message_filters::Cache< M > Class Template Reference

Stores a time history of messages. More...

#include <cache.h>

Inheritance diagram for message_filters::Cache< M >:

[legend]

List of all members.

Public Types
typedef ros::MessageEvent< M const >	EventType
typedef boost::shared_ptr< M const >	MConstPtr
Public Member Functions
void	add (const EventType &evt)
	Add a message to the cache, and pop off any elements that are too old. This method is registered with a data provider when connectTo is called.
void	add (const MConstPtr &msg)
	Add a message to the cache, and pop off any elements that are too old. This method is registered with a data provider when connectTo is called.
	Cache (unsigned int cache_size=1)
template<class F >
	Cache (F &f, unsigned int cache_size=1)
template<class F >
void	connectInput (F &f)
MConstPtr	getElemAfterTime (const ros::Time &time) const
	Grab the oldest element that occurs right after the specified time.
MConstPtr	getElemBeforeTime (const ros::Time &time) const
	Grab the newest element that occurs right before the specified time.
std::vector< MConstPtr >	getInterval (const ros::Time &start, const ros::Time &end) const
	Receive a vector of messages that occur between a start and end time (inclusive).
ros::Time	getLatestTime () const
	Returns the timestamp associated with the newest packet cache.
ros::Time	getOldestTime () const
	Returns the timestamp associated with the oldest packet cache.
std::vector< MConstPtr >	getSurroundingInterval (const ros::Time &start, const ros::Time &end) const
	Retrieve the smallest interval of messages that surrounds an interval from start to end.
void	setCacheSize (unsigned int cache_size)
	~Cache ()
Private Member Functions
void	callback (const EventType &evt)
Private Attributes
std::deque< EventType >	cache_
	Cache for the messages.
boost::mutex	cache_lock_
	Lock for cache_.
unsigned int	cache_size_
	Maximum number of elements allowed in the cache.
Connection	incoming_connection_

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Detailed Description

template<class M>
class message_filters::Cache< M >

Stores a time history of messages.

Given a stream of messages, the most recent N messages are cached in a ring buffer, from which time intervals of the cache can then be retrieved by the client.

Cache immediately passes messages through to its output connections.

CONNECTIONS

Cache's input and output connections are both of the same signature as roscpp subscription callbacks, ie.

void callback(const boost::shared_ptr<M const>&);

Definition at line 64 of file cache.h.

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Member Typedef Documentation

template<class M>

typedef ros::MessageEvent<M const> message_filters::Cache< M >::EventType

Reimplemented from message_filters::SimpleFilter< M >.

Definition at line 49 of file cache.h.

template<class M>

typedef boost::shared_ptr<M const> message_filters::Cache< M >::MConstPtr

Reimplemented from message_filters::SimpleFilter< M >.

Definition at line 48 of file cache.h.

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Constructor & Destructor Documentation

template<class M>

template<class F >

message_filters::Cache< M >::Cache	(	F &	f,
		unsigned int	cache_size = 1
	)			[inline]

Definition at line 52 of file cache.h.

template<class M>

message_filters::Cache< M >::Cache

(

unsigned int

cache_size = 1

)

[inline]

Initializes a Message Cache without specifying a parent filter. This implies that in order to populate the cache, the user then has to call add themselves, or connectInput() is called later

Definition at line 63 of file cache.h.

template<class M>

message_filters::Cache< M >::~Cache

(

)

[inline]

Definition at line 74 of file cache.h.

---

Member Function Documentation

template<class M>

void message_filters::Cache< M >::add

(

const EventType &

evt

)

[inline]

Add a message to the cache, and pop off any elements that are too old. This method is registered with a data provider when connectTo is called.

Definition at line 107 of file cache.h.

template<class M>

void message_filters::Cache< M >::add

(

const MConstPtr &

msg

)

[inline]

Add a message to the cache, and pop off any elements that are too old. This method is registered with a data provider when connectTo is called.

Definition at line 98 of file cache.h.

template<class M>

void message_filters::Cache< M >::callback

(

const EventType &

evt

)

[inline, private]

Definition at line 307 of file cache.h.

template<class M>

template<class F >

void message_filters::Cache< M >::connectInput

(

F &

f

)

[inline]

Definition at line 69 of file cache.h.

template<class M>

MConstPtr message_filters::Cache< M >::getElemAfterTime

(

const ros::Time &

time

)

const [inline]

Grab the oldest element that occurs right after the specified time.

Parameters:

time

Time that must occur right before the returned elem

Returns:

shared_ptr to the oldest elem that occurs after 'time'. NULL if doesn't exist

Definition at line 246 of file cache.h.

template<class M>

MConstPtr message_filters::Cache< M >::getElemBeforeTime

(

const ros::Time &

time

)

const [inline]

Grab the newest element that occurs right before the specified time.

Parameters:

time

Time that must occur right after the returned elem

Returns:

shared_ptr to the newest elem that occurs before 'time'. NULL if doesn't exist

Definition at line 218 of file cache.h.

template<class M>

std::vector<MConstPtr> message_filters::Cache< M >::getInterval	(	const ros::Time &	start,
		const ros::Time &	end
	)			const [inline]

Receive a vector of messages that occur between a start and end time (inclusive).

This call is non-blocking, and only aggregates messages it has already received. It will not wait for messages have not yet been received, but occur in the interval.

Parameters:

	start	The start of the requested interval
	end	The end of the requested interval

Definition at line 145 of file cache.h.

template<class M>

ros::Time message_filters::Cache< M >::getLatestTime

(

)

const [inline]

Returns the timestamp associated with the newest packet cache.

Definition at line 274 of file cache.h.

template<class M>

ros::Time message_filters::Cache< M >::getOldestTime

(

)

const [inline]

Returns the timestamp associated with the oldest packet cache.

Definition at line 291 of file cache.h.

template<class M>

std::vector<MConstPtr> message_filters::Cache< M >::getSurroundingInterval	(	const ros::Time &	start,
		const ros::Time &	end
	)			const [inline]

Retrieve the smallest interval of messages that surrounds an interval from start to end.

If the messages in the cache do not surround (start,end), then this will return the interval that gets closest to surrounding (start,end)

Definition at line 184 of file cache.h.

template<class M>

void message_filters::Cache< M >::setCacheSize

(

unsigned int

cache_size

)

[inline]

Set the size of the cache.

Parameters:

cache_size

The new size the cache should be. Must be > 0

Definition at line 83 of file cache.h.

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Member Data Documentation

template<class M>

std::deque<EventType> message_filters::Cache< M >::cache_ [private]

Cache for the messages.

Definition at line 313 of file cache.h.

template<class M>

boost::mutex message_filters::Cache< M >::cache_lock_ [mutable, private]

Lock for cache_.

Definition at line 312 of file cache.h.

template<class M>

unsigned int message_filters::Cache< M >::cache_size_ [private]

Maximum number of elements allowed in the cache.

Definition at line 314 of file cache.h.

template<class M>

Connection message_filters::Cache< M >::incoming_connection_ [private]

Definition at line 316 of file cache.h.

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

• cache.h