sdk/python/arvados/keep.py

   1 # Copyright (C) The Arvados Authors. All rights reserved.
   2 #
   3 # SPDX-License-Identifier: Apache-2.0
   4
   5 from __future__ import absolute_import
   6 from __future__ import division
   7 import copy
   8 from future import standard_library
   9 from future.utils import native_str
  10 standard_library.install_aliases()
  11 from builtins import next
  12 from builtins import str
  13 from builtins import range
  14 from builtins import object
  15 import collections
  16 import datetime
  17 import hashlib
  18 import errno
  19 import io
  20 import logging
  21 import math
  22 import os
  23 import pycurl
  24 import queue
  25 import re
  26 import socket
  27 import ssl
  28 import sys
  29 import threading
  30 import resource
  31 from . import timer
  32 import urllib.parse
  33 import traceback
  34 import weakref
  35
  36 if sys.version_info >= (3, 0):
  37     from io import BytesIO
  38 else:
  39     from cStringIO import StringIO as BytesIO
  40
  41 import arvados
  42 import arvados.config as config
  43 import arvados.errors
  44 import arvados.retry as retry
  45 import arvados.util
  46 import arvados.diskcache
  47 from arvados._pycurlhelper import PyCurlHelper
  48
  49 _logger = logging.getLogger('arvados.keep')
  50 global_client_object = None
  51
  52
  53 # Monkey patch TCP constants when not available (apple). Values sourced from:
  54 # http://www.opensource.apple.com/source/xnu/xnu-2422.115.4/bsd/netinet/tcp.h
  55 if sys.platform == 'darwin':
  56     if not hasattr(socket, 'TCP_KEEPALIVE'):
  57         socket.TCP_KEEPALIVE = 0x010
  58     if not hasattr(socket, 'TCP_KEEPINTVL'):
  59         socket.TCP_KEEPINTVL = 0x101
  60     if not hasattr(socket, 'TCP_KEEPCNT'):
  61         socket.TCP_KEEPCNT = 0x102
  62
  63
  64 class KeepLocator(object):
  65     EPOCH_DATETIME = datetime.datetime.utcfromtimestamp(0)
  66     HINT_RE = re.compile(r'^[A-Z][A-Za-z0-9@_-]+$')
  67
  68     def __init__(self, locator_str):
  69         self.hints = []
  70         self._perm_sig = None
  71         self._perm_expiry = None
  72         pieces = iter(locator_str.split('+'))
  73         self.md5sum = next(pieces)
  74         try:
  75             self.size = int(next(pieces))
  76         except StopIteration:
  77             self.size = None
  78         for hint in pieces:
  79             if self.HINT_RE.match(hint) is None:
  80                 raise ValueError("invalid hint format: {}".format(hint))
  81             elif hint.startswith('A'):
  82                 self.parse_permission_hint(hint)
  83             else:
  84                 self.hints.append(hint)
  85
  86     def __str__(self):
  87         return '+'.join(
  88             native_str(s)
  89             for s in [self.md5sum, self.size,
  90                       self.permission_hint()] + self.hints
  91             if s is not None)
  92
  93     def stripped(self):
  94         if self.size is not None:
  95             return "%s+%i" % (self.md5sum, self.size)
  96         else:
  97             return self.md5sum
  98
  99     def _make_hex_prop(name, length):
 100         # Build and return a new property with the given name that
 101         # must be a hex string of the given length.
 102         data_name = '_{}'.format(name)
 103         def getter(self):
 104             return getattr(self, data_name)
 105         def setter(self, hex_str):
 106             if not arvados.util.is_hex(hex_str, length):
 107                 raise ValueError("{} is not a {}-digit hex string: {!r}".
 108                                  format(name, length, hex_str))
 109             setattr(self, data_name, hex_str)
 110         return property(getter, setter)
 111
 112     md5sum = _make_hex_prop('md5sum', 32)
 113     perm_sig = _make_hex_prop('perm_sig', 40)
 114
 115     @property
 116     def perm_expiry(self):
 117         return self._perm_expiry
 118
 119     @perm_expiry.setter
 120     def perm_expiry(self, value):
 121         if not arvados.util.is_hex(value, 1, 8):
 122             raise ValueError(
 123                 "permission timestamp must be a hex Unix timestamp: {}".
 124                 format(value))
 125         self._perm_expiry = datetime.datetime.utcfromtimestamp(int(value, 16))
 126
 127     def permission_hint(self):
 128         data = [self.perm_sig, self.perm_expiry]
 129         if None in data:
 130             return None
 131         data[1] = int((data[1] - self.EPOCH_DATETIME).total_seconds())
 132         return "A{}@{:08x}".format(*data)
 133
 134     def parse_permission_hint(self, s):
 135         try:
 136             self.perm_sig, self.perm_expiry = s[1:].split('@', 1)
 137         except IndexError:
 138             raise ValueError("bad permission hint {}".format(s))
 139
 140     def permission_expired(self, as_of_dt=None):
 141         if self.perm_expiry is None:
 142             return False
 143         elif as_of_dt is None:
 144             as_of_dt = datetime.datetime.now()
 145         return self.perm_expiry <= as_of_dt
 146
 147
 148 class Keep(object):
 149     """Simple interface to a global KeepClient object.
 150
 151     THIS CLASS IS DEPRECATED.  Please instantiate your own KeepClient with your
 152     own API client.  The global KeepClient will build an API client from the
 153     current Arvados configuration, which may not match the one you built.
 154     """
 155     _last_key = None
 156
 157     @classmethod
 158     def global_client_object(cls):
 159         global global_client_object
 160         # Previously, KeepClient would change its behavior at runtime based
 161         # on these configuration settings.  We simulate that behavior here
 162         # by checking the values and returning a new KeepClient if any of
 163         # them have changed.
 164         key = (config.get('ARVADOS_API_HOST'),
 165                config.get('ARVADOS_API_TOKEN'),
 166                config.flag_is_true('ARVADOS_API_HOST_INSECURE'),
 167                config.get('ARVADOS_KEEP_PROXY'),
 168                os.environ.get('KEEP_LOCAL_STORE'))
 169         if (global_client_object is None) or (cls._last_key != key):
 170             global_client_object = KeepClient()
 171             cls._last_key = key
 172         return global_client_object
 173
 174     @staticmethod
 175     def get(locator, **kwargs):
 176         return Keep.global_client_object().get(locator, **kwargs)
 177
 178     @staticmethod
 179     def put(data, **kwargs):
 180         return Keep.global_client_object().put(data, **kwargs)
 181
 182 class KeepBlockCache(object):
 183     def __init__(self, cache_max=0, max_slots=0, disk_cache=False, disk_cache_dir=None):
 184         self.cache_max = cache_max
 185         self._cache = []
 186         self._cache_lock = threading.Lock()
 187         self._max_slots = max_slots
 188         self._disk_cache = disk_cache
 189         self._disk_cache_dir = disk_cache_dir
 190         self._cache_updating = threading.Condition(self._cache_lock)
 191
 192         if self._disk_cache and self._disk_cache_dir is None:
 193             self._disk_cache_dir = os.path.join(os.path.expanduser("~"), ".cache", "arvados", "keep")
 194             os.makedirs(self._disk_cache_dir, mode=0o700, exist_ok=True)
 195
 196         if self._max_slots == 0:
 197             if self._disk_cache:
 198                 # Each block uses two file descriptors, one used to
 199                 # open it initially and hold the flock(), and a second
 200                 # hidden one used by mmap().
