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Diffstat (limited to 'railties/lib/breakpoint.rb')
-rwxr-xr-x | railties/lib/breakpoint.rb | 525 |
1 files changed, 0 insertions, 525 deletions
diff --git a/railties/lib/breakpoint.rb b/railties/lib/breakpoint.rb deleted file mode 100755 index 6de2d64a7e..0000000000 --- a/railties/lib/breakpoint.rb +++ /dev/null @@ -1,525 +0,0 @@ -# The Breakpoint library provides the convenience of
-# being able to inspect and modify state, diagnose
-# bugs all via IRB by simply setting breakpoints in
-# your applications by the call of a method.
-#
-# This library was written and is supported by me,
-# Florian Gross. I can be reached at flgr@ccan.de
-# and enjoy getting feedback about my libraries.
-#
-# The whole library (including breakpoint_client.rb
-# and binding_of_caller.rb) is licensed under the
-# same license that Ruby uses. (Which is currently
-# either the GNU General Public License or a custom
-# one that allows for commercial usage.) If you for
-# some good reason need to use this under another
-# license please contact me.
-
-require 'irb'
-require 'binding_of_caller'
-require 'drb'
-require 'drb/acl'
-
-module Breakpoint
- extend self
-
- # This will pop up an interactive ruby session at a
- # pre-defined break point in a Ruby application. In
- # this session you can examine the environment of
- # the break point.
- #
- # You can get a list of variables in the context using
- # local_variables via +local_variables+. You can then
- # examine their values by typing their names.
- #
- # You can have a look at the call stack via +caller+.
- #
- # The source code around the location where the breakpoint
- # was executed can be examined via +source_lines+. Its
- # argument specifies how much lines of context to display.
- # The default amount of context is 5 lines. Note that
- # the call to +source_lines+ can raise an exception when
- # it isn't able to read in the source code.
- #
- # breakpoints can also return a value. They will execute
- # a supplied block for getting a default return value.
- # A custom value can be returned from the session by doing
- # +throw(:debug_return, value)+.
- #
- # You can also give names to break points which will be
- # used in the message that is displayed upon execution
- # of them.
- #
- # Here's a sample of how breakpoints should be placed:
- #
- # class Person
- # def initialize(name, age)
- # @name, @age = name, age
- # breakpoint("Person#initialize")
- # end
- #
- # attr_reader :age
- # def name
- # breakpoint("Person#name") { @name }
- # end
- # end
- #
- # person = Person.new("Random Person", 23)
- # puts "Name: #{person.name}"
- #
- # And here is a sample debug session:
- #
- # Executing break point "Person#initialize" at file.rb:4 in `initialize'
- # irb(#<Person:0x292fbe8>):001:0> local_variables
- # => ["name", "age", "_", "__"]
- # irb(#<Person:0x292fbe8>):002:0> [name, age]
- # => ["Random Person", 23]
- # irb(#<Person:0x292fbe8>):003:0> [@name, @age]
- # => ["Random Person", 23]
- # irb(#<Person:0x292fbe8>):004:0> self
- # => #<Person:0x292fbe8 @age=23, @name="Random Person">
- # irb(#<Person:0x292fbe8>):005:0> @age += 1; self
- # => #<Person:0x292fbe8 @age=24, @name="Random Person">
- # irb(#<Person:0x292fbe8>):006:0> exit
- # Executing break point "Person#name" at file.rb:9 in `name'
- # irb(#<Person:0x292fbe8>):001:0> throw(:debug_return, "Overriden name")
- # Name: Overriden name
- #
- # Breakpoint sessions will automatically have a few
- # convenience methods available. See Breakpoint::CommandBundle
- # for a list of them.
- #
- # Breakpoints can also be used remotely over sockets.
- # This is implemented by running part of the IRB session
- # in the application and part of it in a special client.
- # You have to call Breakpoint.activate_drb to enable
- # support for remote breakpoints and then run
- # breakpoint_client.rb which is distributed with this
- # library. See the documentation of Breakpoint.activate_drb
- # for details.
