[Abandoned] Move url_open with dependencies to utils.net module.

run_isolated.py

Index: run_isolated.py
diff --git a/run_isolated.py b/run_isolated.py
index bec8b556449001e27b2e9540d43961501d462390..59bae1309324cb306c5f877037aca63fac682bd0 100755
--- a/run_isolated.py
+++ b/run_isolated.py
@@ -8,49 +8,34 @@
 Keeps a local cache.
 """
 
-import cookielib
 import ctypes
 import functools
 import hashlib
 import httplib
-import itertools
 import json
 import logging
-import math
 import optparse
 import os
 import Queue
 import random
 import re
 import shutil
-import socket
-import ssl
 import stat
 import subprocess
 import sys
 import tempfile
-import threading
 import time
-import urllib
-import urllib2
-import urlparse
 import zlib
 
-from third_party.rietveld import upload
 from third_party.depot_tools import fix_encoding
 
 from utils import lru
+from utils import net
 from utils import threading_utils
 from utils import tools
 from utils import zip_package
 
 
-# Hack out upload logging.info()
-upload.logging = logging.getLogger('upload')
-# Mac pylint choke on this line.
-upload.logging.setLevel(logging.WARNING)  # pylint: disable=E1103
-
-
 # Absolute path to this file (can be None if running from zip on Mac).
 THIS_FILE_PATH = os.path.abspath(__file__) if __file__ else None
 
@@ -88,22 +73,10 @@ DELAY_BETWEEN_UPDATES_IN_SECS = 30
 # and all stack frames for all threads are dumped to log.
 DEADLOCK_TIMEOUT = 5 * 60
 
-# The name of the key to store the count of url attempts.
-COUNT_KEY = 'UrlOpenAttempt'
-
-# Default maximum number of attempts to trying opening a url before aborting.
-URL_OPEN_MAX_ATTEMPTS = 30
-# Default timeout when retrying.
-URL_OPEN_TIMEOUT = 6*60.
-
 # Read timeout in seconds for downloads from isolate storage. If there's no
 # response from the server within this timeout whole download will be aborted.
 DOWNLOAD_READ_TIMEOUT = 60
 
-# Global (for now) map: server URL (http://example.com) -> HttpService instance.
-# Used by get_http_service to cache HttpService instances.
-_http_services = {}
-_http_services_lock = threading.Lock()
 
 # Used by get_flavor().
 FLAVOR_MAPPING = {
@@ -126,14 +99,6 @@ class MappingError(OSError):
   pass
 
 
-class TimeoutError(IOError):
-  """Timeout while reading HTTP response."""
-
-  def __init__(self, inner_exc=None):
-    super(TimeoutError, self).__init__(str(inner_exc or 'Timeout'))
-    self.inner_exc = inner_exc
-
-
 def get_as_zip_package(executable=True):
   """Returns ZipPackage with this module and all its dependencies.
 
