This file is indexed.

/usr/lib/python2.7/dist-packages/rados.py is in python-ceph 0.80.11-0ubuntu1.14.04.3.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
"""
This module is a thin wrapper around librados.

Copyright 2011, Hannu Valtonen <hannu.valtonen@ormod.com>
"""
from ctypes import CDLL, c_char_p, c_size_t, c_void_p, c_char, c_int, c_long, \
    c_ulong, create_string_buffer, byref, Structure, c_uint64, c_ubyte, \
    pointer, CFUNCTYPE
from ctypes.util import find_library
import ctypes
import errno
import threading
import time
from datetime import datetime

ANONYMOUS_AUID = 0xffffffffffffffff
ADMIN_AUID = 0

class Error(Exception):
    """ `Error` class, derived from `Exception` """
    pass

class InterruptedOrTimeoutError(Error):
    """ `InterruptedOrTimeoutError` class, derived from `Error` """
    pass

class PermissionError(Error):
    """ `PermissionError` class, derived from `Error` """
    pass

class ObjectNotFound(Error):
    """ `ObjectNotFound` class, derived from `Error` """
    pass

class NoData(Error):
    """ `NoData` class, derived from `Error` """
    pass

class ObjectExists(Error):
    """ `ObjectExists` class, derived from `Error` """
    pass

class IOError(Error):
    """ `IOError` class, derived from `Error` """
    pass

class NoSpace(Error):
    """ `NoSpace` class, derived from `Error` """
    pass

class IncompleteWriteError(Error):
    """ `IncompleteWriteError` class, derived from `Error` """
    pass

class RadosStateError(Error):
    """ `RadosStateError` class, derived from `Error` """
    pass

class IoctxStateError(Error):
    """ `IoctxStateError` class, derived from `Error` """
    pass

class ObjectStateError(Error):
    """ `ObjectStateError` class, derived from `Error` """
    pass

class LogicError(Error):
    """ `` class, derived from `Error` """
    pass

class TimedOut(Error):
    """ `TimedOut` class, derived from `Error` """
    pass

def make_ex(ret, msg):
    """
    Translate a librados return code into an exception.

    :param ret: the return code
    :type ret: int
    :param msg: the error message to use
    :type msg: str
    :returns: a subclass of :class:`Error`
    """

    errors = {
        errno.EPERM     : PermissionError,
        errno.ENOENT    : ObjectNotFound,
        errno.EIO       : IOError,
        errno.ENOSPC    : NoSpace,
        errno.EEXIST    : ObjectExists,
        errno.ENODATA   : NoData,
        errno.EINTR     : InterruptedOrTimeoutError,
        errno.ETIMEDOUT : TimedOut
        }
    ret = abs(ret)
    if ret in errors:
        return errors[ret](msg)
    else:
        return Error(msg + (": errno %s" % errno.errorcode[ret]))

class rados_pool_stat_t(Structure):
    """ Usage information for a pool """
    _fields_ = [("num_bytes", c_uint64),
                ("num_kb", c_uint64),
                ("num_objects", c_uint64),
                ("num_object_clones", c_uint64),
                ("num_object_copies", c_uint64),
                ("num_objects_missing_on_primary", c_uint64),
                ("num_objects_unfound", c_uint64),
                ("num_objects_degraded", c_uint64),
                ("num_rd", c_uint64),
                ("num_rd_kb", c_uint64),
                ("num_wr", c_uint64),
                ("num_wr_kb", c_uint64)]

class rados_cluster_stat_t(Structure):
    """ Cluster-wide usage information """
    _fields_ = [("kb", c_uint64),
                ("kb_used", c_uint64),
                ("kb_avail", c_uint64),
                ("num_objects", c_uint64)]

class Version(object):
    """ Version information """
    def __init__(self, major, minor, extra):
        self.major = major
        self.minor = minor
        self.extra = extra

    def __str__(self):
        return "%d.%d.%d" % (self.major, self.minor, self.extra)

class RadosThread(threading.Thread):
    def __init__(self, target, args=None):
        self.args = args
        self.target = target
        threading.Thread.__init__(self)

    def run(self):
        self.retval = self.target(*self.args)

# time in seconds between each call to t.join() for child thread
POLL_TIME_INCR = 0.5

def run_in_thread(target, args, timeout=0):
    import sys
    interrupt = False

    countdown = timeout
    t = RadosThread(target, args)

    # allow the main thread to exit (presumably, avoid a join() on this
    # subthread) before this thread terminates.  This allows SIGINT
    # exit of a blocked call.  See below.
    t.daemon = True

    t.start()
    try:
        # poll for thread exit
        while t.is_alive():
            t.join(POLL_TIME_INCR)
            if timeout:
                countdown = countdown - POLL_TIME_INCR
                if countdown <= 0:
                    raise KeyboardInterrupt

        t.join()        # in case t exits before reaching the join() above
    except KeyboardInterrupt:
        # ..but allow SIGINT to terminate the waiting.  Note: this
        # relies on the Linux kernel behavior of delivering the signal
        # to the main thread in preference to any subthread (all that's
        # strictly guaranteed is that *some* thread that has the signal
        # unblocked will receive it).  But there doesn't seem to be
        # any interface to create t with SIGINT blocked.
        interrupt = True

    if interrupt:
        t.retval = -errno.EINTR
    return t.retval

class Rados(object):
    """librados python wrapper"""
    def require_state(self, *args):
        """ 
        Checks if the Rados object is in a special state

        :raises: RadosStateError
        """
        for a in args:
            if self.state == a:
                return
        raise RadosStateError("You cannot perform that operation on a \
Rados object in state %s." % (self.state))

    def __init__(self, rados_id=None, name=None, clustername=None,
                 conf_defaults=None, conffile=None, conf=None, flags=0):
        librados_path = find_library('rados')
        if not librados_path:
            #maybe find_library can not find it correctly on all platforms.
            try:
                self.librados = CDLL('librados.so.2')
            except OSError as e:
                    raise EnvironmentError("Unable to load librados: %s" % e)
            except:
                raise Error("Unexpected error")
        else:
            self.librados = CDLL(librados_path)
        self.cluster = c_void_p()
        self.rados_id = rados_id
        if rados_id is not None and not isinstance(rados_id, str):
            raise TypeError('rados_id must be a string or None')
        if conffile is not None and not isinstance(conffile, str):
            raise TypeError('conffile must be a string or None')
        if name is not None and not isinstance(name, str):
            raise TypeError('name must be a string or None')
        if clustername is not None and not isinstance(clustername, str):
            raise TypeError('clustername must be a string or None')
        if rados_id and name:
            raise Error("Rados(): can't supply both rados_id and name")
        if rados_id:
            name = 'client.' +  rados_id
        if name is None:
            name = 'client.admin'
        if clustername is None:
            clustername = 'ceph'
        ret = run_in_thread(self.librados.rados_create2,
                            (byref(self.cluster), c_char_p(clustername),
                            c_char_p(name), c_uint64(flags)))