- def breakpoint(id = nil, context = nil, &block)
- callstack = caller
- callstack.slice!(0, 3) if callstack.first["breakpoint"]
- file, line, method = *callstack.first.match(/^(.+?):(\d+)(?::in `(.*?)')?/).captures
-
- message = "Executing break point " + (id ? "#{id.inspect} " : "") +
- "at #{file}:#{line}" + (method ? " in `#{method}'" : "")
-
- if context then
- return handle_breakpoint(context, message, file, line, &block)
- end
-
- Binding.of_caller do |binding_context|
- handle_breakpoint(binding_context, message, file, line, &block)
- end
- end
-
- module CommandBundle #:nodoc:
- # Proxy to a Breakpoint client. Lets you directly execute code
- # in the context of the client.
- class Client#:nodoc:
- def initialize(eval_handler) # :nodoc:
- @eval_handler = eval_handler
- end
-
- instance_methods.each do |method|
- next if method[/^__.+__$/]
- undef_method method
- end
-
- # Executes the specified code at the client.
- def eval(code)
- @eval_handler.call(code)
- end
-
- # Will execute the specified statement at the client.
- def method_missing(method, *args)
- if args.empty?
- result = eval("#{method}")
- else
- result = eval("#{method}(*Marshal.load(#{Marshal.dump(args).inspect}))")
- end
-
- unless [true, false, nil].include?(result)
- result.extend(DRbUndumped) if result
- end
-
- return result
- end
- end
-
- # Returns the source code surrounding the location where the
- # breakpoint was issued.
- def source_lines(context = 5, return_line_numbers = false)
- lines = File.readlines(@__bp_file).map { |line| line.chomp }
-
- break_line = @__bp_line
- start_line = [break_line - context, 1].max
- end_line = break_line + context
-
- result = lines[(start_line - 1) .. (end_line - 1)]
-
- if return_line_numbers then
- return [start_line, break_line, result]
- else
- return result
- end
- end
-
- # Lets an object that will forward method calls to the breakpoint
- # client. This is useful for outputting longer things at the client
- # and so on. You can for example do these things:
- #
- # client.puts "Hello" # outputs "Hello" at client console
- # # outputs "Hello" into the file temp.txt at the client
- # client.File.open("temp.txt", "w") { |f| f.puts "Hello" }
- def client()
- if Breakpoint.use_drb? then
- Client.new(Breakpoint.drb_service.eval_handler)
- else
- Client.new(lambda { |code| eval(code, TOPLEVEL_BINDING) })
- end
- end
- end
-
- def handle_breakpoint(context, message, file = "", line = "", &block) # :nodoc:
- catch(:debug_return) do |value|
- eval(%{
- @__bp_file = #{file.inspect}
- @__bp_line = #{line}
- extend Breakpoint::CommandBundle
- extend DRbUndumped if self
- }, context) rescue nil
-
- if not use_drb? then
- puts message
- IRB.start(nil, IRB::WorkSpace.new(context))
- else
- @drb_service.add_breakpoint(context, message)
- end
-
- block.call if block
- end
- end
-
- # These exceptions will be raised on failed asserts
- # if Breakpoint.asserts_cause_exceptions is set to
- # true.
- class FailedAssertError < RuntimeError#:nodoc:
- end
-
- # This asserts that the block evaluates to true.
- # If it doesn't evaluate to true a breakpoint will
- # automatically be created at that execution point.
- #
- # You can disable assert checking in production
- # code by setting Breakpoint.optimize_asserts to
- # true. (It will still be enabled when Ruby is run
- # via the -d argument.)
- #
- # Example:
- # person_name = "Foobar"
- # assert { not person_name.nil? }
- #
- # Note: If you want to use this method from an
- # unit test, you will have to call it by its full
- # name, Breakpoint.assert.
- def assert(context = nil, &condition)
- return if Breakpoint.optimize_asserts and not $DEBUG
- return if yield
-
- callstack = caller
- callstack.slice!(0, 3) if callstack.first["assert"]
- file, line, method = *callstack.first.match(/^(.+?):(\d+)(?::in `(.*?)')?/).captures
-
- message = "Assert failed at #{file}:#{line}#{" in `#{method}'" if method}."