 201                 #
 202                 # Set max slots to 1/8 of maximum file handles.  This
 203                 # means we'll use at most 1/4 of total file handles.
 204                 #
 205                 # NOFILE typically defaults to 1024 on Linux so this
 206                 # is 128 slots (256 file handles), which means we can
 207                 # cache up to 8 GiB of 64 MiB blocks.  This leaves
 208                 # 768 file handles for sockets and other stuff.
 209                 #
 210                 # When we want the ability to have more cache (e.g. in
 211                 # arv-mount) we'll increase rlimit before calling
 212                 # this.
 213                 self._max_slots = int(resource.getrlimit(resource.RLIMIT_NOFILE)[0] / 8)
 214             else:
 215                 # RAM cache slots
 216                 self._max_slots = 512
 217
 218         if self.cache_max == 0:
 219             if self._disk_cache:
 220                 fs = os.statvfs(self._disk_cache_dir)
 221                 # Calculation of available space incorporates existing cache usage
 222                 existing_usage = arvados.diskcache.DiskCacheSlot.cache_usage(self._disk_cache_dir)
 223                 avail = (fs.f_bavail * fs.f_bsize + existing_usage) / 4
 224                 maxdisk = int((fs.f_blocks * fs.f_bsize) * 0.10)
 225                 # pick smallest of:
 226                 # 10% of total disk size
 227                 # 25% of available space
 228                 # max_slots * 64 MiB
 229                 self.cache_max = min(min(maxdisk, avail), (self._max_slots * 64 * 1024 * 1024))
 230             else:
 231                 # 256 MiB in RAM
 232                 self.cache_max = (256 * 1024 * 1024)
 233
 234         self.cache_max = max(self.cache_max, 64 * 1024 * 1024)
 235
 236         if self._disk_cache:
 237             self._cache = arvados.diskcache.DiskCacheSlot.init_cache(self._disk_cache_dir, self._max_slots)
 238             self.cap_cache()
 239
 240
 241     class CacheSlot(object):
 242         __slots__ = ("locator", "ready", "content")
 243
 244         def __init__(self, locator):
 245             self.locator = locator
 246             self.ready = threading.Event()
 247             self.content = None
 248
 249         def get(self):
 250             self.ready.wait()
 251             return self.content
 252
 253         def set(self, value):
 254             self.content = value
 255             self.ready.set()
 256
 257         def size(self):
 258             if self.content is None:
 259                 return 0
 260             else:
 261                 return len(self.content)
 262
 263         def evict(self):
 264             self.content = None
 265             return self.gone()
 266
 267         def gone(self):
 268             return (self.content is None)
 269
 270     def _resize_cache(self, cache_max, max_slots):
 271         # Try and make sure the contents of the cache do not exceed
 272         # the supplied maximums.
 273
 274         # Select all slots except those where ready.is_set() and content is
 275         # None (that means there was an error reading the block).
 276         self._cache = [c for c in self._cache if not (c.ready.is_set() and c.content is None)]
 277         sm = sum([slot.size() for slot in self._cache])
 278         while len(self._cache) > 0 and (sm > cache_max or len(self._cache) > max_slots):
 279             for i in range(len(self._cache)-1, -1, -1):
 280                 # start from the back, find a slot that is a candidate to evict
 281                 if self._cache[i].ready.is_set():
 282                     sz = self._cache[i].size()
 283
 284                     # If evict returns false it means the
 285                     # underlying disk cache couldn't lock the file
 286                     # for deletion because another process was using
 287                     # it. Don't count it as reducing the amount
 288                     # of data in the cache, find something else to
 289                     # throw out.
 290                     if self._cache[i].evict():
 291                         sm -= sz
 292
 293                     # check to make sure the underlying data is gone
 294                     if self._cache[i].gone():
 295                         # either way we forget about it.  either the
 296                         # other process will delete it, or if we need
 297                         # it again and it is still there, we'll find
 298                         # it on disk.
 299                         del self._cache[i]
 300                     break
 301
 302
 303     def cap_cache(self):
 304         '''Cap the cache size to self.cache_max'''
 305         with self._cache_updating:
 306             self._resize_cache(self.cache_max, self._max_slots)
 307             self._cache_updating.notify_all()
 308
 309     def _get(self, locator):
 310         # Test if the locator is already in the cache
 311         for i in range(0, len(self._cache)):
 312             if self._cache[i].locator == locator:
 313                 n = self._cache[i]
 314                 if i != 0:
 315                     # move it to the front
 316                     del self._cache[i]
 317                     self._cache.insert(0, n)
 318                 return n
 319         if self._disk_cache:
 320             # see if it exists on disk
 321             n = arvados.diskcache.DiskCacheSlot.get_from_disk(locator, self._disk_cache_dir)
 322             if n is not None:
 323                 self._cache.insert(0, n)
 324                 return n
 325         return None
 326
 327     def get(self, locator):
 328         with self._cache_lock:
 329             return self._get(locator)
 330
 331     def reserve_cache(self, locator):
 332         '''Reserve a cache slot for the specified locator,
 333         or return the existing slot.'''
 334         with self._cache_updating:
 335             n = self._get(locator)
 336             if n:
 337                 return n, False
 338             else:
 339                 # Add a new cache slot for the locator
 340                 self._resize_cache(self.cache_max, self._max_slots-1)
 341                 while len(self._cache) >= self._max_slots:
 342                     # If there isn't a slot available, need to wait
 343                     # for something to happen that releases one of the
 344                     # cache slots.  Idle for 200 ms or woken up by
 345                     # another thread
 346                     self._cache_updating.wait(timeout=0.2)
 347                     self._resize_cache(self.cache_max, self._max_slots-1)
 348
 349                 if self._disk_cache:
 350                     n = arvados.diskcache.DiskCacheSlot(locator, self._disk_cache_dir)
 351                 else:
 352                     n = KeepBlockCache.CacheSlot(locator)
 353                 self._cache.insert(0, n)
 354                 return n, True
 355
 356     def set(self, slot, blob):
 357         try:
 358             slot.set(blob)
 359             return
 360         except OSError as e:
 361             if e.errno == errno.ENOMEM:
 362                 # Reduce max slots to current - 4, cap cache and retry
 363                 with self._cache_lock:
 364                     self._max_slots = max(4, len(self._cache) - 4)
 365             elif e.errno == errno.ENOSPC:
 366                 # Reduce disk max space to current - 256 MiB, cap cache and retry
 367                 with self._cache_lock:
 368                     sm = sum([st.size() for st in self._cache])
 369                     self.cache_max = max((256 * 1024 * 1024), sm - (256 * 1024 * 1024))
 370             elif e.errno == errno.ENODEV:
 371                 _logger.error("Unable to use disk cache: The underlying filesystem does not support memory mapping.")
 372         except Exception as e:
 373             pass
 374         finally:
 375             # Check if we should evict things from the cache.  Either
 376             # because we added a new thing or there was an error and
 377             # we possibly adjusted the limits down, so we might need
 378             # to push something out.
