Class: Spring::Watcher::Abstract

Inherits:
Object
  • Object
show all
Includes:
Mutex_m
Defined in:
lib/spring/watcher/abstract.rb

Overview

A user of a watcher can use IO.select to wait for changes:

watcher = MyWatcher.new(root, latency)
IO.select([watcher]) # watcher is running in background
watcher.stale? # => true

Direct Known Subclasses

Polling

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(root, latency) ⇒ Abstract


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# File 'lib/spring/watcher/abstract.rb', line 17

def initialize(root, latency)
  super()

  @root        = File.realpath(root)
  @latency     = latency
  @files       = Set.new
  @directories = Set.new
  @stale       = false
  @listeners   = []

  @on_debug    = nil
end

Instance Attribute Details

#directoriesObject (readonly)

Returns the value of attribute directories


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# File 'lib/spring/watcher/abstract.rb', line 15

def directories
  @directories
end

#filesObject (readonly)

Returns the value of attribute files


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# File 'lib/spring/watcher/abstract.rb', line 15

def files
  @files
end

#latencyObject (readonly)

Returns the value of attribute latency


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# File 'lib/spring/watcher/abstract.rb', line 15

def latency
  @latency
end

#rootObject (readonly)

Returns the value of attribute root


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# File 'lib/spring/watcher/abstract.rb', line 15

def root
  @root
end

Instance Method Details

#add(*items) ⇒ Object


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# File 'lib/spring/watcher/abstract.rb', line 38

def add(*items)
  debug { "watcher: add: #{items.inspect}" }

  items = items.flatten.map do |item|
    item = Pathname.new(item)

    if item.relative?
      Pathname.new("#{root}/#{item}")
    else
      item
    end
  end

  items = items.select do |item|
    if item.symlink?
      item.readlink.exist?.tap do |exists|
        if !exists
          debug { "add: ignoring dangling symlink: #{item.inspect} -> #{item.readlink.inspect}" }
        end
      end
    else
      item.exist?
    end
  end

  synchronize {
    items.each do |item|
      if item.directory?
        directories << item.realpath.to_s
      else
        begin
          files << item.realpath.to_s
        rescue Errno::ENOENT
          # Race condition. Ignore symlinks whose target was removed
          # since the check above, or are deeply chained.
          debug { "add: ignoring now-dangling symlink: #{item.inspect} -> #{item.readlink.inspect}" }
        end
      end
    end

    subjects_changed
  }
end

#debugObject


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# File 'lib/spring/watcher/abstract.rb', line 34

def debug
  @on_debug.call(yield) if @on_debug
end

#mark_staleObject


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# File 'lib/spring/watcher/abstract.rb', line 91

def mark_stale
  return if stale?
  @stale = true
  debug { "marked stale, calling listeners: listeners=#{@listeners.inspect}" }
  @listeners.each(&:call)
end

#on_debug(&block) ⇒ Object


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# File 'lib/spring/watcher/abstract.rb', line 30

def on_debug(&block)
  @on_debug = block
end

#on_stale(&block) ⇒ Object


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# File 'lib/spring/watcher/abstract.rb', line 86

def on_stale(&block)
  debug { "added listener: #{block.inspect}" }
  @listeners << block
end

#restartObject


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# File 'lib/spring/watcher/abstract.rb', line 98

def restart
  debug { "restarting" }
  stop
  start
end

#stale?Boolean


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# File 'lib/spring/watcher/abstract.rb', line 82

def stale?
  @stale
end

#startObject

Raises:

  • (NotImplementedError)

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# File 'lib/spring/watcher/abstract.rb', line 104

def start
  raise NotImplementedError
end

#stopObject

Raises:

  • (NotImplementedError)

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# File 'lib/spring/watcher/abstract.rb', line 108

def stop
  raise NotImplementedError
end

#subjects_changedObject

Raises:

  • (NotImplementedError)

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# File 'lib/spring/watcher/abstract.rb', line 112

def subjects_changed
  raise NotImplementedError
end