-
- if Breakpoint.asserts_cause_exceptions and not $DEBUG then
- raise(Breakpoint::FailedAssertError, message)
- end
-
- message += " Executing implicit breakpoint."
-
- if context then
- return handle_breakpoint(context, message, file, line)
- end
-
- Binding.of_caller do |context|
- handle_breakpoint(context, message, file, line)
- end
- end
-
- # Whether asserts should be ignored if not in debug mode.
- # Debug mode can be enabled by running ruby with the -d
- # switch or by setting $DEBUG to true.
- attr_accessor :optimize_asserts
- self.optimize_asserts = false
-
- # Whether an Exception should be raised on failed asserts
- # in non-$DEBUG code or not. By default this is disabled.
- attr_accessor :asserts_cause_exceptions
- self.asserts_cause_exceptions = false
- @use_drb = false
-
- attr_reader :drb_service # :nodoc:
-
- class DRbService # :nodoc:
- include DRbUndumped
-
- def initialize
- @handler = @eval_handler = @collision_handler = nil
-
- IRB.instance_eval { @CONF[:RC] = true }
- IRB.run_config
- end
-
- def collision
- sleep(0.5) until @collision_handler
-
- @collision_handler.call
- end
-
- def ping; end
-
- def add_breakpoint(context, message)
- workspace = IRB::WorkSpace.new(context)
- workspace.extend(DRbUndumped)
-
- sleep(0.5) until @handler
-
- @handler.call(workspace, message)
- end
-
- def register_handler(&block)
- @handler = block
- end
-
- def unregister_handler
- @handler = nil
- end
-
- attr_reader :eval_handler
-
- def register_eval_handler(&block)
- @eval_handler = block
- end
-
- def unregister_eval_handler
- @eval_handler = lambda { }
- end
-
- def register_collision_handler(&block)
- @collision_handler = block
- end
-
- def unregister_collision_handler
- @collision_handler = lambda { }
- end
- end
-
- # Will run Breakpoint in DRb mode. This will spawn a server
- # that can be attached to via the breakpoint-client command
- # whenever a breakpoint is executed. This is useful when you
- # are debugging CGI applications or other applications where
- # you can't access debug sessions via the standard input and
- # output of your application.
- #
- # You can specify an URI where the DRb server will run at.
- # This way you can specify the port the server runs on. The
- # default URI is druby://localhost:42531.
- #
- # Please note that breakpoints will be skipped silently in
- # case the DRb server can not spawned. (This can happen if
- # the port is already used by another instance of your
- # application on CGI or another application.)
- #
- # Also note that by default this will only allow access
- # from localhost. You can however specify a list of
- # allowed hosts or nil (to allow access from everywhere).
- # But that will still not protect you from somebody
- # reading the data as it goes through the net.
- #
- # A good approach for getting security and remote access
- # is setting up an SSH tunnel between the DRb service
- # and the client. This is usually done like this:
- #
- # $ ssh -L20000:127.0.0.1:20000 -R10000:127.0.0.1:10000 example.com
- # (This will connect port 20000 at the client side to port
- # 20000 at the server side, and port 10000 at the server
- # side to port 10000 at the client side.)
- #
- # After that do this on the server side: (the code being debugged)
- # Breakpoint.activate_drb("druby://127.0.0.1:20000", "localhost")
- #
- # And at the client side:
- # ruby breakpoint_client.rb -c druby://127.0.0.1:10000 -s druby://127.0.0.1:20000
- #
- # Running through such a SSH proxy will also let you use
- # breakpoint.rb in case you are behind a firewall.
