Class: Chainsaw::Filter

Inherits:
Object
  • Object
show all
Defined in:
lib/chainsaw/filter.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(logfile, range, options = OpenStruct.new) ⇒ Filter

Initialize a Filter instance. We read the logfile here and attempt to detect what type of logfile it is.

logfile - the String path of the logfile to be filtered range - the “time” range to filter through (Time or Range) options - an OpenStruct representing the options

Returns the Filter instance



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# File 'lib/chainsaw/filter.rb', line 13

def initialize(logfile, range, options = OpenStruct.new)
  @logfile    = logfile
  @range      = range
  @options    = options
  @log        = File.open(@logfile)
  @format     = Detector.detect(@log)
  @line_count = 0

  @log.rewind

  self
end

Instance Attribute Details

#line_count ⇒ Object (readonly)

Returns the value of attribute line_count.



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# File 'lib/chainsaw/filter.rb', line 3

def line_count
  @line_count
end

Class Method Details

.filter(*args) ⇒ Object

A convinence method to initialize a Filter object using the given args and start filtering it



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# File 'lib/chainsaw/filter.rb', line 100

def self.filter(*args)
  new(*args).start
end

.parse_timestamp(timestamp, time_format) ⇒ Object

Parse a timestamp using the given time_format.

timestamp - the String timestamp time_format - the String time format used to parse

Returns a parsed Time object



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# File 'lib/chainsaw/filter.rb', line 91

def self.parse_timestamp(timestamp, time_format)
  dt = DateTime.strptime(timestamp, time_format)

  Time.local(dt.year, dt.month, dt.day, dt.hour, dt.min, dt.sec)
end

Instance Method Details

#found(line, timestamp) ⇒ Object

A matching line was found, set @outputting incase we run into lines that aren’t timestamped.

line - the String logline timestamp - the String timestamp from the logline



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# File 'lib/chainsaw/filter.rb', line 62

def found(line, timestamp)
  @outputting = true
  @line_count += 1

  out(line, timestamp)

  STDIN.gets if @options.interactive && !@options.output_file
end

#out(line, timestamp = nil) ⇒ Object

Output the logline to STDOUT or File. We also colorize if requested.

line - the String logline timestamp - the String timestamp from the logline



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# File 'lib/chainsaw/filter.rb', line 75

def out(line, timestamp = nil)
  if @options.output_file
    File.open(@options.output_file, 'a') { |f| f.write(line) }
  elsif @options.colorize && timestamp
    puts line.sub(timestamp, "\033[32m#{timestamp}\033[0m")
  else
    puts line
  end
end

#start ⇒ Object

Start iterating through the log lines and filtering them accordingly.



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# File 'lib/chainsaw/filter.rb', line 27

def start
  @log.each_line do |line|
    filter    = @options.filter
    match     = line.match(@format.pattern)

    if match
      timestamp = match[1]
      time      = Filter.parse_timestamp(timestamp, @format.time_format)
    else
      timestamp = time = nil
    end

    # a match was found if we are filtering additional text, check that too
    if match && @range.cover?(time) && ( !filter || filter && line.include?(filter) )
      found(line, timestamp)
    # a match was found and we are outputting non-timestamped lines
    elsif match && @outputting
      @outputting = false
    # outputting non-timestamped lines
    elsif @outputting
      out(line)
    end
  end

  unless @options.output_file
    hind = (@line_count.zero? || @line_count > 1) ? 's' : ''
    puts "\n\033[33mFound #{@line_count} line#{hind} \033[0m"
  end
end