@@ -371,450 +336,6 @@ def load_isolated(content, os_flavor=None):
   return data
 
 
-def url_open(url, **kwargs):
-  """Attempts to open the given url multiple times.
-
-  |data| can be either:
-    -None for a GET request
-    -str for pre-encoded data
-    -list for data to be encoded
-    -dict for data to be encoded (COUNT_KEY will be added in this case)
-
-  Returns HttpResponse object, where the response may be read from, or None
-  if it was unable to connect.
-  """
-  urlhost, urlpath = split_server_request_url(url)
-  service = get_http_service(urlhost)
-  return service.request(urlpath, **kwargs)
-
-
-def url_read(url, **kwargs):
-  """Attempts to open the given url multiple times and read all data from it.
-
-  Accepts same arguments as url_open function.
-
-  Returns all data read or None if it was unable to connect or read the data.
-  """
-  response = url_open(url, **kwargs)
-  if not response:
-    return None
-  try:
-    return response.read()
-  except TimeoutError:
-    return None
-
-
-def split_server_request_url(url):
-  """Splits the url into scheme+netloc and path+params+query+fragment."""
-  url_parts = list(urlparse.urlparse(url))
-  urlhost = '%s://%s' % (url_parts[0], url_parts[1])
-  urlpath = urlparse.urlunparse(['', ''] + url_parts[2:])
-  return urlhost, urlpath
-
-
-def get_http_service(urlhost):
-  """Returns existing or creates new instance of HttpService that can send
-  requests to given base urlhost.
-  """
-  # Ensure consistency.
-  urlhost = str(urlhost).lower().rstrip('/')
-  with _http_services_lock:
-    service = _http_services.get(urlhost)
-    if not service:
-      service = AppEngineService(urlhost)
-      _http_services[urlhost] = service
-    return service
-
-
-class HttpService(object):
-  """Base class for a class that provides an API to HTTP based service:
-    - Provides 'request' method.
-    - Supports automatic request retries.
-    - Supports persistent cookies.
-    - Thread safe.
-  """
-
-  # File to use to store all auth cookies.
-  COOKIE_FILE = os.path.join(os.path.expanduser('~'), '.isolated_cookies')
-
-  # CookieJar reused by all services + lock that protects its instantiation.
-  _cookie_jar = None
-  _cookie_jar_lock = threading.Lock()
-
-  def __init__(self, urlhost):
-    self.urlhost = urlhost
-    self.cookie_jar = self.load_cookie_jar()
-    self.opener = self.create_url_opener()
-
-  def authenticate(self):  # pylint: disable=R0201
-    """Called when HTTP server asks client to authenticate.
-    Can be implemented in subclasses.
-    """
-    return False
-
-  @staticmethod
-  def load_cookie_jar():
-    """Returns global CoookieJar object that stores cookies in the file."""
-    with HttpService._cookie_jar_lock:
-      if HttpService._cookie_jar is not None:
-        return HttpService._cookie_jar
-      jar = ThreadSafeCookieJar(HttpService.COOKIE_FILE)
-      jar.load()
-      HttpService._cookie_jar = jar
-      return jar
-
-  @staticmethod
-  def save_cookie_jar():
-    """Called when cookie jar needs to be flushed to disk."""
-    with HttpService._cookie_jar_lock:
-      if HttpService._cookie_jar is not None:
-        HttpService._cookie_jar.save()
-
-  def create_url_opener(self):  # pylint: disable=R0201
-    """Returns OpenerDirector that will be used when sending requests.
-    Can be reimplemented in subclasses."""
-    return urllib2.build_opener(urllib2.HTTPCookieProcessor(self.cookie_jar))
-
-  def request(self, urlpath, data=None, content_type=None, **kwargs):
-    """Attempts to open the given url multiple times.
-
-    |urlpath| is relative to the server root, i.e. '/some/request?param=1'.
-
-    |data| can be either:
-      -None for a GET request
-      -str for pre-encoded data
-      -list for data to be encoded
-      -dict for data to be encoded (COUNT_KEY will be added in this case)
-
-    Returns a file-like object, where the response may be read from, or None
-    if it was unable to connect.
-    """
-    assert urlpath and urlpath[0] == '/'
-
-    if isinstance(data, dict) and COUNT_KEY in data:
-      logging.error('%s already existed in the data passed into UlrOpen. It '
-                    'would be overwritten. Aborting UrlOpen', COUNT_KEY)
-      return None
-
-    method = 'GET' if data is None else 'POST'
