Inheritance diagram for org.wpilib.datalog.DataLog:

Public Member Functions
void	flush ()
void	pause ()
void	resume ()
void	stop ()
boolean	hasSchema (String name)
void	addSchema (String name, String type, byte[] schema, long timestamp)
void	addSchema (String name, String type, byte[] schema)
void	addSchema (String name, String type, String schema, long timestamp)
void	addSchema (String name, String type, String schema)
void	addSchema (Protobuf<?, ?> proto, long timestamp)
void	addSchema (Protobuf<?, ?> proto)
void	addSchema (Struct<?> struct, long timestamp)
void	addSchema (Struct<?> struct)
int	start (String name, String type, String metadata, long timestamp)
int	start (String name, String type, String metadata)
int	start (String name, String type)
void	finish (int entry, long timestamp)
void	finish (int entry)
void	setMetadata (int entry, String metadata, long timestamp)
void	setMetadata (int entry, String metadata)
void	close ()
void	appendRaw (int entry, byte[] data, long timestamp)
void	appendRaw (int entry, byte[] data, int start, int len, long timestamp)
void	appendRaw (int entry, ByteBuffer data, long timestamp)
void	appendRaw (int entry, ByteBuffer data, int start, int len, long timestamp)
void	appendBoolean (int entry, boolean value, long timestamp)
void	appendInteger (int entry, long value, long timestamp)
void	appendFloat (int entry, float value, long timestamp)
void	appendDouble (int entry, double value, long timestamp)
void	appendString (int entry, String value, long timestamp)
void	appendBooleanArray (int entry, boolean[] arr, long timestamp)
void	appendIntegerArray (int entry, long[] arr, long timestamp)
void	appendFloatArray (int entry, float[] arr, long timestamp)
void	appendDoubleArray (int entry, double[] arr, long timestamp)
void	appendStringArray (int entry, String[] arr, long timestamp)
long	getImpl ()

Protected Member Functions
	DataLog (long impl)

Protected Attributes
long	m_impl

Detailed Description

A data log for high-speed writing of data values.

The finish() function is needed only to indicate in the log that a particular entry is no longer being used (it releases the name to ID mapping). The finish() function is not required to be called for data to be flushed to disk; entries in the log are written as append() calls are being made. In fact, finish() does not need to be called at all.

DataLog calls are thread safe. DataLog uses a typical multiple-supplier, single-consumer setup. Writes to the log are atomic, but there is no guaranteed order in the log when multiple threads are writing to it; whichever thread grabs the write mutex first will get written first. For this reason (as well as the fact that timestamps can be set to arbitrary values), records in the log are not guaranteed to be sorted by timestamp.

Definition at line 30 of file DataLog.java.

Constructor & Destructor Documentation

◆ DataLog()

org.wpilib.datalog.DataLog.DataLog ( long impl )

protected

Constructs.

Parameters

impl	implementation handle

Definition at line 36 of file DataLog.java.

Member Function Documentation

◆ addSchema() [1/8]

void org.wpilib.datalog.DataLog.addSchema ( Protobuf<?, ?> proto )

Registers a protobuf schema. Duplicate calls to this function with the same name are silently ignored.

Parameters

proto protobuf serialization object

Definition at line 162 of file DataLog.java.

◆ addSchema() [2/8]

void org.wpilib.datalog.DataLog.addSchema	(	Protobuf<?, ?>	proto,
		long	timestamp )

Registers a protobuf schema. Duplicate calls to this function with the same name are silently ignored.

Parameters

proto	protobuf serialization object
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 148 of file DataLog.java.

◆ addSchema() [3/8]

void org.wpilib.datalog.DataLog.addSchema	(	String	name,
		String	type,
		byte[]	schema )

Registers a data schema. Data schemas provide information for how a certain data type string can be decoded. The type string of a data schema indicates the type of the schema itself (e.g. "protobuf" for protobuf schemas, "struct" for struct schemas, etc). In the data log, schemas are saved just like normal records, with the name being generated from the provided name: "/.schema/name". Duplicate calls to this function with the same name are silently ignored.

Parameters

name	Name (the string passed as the data type for records using this schema)
type	Type of schema (e.g. "protobuf", "struct", etc)
schema	Schema data

Definition at line 103 of file DataLog.java.

