.g. AppendX is a no-op). Has no effect on entry starts / finishes / metadata changes.

Reimplemented from wpi::log::DataLog.

◆ Resume()

void wpi::log::DataLogBackgroundWriter::Resume ( )

finalvirtual

Resumes appending of data records to the log.

If called after Stop(), opens a new file (with random name if SetFilename was not called after Stop()) and appends Start records and schema data values for all previously started entries and schemas.

Reimplemented from wpi::log::DataLog.

◆ SetFilename()

void wpi::log::DataLogBackgroundWriter::SetFilename ( std::string_view filename )

Change log filename.

Parameters

filename filename

◆ Stop()

void wpi::log::DataLogBackgroundWriter::Stop ( )

finalvirtual

Stops appending all records to the log, and closes the log file.

Reimplemented from wpi::log::DataLog.

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

wpi/DataLogBackgroundWriter.h

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ DataLogBackgroundWriter() [1/6]

◆ DataLogBackgroundWriter() [2/6]

◆ DataLogBackgroundWriter() [3/6]

◆ DataLogBackgroundWriter() [4/6]

◆ ~DataLogBackgroundWriter()

◆ DataLogBackgroundWriter() [5/6]

◆ DataLogBackgroundWriter() [6/6]

Member Function Documentation

◆ Flush()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ Pause()

◆ Resume()

◆ SetFilename()

◆ Stop()