text: from __future__ import absolute_import
  
  import re
  import json
  import time
  import logging
  import random
  import six
  
  from django.conf import settings
  from django.core.cache import cache
  from six.moves.urllib.parse import parse_qsl
  
  from sentry import http
  from sentry.utils.safe import get_path
  from sentry.utils.strings import count_sprintf_parameters
  
  logger = logging.getLogger(__name__)
  
  SOFT_TIMEOUT = 600
  SOFT_TIMEOUT_FUZZINESS = 10
  HARD_TIMEOUT = 7200
  
  REACT_MAPPING_URL = (
      "https://raw.githubusercontent.com/facebook/" "react/master/scripts/error-codes/codes.json"
  )
  
  error_processors = {}
  
  
  def is_expired(ts):
      return ts > (time.time() - SOFT_TIMEOUT - random.random() * SOFT_TIMEOUT_FUZZINESS)
  
  
  class Processor(object):
      def __init__(self, vendor, mapping_url, regex, func):
          self.vendor = vendor
          self.mapping_url = mapping_url
          self.regex = re.compile(regex)
          self.func = func
  
      def load_mapping(self):
          key = "javascript.errormapping:%s" % self.vendor
          mapping = cache.get(key)
          cached_rv = None
          if mapping is not None:
              ts, cached_rv = json.loads(mapping)
              if not is_expired(ts):
                  return cached_rv
  
          try:
              http_session = http.build_session()
              response = http_session.get(
                  self.mapping_url, allow_redirects=True, timeout=settings.SENTRY_SOURCE_FETCH_TIMEOUT
              )
              # Make sure we only get a 2xx to prevent caching bad data
              response.raise_for_status()
              data = response.json()
              cache.set(key, json.dumps([time.time(), data]), HARD_TIMEOUT)
          except Exception:
              if cached_rv is None:
                  raise
              return cached_rv
          return data
  
      def try_process(self, exc):
          if not exc.get("value"):
              return False
          match = self.regex.search(exc["value"])
          if match is None:
              return False
          mapping = self.load_mapping()
          return self.func(exc, match, mapping)
  
  
  def minified_error(vendor, mapping_url, regex):
      def decorator(f):
          error_processors[vendor] = Processor(vendor, mapping_url, regex, f)
  
      return decorator
  
  
  @minified_error(
      vendor="react",
      mapping_url=REACT_MAPPING_URL,
      regex=r"Minified React error #(\d+); visit https?://[^?]+\?(\S+)",
  )
  def process_react_exception(exc, match, mapping):
      error_id, qs = match.groups()
      msg_format = mapping.get(error_id)
      if msg_format is None:
          return False
  
      arg_count = count_sprintf_parameters(msg_format)
      args = []
      for k, v in parse_qsl(qs, keep_blank_values=True):
          if k == "args[]":
              if isinstance(v, six.binary_type):
                  v = v.decode("utf-8", "replace")
              args.append(v)
  
      # Due to truncated error messages we sometimes might not be able to
      # get all arguments.  In that case we fill up missing parameters for
      # the format string with <redacted>.
      args = tuple(args + [u"<redacted>"] * (arg_count - len(args)))[:arg_count]
      exc["value"] = msg_format % args
  
      return True
  
  
  def rewrite_exception(data):
      """Rewrite an exception in an event if needed.  Updates the exception
      in place and returns `True` if a modification was performed or `False`
      otherwise.
      """
      rv = False
      for exc in get_path(data, "exception", "values", filter=True, default=()):
          for processor in six.itervalues(error_processors):
              try:
                  if processor.try_process(exc):
                      rv = True
                      break
              except Exception as e:
                  logger.error('Failed to run processor "%s": %s', processor.vendor, e, exc_info=True)
  
      return rv
  