        if ret != 0:
            raise Error("rados_initialize failed with error code: %d" % ret)
        self.state = "configuring"
        # order is important: conf_defaults, then conffile, then conf
        if conf_defaults:
            for key, value in conf_defaults.iteritems():
                self.conf_set(key, value)
        if conffile is not None:
            # read the default conf file when '' is given
            if conffile == '':
                conffile = None
            self.conf_read_file(conffile)
        if conf:
            for key, value in conf.iteritems():
                self.conf_set(key, value)

    def shutdown(self):
        """
        Disconnects from the cluster.  Call this explicitly when a
        Rados.connect()ed object is no longer used.
        """
        if (self.__dict__.has_key("state") and self.state != "shutdown"):
            run_in_thread(self.librados.rados_shutdown, (self.cluster,))
            self.state = "shutdown"

    def __enter__(self):
        self.connect()
        return self

    def __exit__(self, type_, value, traceback):
        self.shutdown()
        return False

    def version(self):
        """
        Get the version number of the ``librados`` C library.
    
        :returns: a tuple of ``(major, minor, extra)`` components of the
                  librados version
        """
        major = c_int(0)
        minor = c_int(0)
        extra = c_int(0)
        run_in_thread(self.librados.rados_version,
                      (byref(major), byref(minor), byref(extra)))
        return Version(major.value, minor.value, extra.value)

    def conf_read_file(self, path=None):
        """
        Configure the cluster handle using a Ceph config file.

        :param path: path to the config file
        :type path: str
        """
        self.require_state("configuring", "connected")
        if path is not None and not isinstance(path, str):
            raise TypeError('path must be a string')
        ret = run_in_thread(self.librados.rados_conf_read_file,
                            (self.cluster, c_char_p(path)))
        if (ret != 0):
            raise make_ex(ret, "error calling conf_read_file")

    def conf_parse_argv(self, args):
        """
        Parse known arguments from args, and remove; returned
        args contain only those unknown to ceph
        """
        self.require_state("configuring", "connected")
        if not args:
            return
        # create instances of arrays of c_char_p's, both len(args) long
        # cretargs will always be a subset of cargs (perhaps identical)
        cargs = (c_char_p * len(args))(*args)
        cretargs = (c_char_p * len(args))()
        ret = run_in_thread(self.librados.rados_conf_parse_argv_remainder,
                            (self.cluster, len(args), cargs, cretargs))
        if ret:
            raise make_ex(ret, "error calling conf_parse_argv_remainder")

        # cretargs was allocated with fixed length; collapse return
        # list to eliminate any missing args

        retargs = [a for a in cretargs if a is not None]
        return retargs

    def conf_parse_env(self, var='CEPH_ARGS'):
        """
        Parse known arguments from an environment variable, normally
        CEPH_ARGS.
        """
        self.require_state("configuring", "connected")
        if not var:
            return
        ret = run_in_thread(self.librados.rados_conf_parse_env,
                            (self.cluster, c_char_p(var)))
        if (ret != 0):
            raise make_ex(ret, "error calling conf_parse_env")

    def conf_get(self, option):
        """
        Get the value of a configuration option

        :param option: which option to read
        :type option: str

        :returns: str - value of the option or None
        :raises: :class:`TypeError`
        """
        self.require_state("configuring", "connected")
        if not isinstance(option, str):
            raise TypeError('option must be a string')
        length = 20
        while True:
            ret_buf = create_string_buffer(length)
            ret = run_in_thread(self.librados.rados_conf_get,
                                (self.cluster, c_char_p(option), ret_buf,
                                c_size_t(length)))
            if (ret == 0):
                return ret_buf.value
            elif (ret == -errno.ENAMETOOLONG):
                length = length * 2
            elif (ret == -errno.ENOENT):
                return None
            else:
                raise make_ex(ret, "error calling conf_get")

    def conf_set(self, option, val):
        """
        Set the value of a configuration option

        :param option: which option to set
        :type option: str
        :param option: value of the option
        :type option: str

        :raises: :class:`TypeError`, :class:`ObjectNotFound`
        """
        self.require_state("configuring", "connected")
        if not isinstance(option, str):
            raise TypeError('option must be a string')
        if not isinstance(val, str):
            raise TypeError('val must be a string')
        ret = run_in_thread(self.librados.rados_conf_set,
                            (self.cluster, c_char_p(option), c_char_p(val)))
        if (ret != 0):
            raise make_ex(ret, "error calling conf_set")


    def ping_monitor(self, mon_id):
      """
      Ping a monitor to assess liveness

      May be used as a simply way to assess liveness, or to obtain
      information about the monitor in a simple way even in the
      absence of quorum.

      :param mon_id: the ID portion of the monitor's name (i.e., mon.<ID>)
      :type mon_id: str
      :returns: the string reply from the monitor
      """

      self.require_state("configuring", "connected")

      outstrp = pointer(pointer(c_char()))
      outstrlen = c_long()

      ret = run_in_thread(self.librados.rados_ping_monitor,
                          (self.cluster, c_char_p(mon_id),
                           outstrp, byref(outstrlen)))

      my_outstr = outstrp.contents[:(outstrlen.value)]
      if outstrlen.value:
        run_in_thread(self.librados.rados_buffer_free, (outstrp.contents,))

      if ret != 0:
        raise make_ex(ret, "error calling ping_monitor")
      return my_outstr

    def connect(self, timeout=0):
        """
        Connect to the cluster.  Use shutdown() to release resources.
        """
        self.require_state("configuring")
        ret = run_in_thread(self.librados.rados_connect, (self.cluster,),
                            timeout)
        if (ret != 0):
            raise make_ex(ret, "error calling connect")
        self.state = "connected"

    def get_cluster_stats(self):
        """
        Read usage info about the cluster
        
        This tells you total space, space used, space available, and number
        of objects. These are not updated immediately when data is written,
        they are eventually consistent.

        :returns: dict - contains the following keys:

            - ``kb`` (int) - total space 

            - ``kb_used`` (int) - space used

            - ``kb_avail`` (int) - free space available

            - ``num_objects`` (int) - number of objects

        """
        stats = rados_cluster_stat_t()
        ret = run_in_thread(self.librados.rados_cluster_stat,
                            (self.cluster, byref(stats)))
        if ret < 0:
            raise make_ex(
                ret, "Rados.get_cluster_stats(%s): get_stats failed" % self.rados_id)
        return {'kb': stats.kb,
                'kb_used': stats.kb_used,
                'kb_avail': stats.kb_avail,
                'num_objects': stats.num_objects}

    def pool_exists(self, pool_name):
        """
        Checks if a given pool exists.

