1 files changed, 75 insertions, 0 deletions
diff --git a/lib/tracer.rb b/lib/tracer.rb
new file mode 100644
index 0000000000..d37339fd62
--- /dev/null
+++ b/lib/tracer.rb
@@ -0,0 +1,75 @@
+class Tracer
+  MY_FILE_NAME_PATTERN = /^tracer\.(rb)?/
+  Threads = Hash.new
+  Sources = Hash.new
+  
+  EVENT_SYMBOL = {
+    "line" => "-",
+    "call" => ">",
+    "return" => "<",
+    "class" => "C",
+    "end" => "E"}
+  
+  def on
+    set_trace_func proc{|event, file, line, id, binding|
+      trace_func event, file, line, id, binding
+    }
+    print "Trace on\n"
+  end
+  
+  def off
+    set_trace_func nil
+    print "Trace off\n"
+  end
+  
+  def get_thread_no
+    unless no =  Threads[Thread.current.id]
+      Threads[Thread.current.id] = no = Threads.size
+    end
+    no
+  end
+  
+  def get_line(file, line)
+    unless list = Sources[file]
+      f =open(file)
+      begin 
+	Sources[file] = list = f.readlines
+      ensure
+	f.close
+      end
+    end
+    list[line - 1]
+  end
+  
+  def trace_func(event, file, line, id, binding)
+    return if File.basename(file) =~ MY_FILE_NAME_PATTERN
+    
+    Thread.critical = TRUE
+    printf("#%d:%s:%d:%s: %s",
+	   get_thread_no,
+	   file,
+	   line,
+	   EVENT_SYMBOL[event],
+	   get_line(file, line))
+    Thread.critical = FALSE
+  end
+
+  Single = new
+  def Tracer.on
+    Single.on
+  end
+  
+  def Tracer.off
+    Single.off
+  end
+  
+end
+
+if File.basename($0) =~ Tracer::MY_FILE_NAME_PATTERN
+  $0 = ARGV.shift
+  
+  Tracer.on
+  load $0
+else
+  Tracer.on
+end