Class: FileMonitoring::FileStat

Inherits:
Object
  • Object
show all
Defined in:
lib/file_monitoring/monitor_path.rb

Overview

This class holds current state of file and methods to control and report changes

Direct Known Subclasses

DirStat

Constant Summary collapse

DEFAULT_STABLE_STATE = 
10
@@log = 
nil

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(path, stable_state = DEFAULT_STABLE_STATE) ⇒ FileStat

Initializes new file monitoring object

Arguments:

  • path - File location

  • stable_state - Number of iterations to move unchanged file to stable state



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# File 'lib/file_monitoring/monitor_path.rb', line 34

def initialize(path, stable_state = DEFAULT_STABLE_STATE)
  ObjectSpace.define_finalizer(self,
                               self.class.method(:finalize).to_proc)
  if Params['enable_monitoring']
    Params['process_vars'].inc('obj add FileStat')
  end
  @path ||= path
  @size = nil
  @creation_time = nil
  @modification_time = nil
  @cycles = 0  # number of iterations from the last file modification
  @state = FileStatEnum::NON_EXISTING

  @stable_state = stable_state  # number of iteration to move unchanged file to stable state
end

Instance Attribute Details

#cycles ⇒ Object (readonly)

Returns the value of attribute cycles.



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# File 'lib/file_monitoring/monitor_path.rb', line 23

def cycles
  @cycles
end

#modification_time ⇒ Object (readonly)

Returns the value of attribute modification_time.



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# File 'lib/file_monitoring/monitor_path.rb', line 23

def modification_time
  @modification_time
end

#path ⇒ Object (readonly)

Returns the value of attribute path.



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# File 'lib/file_monitoring/monitor_path.rb', line 23

def path
  @path
end

#size ⇒ Object (readonly)

Returns the value of attribute size.



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# File 'lib/file_monitoring/monitor_path.rb', line 23

def size
  @size
end

#stable_state ⇒ Object (readonly)

Returns the value of attribute stable_state.



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# File 'lib/file_monitoring/monitor_path.rb', line 23

def stable_state
  @stable_state
end

#state ⇒ Object

Returns the value of attribute state.



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# File 'lib/file_monitoring/monitor_path.rb', line 23

def state
  @state
end

Class Method Details

.finalize(id) ⇒ Object 



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# File 'lib/file_monitoring/monitor_path.rb', line 50

def self.finalize(id)
  if Params['enable_monitoring']
    Params['process_vars'].inc('obj rem FileStat')
  end
end

.set_log(log) ⇒ Object

Sets a log file to report changes

Arguments:

  • log - already opened ruby File object



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# File 'lib/file_monitoring/monitor_path.rb', line 64

def self.set_log (log)
  @@log = log
end

Instance Method Details

#==(other) ⇒ Object

Checks whether path and state are the same as of the argument



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# File 'lib/file_monitoring/monitor_path.rb', line 130

def == (other)
  @path == other.path and @stable_state == other.stable_state
end

#changed?(file_stats) ⇒ Boolean

Checks that stored file attributes are the same as file attributes taken from file system.

Returns:

  • (Boolean) 


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# File 'lib/file_monitoring/monitor_path.rb', line 104

def changed?(file_stats)
  not (file_stats.size == @size &&
      file_stats.ctime.utc == @creation_time.utc &&
      file_stats.mtime.utc == @modification_time.utc)
end

#monitor ⇒ Object

Checks whether file was changed from the last iteration. For files, size and modification time are checked.



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# File 'lib/file_monitoring/monitor_path.rb', line 70

def monitor
  file_stats = File.lstat(@path) rescue nil
  new_state = nil
  if file_stats == nil
    new_state = FileStatEnum::NON_EXISTING
    @size = nil
    @creation_time = nil
    @modification_time = nil
    @cycles = 0
  elsif @size == nil
    new_state = FileStatEnum::NEW
    @size = file_stats.size
    @creation_time = file_stats.ctime.utc
    @modification_time = file_stats.mtime.utc
    @cycles = 0
  elsif changed?(file_stats)
    new_state = FileStatEnum::CHANGED
    @size = file_stats.size
    @creation_time = file_stats.ctime.utc
    @modification_time = file_stats.mtime.utc
    @cycles = 0
  else
    new_state = FileStatEnum::UNCHANGED
    @cycles += 1
    if @cycles >= @stable_state
      new_state = FileStatEnum::STABLE
    end
  end

  # The assignment
  self.state= new_state
end

#set_event_queue(queue) ⇒ Object 



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# File 'lib/file_monitoring/monitor_path.rb', line 110

def set_event_queue(queue)
  @event_queue = queue
end

#set_output_queue(event_queue) ⇒ Object 



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# File 'lib/file_monitoring/monitor_path.rb', line 56

def set_output_queue(event_queue)
  @event_queue = event_queue
end

#to_s(indent = 0) ⇒ Object

Returns path and state of the file with indentation



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# File 'lib/file_monitoring/monitor_path.rb', line 135

def to_s (indent = 0)
  (" " * indent) + path.to_s + " : " + state.to_s
end