| """Control of and utilities for debugging.""" |
| |
| import os |
| |
| |
| # When debugging, it can be helpful to force some options, especially when |
| # debugging the configuration mechanisms you usually use to control debugging! |
| # This is a list of forced debugging options. |
| FORCED_DEBUG = [] |
| |
| |
| class DebugControl(object): |
| """Control and output for debugging.""" |
| |
| def __init__(self, options, output): |
| """Configure the options and output file for debugging.""" |
| self.options = options |
| self.output = output |
| |
| def should(self, option): |
| """Decide whether to output debug information in category `option`.""" |
| return (option in self.options or option in FORCED_DEBUG) |
| |
| def write(self, msg): |
| """Write a line of debug output.""" |
| if self.should('pid'): |
| msg = "pid %5d: %s" % (os.getpid(), msg) |
| self.output.write(msg+"\n") |
| self.output.flush() |
| |
| def write_formatted_info(self, info): |
| """Write a sequence of (label,data) pairs nicely.""" |
| for line in info_formatter(info): |
| self.write(" %s" % line) |
| |
| |
| def info_formatter(info): |
| """Produce a sequence of formatted lines from info. |
| |
| `info` is a sequence of pairs (label, data). The produced lines are |
| nicely formatted, ready to print. |
| |
| """ |
| label_len = max([len(l) for l, _d in info]) |
| for label, data in info: |
| if data == []: |
| data = "-none-" |
| if isinstance(data, (list, tuple)): |
| prefix = "%*s:" % (label_len, label) |
| for e in data: |
| yield "%*s %s" % (label_len+1, prefix, e) |
| prefix = "" |
| else: |
| yield "%*s: %s" % (label_len, label, data) |