        :param pool_name: name of the pool to check
        :type pool_name: str

        :raises: :class:`TypeError`, :class:`Error`
        :returns: bool - whether the pool exists, false otherwise.
        """
        self.require_state("connected")
        if not isinstance(pool_name, str):
            raise TypeError('pool_name must be a string')
        ret = run_in_thread(self.librados.rados_pool_lookup,
                            (self.cluster, c_char_p(pool_name)))
        if (ret >= 0):
            return True
        elif (ret == -errno.ENOENT):
            return False
        else:
            raise make_ex(ret, "error looking up pool '%s'" % pool_name)

    def create_pool(self, pool_name, auid=None, crush_rule=None):
        """
        Create a pool:
        - with default settings: if auid=None and crush_rule=None
        - owned by a specific auid: auid given and crush_rule=None
        - with a specific CRUSH rule: if auid=None and crush_rule given
        - with a specific CRUSH rule and auid: if auid and crush_rule given

        :param pool_name: name of the pool to create
        :type pool_name: str
        :param auid: the id of the owner of the new pool
        :type auid: int
        :param crush_rule: rule to use for placement in the new pool
        :type crush_rule: str

        :raises: :class:`TypeError`, :class:`Error`
        """
        self.require_state("connected")
        if not isinstance(pool_name, str):
            raise TypeError('pool_name must be a string')
        if crush_rule is not None and not isinstance(crush_rule, str):
            raise TypeError('cruse_rule must be a string')
        if (auid == None):
            if (crush_rule == None):
                ret = run_in_thread(self.librados.rados_pool_create,
                                    (self.cluster, c_char_p(pool_name)))
            else:
                ret = run_in_thread(self.librados.\
                                    rados_pool_create_with_crush_rule,
                                    (self.cluster, c_char_p(pool_name),
                                    c_ubyte(crush_rule)))

        elif (crush_rule == None):
            ret = run_in_thread(self.librados.rados_pool_create_with_auid,
                                (self.cluster, c_char_p(pool_name),
                                c_uint64(auid)))
        else:
            ret = run_in_thread(self.librados.rados_pool_create_with_all,
                                (self.cluster, c_char_p(pool_name),
                                c_uint64(auid), c_ubyte(crush_rule)))
        if ret < 0:
            raise make_ex(ret, "error creating pool '%s'" % pool_name)

    def delete_pool(self, pool_name):
        """
        Delete a pool and all data inside it.

        The pool is removed from the cluster immediately,
        but the actual data is deleted in the background.

        :param pool_name: name of the pool to delete 
        :type pool_name: str

        :raises: :class:`TypeError`, :class:`Error`
        """
        self.require_state("connected")
        if not isinstance(pool_name, str):
            raise TypeError('pool_name must be a string')
        ret = run_in_thread(self.librados.rados_pool_delete,
                            (self.cluster, c_char_p(pool_name)))
        if ret < 0:
            raise make_ex(ret, "error deleting pool '%s'" % pool_name)

    def list_pools(self):
        """
        Gets a list of pool names. 

        :returns: list - of pool names.
        """
        self.require_state("connected")
        size = c_size_t(512)
        while True:
            c_names = create_string_buffer(size.value)
            ret = run_in_thread(self.librados.rados_pool_list,
                                (self.cluster, byref(c_names), size))
            if ret > size.value:
                size = c_size_t(ret)
            else:
                break
        return filter(lambda name: name != '', c_names.raw.split('\0'))

    def get_fsid(self):
        """
        Get the fsid of the cluster as a hexadecimal string.

        :raises: :class:`Error`
        :returns: str - cluster fsid
        """
        self.require_state("connected")
        buf_len = 37
        fsid = create_string_buffer(buf_len)
        ret = run_in_thread(self.librados.rados_cluster_fsid,
                            (self.cluster, byref(fsid), c_size_t(buf_len)))
        if ret < 0:
            raise make_ex(ret, "error getting cluster fsid")
        return fsid.value

    def open_ioctx(self, ioctx_name):
        """
        Create an io context

        The io context allows you to perform operations within a particular
        pool. 

        :param ioctx_name: name of the pool 
        :type ioctx_name: str

        :raises: :class:`TypeError`, :class:`Error`
        :returns: Ioctx - Rados Ioctx object 
        """
        self.require_state("connected")
        if not isinstance(ioctx_name, str):
            raise TypeError('ioctx_name must be a string')
        ioctx = c_void_p()
        ret = run_in_thread(self.librados.rados_ioctx_create,
                            (self.cluster, c_char_p(ioctx_name), byref(ioctx)))
        if ret < 0:
            raise make_ex(ret, "error opening ioctx '%s'" % ioctx_name)
        return Ioctx(ioctx_name, self.librados, ioctx)

    def mon_command(self, cmd, inbuf, timeout=0, target=None):
        """
        mon_command[_target](cmd, inbuf, outbuf, outbuflen, outs, outslen)
        returns (int ret, string outbuf, string outs)
        """
        import sys
        self.require_state("connected")
        outbufp = pointer(pointer(c_char()))
        outbuflen = c_long()
        outsp = pointer(pointer(c_char()))
        outslen = c_long()
        cmdarr = (c_char_p * len(cmd))(*cmd)

        if target:
            ret = run_in_thread(self.librados.rados_mon_command_target,
                                (self.cluster, c_char_p(target), cmdarr,
                                 len(cmd), c_char_p(inbuf), len(inbuf),
                                 outbufp, byref(outbuflen), outsp,
                                 byref(outslen)), timeout)
        else:
            ret = run_in_thread(self.librados.rados_mon_command,
                                (self.cluster, cmdarr, len(cmd),
                                 c_char_p(inbuf), len(inbuf),
                                 outbufp, byref(outbuflen), outsp, byref(outslen)),
                                timeout)

        # copy returned memory (ctypes makes a copy, not a reference)
        my_outbuf = outbufp.contents[:(outbuflen.value)]
        my_outs = outsp.contents[:(outslen.value)]

