# This Source Code Form is subject to the terms of the Mozilla Public # License, v. 2.0. If a copy of the MPL was not distributed with this # file, You can obtain one at http://mozilla.org/MPL/2.0/. from __future__ import absolute_import, print_function, unicode_literals import codecs import itertools import locale import logging import os import sys from collections import deque from contextlib import contextmanager from distutils.version import LooseVersion def getpreferredencoding(): # locale._parse_localename makes locale.getpreferredencoding # return None when LC_ALL is C, instead of e.g. 'US-ASCII' or # 'ANSI_X3.4-1968' when it uses nl_langinfo. encoding = None try: encoding = locale.getpreferredencoding() except ValueError: # On english OSX, LC_ALL is UTF-8 (not en-US.UTF-8), and # that throws off locale._parse_localename, which ends up # being used on e.g. homebrew python. if os.environ.get('LC_ALL', '').upper() == 'UTF-8': encoding = 'utf-8' return encoding class Version(LooseVersion): '''A simple subclass of distutils.version.LooseVersion. Adds attributes for `major`, `minor`, `patch` for the first three version components so users can easily pull out major/minor versions, like: v = Version('1.2b') v.major == 1 v.minor == 2 v.patch == 0 ''' def __init__(self, version): # Can't use super, LooseVersion's base class is not a new-style class. LooseVersion.__init__(self, version) # Take the first three integer components, stopping at the first # non-integer and padding the rest with zeroes. (self.major, self.minor, self.patch) = list(itertools.chain( itertools.takewhile(lambda x:isinstance(x, int), self.version), (0, 0, 0)))[:3] def __cmp__(self, other): # LooseVersion checks isinstance(StringType), so work around it. if isinstance(other, unicode): other = other.encode('ascii') return LooseVersion.__cmp__(self, other) class ConfigureOutputHandler(logging.Handler): '''A logging handler class that sends info messages to stdout and other messages to stderr. Messages sent to stdout are not formatted with the attached Formatter. Additionally, if they end with '... ', no newline character is printed, making the next message printed follow the '... '. Only messages above log level INFO (included) are logged. Messages below that level can be kept until an ERROR message is received, at which point the last `maxlen` accumulated messages below INFO are printed out. This feature is only enabled under the `queue_debug` context manager. ''' def __init__(self, stdout=sys.stdout, stderr=sys.stderr, maxlen=20): super(ConfigureOutputHandler, self).__init__() # Python has this feature where it sets the encoding of pipes to # ascii, which blatantly fails when trying to print out non-ascii. def fix_encoding(fh): try: isatty = fh.isatty() except AttributeError: isatty = True if not isatty: encoding = getpreferredencoding() if encoding: return codecs.getwriter(encoding)(fh) return fh self._stdout = fix_encoding(stdout) self._stderr = fix_encoding(stderr) if stdout != stderr else self._stdout try: fd1 = self._stdout.fileno() fd2 = self._stderr.fileno() self._same_output = self._is_same_output(fd1, fd2) except AttributeError: self._same_output = self._stdout == self._stderr self._stdout_waiting = None self._debug = deque(maxlen=maxlen + 1) self._keep_if_debug = self.THROW self._queue_is_active = False @staticmethod def _is_same_output(fd1, fd2): if fd1 == fd2: return True stat1 = os.fstat(fd1) stat2 = os.fstat(fd2) return stat1.st_ino == stat2.st_ino and stat1.st_dev == stat2.st_dev # possible values for _stdout_waiting WAITING = 1 INTERRUPTED = 2 # possible values for _keep_if_debug THROW = 0 KEEP = 1 PRINT = 2 def emit(self, record): try: if record.levelno == logging.INFO: stream = self._stdout msg = record.getMessage() if (self._stdout_waiting == self.INTERRUPTED and self._same_output): msg = ' ... %s' % msg self._stdout_waiting = msg.endswith('... ') if msg.endswith('... '): self._stdout_waiting = self.WAITING else: self._stdout_waiting = None msg = '%s\n' % msg elif (record.levelno < logging.INFO and self._keep_if_debug != self.PRINT): if self._keep_if_debug == self.KEEP: self._debug.append(record) return else: if record.levelno >= logging.ERROR and len(self._debug): self._emit_queue() if self._stdout_waiting == self.WAITING and self._same_output: self._stdout_waiting = self.INTERRUPTED self._stdout.write('\n') self._stdout.flush() stream = self._stderr msg = '%s\n' % self.format(record) stream.write(msg) stream.flush() except (KeyboardInterrupt, SystemExit): raise except: self.handleError(record) @contextmanager def queue_debug(self): if self._queue_is_active: yield return self._queue_is_active = True self._keep_if_debug = self.KEEP try: yield except Exception: self._emit_queue() # The exception will be handled and very probably printed out by # something upper in the stack. raise finally: self._queue_is_active = False self._keep_if_debug = self.THROW self._debug.clear() def _emit_queue(self): self._keep_if_debug = self.PRINT if len(self._debug) == self._debug.maxlen: r = self._debug.popleft() self.emit(logging.LogRecord( r.name, r.levelno, r.pathname, r.lineno, '', (), None)) while True: try: self.emit(self._debug.popleft()) except IndexError: break self._keep_if_debug = self.KEEP class LineIO(object): '''File-like class that sends each line of the written data to a callback (without carriage returns). ''' def __init__(self, callback): self._callback = callback self._buf = '' self._encoding = getpreferredencoding() def write(self, buf): if self._encoding and isinstance(buf, str): buf = buf.decode(self._encoding) lines = buf.splitlines() if not lines: return if self._buf: lines[0] = self._buf + lines[0] self._buf = '' if not buf.endswith('\n'): self._buf = lines.pop() for line in lines: self._callback(line) def close(self): if self._buf: self._callback(self._buf) self._buf = '' def __enter__(self): return self def __exit__(self, *args): self.close()