Class: RequestLogAnalyzer::LogProcessor

Inherits:
Object
  • Object
show all
Defined in:
lib/request_log_analyzer/log_processor.rb

Overview

The Logprocessor class is used to perform simple processing actions over log files. It will go over the log file/stream line by line, pass the line to a processor and write the result back to the output file or stream. The processor can alter the contents of the line, remain it intact or remove it altogether, based on the current file format

Currently, one processors is supported:

* :strip will remove all irrelevent lines (according to the file format) from the 
  sources. A compact, information packed log will remain/.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(format, mode, options = {}) ⇒ LogProcessor

Initializes a new LogProcessor instance. format The file format to use (e.g. :rails). mode The processing mode options A hash with options to take into account



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# File 'lib/request_log_analyzer/log_processor.rb', line 43

def initialize(format, mode, options = {})
  @options     = options
  @mode        = mode
  @sources     = []
  @file_format = format
  $output_file = nil
end

Instance Attribute Details

#file_format ⇒ Object (readonly)

Returns the value of attribute file_format.



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# File 'lib/request_log_analyzer/log_processor.rb', line 15

def file_format
  @file_format
end

#mode ⇒ Object (readonly)

Returns the value of attribute mode.



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# File 'lib/request_log_analyzer/log_processor.rb', line 15

def mode
  @mode
end

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/request_log_analyzer/log_processor.rb', line 15

def options
  @options
end

#output_file ⇒ Object

Returns the value of attribute output_file.



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# File 'lib/request_log_analyzer/log_processor.rb', line 16

def output_file
  @output_file
end

#sources ⇒ Object (readonly)

Returns the value of attribute sources.



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# File 'lib/request_log_analyzer/log_processor.rb', line 15

def sources
  @sources
end

Class Method Details

.build(command, arguments) ⇒ Object

Builds a logprocessor instance from the arguments given on the command line command The command hat was used to start the log processor. This will set the 

processing mode. Currently, only :strip is supported.

arguments The parsed command line arguments (a CommandLine::Arguments instance)



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# File 'lib/request_log_analyzer/log_processor.rb', line 22

def self.build(command, arguments)
  
  options = { 
      :discard_teaser_lines => arguments[:discard_teaser_lines], 
      :keep_junk_lines      => arguments[:keep_junk_lines], 
    }
      
  log_processor = RequestLogAnalyzer::LogProcessor.new(arguments[:format].to_sym, command, options)
  log_processor.output_file = arguments[:output] if arguments[:output]

  arguments.parameters.each do |input|
    log_processor.sources << input
  end
  
  return log_processor
end

Instance Method Details

#process_file(file) ⇒ Object

Processes input files by opening it and sending the filestream to process_io, in which the actual processing is performed. file The file to process



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# File 'lib/request_log_analyzer/log_processor.rb', line 54

def process_file(file)
  File.open(file, 'r') { |file| process_io(file) }
end

#process_io(io) ⇒ Object

Processes an input stream by iteration over each line and processing it according to the current operation mode io The IO instance to process.



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# File 'lib/request_log_analyzer/log_processor.rb', line 61

def process_io(io)
  case mode
    when :strip;     io.each_line { |line| @output << strip_line(line) }
  end
end

#run! ⇒ Object

Runs the log processing by setting up the output stream and iterating over all the input sources. Input sources can either be filenames (String instances) or IO streams (IO instances). The strings “-” and “STDIN” will be substituted for the $stdin variable.



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# File 'lib/request_log_analyzer/log_processor.rb', line 77

def run!
  if @output_file.nil?
    @output = $stdout 
  else
    @output = File.new(@output_file, 'a')        
  end
  
  @sources.each do |source|
    if source.kind_of?(String) && File.exist?(source)
      process_file(source)
    elsif source.kind_of?(IO)
      process_io(source)
    elsif ['-', 'STDIN'].include?(source)
      process_io($stdin)        
    end
  end

ensure
  @output.close if @output.kind_of?(File)
end

#strip_line(line) ⇒ Object

Returns the line itself if the string matches any of the line definitions. If no match is found, an empty line is returned, which will strip the line from the output. line The line to strip



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# File 'lib/request_log_analyzer/log_processor.rb', line 70

def strip_line(line)
  file_format.line_definitions.any? { |name, definition| definition =~ line } ? line : ""
end