- #
- # Detailed information about running DRb through firewalls is
- # available at http://www.rubygarden.org/ruby?DrbTutorial
- def activate_drb(uri = nil, allowed_hosts = ['localhost', '127.0.0.1', '::1'], ignore_collisions = false) #:nodoc:
-
- return false if @use_drb
-
- uri ||= 'druby://localhost:42531'
-
- if allowed_hosts then
- acl = ["deny", "all"]
-
- Array(allowed_hosts).each do |host|
- acl += ["allow", host]
- end
-
- DRb.install_acl(ACL.new(acl))
- end
-
- @use_drb = true
- @drb_service = DRbService.new
- did_collision = false
- begin
- @service = DRb.start_service(uri, @drb_service)
- rescue Errno::EADDRINUSE
- if ignore_collisions then
- nil
- else
- # The port is already occupied by another
- # Breakpoint service. We will try to tell
- # the old service that we want its port.
- # It will then forward that request to the
- # user and retry.
- unless did_collision then
- DRbObject.new(nil, uri).collision
- did_collision = true
- end
- sleep(10)
- retry
- end
- end
-
- return true
- end
-
- # Deactivates a running Breakpoint service.
- def deactivate_drb #:nodoc:
- @service.stop_service unless @service.nil?
- @service = nil
- @use_drb = false
- @drb_service = nil
- end
-
- # Returns true when Breakpoints are used over DRb.
- # Breakpoint.activate_drb causes this to be true.
- def use_drb? #:nodoc:
- @use_drb == true
- end
-end
-
-module IRB # :nodoc:
- class << self; remove_method :start; end
- def self.start(ap_path = nil, main_context = nil, workspace = nil)
- $0 = File::basename(ap_path, ".rb") if ap_path
-
- # suppress some warnings about redefined constants
- old_verbose, $VERBOSE = $VERBOSE, nil
- IRB.setup(ap_path)
- $VERBOSE = old_verbose
-
- if @CONF[:SCRIPT] then
- irb = Irb.new(main_context, @CONF[:SCRIPT])
- else
- irb = Irb.new(main_context)
- end
-
- if workspace then
- irb.context.workspace = workspace
- end
-
- @CONF[:IRB_RC].call(irb.context) if @CONF[:IRB_RC]
- @CONF[:MAIN_CONTEXT] = irb.context
-
- old_sigint = trap("SIGINT") do
- irb.signal_handle
- end
-
- catch(:IRB_EXIT) do
- irb.eval_input
- end
- ensure
- trap("SIGINT", old_sigint)
- end
-
- class << self
- alias :old_CurrentContext :CurrentContext
- remove_method :CurrentContext
- end
- def IRB.CurrentContext
- if old_CurrentContext.nil? and Breakpoint.use_drb? then
- result = Object.new
- def result.last_value; end
- return result
- else
- old_CurrentContext
- end
- end
-
- class Context#:nodoc:
- alias :old_evaluate :evaluate
- def evaluate(line, line_no)
- if line.chomp == "exit" then
- exit
- else
- old_evaluate(line, line_no)
- end
- end
- end
-
- class WorkSpace#:nodoc:
- alias :old_evaluate :evaluate
-
- def evaluate(*args)
- if Breakpoint.use_drb? then
- result = old_evaluate(*args)
- if args[0] != :no_proxy and
- not [true, false, nil].include?(result)
- then
- result.extend(DRbUndumped) rescue nil
- end
- return result
- else
- old_evaluate(*args)
- end
- end
- end
-
- module InputCompletor#:nodoc:
- def self.eval(code, context, *more)
- # Big hack, this assumes that InputCompletor
- # will only call eval() when it wants code
- # to be executed in the IRB context.
- IRB.conf[:MAIN_CONTEXT].workspace.evaluate(:no_proxy, code, *more)
- end
- end
-end
-
-module DRb # :nodoc:
- class DRbObject#:nodoc:
- undef :inspect
- undef :clone
- end
-end
-
-# See Breakpoint.breakpoint
-def breakpoint(id = nil, &block)
- Binding.of_caller do |context|
- Breakpoint.breakpoint(id, context, &block)
- end
-end
-
-# See Breakpoint.assert
-def assert(&block)
- Binding.of_caller do |context|
- Breakpoint.assert(context, &block)
- end
-end
\ No newline at end of file |