class LogfileReader

Attributes

last_offset[R]

path[W]

Public Class Methods

new(path) click to toggle source

# File lib/picky-statistics/logfile_reader.rb, line 15
def initialize path
  @path = File.expand_path path
  check_file
end

Public Instance Methods

calculate_last_offset_from(statistics) click to toggle source

# File lib/picky-statistics/logfile_reader.rb, line 75
def calculate_last_offset_from statistics
  @last_offset += last_offset_from statistics
end

check_file() click to toggle source

# File lib/picky-statistics/logfile_reader.rb, line 19
def check_file
  if File.exists? @path
    exclaim "Logfile #{@path} found."
  else
    raise "Log file #{@path} not found."
  end
end

exclaim(text) click to toggle source

# File lib/picky-statistics/logfile_reader.rb, line 9
def exclaim text
  puts text
end

last_offset_from(statistics) click to toggle source

# File lib/picky-statistics/logfile_reader.rb, line 78
def last_offset_from statistics
  `wc #{statistics}`.split(/\s+/)[3].to_i
end

process(line) click to toggle source

Processes one line and returns an array.

# File lib/picky-statistics/logfile_reader.rb, line 64
def process line
  [
    line[2,  19],
    Float(line[22, 8]),
    line[31, 50].gsub!(/\s*\z/, ''),
    Integer(line[82, 8]),
    Integer(line[92, 3]),
    Integer(line[96, 2])
  ]
end

reset() click to toggle source

# File lib/picky-statistics/logfile_reader.rb, line 27
def reset
  @last_offset = 0
end

reset_from(time) click to toggle source

# File lib/picky-statistics/logfile_reader.rb, line 84
def reset_from time
  with_temp_file(offset) do |statistics|
    full[:total].reset_from statistics
  end
  @counts
end

since(log_offset = nil) click to toggle source

# File lib/picky-statistics/logfile_reader.rb, line 31
def since log_offset = nil
  @last_offset = log_offset || 0
  
  start_time = Time.now

  # Add all the data to the results.
  #
  results = []
  with_temp_file(log_offset) do |statistics|
    calculate_last_offset_from statistics
    
    File.open(statistics, 'r') do |file|
      while line = file.gets
        next if line =~ /\A\s*\#/
        results << process(line) rescue nil
      end
    end
  end

  duration = Time.now - start_time
  exclaim "Parsed log from byte #{log_offset} in #{duration}s"
    
  results
end

since_last() click to toggle source

# File lib/picky-statistics/logfile_reader.rb, line 58
def since_last
  since @last_offset
end

with_temp_file(offset = 0) { |temp_path| ... } click to toggle source

Use the offset to speed up statistics gathering.

# File lib/picky-statistics/logfile_reader.rb, line 93
def with_temp_file offset = 0
  # Quickly return if no logs have been written since the last time.
  #
  return if last_offset_from(@path) <= last_offset

  Tempfile.open 'picky' do |temp_file|
    temp_path = temp_file.path
    `tail -c +#{offset} #{@path} > #{temp_path}`
      
    yield temp_path
  end
end