aboutsummaryrefslogtreecommitdiffstats
path: root/railties/lib/breakpoint_client.rb
blob: 8a8bc755947ac11087d354d8797fd112227a0e60 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
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
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
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
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
require 'breakpoint'
require 'optparse'
require 'timeout'

options = {
  :ClientURI  => nil,
  :ServerURI  => "druby://localhost:42531",
  :RetryDelay => 1,
  :Verbose    => false
}

ARGV.options do |opts|
  script_name = File.basename($0)
  opts.banner = [
    "Usage: ruby #{script_name} [options] [server uri]",
    "",
    "This tool lets you connect to a breakpoint service ",
    "which was started via Breakpoint.activate_drb.",
    "",
    "The server uri defaults to druby://localhost:42531"
  ].join("\n")

  opts.separator ""

  opts.on("-c", "--client-uri=uri",
    "Run the client on the specified uri.",
    "This can be used to specify the port",
    "that the client uses to allow for back",
    "connections from the server.",
    "Default: Find a good URI automatically.",
    "Example: -c druby://localhost:12345"
  ) { |options[:ClientURI]| }

  opts.on("-s", "--server-uri=uri",
    "Connect to the server specified at the",
    "specified uri.",
    "Default: druby://localhost:42531"
  ) { |options[:ServerURI]| }

  opts.on("-v", "--verbose",
    "Report all connections and disconnections",
    "Default: false"
  ) { |options[:Verbose]| }

  opts.on("-R", "--retry-delay=delay", Integer,
    "Automatically try to reconnect to the",
    "server after delay seconds when the",
    "connection failed or timed out.",
    "A value of 0 disables automatical",
    "reconnecting completely.",
    "Default: 10"
  ) { |options[:RetryDelay]| }

  opts.separator ""

  opts.on("-h", "--help",
    "Show this help message."
  ) { puts opts; exit }

  opts.parse!
end

options[:ServerURI] = ARGV[0] if ARGV[0]

puts "Waiting for initial breakpoint..."

loop do
  DRb.start_service(options[:ClientURI])

  begin
    service = DRbObject.new(nil, options[:ServerURI])

    begin
      timeout(10) { service.ping }
    rescue Timeout::Error, DRb::DRbConnError
      if options[:Verbose]
        puts "",
          "  *** Breakpoint service didn't respond to ping request ***",
          "  This likely happened because of a misconfigured ACL (see the",
          "  documentation of Breakpoint.activate_drb, note that by default",
          "  you can only connect to a remote Breakpoint service via a SSH",
          "  tunnel), but might also be caused by an extremely slow connection.",
          ""
        end
      raise
    end

    begin
      service.register_eval_handler do |code|
        result = eval(code, TOPLEVEL_BINDING)
        if result
          DRbObject.new(result)
        else
          result
        end
      end 

      service.register_collision_handler do
        msg = [
          "  *** Breakpoint service collision ***",
          "  Another Breakpoint service tried to use the",
          "  port already occupied by this one. It will",
          "  keep waiting until this Breakpoint service",
          "  is shut down.",
          "  ",
          "  If you are using the Breakpoint library for",
          "  debugging a Rails or other CGI application",
          "  this likely means that this Breakpoint",
          "  session belongs to an earlier, outdated",
          "  request and should be shut down via 'exit'."
        ].join("\n")

        if RUBY_PLATFORM["win"] then
          # This sucks. Sorry, I'm not doing this because
          # I like funky message boxes -- I need to do this
          # because on Windows I have no way of displaying
          # my notification via puts() when gets() is still
          # being performed on STDIN. I have not found a
          # better solution.
          begin
            require 'tk'
            root = TkRoot.new { withdraw }
            Tk.messageBox('message' => msg, 'type' => 'ok')
            root.destroy
          rescue Exception
            puts "", msg, ""
          end
        else
          puts "", msg, ""
        end
      end

      service.register_handler do |workspace, message|
        puts message
        IRB.start(nil, nil, workspace)
        puts "", "Resumed execution. Waiting for next breakpoint...", ""
      end

      puts "Connection established. Waiting for breakpoint...", "" if options[:Verbose]

      loop do
        begin
          service.ping
        rescue DRb::DRbConnError => error
          puts "Server exited. Closing connection..." if options[:Verbose]
          break
        end

        sleep(0.5)
      end
    ensure
      service.unregister_handler
    end
  rescue Exception => error
    if options[:RetryDelay] > 0 then
      puts "No connection to breakpoint service at #{options[:ServerURI]}:", "  (#{error.inspect})" if options[:Verbose]
      error.backtrace if $DEBUG

      puts "  Reconnecting in #{options[:RetryDelay]} seconds..." if options[:Verbose]
 
      sleep options[:RetryDelay]
      retry
    else
      raise
    end
  end
end