-    assert not ((method != 'POST') and content_type), (
-        'Can\'t use content_type on GET')
-
-    def make_request(extra):
-      """Returns a urllib2.Request instance for this specific retry."""
-      if isinstance(data, str) or data is None:
-        payload = data
-      else:
-        if isinstance(data, dict):
-          payload = data.items()
-        else:
-          payload = data[:]
-        payload.extend(extra.iteritems())
-        payload = urllib.urlencode(payload)
-      new_url = urlparse.urljoin(self.urlhost, urlpath[1:])
-      if isinstance(data, str) or data is None:
-        # In these cases, add the extra parameter to the query part of the url.
-        url_parts = list(urlparse.urlparse(new_url))
-        # Append the query parameter.
-        if url_parts[4] and extra:
-          url_parts[4] += '&'
-        url_parts[4] += urllib.urlencode(extra)
-        new_url = urlparse.urlunparse(url_parts)
-      request = urllib2.Request(new_url, data=payload)
-      if payload is not None:
-        if content_type:
-          request.add_header('Content-Type', content_type)
-        request.add_header('Content-Length', len(payload))
-      return request
-
-    return self._retry_loop(make_request, **kwargs)
-
-  def _retry_loop(
-      self,
-      make_request,
-      max_attempts=URL_OPEN_MAX_ATTEMPTS,
-      retry_404=False,
-      retry_50x=True,
-      timeout=URL_OPEN_TIMEOUT,
-      read_timeout=None):
-    """Runs internal request-retry loop.
-
-    - Optionally retries HTTP 404 and 50x.
-    - Retries up to |max_attempts| times. If None or 0, there's no limit in the
-      number of retries.
-    - Retries up to |timeout| duration in seconds. If None or 0, there's no
-      limit in the time taken to do retries.
-    - If both |max_attempts| and |timeout| are None or 0, this functions retries
-      indefinitely.
-
-    If |read_timeout| is not None will configure underlying socket to
-    raise TimeoutError exception whenever there's no response from the server
-    for more than |read_timeout| seconds. It can happen during any read
-    operation so once you pass non-None |read_timeout| be prepared to handle
-    these exceptions in subsequent reads from the stream.
-    """
-    authenticated = False
-    last_error = None
-    attempt = 0
-    start = self._now()
-    for attempt in itertools.count():
-      if max_attempts and attempt >= max_attempts:
-        # Too many attempts.
-        break
-      if timeout and (self._now() - start) >= timeout:
-        # Retried for too long.
-        break
-      extra = {COUNT_KEY: attempt} if attempt else {}
-      request = make_request(extra)
-      try:
-        url_response = self._url_open(request, timeout=read_timeout)
-        logging.debug('url_open(%s) succeeded', request.get_full_url())
-        return HttpResponse(url_response, request.get_full_url())
-      except urllib2.HTTPError as e:
-        # Unauthorized. Ask to authenticate and then try again.
-        if e.code in (401, 403):
-          # Try to authenticate only once. If it doesn't help, then server does
-          # not support app engine authentication.
-          logging.error(
-              'Authentication is required for %s on attempt %d.\n%s',
-              request.get_full_url(), attempt,
-              self._format_exception(e, verbose=True))
-          if not authenticated and self.authenticate():
-            authenticated = True
-            # Do not sleep.
-            continue
-          # If authentication failed, return.
-          logging.error(
-              'Unable to authenticate to %s.\n%s',
-              request.get_full_url(), self._format_exception(e, verbose=True))
-          return None
-
-        if ((e.code < 500 and not (retry_404 and e.code == 404)) or
-            (e.code >= 500 and not retry_50x)):
-          # This HTTPError means we reached the server and there was a problem
-          # with the request, so don't retry.
-          logging.error(
-              'Able to connect to %s but an exception was thrown.\n%s',
-              request.get_full_url(), self._format_exception(e, verbose=True))
-          return None
-
-        # The HTTPError was due to a server error, so retry the attempt.
-        logging.warning('Able to connect to %s on attempt %d.\n%s',