        # free callee's allocations
        if outbuflen.value:
            run_in_thread(self.librados.rados_buffer_free, (outbufp.contents,))
        if outslen.value:
            run_in_thread(self.librados.rados_buffer_free, (outsp.contents,))

        return (ret, my_outbuf, my_outs)

    def osd_command(self, osdid, cmd, inbuf, timeout=0):
        """
        osd_command(osdid, cmd, inbuf, outbuf, outbuflen, outs, outslen)
        returns (int ret, string outbuf, string outs)
        """
        import sys
        self.require_state("connected")
        outbufp = pointer(pointer(c_char()))
        outbuflen = c_long()
        outsp = pointer(pointer(c_char()))
        outslen = c_long()
        cmdarr = (c_char_p * len(cmd))(*cmd)
        ret = run_in_thread(self.librados.rados_osd_command,
                            (self.cluster, osdid, cmdarr, len(cmd),
                            c_char_p(inbuf), len(inbuf),
                            outbufp, byref(outbuflen), outsp, byref(outslen)),
                            timeout)

        # copy returned memory (ctypes makes a copy, not a reference)
        my_outbuf = outbufp.contents[:(outbuflen.value)]
        my_outs = outsp.contents[:(outslen.value)]

        # free callee's allocations
        if outbuflen.value:
            run_in_thread(self.librados.rados_buffer_free, (outbufp.contents,))
        if outslen.value:
            run_in_thread(self.librados.rados_buffer_free, (outsp.contents,))

        return (ret, my_outbuf, my_outs)

    def pg_command(self, pgid, cmd, inbuf, timeout=0):
        """
        pg_command(pgid, cmd, inbuf, outbuf, outbuflen, outs, outslen)
        returns (int ret, string outbuf, string outs)
        """
        import sys
        self.require_state("connected")
        outbufp = pointer(pointer(c_char()))
        outbuflen = c_long()
        outsp = pointer(pointer(c_char()))
        outslen = c_long()
        cmdarr = (c_char_p * len(cmd))(*cmd)
        ret = run_in_thread(self.librados.rados_pg_command,
                            (self.cluster, c_char_p(pgid), cmdarr, len(cmd),
                            c_char_p(inbuf), len(inbuf),
                            outbufp, byref(outbuflen), outsp, byref(outslen)),
                            timeout)

        # copy returned memory (ctypes makes a copy, not a reference)
        my_outbuf = outbufp.contents[:(outbuflen.value)]
        my_outs = outsp.contents[:(outslen.value)]

        # free callee's allocations
        if outbuflen.value:
            run_in_thread(self.librados.rados_buffer_free, (outbufp.contents,))
        if outslen.value:
            run_in_thread(self.librados.rados_buffer_free, (outsp.contents,))

        return (ret, my_outbuf, my_outs)

class ObjectIterator(object):
    """rados.Ioctx Object iterator"""
    def __init__(self, ioctx):
        self.ioctx = ioctx
        self.ctx = c_void_p()
        ret = run_in_thread(self.ioctx.librados.rados_objects_list_open,
                            (self.ioctx.io, byref(self.ctx)))
        if ret < 0:
            raise make_ex(ret, "error iterating over the objects in ioctx '%s'" \
                % self.ioctx.name)

    def __iter__(self):
        return self

    def next(self):
        """
        Get the next object name and locator in the pool

        :raises: StopIteration
        :returns: next rados.Ioctx Object
        """
        key = c_char_p()
        locator = c_char_p()
        ret = run_in_thread(self.ioctx.librados.rados_objects_list_next,
                            (self.ctx, byref(key), byref(locator)))
        if ret < 0:
            raise StopIteration()
        return Object(self.ioctx, key.value, locator.value)

    def __del__(self):
        run_in_thread(self.ioctx.librados.rados_objects_list_close, (self.ctx,))

class XattrIterator(object):
    """Extended attribute iterator"""
    def __init__(self, ioctx, it, oid):
        self.ioctx = ioctx
        self.it = it
        self.oid = oid

    def __iter__(self):
        return self

    def next(self):
        """
        Get the next xattr on the object

        :raises: StopIteration
        :returns: pair - of name and value of the next Xattr
        """
        name_ = c_char_p(0)
        val_ = c_char_p(0)
        len_ = c_int(0)
        ret = run_in_thread(self.ioctx.librados.rados_getxattrs_next,
                            (self.it, byref(name_), byref(val_), byref(len_)))
        if (ret != 0):
            raise make_ex(ret, "error iterating over the extended attributes \
in '%s'" % self.oid)
        if name_.value == None:
            raise StopIteration()
        name = ctypes.string_at(name_)
        val = ctypes.string_at(val_, len_)
        return (name, val)

    def __del__(self):
        run_in_thread(self.ioctx.librados.rados_getxattrs_end, (self.it,))

class SnapIterator(object):
    """Snapshot iterator"""
    def __init__(self, ioctx):
        self.ioctx = ioctx
        # We don't know how big a buffer we need until we've called the
        # function. So use the exponential doubling strategy.
        num_snaps = 10
        while True:
            self.snaps = (ctypes.c_uint64 * num_snaps)()
            ret = run_in_thread(self.ioctx.librados.rados_ioctx_snap_list,
                                (self.ioctx.io, self.snaps, c_int(num_snaps)))
            if (ret >= 0):
                self.max_snap = ret
                break
            elif (ret != -errno.ERANGE):
                raise make_ex(ret, "error calling rados_snap_list for \
ioctx '%s'" % self.ioctx.name)
            num_snaps = num_snaps * 2
        self.cur_snap = 0

    def __iter__(self):
        return self

    def next(self):
        """
        Get the next Snapshot

        :raises: :class:`Error`, StopIteration 
        :returns: Snap - next snapshot
        """
        if (self.cur_snap >= self.max_snap):
            raise StopIteration
        snap_id = self.snaps[self.cur_snap]
        name_len = 10
        while True:
            name = create_string_buffer(name_len)
            ret = run_in_thread(self.ioctx.librados.rados_ioctx_snap_get_name,
                                (self.ioctx.io, c_uint64(snap_id), byref(name),
                                 c_int(name_len)))
            if (ret == 0):
                name_len = ret
                break
            elif (ret != -errno.ERANGE):
                raise make_ex(ret, "rados_snap_get_name error")
            name_len = name_len * 2
        snap = Snap(self.ioctx, name.value, snap_id)
        self.cur_snap = self.cur_snap + 1
        return snap

class Snap(object):
    """Snapshot object"""
    def __init__(self, ioctx, name, snap_id):
        self.ioctx = ioctx
        self.name = name
        self.snap_id = snap_id

    def __str__(self):
        return "rados.Snap(ioctx=%s,name=%s,snap_id=%d)" \
            % (str(self.ioctx), self.name, self.snap_id)

    def get_timestamp(self):
        """
        Find when a snapshot in the current pool occurred

        :raises: :class:`Error`
        :returns: datetime - the data and time the snapshot was created
        """
        snap_time = c_long(0)
        ret = run_in_thread(self.ioctx.librados.rados_ioctx_snap_get_stamp,
                            (self.ioctx.io, self.snap_id, byref(snap_time)))
        if (ret != 0):
            raise make_ex(ret, "rados_ioctx_snap_get_stamp error")
        return datetime.fromtimestamp(snap_time.value)

class Completion(object):
    """completion object"""
    def __init__(self, ioctx, rados_comp, oncomplete, onsafe,
                 complete_cb, safe_cb):
        self.rados_comp = rados_comp
        self.oncomplete = oncomplete
        self.onsafe = onsafe
        self.ioctx = ioctx
        self.complete_cb = complete_cb
        self.safe_cb = safe_cb

    def wait_for_safe(self):
        """
        Is an asynchronous operation safe?