 379             self.cap_cache()
 380
 381         try:
 382             # Only gets here if there was an error the first time. The
 383             # exception handler adjusts limits downward in some cases
 384             # to free up resources, which would make the operation
 385             # succeed.
 386             slot.set(blob)
 387         except Exception as e:
 388             # It failed again.  Give up.
 389             slot.set(None)
 390             raise arvados.errors.KeepCacheError("Unable to save block %s to disk cache: %s" % (slot.locator, e))
 391
 392         self.cap_cache()
 393
 394 class Counter(object):
 395     def __init__(self, v=0):
 396         self._lk = threading.Lock()
 397         self._val = v
 398
 399     def add(self, v):
 400         with self._lk:
 401             self._val += v
 402
 403     def get(self):
 404         with self._lk:
 405             return self._val
 406
 407
 408 class KeepClient(object):
 409     DEFAULT_TIMEOUT = PyCurlHelper.DEFAULT_TIMEOUT
 410     DEFAULT_PROXY_TIMEOUT = PyCurlHelper.DEFAULT_PROXY_TIMEOUT
 411
 412     class KeepService(PyCurlHelper):
 413         """Make requests to a single Keep service, and track results.
 414
 415         A KeepService is intended to last long enough to perform one
 416         transaction (GET or PUT) against one Keep service. This can
 417         involve calling either get() or put() multiple times in order
 418         to retry after transient failures. However, calling both get()
 419         and put() on a single instance -- or using the same instance
 420         to access two different Keep services -- will not produce
 421         sensible behavior.
 422         """
 423
 424         HTTP_ERRORS = (
 425             socket.error,
 426             ssl.SSLError,
 427             arvados.errors.HttpError,
 428         )
 429
 430         def __init__(self, root, user_agent_pool=queue.LifoQueue(),
 431                      upload_counter=None,
 432                      download_counter=None,
 433                      headers={},
 434                      insecure=False):
 435             super(KeepClient.KeepService, self).__init__()
 436             self.root = root
 437             self._user_agent_pool = user_agent_pool
 438             self._result = {'error': None}
 439             self._usable = True
 440             self._session = None
 441             self._socket = None
 442             self.get_headers = {'Accept': 'application/octet-stream'}
 443             self.get_headers.update(headers)
 444             self.put_headers = headers
 445             self.upload_counter = upload_counter
 446             self.download_counter = download_counter
 447             self.insecure = insecure
 448
 449         def usable(self):
 450             """Is it worth attempting a request?"""
 451             return self._usable
 452
 453         def finished(self):
 454             """Did the request succeed or encounter permanent failure?"""
 455             return self._result['error'] == False or not self._usable
 456
 457         def last_result(self):
 458             return self._result
 459
 460         def _get_user_agent(self):
 461             try:
 462                 return self._user_agent_pool.get(block=False)
 463             except queue.Empty:
 464                 return pycurl.Curl()
 465
 466         def _put_user_agent(self, ua):
 467             try:
 468                 ua.reset()
 469                 self._user_agent_pool.put(ua, block=False)
 470             except:
 471                 ua.close()
 472
 473         def get(self, locator, method="GET", timeout=None):
 474             # locator is a KeepLocator object.
 475             url = self.root + str(locator)
 476             _logger.debug("Request: %s %s", method, url)
 477             curl = self._get_user_agent()
 478             ok = None
 479             try:
 480                 with timer.Timer() as t:
 481                     self._headers = {}
 482                     response_body = BytesIO()
 483                     curl.setopt(pycurl.NOSIGNAL, 1)
 484                     curl.setopt(pycurl.OPENSOCKETFUNCTION,
 485                                 lambda *args, **kwargs: self._socket_open(*args, **kwargs))
 486                     curl.setopt(pycurl.URL, url.encode('utf-8'))
 487                     curl.setopt(pycurl.HTTPHEADER, [
 488                         '{}: {}'.format(k,v) for k,v in self.get_headers.items()])
 489                     curl.setopt(pycurl.WRITEFUNCTION, response_body.write)
 490                     curl.setopt(pycurl.HEADERFUNCTION, self._headerfunction)
 491                     if self.insecure:
 492                         curl.setopt(pycurl.SSL_VERIFYPEER, 0)
 493                         curl.setopt(pycurl.SSL_VERIFYHOST, 0)
 494                     else:
 495                         curl.setopt(pycurl.CAINFO, arvados.util.ca_certs_path())
 496                     if method == "HEAD":
 497                         curl.setopt(pycurl.NOBODY, True)
 498                     else:
 499                         curl.setopt(pycurl.HTTPGET, True)
 500                     self._setcurltimeouts(curl, timeout, method=="HEAD")
 501
 502                     try:
 503                         curl.perform()
 504                     except Exception as e:
 505                         raise arvados.errors.HttpError(0, str(e))
 506                     finally:
 507                         if self._socket:
 508                             self._socket.close()
 509                             self._socket = None
 510                     self._result = {
 511                         'status_code': curl.getinfo(pycurl.RESPONSE_CODE),
 512                         'body': response_body.getvalue(),
 513                         'headers': self._headers,
 514                         'error': False,
 515                     }
 516
 517                 ok = retry.check_http_response_success(self._result['status_code'])
 518                 if not ok:
 519                     self._result['error'] = arvados.errors.HttpError(
 520                         self._result['status_code'],
 521                         self._headers.get('x-status-line', 'Error'))
 522             except self.HTTP_ERRORS as e:
 523                 self._result = {
 524                     'error': e,
 525                 }
 526             self._usable = ok != False
 527             if self._result.get('status_code', None):
 528                 # The client worked well enough to get an HTTP status
 529                 # code, so presumably any problems are just on the
 530                 # server side and it's OK to reuse the client.
 531                 self._put_user_agent(curl)
 532             else:
 533                 # Don't return this client to the pool, in case it's
 534                 # broken.
 535                 curl.close()
 536             if not ok:
 537                 _logger.debug("Request fail: GET %s => %s: %s",
 538                               url, type(self._result['error']), str(self._result['error']))
 539                 return None
 540             if method == "HEAD":
 541                 _logger.info("HEAD %s: %s bytes",
 542                          self._result['status_code'],
 543                          self._result.get('content-length'))
 544                 if self._result['headers'].get('x-keep-locator'):
 545                     # This is a response to a remote block copy request, return
 546                     # the local copy block locator.
