Class: INotify::Notifier
- Inherits:
-
Object
- Object
- INotify::Notifier
- Defined in:
- lib/rb-inotify/notifier.rb
Overview
Notifier wraps a single instance of inotify. It's possible to have more than one instance, but usually unnecessary.
Constant Summary collapse
- NON_RECURSIVE =
- Files in
/dev/fd
sometimes register as directories, but are not enumerable.
- Files in
"/dev/fd"
Instance Method Summary collapse
-
#close ⇒ Object
Close the notifier.
-
#fd ⇒ Fixnum
The underlying file descriptor for this notifier.
-
#initialize ⇒ Notifier
constructor
Creates a new Notifier.
-
#process ⇒ Object
Blocks until there are one or more filesystem events that this notifier has watchers registered for.
-
#read_events ⇒ Object
Blocks until there are one or more filesystem events that this notifier has watchers registered for.
-
#run ⇒ Object
Starts the notifier watching for filesystem events.
-
#stop ⇒ Object
Stop watching for filesystem events.
-
#to_io ⇒ IO
Returns a Ruby IO object wrapping the underlying file descriptor.
-
#watch(path, *flags) {|event| ... } ⇒ Watcher
Watches a file or directory for changes, calling the callback when there are.
Constructor Details
#initialize ⇒ Notifier
Creates a new INotify::Notifier.
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# File 'lib/rb-inotify/notifier.rb', line 49 def initialize @running = Mutex.new @stop = false @pipe = IO.pipe # JRuby shutdown sometimes runs IO finalizers before all threads finish. if RUBY_ENGINE == 'jruby' @pipe[0].autoclose = false @pipe[1].autoclose = false end @watchers = {} fd = Native.inotify_init unless fd < 0 @handle = IO.new(fd) @handle.autoclose = false if RUBY_ENGINE == 'jruby' return end raise SystemCallError.new( "Failed to initialize inotify" + case FFI.errno when Errno::EMFILE::Errno; ": the user limit on the total number of inotify instances has been reached." when Errno::ENFILE::Errno; ": the system limit on the total number of file descriptors has been reached." when Errno::ENOMEM::Errno; ": insufficient kernel memory is available." else; "" end, FFI.errno) end |
Instance Method Details
#close ⇒ Object
Close the notifier.
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# File 'lib/rb-inotify/notifier.rb', line 268 def close stop @handle.close @watchers.clear end |
#fd ⇒ Fixnum
The underlying file descriptor for this notifier. This is a valid OS file descriptor, and can be used as such (except under JRuby -- see #to_io).
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# File 'lib/rb-inotify/notifier.rb', line 41 def fd @handle.fileno end |
#process ⇒ Object
Blocks until there are one or more filesystem events that this notifier has watchers registered for. Once there are events, the appropriate callbacks are called and this function returns.
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# File 'lib/rb-inotify/notifier.rb', line 258 def process read_events.each do |event| event.callback! event.flags.include?(:ignored) && event.notifier.watchers.delete(event.watcher_id) end end |
#read_events ⇒ Object
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# File 'lib/rb-inotify/notifier.rb', line 281 def read_events size = Native::Event.size + Native.fpathconf(fd, Native::Flags::PC_NAME_MAX) + 1 tries = 1 begin data = readpartial(size) rescue SystemCallError => er # EINVAL means that there's more data to be read # than will fit in the buffer size raise er unless er.errno == Errno::EINVAL::Errno && tries < 5 size *= 2 tries += 1 retry end return [] if data.nil? events = [] = {} while event = Event.consume(data, self) events << event next if event. == 0 [event.] ||= [] [event.] << event end .each {|c, evs| evs.each {|ev| ev..replace(evs - [ev]).freeze}} events end |
#run ⇒ Object
Starts the notifier watching for filesystem events. Blocks until #stop is called.
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# File 'lib/rb-inotify/notifier.rb', line 227 def run @running.synchronize do Thread.current[:INOTIFY_RUN_THREAD] = true process until @stop end ensure Thread.current[:INOTIFY_RUN_THREAD] = false @stop = false end |
#stop ⇒ Object
Stop watching for filesystem events. That is, if we're in a #run loop, exit out as soon as we finish handling the events.
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# File 'lib/rb-inotify/notifier.rb', line 241 def stop @stop = true @pipe.last.write "." unless Thread.current[:INOTIFY_RUN_THREAD] @running.synchronize do # no-op: we just needed to wait until the lock was available end end end |
#to_io ⇒ IO
Returns a Ruby IO object wrapping the underlying file descriptor.
Since this file descriptor is fully functional (except under JRuby),
this IO object can be used in any way a Ruby-created IO object can.
This includes passing it to functions like #select
.
Note that this always returns the same IO object. Creating lots of IO objects for the same file descriptor can cause some odd problems.
This is not supported under JRuby. JRuby currently doesn't use native file descriptors for the IO object, so we can't use this file descriptor as a stand-in.
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# File 'lib/rb-inotify/notifier.rb', line 94 def to_io @handle end |
#watch(path, *flags) {|event| ... } ⇒ Watcher
Watches a file or directory for changes, calling the callback when there are. This is only activated once #process or #run is called.
Note that by default, this does not recursively watch subdirectories
of the watched directory.
To do so, use the :recursive
flag.
Flags
:access
: A file is accessed (that is, read).
:attrib
: A file's metadata is changed (e.g. permissions, timestamps, etc).
:close_write
: A file that was opened for writing is closed.
:close_nowrite
: A file that was not opened for writing is closed.
:modify
: A file is modified.
:open
: A file is opened.
Directory-Specific Flags
These flags only apply when a directory is being watched.
:moved_from
: A file is moved out of the watched directory.
:moved_to
: A file is moved into the watched directory.
:create
: A file is created in the watched directory.
:delete
: A file is deleted in the watched directory.
:delete_self
: The watched file or directory itself is deleted.
:move_self
: The watched file or directory itself is moved.
Helper Flags
These flags are just combinations of the flags above.
:close
: Either :close_write
or :close_nowrite
is activated.
:move
: Either :moved_from
or :moved_to
is activated.
:all_events
: Any event above is activated.
Options Flags
These flags don't actually specify events. Instead, they specify options for the watcher.
:onlydir
: Only watch the path if it's a directory.
:dont_follow
: Don't follow symlinks.
:mask_add
: Add these flags to the pre-existing flags for this path.
:oneshot
: Only send the event once, then shut down the watcher.
:recursive
: Recursively watch any subdirectories that are created.
Note that this is a feature of rb-inotify,
rather than of inotify itself, which can only watch one level of a directory.
This means that the Event#name field
will contain only the basename of the modified file.
When using :recursive
, Event#absolute_name should always be used.
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# File 'lib/rb-inotify/notifier.rb', line 196 def watch(path, *flags, &callback) return Watcher.new(self, path, *flags, &callback) unless flags.include?(:recursive) dont_follow = flags.include?(:dont_follow) Dir.each_child(path) do |base| d = File.join(path, base) next unless File.directory?(d) next if dont_follow && File.symlink?(d) next if NON_RECURSIVE == d watch(d, *flags, &callback) end rec_flags = [:create, :moved_to] return watch(path, *((flags - [:recursive]) | rec_flags)) do |event| callback.call(event) if flags.include?(:all_events) || !(flags & event.flags).empty? next if (rec_flags & event.flags).empty? || !event.flags.include?(:isdir) begin watch(event.absolute_name, *flags, &callback) rescue Errno::ENOENT # If the file has been deleted since the glob was run, we don't want to error out. end end end |