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Feature #4720 ยป 0001-Added-documentation-for-lib-tracer.rb.patch

rramsden (Richard Ramsden), 05/17/2011 04:23 PM

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lib/tracer.rb
# tracer.rb -
# $Release Version: 0.3$
# $Revision: 1.12 $
# by Keiju ISHITSUKA(keiju@ishitsuka.com)
##
# = Tracer
#
# --
# Tracer outputs a source level execution trace of a Ruby program. It does this by
# registering an event handler with <code>Kernel#set_trace_func</code> for processing incoming events.
# It also provides methods for filtering unwanted trace output (see Tracer.add_filter, Tracer.on, and Tracer.off).
#
# == Example
#
# Consider the following ruby script
#
# class A
# def square(a)
# return a*a
# end
# end
#
# a = A.new
# a.square(5)
#
# Running the above script using <code>ruby -r tracer example.rb</code> will
# output the following trace to STDOUT (Note you can also explicitly <code>require 'tracer'</code>)
#
# #0:<internal:lib/rubygems/custom_require>:38:Kernel:<: -
# #0:example.rb:3::-: class A
# #0:example.rb:3::C: class A
# #0:example.rb:4::-: def square(a)
# #0:example.rb:7::E: end
# #0:example.rb:9::-: a = A.new
# #0:example.rb:10::-: a.square(5)
# #0:example.rb:4:A:>: def square(a)
# #0:example.rb:5:A:-: return a*a
# #0:example.rb:6:A:<: end
# | | | | |
# | | | | ---------------------+ event
# | | | ------------------------+ class
# | | --------------------------+ line
# | ------------------------------------+ filename
# ---------------------------------------+ thread
#
# Symbol table used for displaying incoming events:
#
# * <tt>}</tt> (call a C-language routine)
# * <tt>{</tt> (return from a C-language routine)
# * <tt>></tt> (call a Ruby method)
# * <tt>C</tt> (start a class or module definition)
# * <tt>E</tt> (finish a class or module definition)
# * <tt>-</tt> (execute code on a new line)
# * <tt>^</tt> (raise an exception)
# * <tt><</tt> (return from a Ruby method)
#
# == Copyright
#
# by Keiju ISHITSUKA(keiju@ishitsuka.com)
#
# --
# $Release Version: 0.3$
# $Revision: 1.12 $
require "thread"
#
......
#
class Tracer
class << self
# display additional debug information (defaults to false)
attr_accessor :verbose
alias verbose? verbose
# output stream used to output trace (defaults to STDOUT)
attr_accessor :stdout
# mutex lock used by tracer for displaying trace output
attr_reader :stdout_mutex
# display process id?
# display process id in trace output (defaults to false)
attr_accessor :display_process_id
alias display_process_id? display_process_id
# display thread id?
# display thread id in trace output (defaults to true)
attr_accessor :display_thread_id
alias display_thread_id? display_thread_id
# display builtin method call?
# display C-routine calls in trace output (defaults to false)
attr_accessor :display_c_call
alias display_c_call? display_c_call
end
Tracer::stdout = STDOUT
Tracer::verbose = false
Tracer::display_process_id = false
......
@stdout_mutex = Mutex.new
# Symbol table used for displaying trace information
EVENT_SYMBOL = {
"line" => "-",
"call" => ">",
......
"unknown" => "?"
}
def initialize
def initialize # :nodoc:
@threads = Hash.new
if defined? Thread.main
@threads[Thread.main.object_id] = 0
......
@filters = []
end
def stdout
def stdout # :nodoc:
Tracer.stdout
end
def on
def on # :nodoc:
if block_given?
on
begin
......
end
end
def off
def off # :nodoc:
set_trace_func nil
stdout.print "Trace off\n" if Tracer.verbose?
end
def add_filter(p = proc)
def add_filter(p = proc) # :nodoc:
@filters.push p
end
def set_get_line_procs(file, p = proc)
def set_get_line_procs(file, p = proc) # :nodoc:
@get_line_procs[file] = p
end
def get_line(file, line)
def get_line(file, line) # :nodoc:
if p = @get_line_procs[file]
return p.call(line)
end
......
end
end
def get_thread_no
def get_thread_no # :nodoc:
if no = @threads[Thread.current.object_id]
no
else
......
end
end
def trace_func(event, file, line, id, binding, klass, *)
def trace_func(event, file, line, id, binding, klass, *) # :nodoc:
return if file == __FILE__
for p in @filters
......
end
# Reference to singleton instance of Tracer
Single = new
##
# Start tracing
#
# === Example
#
# Tracer.on
# # code to trace here
# Tracer.off
#
# You can also pass a block:
#
# Tracer.on {
# # trace everything in this block
# }
def Tracer.on
if block_given?
Single.on{yield}
......
end
end
##
# Disable tracing
def Tracer.off
Single.off
end
##
# Register an event handler <code>p</code> which is called
# everytime a line in +file_name+ is executed.
#
# ==== Example
#
# Tracer.set_get_line_procs("example.rb", lambda { |line|
# puts "line number executed is #{line}"
# })
def Tracer.set_get_line_procs(file_name, p = proc)
Single.set_get_line_procs(file_name, p)
end
##
# Used to filter unwanted trace output
#
# === Example
#
# Only output lines of code executed within the Kernel class:
#
# Tracer.add_filter do |event, file, line, id, binding, klass, *rest|
# "Kernel" == klass.to_s
# end
def Tracer.add_filter(p = proc)
Single.add_filter(p)
end
end
# :stopdoc:
SCRIPT_LINES__ = {} unless defined? SCRIPT_LINES__
if $0 == __FILE__
......
elsif caller.count {|bt| /\A<internal:[^<>]+>:/ !~ bt} <= 1
Tracer.on
end
# :startdoc:
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