class INotify::Watcher
Watchers monitor a single path for changes, specified by {INotify::Notifier#watch event flags}. A watcher is usually created via {Notifier#watch}.
One {Notifier} may have many {Watcher}s. The Notifier
actually takes care of the checking for events, via {Notifier#run run} or {Notifier#process process}. The main purpose of having Watcher
objects is to be able to disable them using {#close}.
Attributes
The {INotify::Notifier#watch flags} specifying the events that this Watcher
is watching for, and potentially some options as well.
@return [Array<Symbol>]
The {Notifier} that this Watcher
belongs to.
@return [Notifier]
The path that this Watcher
is watching.
@return [String]
Public Class Methods
Creates a new {Watcher}.
@private @see Notifier#watch
# File lib/rb-inotify/watcher.rb, line 61 def initialize(notifier, path, *flags, &callback) @notifier = notifier @callback = callback || proc {} @path = path @flags = flags.freeze @id = Native.inotify_add_watch(@notifier.fd, path.dup, Native::Flags.to_mask(flags)) unless @id < 0 @notifier.watchers[@id] = self return end raise SystemCallError.new( "Failed to watch #{path.inspect}" + case FFI.errno when Errno::EACCES::Errno; ": read access to the given file is not permitted." when Errno::EBADF::Errno; ": the given file descriptor is not valid." when Errno::EFAULT::Errno; ": path points outside of the process's accessible address space." when Errno::EINVAL::Errno; ": the given event mask contains no legal events; or fd is not an inotify file descriptor." when Errno::ENOMEM::Errno; ": insufficient kernel memory was available." when Errno::ENOSPC::Errno; ": The user limit on the total number of inotify watches was reached or the kernel failed to allocate a needed resource." else; "" end, FFI.errno) end
Public Instance Methods
Calls this Watcher’s callback with the given {Event}.
@private @param event [Event]
# File lib/rb-inotify/watcher.rb, line 40 def callback!(event) @callback[event] end
Disables this Watcher
, so that it doesn’t fire any more events.
@raise [SystemCallError] if the watch fails to be disabled for some reason
# File lib/rb-inotify/watcher.rb, line 47 def close if Native.inotify_rm_watch(@notifier.fd, @id) == 0 @notifier.watchers.delete(@id) return end raise SystemCallError.new("Failed to stop watching #{path.inspect}", FFI.errno) end