Class: SlidingStats::Window

Inherits:
Object
  • Object
show all
Defined in:
lib/sliding-stats/window.rb

Overview

Provides a "sliding window" over the stats. You provide a limit, and then feeds data into it. When the number of lines of data exceeds the limit, the oldest gets removed.

The actual stats calculation is handled by the Stats class

At any point you can extract stats from from the current window.

The following options can be passed in the opts argument:

  • :limit => the number of stats lines to keep
  • :ignore => Requests where this matches either the referer or the request or the user agent will not be considered at all.
  • :request_methods => Array of HTTP methods to track. Defaults to :get as POST, PUT etc. on "normal" sites rarely happen on inbound referrals, and so we'd be likely to overcount access to a specific page
  • :exclude_[referers|pages] => Arrays that will be matched against REQUEST_URI and HTTP_REFERER to decide whether or not to exclude this request from the appropriate stats.
  • :rewrite_referer => An Array of arrays consisting of regexps and a rewrite pattern to filter the HTTP_REFERER against

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(app, opts = {}) ⇒ Window

Returns a new instance of Window.



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# File 'lib/sliding-stats/window.rb', line 37

def initialize app, opts = {}
  @app = app
  @limit = (opts[:limit] || DEFAULT_WINDOW).to_i
  @exclude_referers = opts[:exclude_referers] || []
  @rewrite_referers = opts[:rewrite_referers] || []
  @request_methods = opts[:request_methods] || [:get]
  @exclude_pages = opts[:exclude_pages] || []
  @ignore = opts[:ignore] || []
  @persist = opts[:persist]
  
  @requests = []
  if @persist.is_a?(Numeric)
    @persist = SlidingStats::Persist.new(@persist)
    @requests = @persist.load
  end
  @stats = Stats.new(@requests,@exclude_referers,@exclude_pages)
end

Instance Attribute Details

#stats ⇒ Object (readonly)

Returns the value of attribute stats.



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# File 'lib/sliding-stats/window.rb', line 35

def stats
  @stats
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/sliding-stats/window.rb', line 55

def call env
  ref = env["HTTP_REFERER"] || "-"
  req = env["REQUEST_URI"]
  ua = env["HTTP_USER_AGENT"]
  req_meth = env["REQUEST_METHOD"].downcase.to_sym

  if @request_methods.include?(req_meth) && !@ignore.detect{|pat| ref =~ pat || req =~ pat || ua =~ pat}
    newref = @rewrite_referers.inject(ref) { |nr,r| nr.gsub(r[0],r[1]) }
    ref = CGI.unescape(newref) if newref != ref
  
    stats = {
      "HTTP_REFERER" => ref,
      "REQUEST_URI"  => req
    }
    @requests << stats
    @stats.add(stats)
    while @requests.size > @limit
      @stats.sub(@requests.shift) 
    end
    @persist.save(@requests) if @persist
  end

  env["slidingstats"] = self
  @app.call(env)
end