lib/clogger.rb

   1 # -*- encoding: binary -*-
   2 class Clogger
   3   VERSION = '0.0.3'
   4
   5   OP_LITERAL = 0
   6   OP_REQUEST = 1
   7   OP_RESPONSE = 2
   8   OP_SPECIAL = 3
   9   OP_EVAL = 4
  10   OP_TIME_LOCAL = 5
  11   OP_TIME_UTC = 6
  12   OP_REQUEST_TIME = 7
  13   OP_TIME = 8
  14   OP_COOKIE = 9
  15
  16   # support nginx variables that are less customizable than our own
  17   ALIASES = {
  18     '$request_time' => '$request_time{3}',
  19     '$time_local' => '$time_local{%d/%b/%Y:%H:%M:%S %z}',
  20     '$msec' => '$time{3}',
  21     '$usec' => '$time{6}',
  22   }
  23
  24   SPECIAL_VARS = {
  25     :body_bytes_sent => 0,
  26     :status => 1,
  27     :request => 2, # REQUEST_METHOD PATH_INFO?QUERY_STRING HTTP_VERSION
  28     :request_length => 3, # env['rack.input'].size
  29     :response_length => 4, # like body_bytes_sent, except "-" instead of "0"
  30     :ip => 5, # HTTP_X_FORWARDED_FOR || REMOTE_ADDR || -
  31     :pid => 6, # getpid()
  32     :request_uri => 7
  33   }
  34
  35 private
  36
  37   CGI_ENV = Regexp.new('\A\$(' <<
  38       %w(remote_addr remote_ident remote_user
  39          path_info query_string script_name
  40          server_name server_port).join('|') << ')\z').freeze
  41
  42   SCAN = /([^$]*)(\$+(?:env\{\w+(?:\.[\w\.]+)?\}|
  43                         e\{[^\}]+\}|
  44                         (?:request_)?time\{\d+\}|
  45                         time_(?:utc|local)\{[^\}]+\}|
  46                         \w*))?([^$]*)/x
  47
  48   def compile_format(str)
  49     rv = []
  50     str.scan(SCAN).each do |pre,tok,post|
  51       rv << [ OP_LITERAL, pre ] if pre && pre != ""
  52
  53       unless tok.nil?
  54         if tok.sub!(/\A(\$+)\$/, '$')
  55           rv << [ OP_LITERAL, $1.dup ]
  56         end
  57
  58         compat = ALIASES[tok] and tok = compat
  59
  60         case tok
  61         when /\A(\$*)\z/
  62           rv << [ OP_LITERAL, $1.dup ]
  63         when /\A\$env\{(\w+(?:\.[\w\.]+))\}\z/
  64           rv << [ OP_REQUEST, $1.freeze ]
  65         when /\A\$e\{([^\}]+)\}\z/
  66           rv << [ OP_EVAL, $1.dup ]
  67         when /\A\$cookie_(\w+)\z/
  68           rv << [ OP_COOKIE, $1.dup.freeze ]
  69         when CGI_ENV, /\A\$(http_\w+)\z/
  70           rv << [ OP_REQUEST, $1.upcase.freeze ]
  71         when /\A\$sent_http_(\w+)\z/
  72           rv << [ OP_RESPONSE, $1.downcase.tr('_','-').freeze ]
  73         when /\A\$time_local\{([^\}]+)\}\z/
  74           rv << [ OP_TIME_LOCAL, $1.dup ]
  75         when /\A\$time_utc\{([^\}]+)\}\z/
  76           rv << [ OP_TIME_UTC, $1.dup ]
  77         when /\A\$time\{(\d+)\}\z/
  78           rv << [ OP_TIME, *usec_conv_pair(tok, $1.to_i) ]
  79         when /\A\$request_time\{(\d+)\}\z/
  80           rv << [ OP_REQUEST_TIME, *usec_conv_pair(tok, $1.to_i) ]
  81         else
  82           tok_sym = tok[1..-1].to_sym
  83           if special_code = SPECIAL_VARS[tok_sym]
  84             rv << [ OP_SPECIAL, special_code ]
  85           else
  86             raise ArgumentError, "unable to make sense of token: #{tok}"
  87           end
  88         end
  89       end
  90
  91       rv << [ OP_LITERAL, post ] if post && post != ""
  92     end
  93
  94     # auto-append a newline
  95     last = rv.last or return rv
  96     op = last.first
  97     if (op == OP_LITERAL && /\n\z/ !~ last.last) || op != OP_LITERAL
  98       rv << [ OP_LITERAL, "\n" ]
  99     end
 100
 101     rv
 102   end
 103
 104   def usec_conv_pair(tok, prec)
 105     if prec == 0
 106       [ "%d", 1 ] # stupid...
 107     elsif prec > 6
 108       raise ArgumentError, "#{tok}: too high precision: #{prec} (max=6)"
 109     else
 110       [ "%d.%0#{prec}d", 10 ** (6 - prec) ]
 111     end
 112   end
 113
 114   def need_response_headers?(fmt_ops)
 115     fmt_ops.any? { |op| OP_RESPONSE == op[0] }
 116   end
 117
 118   def need_wrap_body?(fmt_ops)
 119     fmt_ops.any? do |op|
 120       (OP_REQUEST_TIME == op[0]) || (OP_SPECIAL == op[0] &&
 121         (SPECIAL_VARS[:body_bytes_sent] == op[1] ||
 122          SPECIAL_VARS[:response_length] == op[1]))
 123     end
 124   end
 125
 126 end
 127
 128 require 'clogger/format'
 129
 130 begin
 131   require 'clogger_ext'
 132 rescue LoadError
 133   require 'clogger/pure'
 134 end