Class: Carnivore::Files::Util::Fetcher

Inherits:
Object
  • Object
show all
Includes:
Utils::Logging, Celluloid
Defined in:
lib/carnivore-files/util/fetcher.rb,
lib/carnivore-files/util/poll.rb,
lib/carnivore-files/util/penguin.rb

Overview

Fetch lines from file

Direct Known Subclasses

Penguin, Poll

Defined Under Namespace

Classes: Penguin, Poll

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(args = {}) ⇒ Fetcher

Create new instance

Parameters:

  • args (Hash) (defaults to: {}) —

    initialization args

Options Hash (args):

  • :path (String) —

    path to file

  • :delimiter (String) —

    string delimiter to break messages

  • :notify_actor (Celluloid::Actor) —

    actor to be notified on new messages



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# File 'lib/carnivore-files/util/fetcher.rb', line 32

def initialize(args={})
  @leftover = ''
  @path = ::File.expand_path(args[:path])
  @delimiter = args.fetch(:delimiter, "\n")
  @messages = Queue.new
end

Instance Attribute Details

#delimiter ⇒ String (readonly)

Returns string to split messages on.

Returns:

  • (String) —

    string to split messages on



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# File 'lib/carnivore-files/util/fetcher.rb', line 19

def delimiter
  @delimiter
end

#io ⇒ IO

Returns underlying IO instance.

Returns:

  • (IO) —

    underlying IO instance



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# File 'lib/carnivore-files/util/fetcher.rb', line 24

def io
  @io
end

#messages ⇒ Queue

Returns messages.

Returns:

  • (Queue) —

    messages



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# File 'lib/carnivore-files/util/fetcher.rb', line 22

def messages
  @messages
end

#path ⇒ String (readonly)

Returns path to file.

Returns:

  • (String) —

    path to file



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# File 'lib/carnivore-files/util/fetcher.rb', line 17

def path
  @path
end

Instance Method Details

#build_io ⇒ TrueClass, FalseClass

Build the IO and monitor

Returns:

  • (TrueClass, FalseClass) 


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# File 'lib/carnivore-files/util/fetcher.rb', line 77

def build_io
  unless(io)
    if(::File.exists?(path))
      @io = ::File.open(path, 'r')
      unless(@waited)
        @io.seek(0, ::IO::SEEK_END) # fast-forward to EOF
      else
        @waited = false
        retrieve_lines.each do |l|
          self.messages << l
        end
      end
    else
      wait_for_file
      build_io
    end
    true
  else
    false
  end
end

#retrieve_lines ⇒ Object

Retreive lines from file



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# File 'lib/carnivore-files/util/fetcher.rb', line 57

def retrieve_lines
  if(io)
    io.pos = @history_pos if @history_pos
    data = io.read(4096)
    while(data = io.read(4096))
      @leftover << data
      data = io.read(4096)
    end
    @history_pos = io.pos
    result = @leftover.split(delimiter)
    @leftover.replace @leftover.end_with?(delimiter) ? '' : result.pop.to_s
    result
  else
    []
  end
end

#start_fetcher ⇒ Object

Start the line fetcher

Raises:

  • (NotImplementedError) 


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# File 'lib/carnivore-files/util/fetcher.rb', line 40

def start_fetcher
  raise NotImplementedError
end

#write_line(line) ⇒ Integer

Write line to IO

Parameters:

  • line (String)

Returns:

  • (Integer) —

    bytes written



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# File 'lib/carnivore-files/util/fetcher.rb', line 48

def write_line(line)
  if(io)
    io.puts(line)
  else
    raise 'No IO detected! Failed to write.'
  end
end