◆ addSchema() [4/8]

void org.wpilib.datalog.DataLog.addSchema	(	String	name,
		String	type,
		byte[]	schema,
		long	timestamp )

Registers a data schema. Data schemas provide information for how a certain data type string can be decoded. The type string of a data schema indicates the type of the schema itself (e.g. "protobuf" for protobuf schemas, "struct" for struct schemas, etc). In the data log, schemas are saved just like normal records, with the name being generated from the provided name: "/.schema/name". Duplicate calls to this function with the same name are silently ignored.

Parameters

name	Name (the string passed as the data type for records using this schema)
type	Type of schema (e.g. "protobuf", "struct", etc)
schema	Schema data
timestamp	Time stamp in nanoseconds (may be 0 to indicate now)

Definition at line 85 of file DataLog.java.

◆ addSchema() [5/8]

void org.wpilib.datalog.DataLog.addSchema	(	String	name,
		String	type,
		String	schema )

Registers a data schema. Data schemas provide information for how a certain data type string can be decoded. The type string of a data schema indicates the type of the schema itself (e.g. "protobuf" for protobuf schemas, "struct" for struct schemas, etc). In the data log, schemas are saved just like normal records, with the name being generated from the provided name: "/.schema/name". Duplicate calls to this function with the same name are silently ignored.

Parameters

name	Name (the string passed as the data type for records using this schema)
type	Type of schema (e.g. "protobuf", "struct", etc)
schema	Schema data

Definition at line 137 of file DataLog.java.

◆ addSchema() [6/8]

void org.wpilib.datalog.DataLog.addSchema	(	String	name,
		String	type,
		String	schema,
		long	timestamp )

Registers a data schema. Data schemas provide information for how a certain data type string can be decoded. The type string of a data schema indicates the type of the schema itself (e.g. "protobuf" for protobuf schemas, "struct" for struct schemas, etc). In the data log, schemas are saved just like normal records, with the name being generated from the provided name: "/.schema/name". Duplicate calls to this function with the same name are silently ignored.

Parameters

name	Name (the string passed as the data type for records using this schema)
type	Type of schema (e.g. "protobuf", "struct", etc)
schema	Schema data
timestamp	Time stamp in nanoseconds (may be 0 to indicate now)

Definition at line 119 of file DataLog.java.

◆ addSchema() [7/8]

void org.wpilib.datalog.DataLog.addSchema ( Struct<?> struct )

Registers a struct schema. Duplicate calls to this function with the same name are silently ignored.

Parameters

struct struct serialization object

Definition at line 183 of file DataLog.java.

◆ addSchema() [8/8]

void org.wpilib.datalog.DataLog.addSchema	(	Struct<?>	struct,
		long	timestamp )

Registers a struct schema. Duplicate calls to this function with the same name are silently ignored.

Parameters

struct	struct serialization object
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 173 of file DataLog.java.

◆ appendBoolean()

void org.wpilib.datalog.DataLog.appendBoolean	(	int	entry,
		boolean	value,
		long	timestamp )

Appends a boolean record to the log.

Parameters

entry	Entry index, as returned by start()
value	Boolean value to record
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 334 of file DataLog.java.

◆ appendBooleanArray()

void org.wpilib.datalog.DataLog.appendBooleanArray	(	int	entry,
		boolean[]	arr,
		long	timestamp )

Appends a boolean array record to the log.

Parameters

entry	Entry index, as returned by start()
arr	Boolean array to record
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 389 of file DataLog.java.

◆ appendDouble()

void org.wpilib.datalog.DataLog.appendDouble	(	int	entry,
		double	value,
		long	timestamp )

Appends a double record to the log.

Parameters

entry	Entry index, as returned by start()
value	Double value to record
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 367 of file DataLog.java.

◆ appendDoubleArray()

void org.wpilib.datalog.DataLog.appendDoubleArray	(	int	entry,
		double[]	arr,
		long	timestamp )

Appends a double array record to the log.

Parameters

entry	Entry index, as returned by start()
arr	Double array to record
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 422 of file DataLog.java.