 547                     return self._result['headers'].get('x-keep-locator')
 548                 return True
 549
 550             _logger.info("GET %s: %s bytes in %s msec (%.3f MiB/sec)",
 551                          self._result['status_code'],
 552                          len(self._result['body']),
 553                          t.msecs,
 554                          1.0*len(self._result['body'])/2**20/t.secs if t.secs > 0 else 0)
 555
 556             if self.download_counter:
 557                 self.download_counter.add(len(self._result['body']))
 558             resp_md5 = hashlib.md5(self._result['body']).hexdigest()
 559             if resp_md5 != locator.md5sum:
 560                 _logger.warning("Checksum fail: md5(%s) = %s",
 561                                 url, resp_md5)
 562                 self._result['error'] = arvados.errors.HttpError(
 563                     0, 'Checksum fail')
 564                 return None
 565             return self._result['body']
 566
 567         def put(self, hash_s, body, timeout=None, headers={}):
 568             put_headers = copy.copy(self.put_headers)
 569             put_headers.update(headers)
 570             url = self.root + hash_s
 571             _logger.debug("Request: PUT %s", url)
 572             curl = self._get_user_agent()
 573             ok = None
 574             try:
 575                 with timer.Timer() as t:
 576                     self._headers = {}
 577                     body_reader = BytesIO(body)
 578                     response_body = BytesIO()
 579                     curl.setopt(pycurl.NOSIGNAL, 1)
 580                     curl.setopt(pycurl.OPENSOCKETFUNCTION,
 581                                 lambda *args, **kwargs: self._socket_open(*args, **kwargs))
 582                     curl.setopt(pycurl.URL, url.encode('utf-8'))
 583                     # Using UPLOAD tells cURL to wait for a "go ahead" from the
 584                     # Keep server (in the form of a HTTP/1.1 "100 Continue"
 585                     # response) instead of sending the request body immediately.
 586                     # This allows the server to reject the request if the request
 587                     # is invalid or the server is read-only, without waiting for
 588                     # the client to send the entire block.
 589                     curl.setopt(pycurl.UPLOAD, True)
 590                     curl.setopt(pycurl.INFILESIZE, len(body))
 591                     curl.setopt(pycurl.READFUNCTION, body_reader.read)
 592                     curl.setopt(pycurl.HTTPHEADER, [
 593                         '{}: {}'.format(k,v) for k,v in put_headers.items()])
 594                     curl.setopt(pycurl.WRITEFUNCTION, response_body.write)
 595                     curl.setopt(pycurl.HEADERFUNCTION, self._headerfunction)
 596                     if self.insecure:
 597                         curl.setopt(pycurl.SSL_VERIFYPEER, 0)
 598                         curl.setopt(pycurl.SSL_VERIFYHOST, 0)
 599                     else:
 600                         curl.setopt(pycurl.CAINFO, arvados.util.ca_certs_path())
 601                     self._setcurltimeouts(curl, timeout)
 602                     try:
 603                         curl.perform()
 604                     except Exception as e:
 605                         raise arvados.errors.HttpError(0, str(e))
 606                     finally:
 607                         if self._socket:
 608                             self._socket.close()
 609                             self._socket = None
 610                     self._result = {
 611                         'status_code': curl.getinfo(pycurl.RESPONSE_CODE),
 612                         'body': response_body.getvalue().decode('utf-8'),
 613                         'headers': self._headers,
 614                         'error': False,
 615                     }
 616                 ok = retry.check_http_response_success(self._result['status_code'])
 617                 if not ok:
 618                     self._result['error'] = arvados.errors.HttpError(
 619                         self._result['status_code'],
 620                         self._headers.get('x-status-line', 'Error'))
 621             except self.HTTP_ERRORS as e:
 622                 self._result = {
 623                     'error': e,
 624                 }
 625             self._usable = ok != False # still usable if ok is True or None
 626             if self._result.get('status_code', None):
 627                 # Client is functional. See comment in get().
 628                 self._put_user_agent(curl)
 629             else:
 630                 curl.close()
 631             if not ok:
 632                 _logger.debug("Request fail: PUT %s => %s: %s",
 633                               url, type(self._result['error']), str(self._result['error']))
 634                 return False
 635             _logger.info("PUT %s: %s bytes in %s msec (%.3f MiB/sec)",
 636                          self._result['status_code'],
 637                          len(body),
 638                          t.msecs,
 639                          1.0*len(body)/2**20/t.secs if t.secs > 0 else 0)
 640             if self.upload_counter:
 641                 self.upload_counter.add(len(body))
 642             return True
 643
 644
 645     class KeepWriterQueue(queue.Queue):
 646         def __init__(self, copies, classes=[]):
 647             queue.Queue.__init__(self) # Old-style superclass
 648             self.wanted_copies = copies
 649             self.wanted_storage_classes = classes
 650             self.successful_copies = 0
 651             self.confirmed_storage_classes = {}
 652             self.response = None
 653             self.storage_classes_tracking = True
 654             self.queue_data_lock = threading.RLock()
 655             self.pending_tries = max(copies, len(classes))
 656             self.pending_tries_notification = threading.Condition()
 657
 658         def write_success(self, response, replicas_nr, classes_confirmed):
 659             with self.queue_data_lock:
 660                 self.successful_copies += replicas_nr
 661                 if classes_confirmed is None:
 662                     self.storage_classes_tracking = False
 663                 elif self.storage_classes_tracking:
 664                     for st_class, st_copies in classes_confirmed.items():
 665                         try:
 666                             self.confirmed_storage_classes[st_class] += st_copies
 667                         except KeyError:
 668                             self.confirmed_storage_classes[st_class] = st_copies
 669                     self.pending_tries = max(self.wanted_copies - self.successful_copies, len(self.pending_classes()))
 670                 self.response = response
 671             with self.pending_tries_notification:
 672                 self.pending_tries_notification.notify_all()
 673
 674         def write_fail(self, ks):
 675             with self.pending_tries_notification:
 676                 self.pending_tries += 1
 677                 self.pending_tries_notification.notify()
 678
 679         def pending_copies(self):
 680             with self.queue_data_lock:
 681                 return self.wanted_copies - self.successful_copies
 682
 683         def satisfied_classes(self):
 684             with self.queue_data_lock:
 685                 if not self.storage_classes_tracking:
 686                     # Notifies disabled storage classes expectation to
 687                     # the outer loop.