        This does not imply that the safe callback has finished.

        :returns: whether the operation is safe
        """
        return run_in_thread(self.ioctx.librados.rados_aio_is_safe,
                             (self.rados_comp,))

    def wait_for_complete(self):
        """
        Has an asynchronous operation completed?

        This does not imply that the safe callback has finished.

        :returns:  whether the operation is completed
        """
        return run_in_thread(self.ioctx.librados.rados_aio_is_complete,
                             (self.rados_comp,))

    def get_return_value(self):
        """
        Get the return value of an asychronous operation

        The return value is set when the operation is complete or safe,
        whichever comes first.

        :returns: int - return value of the operation
        """
        return run_in_thread(self.ioctx.librados.rados_aio_get_return_value,
                             (self.rados_comp,))

    def __del__(self):
        """ 
        Release a completion 

        Call this when you no longer need the completion. It may not be
        freed immediately if the operation is not acked and committed.
        """
        run_in_thread(self.ioctx.librados.rados_aio_release,
                      (self.rados_comp,))

RADOS_CB = CFUNCTYPE(c_int, c_void_p, c_void_p)

class Ioctx(object):
    """rados.Ioctx object"""
    def __init__(self, name, librados, io):
        self.name = name
        self.librados = librados
        self.io = io
        self.state = "open"
        self.locator_key = ""
        self.safe_cbs = {}
        self.complete_cbs = {}
        self.lock = threading.Lock()

    def __enter__(self):
        return self

    def __exit__(self, type_, value, traceback):
        self.close()
        return False

    def __del__(self):
        self.close()

    def __aio_safe_cb(self, completion, _):
        """ 
        Callback to onsafe() for asynchronous operations 
        """
        cb = None
        with self.lock:
            cb = self.safe_cbs[completion]
            del self.safe_cbs[completion]
        cb.onsafe(cb)
        return 0

    def __aio_complete_cb(self, completion, _):
        """ 
        Callback to oncomplete() for asynchronous operations 
        """
        cb = None
        with self.lock:
            cb = self.complete_cbs[completion]
            del self.complete_cbs[completion]
        cb.oncomplete(cb)
        return 0

    def __get_completion(self, oncomplete, onsafe):
        """
        Constructs a completion to use with asynchronous operations

        :param oncomplete: what to do when the write is safe and complete in memory
            on all replicas
        :type oncomplete: completion
        :param onsafe:  what to do when the write is safe and complete on storage
            on all replicas
        :type onsafe: completion

        :raises: :class:`Error`
        :returns: completion object 
        """
        completion = c_void_p(0)
        complete_cb = None
        safe_cb = None
        if oncomplete:
            complete_cb = RADOS_CB(self.__aio_complete_cb)
        if onsafe:
            safe_cb = RADOS_CB(self.__aio_safe_cb)
        ret = run_in_thread(self.librados.rados_aio_create_completion,
                            (c_void_p(0), complete_cb, safe_cb,
                            byref(completion)))
        if ret < 0:
            raise make_ex(ret, "error getting a completion")
        with self.lock:
            completion_obj = Completion(self, completion, oncomplete, onsafe,
                                        complete_cb, safe_cb)
            if oncomplete:
                self.complete_cbs[completion.value] = completion_obj
            if onsafe:
                self.safe_cbs[completion.value] = completion_obj
        return completion_obj

    def aio_write(self, object_name, to_write, offset=0,
                  oncomplete=None, onsafe=None):
        """
        Write data to an object asynchronously

        Queues the write and returns.

        :param object_name: name of the object
        :type object_name: str
        :param to_write: data to write
        :type to_write: str
        :param offset: byte offset in the object to begin writing at
        :type offset: int
        :param oncomplete: what to do when the write is safe and complete in memory
            on all replicas
        :type oncomplete: completion
        :param onsafe:  what to do when the write is safe and complete on storage
            on all replicas
        :type onsafe: completion

        :raises: :class:`Error`
        :returns: completion object 
        """
        completion = self.__get_completion(oncomplete, onsafe)
        ret = run_in_thread(self.librados.rados_aio_write,
                            (self.io, c_char_p(object_name),
                            completion.rados_comp, c_char_p(to_write),
                            c_size_t(len(to_write)), c_uint64(offset)))
        if ret < 0:
            raise make_ex(ret, "error writing object %s" % object_name)
        return completion

    def aio_write_full(self, object_name, to_write,
                       oncomplete=None, onsafe=None):
        """
        Asychronously write an entire object

        The object is filled with the provided data. If the object exists,
        it is atomically truncated and then written.
        Queues the write and returns.

        :param object_name: name of the object
        :type object_name: str
        :param to_write: data to write
        :type to_write: str
        :param oncomplete: what to do when the write is safe and complete in memory
            on all replicas
        :type oncomplete: completion
        :param onsafe:  what to do when the write is safe and complete on storage
            on all replicas
        :type onsafe: completion

        :raises: :class:`Error`
        :returns: completion object 
        """
        completion = self.__get_completion(oncomplete, onsafe)
        ret = run_in_thread(self.librados.rados_aio_write_full,
                            (self.io, c_char_p(object_name),
                            completion.rados_comp, c_char_p(to_write),
                            c_size_t(len(to_write))))
        if ret < 0:
            raise make_ex(ret, "error writing object %s" % object_name)
        return completion

    def aio_append(self, object_name, to_append, oncomplete=None, onsafe=None):
        """
        Asychronously append data to an object

        Queues the write and returns.