◆ appendFloat()

void org.wpilib.datalog.DataLog.appendFloat	(	int	entry,
		float	value,
		long	timestamp )

Appends a float record to the log.

Parameters

entry	Entry index, as returned by start()
value	Float value to record
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 356 of file DataLog.java.

◆ appendFloatArray()

void org.wpilib.datalog.DataLog.appendFloatArray	(	int	entry,
		float[]	arr,
		long	timestamp )

Appends a float array record to the log.

Parameters

entry	Entry index, as returned by start()
arr	Float array to record
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 411 of file DataLog.java.

◆ appendInteger()

void org.wpilib.datalog.DataLog.appendInteger	(	int	entry,
		long	value,
		long	timestamp )

Appends an integer record to the log.

Parameters

entry	Entry index, as returned by start()
value	Integer value to record
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 345 of file DataLog.java.

◆ appendIntegerArray()

void org.wpilib.datalog.DataLog.appendIntegerArray	(	int	entry,
		long[]	arr,
		long	timestamp )

Appends an integer array record to the log.

Parameters

entry	Entry index, as returned by start()
arr	Integer array to record
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 400 of file DataLog.java.

◆ appendRaw() [1/4]

void org.wpilib.datalog.DataLog.appendRaw	(	int	entry,
		byte[]	data,
		int	start,
		int	len,
		long	timestamp )

Appends a record to the log.

Parameters

entry	Entry index, as returned by start()
data	Byte array to record
start	Start position of data (in byte array)
len	Length of data (must be less than or equal to data.length - start)
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 298 of file DataLog.java.

◆ appendRaw() [2/4]

void org.wpilib.datalog.DataLog.appendRaw	(	int	entry,
		byte[]	data,
		long	timestamp )

Appends a raw record to the log.

Parameters

entry	Entry index, as returned by start()
data	Byte array to record; will send entire array contents
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 285 of file DataLog.java.

◆ appendRaw() [3/4]

void org.wpilib.datalog.DataLog.appendRaw	(	int	entry,
		ByteBuffer	data,
		int	start,
		int	len,
		long	timestamp )

Appends a record to the log.

Parameters

entry	Entry index, as returned by start()
data	Buffer to record
start	Start position of data (in buffer)
len	Length of data (must be less than or equal to data.capacity() - start)
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 323 of file DataLog.java.

◆ appendRaw() [4/4]

void org.wpilib.datalog.DataLog.appendRaw	(	int	entry,
		ByteBuffer	data,
		long	timestamp )

Appends a record to the log.

Parameters

entry	Entry index, as returned by start()
data	Buffer to record; will send from data.position() to data.limit()
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 309 of file DataLog.java.

◆ appendString()

void org.wpilib.datalog.DataLog.appendString	(	int	entry,
		String	value,
		long	timestamp )

Appends a string record to the log.

Parameters

entry	Entry index, as returned by start()
value	String value to record
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 378 of file DataLog.java.

◆ appendStringArray()

void org.wpilib.datalog.DataLog.appendStringArray	(	int	entry,
		String[]	arr,
		long	timestamp )

Appends a string array record to the log.

Parameters

entry	Entry index, as returned by start()
arr	String array to record
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 433 of file DataLog.java.

◆ close()

void org.wpilib.datalog.DataLog.close ( )

Definition at line 273 of file DataLog.java.

◆ finish() [1/2]

void org.wpilib.datalog.DataLog.finish ( int entry )

Finish an entry.

Parameters

entry Entry index

Definition at line 247 of file DataLog.java.

◆ finish() [2/2]

void org.wpilib.datalog.DataLog.finish	(	int	entry,
		long	timestamp )

Finish an entry.

Parameters

entry	Entry index
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 238 of file DataLog.java.

◆ flush()

void org.wpilib.datalog.DataLog.flush ( )

Explicitly flushes the log data to disk.

Definition at line 41 of file DataLog.java.

◆ getImpl()

long org.wpilib.datalog.DataLog.getImpl ( )

Gets the JNI implementation handle.

Returns: data log handle.

Definition at line 442 of file DataLog.java.

◆ hasSchema()

boolean org.wpilib.datalog.DataLog.hasSchema ( String name )

Returns whether there is a data schema already registered with the given name.

