| sbc | 0cec9d7 | 2014-11-24 17:25:29 | [diff] [blame] | 1 | """Control of and utilities for debugging.""" |
| 2 | |
| 3 | import os |
| 4 | |
| 5 | |
| 6 | # When debugging, it can be helpful to force some options, especially when |
| 7 | # debugging the configuration mechanisms you usually use to control debugging! |
| 8 | # This is a list of forced debugging options. |
| 9 | FORCED_DEBUG = [] |
| 10 | |
| 11 | |
| 12 | class DebugControl(object): |
| 13 | """Control and output for debugging.""" |
| 14 | |
| 15 | def __init__(self, options, output): |
| 16 | """Configure the options and output file for debugging.""" |
| 17 | self.options = options |
| 18 | self.output = output |
| 19 | |
| 20 | def should(self, option): |
| 21 | """Decide whether to output debug information in category `option`.""" |
| 22 | return (option in self.options or option in FORCED_DEBUG) |
| 23 | |
| 24 | def write(self, msg): |
| 25 | """Write a line of debug output.""" |
| 26 | if self.should('pid'): |
| 27 | msg = "pid %5d: %s" % (os.getpid(), msg) |
| 28 | self.output.write(msg+"\n") |
| 29 | self.output.flush() |
| 30 | |
| 31 | def write_formatted_info(self, info): |
| 32 | """Write a sequence of (label,data) pairs nicely.""" |
| 33 | for line in info_formatter(info): |
| 34 | self.write(" %s" % line) |
| 35 | |
| 36 | |
| 37 | def info_formatter(info): |
| 38 | """Produce a sequence of formatted lines from info. |
| 39 | |
| 40 | `info` is a sequence of pairs (label, data). The produced lines are |
| 41 | nicely formatted, ready to print. |
| 42 | |
| 43 | """ |
| 44 | label_len = max([len(l) for l, _d in info]) |
| 45 | for label, data in info: |
| 46 | if data == []: |
| 47 | data = "-none-" |
| 48 | if isinstance(data, (list, tuple)): |
| 49 | prefix = "%*s:" % (label_len, label) |
| 50 | for e in data: |
| 51 | yield "%*s %s" % (label_len+1, prefix, e) |
| 52 | prefix = "" |
| 53 | else: |
| 54 | yield "%*s: %s" % (label_len, label, data) |