        :param object_name: name of the object
        :type object_name: str
        :param to_append: data to append
        :type to_append: str
        :param offset: byte offset in the object to begin writing at
        :type offset: int
        :param oncomplete: what to do when the write is safe and complete in memory
            on all replicas
        :type oncomplete: completion
        :param onsafe:  what to do when the write is safe and complete on storage
            on all replicas
        :type onsafe: completion

        :raises: :class:`Error`
        :returns: completion object 
        """
        completion = self.__get_completion(oncomplete, onsafe)
        ret = run_in_thread(self.librados.rados_aio_append,
                            (self.io, c_char_p(object_name),
                            completion.rados_comp, c_char_p(to_append),
                            c_size_t(len(to_append))))
        if ret < 0:
            raise make_ex(ret, "error appending to object %s" % object_name)
        return completion

    def aio_flush(self):
        """
        Block until all pending writes in an io context are safe

        :raises: :class:`Error`
        """
        ret = run_in_thread(self.librados.rados_aio_flush, (self.io,))
        if ret < 0:
            raise make_ex(ret, "error flushing")

    def aio_read(self, object_name, length, offset, oncomplete):
        """
        Asychronously read data from an object

        oncomplete will be called with the returned read value as
        well as the completion:

        oncomplete(completion, data_read)

        :param object_name: name of the object to read from
        :type object_name: str
        :param length: the number of bytes to read
        :type length: int
        :param offset: byte offset in the object to begin reading from
        :type offset: int
        :param oncomplete: what to do when the read is complete
        :type oncomplete: completion

        :raises: :class:`Error`
        :returns: completion object
        """
        buf = create_string_buffer(length)
        def oncomplete_(completion_v):
            return_value = completion_v.get_return_value()
            return oncomplete(completion_v,
                              ctypes.string_at(buf, return_value) if return_value >= 0 else None)

        completion = self.__get_completion(oncomplete_, None)
        ret = run_in_thread(self.librados.rados_aio_read,
                            (self.io, c_char_p(object_name),
                            completion.rados_comp, buf, c_size_t(length),
                            c_uint64(offset)))
        if ret < 0:
            raise make_ex(ret, "error reading %s" % object_name)
        return completion

    def aio_remove(self, object_name, oncomplete=None, onsafe=None):
        """
        Asychronously remove an object

        :param object_name: name of the object to remove
        :type object_name: str
        :param oncomplete: what to do when the remove is safe and complete in memory
            on all replicas
        :type oncomplete: completion
        :param onsafe:  what to do when the remove is safe and complete on storage
            on all replicas
        :type onsafe: completion

        :raises: :class:`Error`
        :returns: completion object
        """
        completion = self.__get_completion(oncomplete, onsafe)
        ret = run_in_thread(self.librados.rados_aio_remove,
                            (self.io, c_char_p(object_name),
                            completion.rados_comp))
        if ret < 0:
            raise make_ex(ret, "error removing %s" % object_name)
        return completion

    def require_ioctx_open(self):
        """
        Checks if the rados.Ioctx object state is 'open'

        :raises: IoctxStateError
        """
        if self.state != "open":
            raise IoctxStateError("The pool is %s" % self.state)

    def change_auid(self, auid):
        """
        Attempt to change an io context's associated auid "owner."

        Requires that you have write permission on both the current and new
        auid.

        :raises: :class:`Error`
        """
        self.require_ioctx_open()
        ret = run_in_thread(self.librados.rados_ioctx_pool_set_auid,
                            (self.io, ctypes.c_uint64(auid)))
        if ret < 0:
            raise make_ex(ret, "error changing auid of '%s' to %d" %\
                (self.name, auid))

    def set_locator_key(self, loc_key):
        """
        Set the key for mapping objects to pgs within an io context.

        The key is used instead of the object name to determine which
        placement groups an object is put in. This affects all subsequent
        operations of the io context - until a different locator key is
        set, all objects in this io context will be placed in the same pg.

        :param loc_key: the key to use as the object locator, or NULL to discard
            any previously set key
        :type loc_key: str

        :raises: :class:`TypeError`
        """
        self.require_ioctx_open()
        if not isinstance(loc_key, str):
            raise TypeError('loc_key must be a string')
        run_in_thread(self.librados.rados_ioctx_locator_set_key,
                     (self.io, c_char_p(loc_key)))
        self.locator_key = loc_key

    def get_locator_key(self):
        """
        Get the locator_key of context

        :returns: locator_key
        """
        return self.locator_key

    def close(self):
        """
        Close a rados.Ioctx object.

        This just tells librados that you no longer need to use the io context.
        It may not be freed immediately if there are pending asynchronous
        requests on it, but you should not use an io context again after
        calling this function on it.
        """
        if self.state == "open":
            self.require_ioctx_open()
            run_in_thread(self.librados.rados_ioctx_destroy, (self.io,))
            self.state = "closed"

    def write(self, key, data, offset=0):
        """
        Write data to an object synchronously

        :param key: name of the object
        :type key: str
        :param data: data to write
        :type data: str
        :param offset: byte offset in the object to begin writing at
        :type offset: int

        :raises: :class:`TypeError`
        :raises: :class:`LogicError`
        :returns: int - number of bytes written 
        """
        self.require_ioctx_open()
        if not isinstance(key, str):
            raise TypeError('key must be a string')
        if not isinstance(data, str):
            raise TypeError('data must be a string')
        length = len(data)
        ret = run_in_thread(self.librados.rados_write,
                            (self.io, c_char_p(key), c_char_p(data),
                            c_size_t(length), c_uint64(offset)))
        if ret == 0:
            return ret
        elif ret < 0:
            raise make_ex(ret, "Ioctx.write(%s): failed to write %s" % \
                (self.name, key))
        else:
            raise LogicError("Ioctx.write(%s): rados_write \
returned %d, but should return zero on success." % (self.name, ret))

    def write_full(self, key, data):
        """
        Write an entire object synchronously.

        The object is filled with the provided data. If the object exists,
        it is atomically truncated and then written.

        :param key: name of the object
        :type key: str
        :param data: data to write
        :type data: str

        :raises: :class:`TypeError`
        :raises: :class:`Error`
        :returns: int - 0 on success
        """
        self.require_ioctx_open()
        if not isinstance(key, str):
            raise TypeError('key must be a string')
        if not isinstance(data, str):
            raise TypeError('data must be a string')
        length = len(data)
        ret = run_in_thread(self.librados.rados_write_full,
                            (self.io, c_char_p(key), c_char_p(data),
                            c_size_t(length)))
        if ret == 0:
            return ret
        elif ret < 0:
            raise make_ex(ret, "Ioctx.write_full(%s): failed to write %s" % \
                (self.name, key))
        else:
            raise LogicError("Ioctx.write_full(%s): rados_write_full \
returned %d, but should return zero on success." % (self.name, ret))

    def append(self, key, data):
        """
        Append data to an object synchronously

        :param key: name of the object
        :type key: str
        :param data: data to write
        :type data: str

