Class: ActiveFacts::Tracer

Inherits:
Object show all
Defined in:
lib/activefacts/tracer.rb

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Tracer

Returns a new instance of Tracer.



14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
 
# File 'lib/activefacts/tracer.rb', line 14

def initialize
  @nested = false   # Set when a block enables all enclosed tracing
  @available = {}

  # First time, initialise the tracing environment
  @indent = 0
  @keys = {}
  if (e = ENV[@@trace_name ||= "TRACE"])
    e.split(/[^_a-zA-Z0-9]/).each{|k| enable(k) }
    if @keys[:help]
      at_exit {
        @stderr.puts "---\nDebugging keys available: #{@available.keys.map{|s| s.to_s}.sort*", "}"
      }
    end
    if @keys[:debug]
      errors = []
      success = false
      (
 [ENV["DEBUG_PREFERENCE"]].compact +
 [
   'pry',
   'debugger',
   'ruby-debug'
 ]
	  ).each do |debugger|
        begin
          require debugger
          puts "Loaded "+debugger
          success = true
          break
        rescue LoadError => e
          errors << e
        end
      end
      unless success
        puts "Can't load any debugger, failed on:\n#{errors.inspect}"
      end
      ::Debugger.start rescue nil
    end
  end
end

Instance Method Details

#disable(key) ⇒ Object 



68
69
70
 
# File 'lib/activefacts/tracer.rb', line 68

def disable key
  !key.to_s.empty? && @keys.delete(key.to_sym)
end

#enable(key) ⇒ Object 



64
65
66
 
# File 'lib/activefacts/tracer.rb', line 64

def enable key
  !key.to_s.empty? && @keys[key.to_sym] = true
end

#enabled(key) ⇒ Object 



60
61
62
 
# File 'lib/activefacts/tracer.rb', line 60

def enabled key
  !key.empty? && @keys[key.to_sym]
end

#keys ⇒ Object 



56
57
58
 
# File 'lib/activefacts/tracer.rb', line 56

def keys
  @available.keys
end

#selected(args) ⇒ Object 



76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
 
# File 'lib/activefacts/tracer.rb', line 76

def selected(args)
  # Figure out whether this trace is enabled (itself or by :all), if it nests, and if we should print the key:
  key =
    if Symbol === args[0]
      control = args.shift
      if (s = control.to_s) =~ /_\Z/
        nested = true
        s.sub(/_\Z/, '').to_sym     # Avoid creating new strings willy-nilly
      else
        control
      end
    else
      :all
    end

  @available[key] ||= key   # Remember that this trace was requested, for help
  enabled = @nested ||      # This trace is enabled because it's in a nested block
            @keys[key] ||   # This trace is enabled in its own right
            @keys[:all]     # This trace is enabled because all are
  @nested = nested
  [
    (enabled ? 1 : 0),
    @keys[:all] ? " %-15s"%control : nil
  ]
end

#show(*args) ⇒ Object 



102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
 
# File 'lib/activefacts/tracer.rb', line 102

def show(*args)
  enabled, key_to_show = selected(args)

  # Emit the message if enabled or a parent is:
  if args.size > 0 && enabled == 1
    puts "\##{key_to_show} " +
      '  '*@indent +
      args.
#            A laudable aim, certainly, but in practise the Procs leak and slow things down:
#            map{|a| a.respond_to?(:call) ? a.call : a}.
        join(' ')
  end
  @indent += enabled
  enabled
end

#toggle(key) ⇒ Object 



72
73
74
 
# File 'lib/activefacts/tracer.rb', line 72

def toggle key
  !key.to_s.empty? and enabled(key) ? (disable(key); false) : (enable(key); true)
end

#trace(*args, &block) ⇒ Object 



118
119
120
121
122
123
124
125
 
# File 'lib/activefacts/tracer.rb', line 118

def trace(*args, &block)
  begin
    old_indent, old_nested, enabled  = @indent, @nested, show(*args)
    return (block || proc { enabled == 1 }).call
  ensure
    @indent, @nested = old_indent, old_nested
  end
end