Class: SequentialFile::Base

Inherits:
Object
  • Object
show all
Includes:
Namer
Defined in:
lib/sequential_file/base.rb

Overview

This is a reference implementation of a File-wrapper class that uses the Namer to determine which file to process

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Namer

included

Constructor Details

#initialize(options = {}, &block) ⇒ Base

Returns a new instance of Base.



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# File 'lib/sequential_file/base.rb', line 14

def initialize(options = {}, &block)
  yield if block_given?
  @complete_path ||= File.join(self.directory_path, self.name)
  @buffer_limit = options[:buffer_limit] || 200 # bytes
  @buffer_size = 0
  @permission_style = options[:permission_style] || File::RDWR|File::CREAT
  @verbose = !!options[:verbose]
end

Instance Attribute Details

#buffer_limit ⇒ Object

Returns the value of attribute buffer_limit.



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# File 'lib/sequential_file/base.rb', line 12

def buffer_limit
  @buffer_limit
end

#buffer_position ⇒ Object

Returns the value of attribute buffer_position.



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# File 'lib/sequential_file/base.rb', line 12

def buffer_position
  @buffer_position
end

#buffer_size ⇒ Object

Returns the value of attribute buffer_size.



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# File 'lib/sequential_file/base.rb', line 12

def buffer_size
  @buffer_size
end

#complete_path ⇒ Object

the complete path to the file



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# File 'lib/sequential_file/base.rb', line 9

def complete_path
  @complete_path
end

#file ⇒ Object

Returns the value of attribute file.



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# File 'lib/sequential_file/base.rb', line 11

def file
  @file
end

#permission_style ⇒ Object

Returns the value of attribute permission_style.



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# File 'lib/sequential_file/base.rb', line 11

def permission_style
  @permission_style
end

#read_position ⇒ Object

the byte position in the file where read stopped and monitor will begin.



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# File 'lib/sequential_file/base.rb', line 10

def read_position
  @read_position
end

#verbose ⇒ Object

Returns the value of attribute verbose.



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# File 'lib/sequential_file/base.rb', line 12

def verbose
  @verbose
end

Instance Method Details

#clear ⇒ Object 



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# File 'lib/sequential_file/base.rb', line 70

def clear
  file_handle.truncate 0
  # Set the file to nil, so it will be reopened when needed.
  close
end

#close ⇒ Object 



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# File 'lib/sequential_file/base.rb', line 64

def close
  file_handle.close
  # Set the file to nil, so it will be reopened when needed.
  self.file = nil
end

#delete ⇒ Object 



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# File 'lib/sequential_file/base.rb', line 76

def delete
  if file
    close # just in case
    File.delete(complete_path)
  end
end

#file_handle ⇒ Object 



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# File 'lib/sequential_file/base.rb', line 27

def file_handle
  # autoclose: false => Keep the file descriptor open until we want to close it.
  File.new(@complete_path, @permission_style, {autoclose: false})
  self.file ||= File.new(@complete_path, @permission_style, {autoclose: false})
end

#flush_if_buffer_full ⇒ Object 



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# File 'lib/sequential_file/base.rb', line 46

def flush_if_buffer_full
  if buffer_size >= buffer_limit
    file_handle.flush
    @buffer_size = 0
  end
end

#info_string ⇒ Object 



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# File 'lib/sequential_file/base.rb', line 23

def info_string
  "PERM: #{@permission_style}\n\tPATH: #{@complete_path}"
end

#num_lines ⇒ Object 



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# File 'lib/sequential_file/base.rb', line 33

def num_lines
  file_handle.seek(0, IO::SEEK_SET)
  file_handle.readlines.size
end

#read(&block) ⇒ Object

Read file from beginning to end, recording position when done Need to remember to close file with self.close after done using the file descriptor



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# File 'lib/sequential_file/base.rb', line 55

def read &block
  prep_read
  data = block_given? ?
    file_handle.each {|line| yield line } :
    file_handle.read
  @read_position = file_handle.pos
  data
end

#write(msg) ⇒ Object

Need to remember to close file with self.close after done using the file descriptor



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# File 'lib/sequential_file/base.rb', line 39

def write(msg)
  prep_write
  puts "#-------> @[ #{@file_handle.pos} ] B[ #{@buffer_size} ] in #{@complete_path} <---------#\n#{msg}" if verbose
  add_to_buffer(msg)
  flush_if_buffer_full
end