        :raises: :class:`TypeError`
        :raises: :class:`LogicError`
        :returns: int - number of bytes written
        """
        self.require_ioctx_open()
        if not isinstance(key, str):
            raise TypeError('key must be a string')
        if not isinstance(data, str):
            raise TypeError('data must be a string')
        length = len(data)
        ret = run_in_thread(self.librados.rados_append,
                            (self.io, c_char_p(key), c_char_p(data),
                            c_size_t(length)))
        if ret == 0:
            return ret
        elif ret < 0:
            raise make_ex(ret, "Ioctx.append(%s): failed to append %s" % \
                (self.name, key))
        else:
            raise LogicError("Ioctx.append(%s): rados_append \
returned %d, but should return zero on success." % (self.name, ret))

    def read(self, key, length=8192, offset=0):
        """
        Read data from an object synchronously

        :param key: name of the object
        :type key: str
        :param length: the number of bytes to read (default=8192)
        :type length: int 
        :param offset: byte offset in the object to begin reading at
        :type offset: int

        :raises: :class:`TypeError`
        :raises: :class:`Error`
        :returns: str - data read from object
        """
        self.require_ioctx_open()
        if not isinstance(key, str):
            raise TypeError('key must be a string')
        ret_buf = create_string_buffer(length)
        ret = run_in_thread(self.librados.rados_read,
                            (self.io, c_char_p(key), ret_buf, c_size_t(length),
                            c_uint64(offset)))
        if ret < 0:
            raise make_ex(ret, "Ioctx.read(%s): failed to read %s" % (self.name, key))
        return ctypes.string_at(ret_buf, ret)

    def get_stats(self):
        """
        Get pool usage statistics

        :returns: dict - contains the following keys:

            - ``num_bytes`` (int) - size of pool in bytes

            - ``num_kb`` (int) - size of pool in kbytes

            - ``num_objects`` (int) - number of objects in the pool

            - ``num_object_clones`` (int) - number of object clones

            - ``num_object_copies`` (int) - number of object copies

            - ``num_objects_missing_on_primary`` (int) - number of objets
                missing on primary

            - ``num_objects_unfound`` (int) - number of unfound objects

            - ``num_objects_degraded`` (int) - number of degraded objects

            - ``num_rd`` (int) - bytes read

            - ``num_rd_kb`` (int) - kbytes read

            - ``num_wr`` (int) - bytes written

            - ``num_wr_kb`` (int) - kbytes written
        """
        self.require_ioctx_open()
        stats = rados_pool_stat_t()
        ret = run_in_thread(self.librados.rados_ioctx_pool_stat,
                            (self.io, byref(stats)))
        if ret < 0:
            raise make_ex(ret, "Ioctx.get_stats(%s): get_stats failed" % self.name)
        return {'num_bytes': stats.num_bytes,
                'num_kb': stats.num_kb,
                'num_objects': stats.num_objects,
                'num_object_clones': stats.num_object_clones,
                'num_object_copies': stats.num_object_copies,
                "num_objects_missing_on_primary": stats.num_objects_missing_on_primary,
                "num_objects_unfound": stats.num_objects_unfound,
                "num_objects_degraded": stats.num_objects_degraded,
                "num_rd": stats.num_rd,
                "num_rd_kb": stats.num_rd_kb,
                "num_wr": stats.num_wr,
                "num_wr_kb": stats.num_wr_kb }

    def remove_object(self, key):
        """
        Delete an object

        This does not delete any snapshots of the object.

        :param key: the name of the object to delete
        :type key: str

        :raises: :class:`TypeError`
        :raises: :class:`Error`
        :returns: bool - True on success
        """
        self.require_ioctx_open()
        if not isinstance(key, str):
            raise TypeError('key must be a string')
        ret = run_in_thread(self.librados.rados_remove,
                            (self.io, c_char_p(key)))
        if ret < 0:
            raise make_ex(ret, "Failed to remove '%s'" % key)
        return True

    def trunc(self, key, size):
        """
        Resize an object

        If this enlarges the object, the new area is logically filled with
        zeroes. If this shrinks the object, the excess data is removed.

        :param key: the name of the object to resize
        :type key: str
        :param size: the new size of the object in bytes
        :type size: int

        :raises: :class:`TypeError`
        :raises: :class:`Error`
        :returns: int - 0 on success, otherwise raises error
        """
        
        self.require_ioctx_open()
        if not isinstance(key, str):
            raise TypeError('key must be a string')
        ret = run_in_thread(self.librados.rados_trunc,
                            (self.io, c_char_p(key), c_uint64(size)))
        if ret < 0:
            raise make_ex(ret, "Ioctx.trunc(%s): failed to truncate %s" % (self.name, key))
        return ret

    def stat(self, key):
        """
        Get object stats (size/mtime)
        
        :param key: the name of the object to get stats from
        :type key: str

        :raises: :class:`TypeError`
        :raises: :class:`Error`
        :returns: (size,timestamp)
        """
        self.require_ioctx_open()
        if not isinstance(key, str):
            raise TypeError('key must be a string')
        psize = c_uint64()
        pmtime = c_uint64()

        ret = run_in_thread(self.librados.rados_stat,
                            (self.io, c_char_p(key), pointer(psize),
                            pointer(pmtime)))
        if ret < 0:
            raise make_ex(ret, "Failed to stat %r" % key)
        return psize.value, time.localtime(pmtime.value)

    def get_xattr(self, key, xattr_name):
        """
        Get the value of an extended attribute on an object.
        
        :param key: the name of the object to get xattr from
        :type key: str
        :param xattr_name: which extended attribute to read
        :type xattr_name: str

        :raises: :class:`TypeError`
        :raises: :class:`Error`
        :returns: str - value of the xattr
        """
        self.require_ioctx_open()
        if not isinstance(xattr_name, str):
            raise TypeError('xattr_name must be a string')
        ret_length = 4096
        while ret_length < 4096 * 1024 * 1024:
            ret_buf = create_string_buffer(ret_length)
            ret = run_in_thread(self.librados.rados_getxattr,
                                (self.io, c_char_p(key), c_char_p(xattr_name),
                                 ret_buf, c_size_t(ret_length)))
            if (ret == -errno.ERANGE):
                ret_length *= 2
            elif ret < 0:
                raise make_ex(ret, "Failed to get xattr %r" % xattr_name)
            else:
                break
        return ctypes.string_at(ret_buf, ret)

    def get_xattrs(self, oid):
        """
        Start iterating over xattrs on an object.
        
        :param oid: the name of the object to get xattrs from
        :type key: str

        :raises: :class:`TypeError`
        :raises: :class:`Error`
        :returns: XattrIterator
        """
        self.require_ioctx_open()
        if not isinstance(oid, str):
            raise TypeError('oid must be a string')
        it = c_void_p(0)
        ret = run_in_thread(self.librados.rados_getxattrs,
                            (self.io, oid, byref(it)))
        if ret != 0:
            raise make_ex(ret, "Failed to get rados xattrs for object %r" % oid)
        return XattrIterator(self, it, oid)

    def set_xattr(self, key, xattr_name, xattr_value):
        """
        Set an extended attribute on an object.
        