 688                     return None
 689             return list(set(self.wanted_storage_classes) - set(self.pending_classes()))
 690
 691         def pending_classes(self):
 692             with self.queue_data_lock:
 693                 if (not self.storage_classes_tracking) or (self.wanted_storage_classes is None):
 694                     return []
 695                 unsatisfied_classes = copy.copy(self.wanted_storage_classes)
 696                 for st_class, st_copies in self.confirmed_storage_classes.items():
 697                     if st_class in unsatisfied_classes and st_copies >= self.wanted_copies:
 698                         unsatisfied_classes.remove(st_class)
 699                 return unsatisfied_classes
 700
 701         def get_next_task(self):
 702             with self.pending_tries_notification:
 703                 while True:
 704                     if self.pending_copies() < 1 and len(self.pending_classes()) == 0:
 705                         # This notify_all() is unnecessary --
 706                         # write_success() already called notify_all()
 707                         # when pending<1 became true, so it's not
 708                         # possible for any other thread to be in
 709                         # wait() now -- but it's cheap insurance
 710                         # against deadlock so we do it anyway:
 711                         self.pending_tries_notification.notify_all()
 712                         # Drain the queue and then raise Queue.Empty
 713                         while True:
 714                             self.get_nowait()
 715                             self.task_done()
 716                     elif self.pending_tries > 0:
 717                         service, service_root = self.get_nowait()
 718                         if service.finished():
 719                             self.task_done()
 720                             continue
 721                         self.pending_tries -= 1
 722                         return service, service_root
 723                     elif self.empty():
 724                         self.pending_tries_notification.notify_all()
 725                         raise queue.Empty
 726                     else:
 727                         self.pending_tries_notification.wait()
 728
 729
 730     class KeepWriterThreadPool(object):
 731         def __init__(self, data, data_hash, copies, max_service_replicas, timeout=None, classes=[]):
 732             self.total_task_nr = 0
 733             if (not max_service_replicas) or (max_service_replicas >= copies):
 734                 num_threads = 1
 735             else:
 736                 num_threads = int(math.ceil(1.0*copies/max_service_replicas))
 737             _logger.debug("Pool max threads is %d", num_threads)
 738             self.workers = []
 739             self.queue = KeepClient.KeepWriterQueue(copies, classes)
 740             # Create workers
 741             for _ in range(num_threads):
 742                 w = KeepClient.KeepWriterThread(self.queue, data, data_hash, timeout)
 743                 self.workers.append(w)
 744
 745         def add_task(self, ks, service_root):
 746             self.queue.put((ks, service_root))
 747             self.total_task_nr += 1
 748
 749         def done(self):
 750             return self.queue.successful_copies, self.queue.satisfied_classes()
 751
 752         def join(self):
 753             # Start workers
 754             for worker in self.workers:
 755                 worker.start()
 756             # Wait for finished work
 757             self.queue.join()
 758
 759         def response(self):
 760             return self.queue.response
 761
 762
 763     class KeepWriterThread(threading.Thread):
 764         class TaskFailed(RuntimeError): pass
 765
 766         def __init__(self, queue, data, data_hash, timeout=None):
 767             super(KeepClient.KeepWriterThread, self).__init__()
 768             self.timeout = timeout
 769             self.queue = queue
 770             self.data = data
 771             self.data_hash = data_hash
 772             self.daemon = True
 773
 774         def run(self):
 775             while True:
 776                 try:
 777                     service, service_root = self.queue.get_next_task()
 778                 except queue.Empty:
 779                     return
 780                 try:
 781                     locator, copies, classes = self.do_task(service, service_root)
 782                 except Exception as e:
 783                     if not isinstance(e, self.TaskFailed):
 784                         _logger.exception("Exception in KeepWriterThread")
 785                     self.queue.write_fail(service)
 786                 else:
 787                     self.queue.write_success(locator, copies, classes)
 788                 finally:
 789                     self.queue.task_done()
 790
 791         def do_task(self, service, service_root):
 792             classes = self.queue.pending_classes()
 793             headers = {}
 794             if len(classes) > 0:
 795                 classes.sort()
 796                 headers['X-Keep-Storage-Classes'] = ', '.join(classes)
 797             success = bool(service.put(self.data_hash,
 798                                         self.data,
 799                                         timeout=self.timeout,
 800                                         headers=headers))
 801             result = service.last_result()
 802
 803             if not success:
 804                 if result.get('status_code'):
 805                     _logger.debug("Request fail: PUT %s => %s %s",
 806                                   self.data_hash,
 807                                   result.get('status_code'),
 808                                   result.get('body'))
 809                 raise self.TaskFailed()
 810
 811             _logger.debug("KeepWriterThread %s succeeded %s+%i %s",
 812                           str(threading.current_thread()),
 813                           self.data_hash,
 814                           len(self.data),
 815                           service_root)
 816             try:
 817                 replicas_stored = int(result['headers']['x-keep-replicas-stored'])
 818             except (KeyError, ValueError):
 819                 replicas_stored = 1
 820
 821             classes_confirmed = {}
 822             try:
 823                 scch = result['headers']['x-keep-storage-classes-confirmed']
 824                 for confirmation in scch.replace(' ', '').split(','):
 825                     if '=' in confirmation:
 826                         stored_class, stored_copies = confirmation.split('=')[:2]
 827                         classes_confirmed[stored_class] = int(stored_copies)
 828             except (KeyError, ValueError):
 829                 # Storage classes confirmed header missing or corrupt
 830                 classes_confirmed = None
 831
 832             return result['body'].strip(), replicas_stored, classes_confirmed
 833
 834
 835     def __init__(self, api_client=None, proxy=None,
 836                  timeout=DEFAULT_TIMEOUT, proxy_timeout=DEFAULT_PROXY_TIMEOUT,
 837                  api_token=None, local_store=None, block_cache=None,
 838                  num_retries=10, session=None):
 839         """Initialize a new KeepClient.
 840
 841         Arguments:
 842         :api_client:
 843           The API client to use to find Keep services.  If not
 844           provided, KeepClient will build one from available Arvados
 845           configuration.
 846
 847         :proxy:
 848           If specified, this KeepClient will send requests to this Keep
 849           proxy.  Otherwise, KeepClient will fall back to the setting of the
 850           ARVADOS_KEEP_SERVICES or ARVADOS_KEEP_PROXY configuration settings.
 851           If you want to KeepClient does not use a proxy, pass in an empty
 852           string.
 853
 854         :timeout:
 855           The initial timeout (in seconds) for HTTP requests to Keep
 856           non-proxy servers.  A tuple of three floats is interpreted as
 857           (connection_timeout, read_timeout, minimum_bandwidth). A connection
 858           will be aborted if the average traffic rate falls below
 859           minimum_bandwidth bytes per second over an interval of read_timeout
 860           seconds. Because timeouts are often a result of transient server
 861           load, the actual connection timeout will be increased by a factor
 862           of two on each retry.
 863           Default: (2, 256, 32768).
 864
 865         :proxy_timeout:
 866           The initial timeout (in seconds) for HTTP requests to
 867           Keep proxies. A tuple of three floats is interpreted as
 868           (connection_timeout, read_timeout, minimum_bandwidth). The behavior
 869           described above for adjusting connection timeouts on retry also
 870           applies.
 871           Default: (20, 256, 32768).
 872
 873         :api_token:
 874           If you're not using an API client, but only talking
 875           directly to a Keep proxy, this parameter specifies an API token
 876           to authenticate Keep requests.  It is an error to specify both
 877           api_client and api_token.  If you specify neither, KeepClient
 878           will use one available from the Arvados configuration.
 879
 880         :local_store:
 881           If specified, this KeepClient will bypass Keep
 882           services, and save data to the named directory.  If unspecified,
 883           KeepClient will fall back to the setting of the $KEEP_LOCAL_STORE
 884           environment variable.  If you want to ensure KeepClient does not
 885           use local storage, pass in an empty string.  This is primarily
 886           intended to mock a server for testing.
 887
 888         :num_retries:
 889           The default number of times to retry failed requests.
 890           This will be used as the default num_retries value when get() and
 891           put() are called.  Default 10.
