TechEmpower.FrameworkBenchmarks/toolset/utils/setup_util.py

import re
import os
import sys
import subprocess

from threading import Thread
from Queue import Queue, Empty


class NonBlockingStreamReader:
    '''
  Enables calling readline in a non-blocking manner with a blocking stream, 
  such as the ones returned from subprocess.Popen

  Originally written by Eyal Arubas, who granted permission to use this inside TFB
  See http://eyalarubas.com/python-subproc-nonblock.html
  '''

    def __init__(self, stream, eof_message=None):
        '''
    stream: the stream to read from.
            Usually a process' stdout or stderr.
    eof_message: A message to print to stdout as soon
      as the stream's end is reached. Useful if you
      want to track the exact moment a stream terminates
    '''

        self._s = stream
        self._q = Queue()
        self._eof_message = eof_message
        self._poisonpill = 'MAGIC_POISONPILL_STRING'

        def _populateQueue(stream, queue):
            while True:
                line = stream.readline()
                if line:  # 'data\n' or '\n'
                    queue.put(line)
                else:  # '' e.g. EOF
                    if self._eof_message:
                        sys.stdout.write(self._eof_message + '\n')
                    queue.put(self._poisonpill)
                    return

        self._t = Thread(target=_populateQueue, args=(self._s, self._q))
        self._t.daemon = True
        self._t.start()

    def readline(self, timeout=None):
        try:
            line = self._q.get(block=timeout is not None, timeout=timeout)
            if line == self._poisonpill:
                raise EndOfStream
            return line
        except Empty:
            return None


class EndOfStream(Exception):
    pass


# Replaces all text found using the regular expression to_replace with the supplied replacement.
def replace_text(file, to_replace, replacement):
    with open(file, "r") as conf:
        contents = conf.read()
    replaced_text = re.sub(to_replace, replacement, contents)
    with open(file, "w") as f:
        f.write(replaced_text)


# Queries the shell for the value of FWROOT
def get_fwroot():

    if os.getenv('FWROOT'):
        return os.environ['FWROOT']
    else:
        return os.getcwd()


# Turns absolute path into path relative to FWROOT
# Assumes path is underneath FWROOT, not above
#
# Useful for clean presentation of paths
# e.g. /foo/bar/benchmarks/go/install.sh
# v.s. FWROOT/go/install.sh
def path_relative_to_root(path):
    # Requires bash shell parameter expansion
    return subprocess.check_output(
        "D=%s && printf \"${D#%s}\"" % (path, get_fwroot()),
        shell=True,
        executable='/bin/bash')