Log Class Reference

Interface to a log file. More...

#include <Log.hh>

Public Member Functions
	Log ()
	constructor More...
	Log (Log &&_old)
	move constructor More...
	~Log ()
	destructor More...
const log::Descriptor *	Descriptor () const
	Get a Descriptor for this log. The Descriptor will be generated the first time that this function is called after a new file has been opened. More...
std::chrono::nanoseconds	EndTime () const
	Get end time of the log, or in other words the time of the last message found in the log. More...
std::string	Filename () const
	Get the name of the log file. More...
bool	InsertMessage (const std::chrono::nanoseconds &_time, const std::string &_topic, const std::string &_type, const void *_data, std::size_t _len)
	Insert a message into the log file. More...
bool	Open (const std::string &_file, std::ios_base::openmode _mode=std::ios_base::in)
	Open a log file. More...
Batch	QueryMessages (const QueryOptions &_options=AllTopics())
	Get messages according to the specified options. By default, it will query all messages over the entire time range of the log. More...
std::chrono::nanoseconds	StartTime () const
	Get start time of the log, or in other words the time of the first message found in the log. More...
bool	Valid () const
	Indicate if a log has been successfully opened. More...
std::string	Version () const
	Get the schema version of the opened log. More...

Detailed Description

Interface to a log file.

Constructor & Destructor Documentation

Log() [1/2]

Log

(

)

constructor

Log() [2/2]

Log

(

Log &&

_old

)

move constructor

Parameters

[in]

_old

the instance being moved into this one

~Log()

~Log

(

)

destructor

Member Function Documentation

Descriptor()

const log::Descriptor* Descriptor

(

)

const

Get a Descriptor for this log. The Descriptor will be generated the first time that this function is called after a new file has been opened.

Returns

A Descriptor for this log, if a log file is currently loaded. If no log file is loaded, this returns a nullptr.

EndTime()

std::chrono::nanoseconds EndTime

(

)

const

Get end time of the log, or in other words the time of the last message found in the log.

Returns

end time of the log, or zero if the log is not valid or if data retrieval failed.

Filename()

std::string Filename

(

)

const

Get the name of the log file.

Returns

The name of the log file, or an empty string if Open has not been successfully called.

InsertMessage()

bool InsertMessage	(	const std::chrono::nanoseconds &	_time,
		const std::string &	_topic,
		const std::string &	_type,
		const void *	_data,
		std::size_t	_len
	)

Insert a message into the log file.

Parameters

[in]	_time	Time the message was received (ns since Unix epoch)
[in]	_topic	Name of the topic the message was on
[in]	_type	Name of the message type
[in]	_data	pointer to a buffer containing the message data
[in]	_len	number of bytes of data

Returns

true if the message was successfully inserted

Open()

bool Open	(	const std::string &	_file,
		std::ios_base::openmode	_mode = std::ios_base::in
	)

Open a log file.

Parameters

[in]	_file	path to log file
[in]	_mode	flag indicating read only or read/write Can use (in or out)

Returns

True if the log file was successfully opened, false otherwise.

QueryMessages()

Batch QueryMessages

(

const QueryOptions &

_options = AllTopics()

)

Get messages according to the specified options. By default, it will query all messages over the entire time range of the log.

Parameters

[in]

_options

A QueryOptions type to indicate what kind of messages you would like to query.

Returns

A Batch which matches the requested QueryOptions.

StartTime()

std::chrono::nanoseconds StartTime

(

)

const

Get start time of the log, or in other words the time of the first message found in the log.

Returns

start time of the log, or zero if the log is not valid or if data retrieval failed.

Valid()

bool Valid

(

)

const

Indicate if a log has been successfully opened.

Returns

true if a log is open

Version()

std::string Version

(

)

const

Get the schema version of the opened log.

Returns

the current version of the schema in the log file

empty string if the log has not been opened

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

• gz/transport/log/Log.hh