 892         """
 893         self.lock = threading.Lock()
 894         if proxy is None:
 895             if config.get('ARVADOS_KEEP_SERVICES'):
 896                 proxy = config.get('ARVADOS_KEEP_SERVICES')
 897             else:
 898                 proxy = config.get('ARVADOS_KEEP_PROXY')
 899         if api_token is None:
 900             if api_client is None:
 901                 api_token = config.get('ARVADOS_API_TOKEN')
 902             else:
 903                 api_token = api_client.api_token
 904         elif api_client is not None:
 905             raise ValueError(
 906                 "can't build KeepClient with both API client and token")
 907         if local_store is None:
 908             local_store = os.environ.get('KEEP_LOCAL_STORE')
 909
 910         if api_client is None:
 911             self.insecure = config.flag_is_true('ARVADOS_API_HOST_INSECURE')
 912         else:
 913             self.insecure = api_client.insecure
 914
 915         self.block_cache = block_cache if block_cache else KeepBlockCache()
 916         self.timeout = timeout
 917         self.proxy_timeout = proxy_timeout
 918         self._user_agent_pool = queue.LifoQueue()
 919         self.upload_counter = Counter()
 920         self.download_counter = Counter()
 921         self.put_counter = Counter()
 922         self.get_counter = Counter()
 923         self.hits_counter = Counter()
 924         self.misses_counter = Counter()
 925         self._storage_classes_unsupported_warning = False
 926         self._default_classes = []
 927
 928         if local_store:
 929             self.local_store = local_store
 930             self.head = self.local_store_head
 931             self.get = self.local_store_get
 932             self.put = self.local_store_put
 933         else:
 934             self.num_retries = num_retries
 935             self.max_replicas_per_service = None
 936             if proxy:
 937                 proxy_uris = proxy.split()
 938                 for i in range(len(proxy_uris)):
 939                     if not proxy_uris[i].endswith('/'):
 940                         proxy_uris[i] += '/'
 941                     # URL validation
 942                     url = urllib.parse.urlparse(proxy_uris[i])
 943                     if not (url.scheme and url.netloc):
 944                         raise arvados.errors.ArgumentError("Invalid proxy URI: {}".format(proxy_uris[i]))
 945                 self.api_token = api_token
 946                 self._gateway_services = {}
 947                 self._keep_services = [{
 948                     'uuid': "00000-bi6l4-%015d" % idx,
 949                     'service_type': 'proxy',
 950                     '_service_root': uri,
 951                     } for idx, uri in enumerate(proxy_uris)]
 952                 self._writable_services = self._keep_services
 953                 self.using_proxy = True
 954                 self._static_services_list = True
 955             else:
 956                 # It's important to avoid instantiating an API client
 957                 # unless we actually need one, for testing's sake.
 958                 if api_client is None:
 959                     api_client = arvados.api('v1')
 960                 self.api_client = api_client
 961                 self.api_token = api_client.api_token
 962                 self._gateway_services = {}
 963                 self._keep_services = None
 964                 self._writable_services = None
 965                 self.using_proxy = None
 966                 self._static_services_list = False
 967                 try:
 968                     self._default_classes = [
 969                         k for k, v in self.api_client.config()['StorageClasses'].items() if v['Default']]
 970                 except KeyError:
 971                     # We're talking to an old cluster
 972                     pass
 973
 974     def current_timeout(self, attempt_number):
 975         """Return the appropriate timeout to use for this client.
 976
 977         The proxy timeout setting if the backend service is currently a proxy,
 978         the regular timeout setting otherwise.  The `attempt_number` indicates
 979         how many times the operation has been tried already (starting from 0
 980         for the first try), and scales the connection timeout portion of the
 981         return value accordingly.
 982
 983         """
 984         # TODO(twp): the timeout should be a property of a
 985         # KeepService, not a KeepClient. See #4488.
 986         t = self.proxy_timeout if self.using_proxy else self.timeout
 987         if len(t) == 2:
 988             return (t[0] * (1 << attempt_number), t[1])
 989         else:
 990             return (t[0] * (1 << attempt_number), t[1], t[2])
 991     def _any_nondisk_services(self, service_list):
 992         return any(ks.get('service_type', 'disk') != 'disk'
 993                    for ks in service_list)
 994
 995     def build_services_list(self, force_rebuild=False):
 996         if (self._static_services_list or
 997               (self._keep_services and not force_rebuild)):
 998             return
 999         with self.lock:
1000             try:
1001                 keep_services = self.api_client.keep_services().accessible()
1002             except Exception:  # API server predates Keep services.
1003                 keep_services = self.api_client.keep_disks().list()
1004
1005             # Gateway services are only used when specified by UUID,
1006             # so there's nothing to gain by filtering them by
1007             # service_type.
1008             self._gateway_services = {ks['uuid']: ks for ks in
1009                                       keep_services.execute()['items']}
1010             if not self._gateway_services:
1011                 raise arvados.errors.NoKeepServersError()
1012
1013             # Precompute the base URI for each service.
1014             for r in self._gateway_services.values():
1015                 host = r['service_host']
1016                 if not host.startswith('[') and host.find(':') >= 0:
1017                     # IPv6 URIs must be formatted like http://[::1]:80/...
1018                     host = '[' + host + ']'
1019                 r['_service_root'] = "{}://{}:{:d}/".format(
1020                     'https' if r['service_ssl_flag'] else 'http',
1021                     host,
1022                     r['service_port'])
1023
1024             _logger.debug(str(self._gateway_services))
1025             self._keep_services = [
1026                 ks for ks in self._gateway_services.values()
1027                 if not ks.get('service_type', '').startswith('gateway:')]
1028             self._writable_services = [ks for ks in self._keep_services
1029                                        if not ks.get('read_only')]
1030
1031             # For disk type services, max_replicas_per_service is 1
1032             # It is unknown (unlimited) for other service types.
1033             if self._any_nondisk_services(self._writable_services):
1034                 self.max_replicas_per_service = None
1035             else:
1036                 self.max_replicas_per_service = 1
1037
1038     def _service_weight(self, data_hash, service_uuid):
1039         """Compute the weight of a Keep service endpoint for a data
1040         block with a known hash.
1041
1042         The weight is md5(h + u) where u is the last 15 characters of
1043         the service endpoint's UUID.
1044         """
1045         return hashlib.md5((data_hash + service_uuid[-15:]).encode()).hexdigest()
1046
1047     def weighted_service_roots(self, locator, force_rebuild=False, need_writable=False):
1048         """Return an array of Keep service endpoints, in the order in
1049         which they should be probed when reading or writing data with
1050         the given hash+hints.
1051         """
1052         self.build_services_list(force_rebuild)
1053
1054         sorted_roots = []
1055         # Use the services indicated by the given +K@... remote
1056         # service hints, if any are present and can be resolved to a
1057         # URI.
1058         for hint in locator.hints:
1059             if hint.startswith('K@'):
1060                 if len(hint) == 7:
1061                     sorted_roots.append(
1062                         "https://keep.{}.arvadosapi.com/".format(hint[2:]))
1063                 elif len(hint) == 29:
1064                     svc = self._gateway_services.get(hint[2:])
1065                     if svc:
1066                         sorted_roots.append(svc['_service_root'])
1067
1068         # Sort the available local services by weight (heaviest first)
1069         # for this locator, and return their service_roots (base URIs)
1070         # in that order.
1071         use_services = self._keep_services
1072         if need_writable:
1073             use_services = self._writable_services
1074         self.using_proxy = self._any_nondisk_services(use_services)
1075         sorted_roots.extend([
1076             svc['_service_root'] for svc in sorted(
1077                 use_services,
1078                 reverse=True,
1079                 key=lambda svc: self._service_weight(locator.md5sum, svc['uuid']))])
1080         _logger.debug("{}: {}".format(locator, sorted_roots))
1081         return sorted_roots
1082
1083     def map_new_services(self, roots_map, locator, force_rebuild, need_writable, headers):
1084         # roots_map is a dictionary, mapping Keep service root strings
1085         # to KeepService objects.  Poll for Keep services, and add any
1086         # new ones to roots_map.  Return the current list of local
1087         # root strings.
