Detailed Description

Filesystem modification notifier.

This is a thin wrapper around inotify(see http://man7.org/linux/man-pages/man7/inotify.7.html), which is the de-facto light-weight filesystem modification watch interface in Linux and can be used to log filesystem activities, reload configurations, etc.

The wrapper provides a buffered read of events, and RAII handling of watches themselves.

Note: Note that this is an experimental feature, and thus any tweaks that are backward incompatible can be made before finally freezing it. Besides, the impl currently does not (yet) handle re-writing watches.

#include <seastar/core/fsnotify.hh>

Classes
struct	event
	A wrapper around inotify_event. More...

class	watch
	Simple RAII wrapper around a fsnotifier::watch_token. More...

Public Types
enum class	flags : uint32_t { access = IN_ACCESS , attrib = IN_ATTRIB , close_write = IN_CLOSE_WRITE , close_nowrite = IN_CLOSE_NOWRITE , create_child = IN_CREATE , delete_child = IN_DELETE , delete_self = IN_DELETE_SELF , modify = IN_MODIFY , move_self = IN_MOVE_SELF , move_from = IN_MOVED_FROM , move_to = IN_MOVED_TO , open = IN_OPEN , close = IN_CLOSE , move = IN_MOVE , oneshot = IN_ONESHOT , ignored = IN_IGNORED , onlydir = IN_ONLYDIR }
	Flags of events supported by FileSystem Notifier. More...

using	watch_token = int32_t
	Token of a watch point.

using	sequence_no = uint32_t
	Unique sequence number of associating related events. More...

Public Member Functions
	fsnotifier (fsnotifier &&)

fsnotifier &	operator= (fsnotifier &&)

future< watch >	create_watch (const sstring &path, flags mask)
	Monitor events specified in mask for the give path. More...

future< std::vector< event > >	wait () const

void	shutdown ()

bool	active () const
	Check if the notifier is activated.

	operator bool () const
	Equivalent to active().

Class Documentation

◆ seastar::experimental::fsnotifier::event

struct seastar::experimental::fsnotifier::event

Class Members
watch_token	id
flags	mask
sstring	name
sequence_no	seq

Member Typedef Documentation

◆ sequence_no

using seastar::experimental::fsnotifier::sequence_no = uint32_t

Unique sequence number of associating related events.

Note: The sequence number is used to connect related events. Currently, it is used only for the rename events(i.e., move_from and move_to), and is 0 for other types.

Member Enumeration Documentation

◆ flags

enum seastar::experimental::fsnotifier::flags : uint32_t

strong

Flags of events supported by FileSystem Notifier.

Note: Note that the flags are bit-matched with inotify and they can be calculated using the bitwise AND and bitwise OR operators (including the assignment form) directly to take intersection or union.

Member Function Documentation

◆ create_watch()

future<watch> seastar::experimental::fsnotifier::create_watch	(	const sstring &	path,
		flags	mask
	)

Monitor events specified in mask for the give path.

Parameters

path	path of the file or directory to monitor for.
mask	events of interest.

Returns: a future that becomes ready when the underlying inotify_add_watch(2) call completes.

◆ shutdown()

void seastar::experimental::fsnotifier::shutdown ( )

Shutdown the notifier and abort any waiting events.

Note: After shutdown, all watches are invalidated, and no new ones can be created.

◆ wait()

future<std::vector<event> > seastar::experimental::fsnotifier::wait ( ) const

Wait for events.

Returns: a future that becomes ready when registered events occur.

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

seastar/core/fsnotify.hh