Parameters

name	Name (the string passed as the data type for records using this schema)

Returns: True if schema already registered

Definition at line 69 of file DataLog.java.

◆ pause()

void org.wpilib.datalog.DataLog.pause ( )

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.

Definition at line 49 of file DataLog.java.

◆ resume()

void org.wpilib.datalog.DataLog.resume ( )

Resumes appending of data records to the log.

Reimplemented in org.wpilib.datalog.DataLogBackgroundWriter.

Definition at line 54 of file DataLog.java.

◆ setMetadata() [1/2]

void org.wpilib.datalog.DataLog.setMetadata	(	int	entry,
		String	metadata )

Updates the metadata for an entry.

Parameters

entry	Entry index
metadata	New metadata for the entry

Definition at line 268 of file DataLog.java.

◆ setMetadata() [2/2]

void org.wpilib.datalog.DataLog.setMetadata	(	int	entry,
		String	metadata,
		long	timestamp )

Updates the metadata for an entry.

Parameters

entry	Entry index
metadata	New metadata for the entry
timestamp	Time stamp in nanoseconds (0 to indicate now)

Definition at line 258 of file DataLog.java.

◆ start() [1/3]

int org.wpilib.datalog.DataLog.start	(	String	name,
		String	type )

Start an entry. Duplicate names are allowed (with the same type), and result in the same index being returned (start/finish are reference counted). A duplicate name with a different type will result in an error message being printed to the console and 0 being returned (which will be ignored by the append functions).

Parameters

name	Name
type	Data type

Returns: Entry index

Definition at line 228 of file DataLog.java.

◆ start() [2/3]

int org.wpilib.datalog.DataLog.start	(	String	name,
		String	type,
		String	metadata )

Start an entry. Duplicate names are allowed (with the same type), and result in the same index being returned (start/finish are reference counted). A duplicate name with a different type will result in an error message being printed to the console and 0 being returned (which will be ignored by the append functions).

Parameters

name	Name
type	Data type
metadata	Initial metadata (e.g. data properties)

Returns: Entry index

Definition at line 214 of file DataLog.java.

◆ start() [3/3]

int org.wpilib.datalog.DataLog.start	(	String	name,
		String	type,
		String	metadata,
		long	timestamp )

Start an entry. Duplicate names are allowed (with the same type), and result in the same index being returned (start/finish are reference counted). A duplicate name with a different type will result in an error message being printed to the console and 0 being returned (which will be ignored by the append functions).

Parameters

name	Name
type	Data type
metadata	Initial metadata (e.g. data properties)
timestamp	Time stamp in nanoseconds (0 to indicate now)

Returns: Entry index

Definition at line 199 of file DataLog.java.

◆ stop()

void org.wpilib.datalog.DataLog.stop ( )

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

Definition at line 59 of file DataLog.java.

Member Data Documentation

◆ m_impl

long org.wpilib.datalog.DataLog.m_impl

protected

Implementation handle.

Definition at line 462 of file DataLog.java.

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

org/wpilib/datalog/DataLog.java

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ DataLog()

Member Function Documentation

◆ addSchema() [1/8]

◆ addSchema() [2/8]

◆ addSchema() [3/8]

◆ addSchema() [4/8]

◆ addSchema() [5/8]

◆ addSchema() [6/8]

◆ addSchema() [7/8]

◆ addSchema() [8/8]

◆ appendBoolean()

◆ appendBooleanArray()

◆ appendDouble()

◆ appendDoubleArray()

◆ appendFloat()

◆ appendFloatArray()

◆ appendInteger()

◆ appendIntegerArray()

◆ appendRaw() [1/4]

◆ appendRaw() [2/4]

◆ appendRaw() [3/4]

◆ appendRaw() [4/4]

◆ appendString()

◆ appendStringArray()

◆ close()

◆ finish() [1/2]

◆ finish() [2/2]

◆ flush()

◆ getImpl()

◆ hasSchema()

◆ pause()

◆ resume()

◆ setMetadata() [1/2]

◆ setMetadata() [2/2]

◆ start() [1/3]

◆ start() [2/3]

◆ start() [3/3]

◆ stop()

Member Data Documentation

◆ m_impl