1088         headers.setdefault('Authorization', "OAuth2 %s" % (self.api_token,))
1089         local_roots = self.weighted_service_roots(locator, force_rebuild, need_writable)
1090         for root in local_roots:
1091             if root not in roots_map:
1092                 roots_map[root] = self.KeepService(
1093                     root, self._user_agent_pool,
1094                     upload_counter=self.upload_counter,
1095                     download_counter=self.download_counter,
1096                     headers=headers,
1097                     insecure=self.insecure)
1098         return local_roots
1099
1100     @staticmethod
1101     def _check_loop_result(result):
1102         # KeepClient RetryLoops should save results as a 2-tuple: the
1103         # actual result of the request, and the number of servers available
1104         # to receive the request this round.
1105         # This method returns True if there's a real result, False if
1106         # there are no more servers available, otherwise None.
1107         if isinstance(result, Exception):
1108             return None
1109         result, tried_server_count = result
1110         if (result is not None) and (result is not False):
1111             return True
1112         elif tried_server_count < 1:
1113             _logger.info("No more Keep services to try; giving up")
1114             return False
1115         else:
1116             return None
1117
1118     def get_from_cache(self, loc_s):
1119         """Fetch a block only if is in the cache, otherwise return None."""
1120         locator = KeepLocator(loc_s)
1121         slot = self.block_cache.get(locator.md5sum)
1122         if slot is not None and slot.ready.is_set():
1123             return slot.get()
1124         else:
1125             return None
1126
1127     def refresh_signature(self, loc):
1128         """Ask Keep to get the remote block and return its local signature"""
1129         now = datetime.datetime.utcnow().isoformat("T") + 'Z'
1130         return self.head(loc, headers={'X-Keep-Signature': 'local, {}'.format(now)})
1131
1132     @retry.retry_method
1133     def head(self, loc_s, **kwargs):
1134         return self._get_or_head(loc_s, method="HEAD", **kwargs)
1135
1136     @retry.retry_method
1137     def get(self, loc_s, **kwargs):
1138         return self._get_or_head(loc_s, method="GET", **kwargs)
1139
1140     def _get_or_head(self, loc_s, method="GET", num_retries=None, request_id=None, headers=None, prefetch=False):
1141         """Get data from Keep.
1142
1143         This method fetches one or more blocks of data from Keep.  It
1144         sends a request each Keep service registered with the API
1145         server (or the proxy provided when this client was
1146         instantiated), then each service named in location hints, in
1147         sequence.  As soon as one service provides the data, it's
1148         returned.
1149
1150         Arguments:
1151         * loc_s: A string of one or more comma-separated locators to fetch.
1152           This method returns the concatenation of these blocks.
1153         * num_retries: The number of times to retry GET requests to
1154           *each* Keep server if it returns temporary failures, with
1155           exponential backoff.  Note that, in each loop, the method may try
1156           to fetch data from every available Keep service, along with any
1157           that are named in location hints in the locator.  The default value
1158           is set when the KeepClient is initialized.
1159         """
1160         if ',' in loc_s:
1161             return ''.join(self.get(x) for x in loc_s.split(','))
1162
1163         self.get_counter.add(1)
1164
1165         request_id = (request_id or
1166                       (hasattr(self, 'api_client') and self.api_client.request_id) or
1167                       arvados.util.new_request_id())
1168         if headers is None:
1169             headers = {}
1170         headers['X-Request-Id'] = request_id
1171
1172         slot = None
1173         blob = None
1174         try:
1175             locator = KeepLocator(loc_s)
1176             if method == "GET":
1177                 while slot is None:
1178                     slot, first = self.block_cache.reserve_cache(locator.md5sum)
1179                     if first:
1180                         # Fresh and empty "first time it is used" slot
1181                         break
1182                     if prefetch:
1183                         # this is request for a prefetch to fill in
1184                         # the cache, don't need to wait for the
1185                         # result, so if it is already in flight return
1186                         # immediately.  Clear 'slot' to prevent
1187                         # finally block from calling slot.set()
1188                         slot = None
1189                         return None
1190
1191                     blob = slot.get()
1192                     if blob is not None:
1193                         self.hits_counter.add(1)
1194                         return blob
1195
1196                     # If blob is None, this means either
1197                     #
1198                     # (a) another thread was fetching this block and
1199                     # failed with an error or
1200                     #
1201                     # (b) cache thrashing caused the slot to be
1202                     # evicted (content set to None) by another thread
1203                     # between the call to reserve_cache() and get().
1204                     #
1205                     # We'll handle these cases by reserving a new slot
1206                     # and then doing a full GET request.
1207                     slot = None
1208
1209             self.misses_counter.add(1)
1210
1211             # If the locator has hints specifying a prefix (indicating a
1212             # remote keepproxy) or the UUID of a local gateway service,
1213             # read data from the indicated service(s) instead of the usual
1214             # list of local disk services.
1215             hint_roots = ['http://keep.{}.arvadosapi.com/'.format(hint[2:])
1216                           for hint in locator.hints if hint.startswith('K@') and len(hint) == 7]
1217             hint_roots.extend([self._gateway_services[hint[2:]]['_service_root']
1218                                for hint in locator.hints if (
1219                                        hint.startswith('K@') and
1220                                        len(hint) == 29 and
1221                                        self._gateway_services.get(hint[2:])
1222                                        )])
1223             # Map root URLs to their KeepService objects.
1224             roots_map = {
1225                 root: self.KeepService(root, self._user_agent_pool,
1226                                        upload_counter=self.upload_counter,
1227                                        download_counter=self.download_counter,
1228                                        headers=headers,
1229                                        insecure=self.insecure)
1230                 for root in hint_roots
1231             }
1232
1233             # See #3147 for a discussion of the loop implementation.  Highlights:
1234             # * Refresh the list of Keep services after each failure, in case
1235             #   it's being updated.
1236             # * Retry until we succeed, we're out of retries, or every available
1237             #   service has returned permanent failure.
1238             sorted_roots = []
1239             roots_map = {}
1240             loop = retry.RetryLoop(num_retries, self._check_loop_result,
1241                                    backoff_start=2)
1242             for tries_left in loop:
1243                 try:
1244                     sorted_roots = self.map_new_services(
1245                         roots_map, locator,
1246                         force_rebuild=(tries_left < num_retries),
1247                         need_writable=False,
1248                         headers=headers)
1249                 except Exception as error:
1250                     loop.save_result(error)
1251                     continue
1252
1253                 # Query KeepService objects that haven't returned
1254                 # permanent failure, in our specified shuffle order.
1255                 services_to_try = [roots_map[root]
1256                                    for root in sorted_roots
1257                                    if roots_map[root].usable()]
1258                 for keep_service in services_to_try:
1259                     blob = keep_service.get(locator, method=method, timeout=self.current_timeout(num_retries-tries_left))
1260                     if blob is not None:
1261                         break
1262                 loop.save_result((blob, len(services_to_try)))
1263
1264             # Always cache the result, then return it if we succeeded.