-                        request.get_full_url(), attempt,
-                        self._format_exception(e))
-        last_error = e
-
-      except (urllib2.URLError, httplib.HTTPException,
-              socket.timeout, ssl.SSLError) as e:
-        logging.warning('Unable to open url %s on attempt %d.\n%s',
-                        request.get_full_url(), attempt,
-                        self._format_exception(e))
-        last_error = e
-
-      # Only sleep if we are going to try again.
-      if max_attempts and attempt != max_attempts:
-        remaining = None
-        if timeout:
-          remaining = timeout - (self._now() - start)
-          if remaining <= 0:
-            break
-        self.sleep_before_retry(attempt, remaining)
-
-    logging.error('Unable to open given url, %s, after %d attempts.\n%s',
-                  request.get_full_url(), max_attempts,
-                  self._format_exception(last_error, verbose=True))
-    return None
-
-  def _url_open(self, request, timeout=None):
-    """Low level method to execute urllib2.Request's.
-
-    To be mocked in tests.
-    """
-    if timeout is not None:
-      return self.opener.open(request, timeout=timeout)
-    else:
-      # Leave original default value for |timeout|. It's nontrivial.
-      return self.opener.open(request)
-
-  @staticmethod
-  def _now():
-    """To be mocked in tests."""
-    return time.time()
-
-  @staticmethod
-  def calculate_sleep_before_retry(attempt, max_duration):
-    # Maximum sleeping time. We're hammering a cloud-distributed service, it'll
-    # survive.
-    MAX_SLEEP = 10.
-    # random.random() returns [0.0, 1.0). Starts with relatively short waiting
-    # time by starting with 1.5/2+1.5^-1 median offset.
-    duration = (random.random() * 1.5) + math.pow(1.5, (attempt - 1))
-    assert duration > 0.1
-    duration = min(MAX_SLEEP, duration)
-    if max_duration:
-      duration = min(max_duration, duration)
-    return duration
-
-  @classmethod
-  def sleep_before_retry(cls, attempt, max_duration):
-    """Sleeps for some amount of time when retrying the request.
-
-    To be mocked in tests.
-    """
-    time.sleep(cls.calculate_sleep_before_retry(attempt, max_duration))
-
-  @staticmethod
-  def _format_exception(exc, verbose=False):
-    """Given an instance of some exception raised by urlopen returns human
-    readable piece of text with detailed information about the error.
-    """
-    out = ['Exception: %s' % (exc,)]
-    if verbose:
-      if isinstance(exc, urllib2.HTTPError):
-        out.append('-' * 10)
-        if exc.hdrs:
-          for header, value in exc.hdrs.items():
-            if not header.startswith('x-'):
-              out.append('%s: %s' % (header.capitalize(), value))
-          out.append('')
-        out.append(exc.read() or '<empty body>')
-        out.append('-' * 10)
-    return '\n'.join(out)
-
-
-class HttpResponse(object):
-  """Response from HttpService."""
-
-  def __init__(self, url_response, url):
-    self._url_response = url_response
-    self._url = url
-    self._read = 0
-
-  @property
-  def content_length(self):
-    """Total length to the response or None if not known in advance."""
-    length = self._url_response.headers.get('Content-Length')
-    return int(length) if length is not None else None
-
-  def read(self, size=None):
-    """Reads up to |size| bytes from the stream and returns them.
-
-    If |size| is None reads all available bytes.
-
-    Raises TimeoutError on read timeout.
-    """
-    try:
-      data = self._url_response.read(size)
-      self._read += len(data)
-      return data
-    except (socket.timeout, ssl.SSLError) as e:
-      logging.error('Timeout while reading from %s, read %d of %s: %s',
-                    self._url, self._read, self.content_length, e)
-      raise TimeoutError(e)
-
-
-class AppEngineService(HttpService):
-  """This class implements authentication support for
-  an app engine based services.
-  """
-
-  # This lock ensures that user won't be confused with multiple concurrent
-  # login prompts.
-  _auth_lock = threading.Lock()
-
-  def __init__(self, urlhost, email=None, password=None):
-    super(AppEngineService, self).__init__(urlhost)
-    self.email = email
-    self.password = password
-    self._keyring = None
-
