class Build::Files::Monitor

def add(handle)
	handle.directories.each do |directory|
		@directories[directory] << handle

		# We just added the first handle:
		if @directories[directory].size == 1
			# If the handle already existed, this might trigger unnecessarily.
			@updated = true
		end
	end
	handle
end

def delete(handle)
	handle.directories.each do |directory|
		@directories[directory].delete(handle)

		# Remove the entire record if there are no handles:
		if @directories[directory].size == 0
			@directories.delete(directory)
	
			@updated = true
		end
	end
end

def initialize
	@directories = Hash.new { |hash, key| hash[key] = Set.new }
	
	@updated = false
end

def roots
	@directories.keys
end

def track_changes(files, &block)
	handle = Handle.new(self, files, &block)
	add(handle)
end

def update(directories, *args)
	directories.each do |directory|
		# directory = File.realpath(directory)
		
		@directories[directory].each do |handle|
			handle.changed!(*args)
		end
	end
end