1265             if loop.success():
1266                 return blob
1267         finally:
1268             if slot is not None:
1269                 self.block_cache.set(slot, blob)
1270
1271         # Q: Including 403 is necessary for the Keep tests to continue
1272         # passing, but maybe they should expect KeepReadError instead?
1273         not_founds = sum(1 for key in sorted_roots
1274                          if roots_map[key].last_result().get('status_code', None) in {403, 404, 410})
1275         service_errors = ((key, roots_map[key].last_result()['error'])
1276                           for key in sorted_roots)
1277         if not roots_map:
1278             raise arvados.errors.KeepReadError(
1279                 "[{}] failed to read {}: no Keep services available ({})".format(
1280                     request_id, loc_s, loop.last_result()))
1281         elif not_founds == len(sorted_roots):
1282             raise arvados.errors.NotFoundError(
1283                 "[{}] {} not found".format(request_id, loc_s), service_errors)
1284         else:
1285             raise arvados.errors.KeepReadError(
1286                 "[{}] failed to read {} after {}".format(request_id, loc_s, loop.attempts_str()), service_errors, label="service")
1287
1288     @retry.retry_method
1289     def put(self, data, copies=2, num_retries=None, request_id=None, classes=None):
1290         """Save data in Keep.
1291
1292         This method will get a list of Keep services from the API server, and
1293         send the data to each one simultaneously in a new thread.  Once the
1294         uploads are finished, if enough copies are saved, this method returns
1295         the most recent HTTP response body.  If requests fail to upload
1296         enough copies, this method raises KeepWriteError.
1297
1298         Arguments:
1299         * data: The string of data to upload.
1300         * copies: The number of copies that the user requires be saved.
1301           Default 2.
1302         * num_retries: The number of times to retry PUT requests to
1303           *each* Keep server if it returns temporary failures, with
1304           exponential backoff.  The default value is set when the
1305           KeepClient is initialized.
1306         * classes: An optional list of storage class names where copies should
1307           be written.
1308         """
1309
1310         classes = classes or self._default_classes
1311
1312         if not isinstance(data, bytes):
1313             data = data.encode()
1314
1315         self.put_counter.add(1)
1316
1317         data_hash = hashlib.md5(data).hexdigest()
1318         loc_s = data_hash + '+' + str(len(data))
1319         if copies < 1:
1320             return loc_s
1321         locator = KeepLocator(loc_s)
1322
1323         request_id = (request_id or
1324                       (hasattr(self, 'api_client') and self.api_client.request_id) or
1325                       arvados.util.new_request_id())
1326         headers = {
1327             'X-Request-Id': request_id,
1328             'X-Keep-Desired-Replicas': str(copies),
1329         }
1330         roots_map = {}
1331         loop = retry.RetryLoop(num_retries, self._check_loop_result,
1332                                backoff_start=2)
1333         done_copies = 0
1334         done_classes = []
1335         for tries_left in loop:
1336             try:
1337                 sorted_roots = self.map_new_services(
1338                     roots_map, locator,
1339                     force_rebuild=(tries_left < num_retries),
1340                     need_writable=True,
1341                     headers=headers)
1342             except Exception as error:
1343                 loop.save_result(error)
1344                 continue
1345
1346             pending_classes = []
1347             if done_classes is not None:
1348                 pending_classes = list(set(classes) - set(done_classes))
1349             writer_pool = KeepClient.KeepWriterThreadPool(data=data,
1350                                                         data_hash=data_hash,
1351                                                         copies=copies - done_copies,
1352                                                         max_service_replicas=self.max_replicas_per_service,
1353                                                         timeout=self.current_timeout(num_retries - tries_left),
1354                                                         classes=pending_classes)
1355             for service_root, ks in [(root, roots_map[root])
1356                                      for root in sorted_roots]:
1357                 if ks.finished():
1358                     continue
1359                 writer_pool.add_task(ks, service_root)
1360             writer_pool.join()
1361             pool_copies, pool_classes = writer_pool.done()
1362             done_copies += pool_copies
1363             if (done_classes is not None) and (pool_classes is not None):
1364                 done_classes += pool_classes
1365                 loop.save_result(
1366                     (done_copies >= copies and set(done_classes) == set(classes),
1367                     writer_pool.total_task_nr))
1368             else:
1369                 # Old keepstore contacted without storage classes support:
1370                 # success is determined only by successful copies.
1371                 #
1372                 # Disable storage classes tracking from this point forward.
1373                 if not self._storage_classes_unsupported_warning:
1374                     self._storage_classes_unsupported_warning = True
1375                     _logger.warning("X-Keep-Storage-Classes header not supported by the cluster")
1376                 done_classes = None
1377                 loop.save_result(
1378                     (done_copies >= copies, writer_pool.total_task_nr))
1379
1380         if loop.success():
1381             return writer_pool.response()
1382         if not roots_map:
1383             raise arvados.errors.KeepWriteError(
1384                 "[{}] failed to write {}: no Keep services available ({})".format(
1385                     request_id, data_hash, loop.last_result()))
1386         else:
1387             service_errors = ((key, roots_map[key].last_result()['error'])
1388                               for key in sorted_roots
1389                               if roots_map[key].last_result()['error'])
1390             raise arvados.errors.KeepWriteError(
1391                 "[{}] failed to write {} after {} (wanted {} copies but wrote {})".format(
1392                     request_id, data_hash, loop.attempts_str(), (copies, classes), writer_pool.done()), service_errors, label="service")
1393
1394     def local_store_put(self, data, copies=1, num_retries=None, classes=[]):
1395         """A stub for put().
1396
1397         This method is used in place of the real put() method when
1398         using local storage (see constructor's local_store argument).
1399
1400         copies and num_retries arguments are ignored: they are here
1401         only for the sake of offering the same call signature as
1402         put().
1403
1404         Data stored this way can be retrieved via local_store_get().
1405         """
1406         md5 = hashlib.md5(data).hexdigest()
1407         locator = '%s+%d' % (md5, len(data))
1408         with open(os.path.join(self.local_store, md5 + '.tmp'), 'wb') as f:
1409             f.write(data)
1410         os.rename(os.path.join(self.local_store, md5 + '.tmp'),
1411                   os.path.join(self.local_store, md5))
1412         return locator
1413
1414     def local_store_get(self, loc_s, num_retries=None):
1415         """Companion to local_store_put()."""
1416         try:
1417             locator = KeepLocator(loc_s)
1418         except ValueError:
1419             raise arvados.errors.NotFoundError(
1420                 "Invalid data locator: '%s'" % loc_s)
1421         if locator.md5sum == config.EMPTY_BLOCK_LOCATOR.split('+')[0]:
1422             return b''
1423         with open(os.path.join(self.local_store, locator.md5sum), 'rb') as f:
1424             return f.read()
1425
1426     def local_store_head(self, loc_s, num_retries=None):
1427         """Companion to local_store_put()."""
1428         try:
1429             locator = KeepLocator(loc_s)
1430         except ValueError:
1431             raise arvados.errors.NotFoundError(
1432                 "Invalid data locator: '%s'" % loc_s)
1433         if locator.md5sum == config.EMPTY_BLOCK_LOCATOR.split('+')[0]:
1434             return True
1435         if os.path.exists(os.path.join(self.local_store, locator.md5sum)):
1436             return True