-  def authenticate(self):
-    """Authenticates in the app engine application.
-    Returns True on success.
-    """
-    if not upload:
-      logging.error('\'upload\' module is missing, '
-                    'app engine authentication is disabled.')
-      return False
-    cookie_jar = self.cookie_jar
-    save_cookie_jar = self.save_cookie_jar
-    # RPC server that uses AuthenticationSupport's cookie jar.
-    class AuthServer(upload.AbstractRpcServer):
-      def _GetOpener(self):
-        # Authentication code needs to know about 302 response.
-        # So make OpenerDirector without HTTPRedirectHandler.
-        opener = urllib2.OpenerDirector()
-        opener.add_handler(urllib2.ProxyHandler())
-        opener.add_handler(urllib2.UnknownHandler())
-        opener.add_handler(urllib2.HTTPHandler())
-        opener.add_handler(urllib2.HTTPDefaultErrorHandler())
-        opener.add_handler(urllib2.HTTPSHandler())
-        opener.add_handler(urllib2.HTTPErrorProcessor())
-        opener.add_handler(urllib2.HTTPCookieProcessor(cookie_jar))
-        return opener
-      def PerformAuthentication(self):
-        self._Authenticate()
-        save_cookie_jar()
-        return self.authenticated
-    with AppEngineService._auth_lock:
-      rpc_server = AuthServer(self.urlhost, self.get_credentials)
-      return rpc_server.PerformAuthentication()
-
-  def get_credentials(self):
-    """Called during authentication process to get the credentials.
-    May be called mutliple times if authentication fails.
-    Returns tuple (email, password).
-    """
-    # 'authenticate' calls this only if 'upload' is present.
-    # Ensure other callers (if any) fail non-cryptically if 'upload' is missing.
-    assert upload, '\'upload\' module is required for this to work'
-    if self.email and self.password:
-      return (self.email, self.password)
-    if not self._keyring:
-      self._keyring = upload.KeyringCreds(self.urlhost,
-                                          self.urlhost,
-                                          self.email)
-    return self._keyring.GetUserCredentials()
-
-
-class ThreadSafeCookieJar(cookielib.MozillaCookieJar):
-  """MozillaCookieJar with thread safe load and save."""
-
-  def load(self, filename=None, ignore_discard=False, ignore_expires=False):
-    """Loads cookies from the file if it exists."""
-    filename = os.path.expanduser(filename or self.filename)
-    with self._cookies_lock:
-      if os.path.exists(filename):
-        try:
-          cookielib.MozillaCookieJar.load(self, filename,
-                                          ignore_discard,
-                                          ignore_expires)
-          logging.debug('Loaded cookies from %s', filename)
-        except (cookielib.LoadError, IOError):
-          pass
-      else:
-        try:
-          fd = os.open(filename, os.O_CREAT, 0600)
-          os.close(fd)
-        except OSError:
-          logging.error('Failed to create %s', filename)
-      try:
-        os.chmod(filename, 0600)
-      except OSError:
-        logging.error('Failed to fix mode for %s', filename)
-
-  def save(self, filename=None, ignore_discard=False, ignore_expires=False):
-    """Saves cookies to the file, completely overwriting it."""
-    logging.debug('Saving cookies to %s', filename or self.filename)
-    with self._cookies_lock:
-      try:
-        cookielib.MozillaCookieJar.save(self, filename,
-                                        ignore_discard,
-                                        ignore_expires)
-      except OSError:
-        logging.error('Failed to save %s', filename)
-
-
 def valid_file(filepath, size):
   """Determines if the given files appears valid (currently it just checks
   the file's size)."""
@@ -924,8 +445,8 @@ class Remote(object):
       # Because the app engine DB is only eventually consistent, retry
       # 404 errors because the file might just not be visible yet (even
       # though it has been uploaded).
-      connection = url_open(zipped_source, retry_404=True,
-                            read_timeout=DOWNLOAD_READ_TIMEOUT)
+      connection = net.url_open(zipped_source, retry_404=True,
+          read_timeout=DOWNLOAD_READ_TIMEOUT)
       if not connection:
         raise IOError('Unable to open connection to %s' % zipped_source)