        :param key: the name of the object to set xattr to
        :type key: str
        :param xattr_name: which extended attribute to set
        :type xattr_name: str
        :param xattr_value: the value of the  extended attribute
        :type xattr_value: str

        :raises: :class:`TypeError`
        :raises: :class:`Error`
        :returns: bool - True on success, otherwise raise an error
        """
        self.require_ioctx_open()
        if not isinstance(key, str):
            raise TypeError('key must be a string')
        if not isinstance(xattr_name, str):
            raise TypeError('xattr_name must be a string')
        if not isinstance(xattr_value, str):
            raise TypeError('xattr_value must be a string')
        ret = run_in_thread(self.librados.rados_setxattr,
                            (self.io, c_char_p(key), c_char_p(xattr_name),
                            c_char_p(xattr_value), c_size_t(len(xattr_value))))
        if ret < 0:
            raise make_ex(ret, "Failed to set xattr %r" % xattr_name)
        return True

    def rm_xattr(self, key, xattr_name):
        """
        Removes an extended attribute on from an object.
        
        :param key: the name of the object to remove xattr from
        :type key: str
        :param xattr_name: which extended attribute to remove
        :type xattr_name: str

        :raises: :class:`TypeError`
        :raises: :class:`Error`
        :returns: bool - True on success, otherwise raise an error
        """
        self.require_ioctx_open()
        if not isinstance(key, str):
            raise TypeError('key must be a string')
        if not isinstance(xattr_name, str):
            raise TypeError('xattr_name must be a string')
        ret = run_in_thread(self.librados.rados_rmxattr,
                            (self.io, c_char_p(key), c_char_p(xattr_name)))
        if ret < 0:
            raise make_ex(ret, "Failed to delete key %r xattr %r" %
                (key, xattr_name))
        return True

    def list_objects(self):
        """ 
        Get ObjectIterator on rados.Ioctx object.

        :returns: ObjectIterator
        """
        self.require_ioctx_open()
        return ObjectIterator(self)

    def list_snaps(self):
        """ 
        Get SnapIterator on rados.Ioctx object.

        :returns: SnapIterator
        """
        self.require_ioctx_open()
        return SnapIterator(self)

    def create_snap(self, snap_name):
        """
        Create a pool-wide snapshot

        :param snap_name: the name of the snapshot
        :type snap_name: str

        :raises: :class:`TypeError`
        :raises: :class:`Error`
        """
        self.require_ioctx_open()
        if not isinstance(snap_name, str):
            raise TypeError('snap_name must be a string')
        ret = run_in_thread(self.librados.rados_ioctx_snap_create,
                            (self.io, c_char_p(snap_name)))
        if (ret != 0):
            raise make_ex(ret, "Failed to create snap %s" % snap_name)

    def remove_snap(self, snap_name):
        """
        Removes a pool-wide snapshot

        :param snap_name: the name of the snapshot
        :type snap_name: str

        :raises: :class:`TypeError`
        :raises: :class:`Error`
        """
        self.require_ioctx_open()
        if not isinstance(snap_name, str):
            raise TypeError('snap_name must be a string')
        ret = run_in_thread(self.librados.rados_ioctx_snap_remove,
                            (self.io, c_char_p(snap_name)))
        if (ret != 0):
            raise make_ex(ret, "Failed to remove snap %s" % snap_name)

    def lookup_snap(self, snap_name):
        """
        Get the id of a pool snapshot

        :param snap_name: the name of the snapshot to lookop
        :type snap_name: str

        :raises: :class:`TypeError`
        :raises: :class:`Error`
        :returns: Snap - on success
        """
        self.require_ioctx_open()
        if not isinstance(snap_name, str):
            raise TypeError('snap_name must be a string')
        snap_id = c_uint64()
        ret = run_in_thread(self.librados.rados_ioctx_snap_lookup,
                           (self.io, c_char_p(snap_name), byref(snap_id)))
        if (ret != 0):
            raise make_ex(ret, "Failed to lookup snap %s" % snap_name)
        return Snap(self, snap_name, snap_id)

    def get_last_version(self):
        """
        Return the version of the last object read or written to.

        This exposes the internal version number of the last object read or
        written via this io context

        :returns: version of the last object used
        """
        self.require_ioctx_open()
        return run_in_thread(self.librados.rados_get_last_version, (self.io,))

def set_object_locator(func):
    def retfunc(self, *args, **kwargs):
        if self.locator_key is not None:
            old_locator = self.ioctx.get_locator_key()
            self.ioctx.set_locator_key(self.locator_key)
            retval = func(self, *args, **kwargs)
            self.ioctx.set_locator_key(old_locator)
            return retval
        else:
            return func(self, *args, **kwargs)
    return retfunc

class Object(object):
    """Rados object wrapper, makes the object look like a file"""
    def __init__(self, ioctx, key, locator_key=None):
        self.key = key
        self.ioctx = ioctx
        self.offset = 0
        self.state = "exists"
        self.locator_key = locator_key

    def __str__(self):
        return "rados.Object(ioctx=%s,key=%s)" % (str(self.ioctx), self.key)

    def require_object_exists(self):
        if self.state != "exists":
            raise ObjectStateError("The object is %s" % self.state)

    @set_object_locator
    def read(self, length = 1024*1024):
        self.require_object_exists()
        ret = self.ioctx.read(self.key, length, self.offset)
        self.offset += len(ret)
        return ret

    @set_object_locator
    def write(self, string_to_write):
        self.require_object_exists()
        ret = self.ioctx.write(self.key, string_to_write, self.offset)
        self.offset += ret
        return ret

    @set_object_locator
    def remove(self):
        self.require_object_exists()
        self.ioctx.remove_object(self.key)
        self.state = "removed"

    @set_object_locator
    def stat(self):
        self.require_object_exists()
        return self.ioctx.stat(self.key)

    def seek(self, position):
        self.require_object_exists()
        self.offset = position

    @set_object_locator
    def get_xattr(self, xattr_name):
        self.require_object_exists()
        return self.ioctx.get_xattr(self.key, xattr_name)

    @set_object_locator
    def get_xattrs(self):
        self.require_object_exists()
        return self.ioctx.get_xattrs(self.key)

    @set_object_locator
    def set_xattr(self, xattr_name, xattr_value):
        self.require_object_exists()
        return self.ioctx.set_xattr(self.key, xattr_name, xattr_value)

    @set_object_locator
    def rm_xattr(self, xattr_name):
        self.require_object_exists()
        return self.ioctx.rm_xattr(self.key, xattr_name)

MONITOR_LEVELS = [
   "debug",
   "info",
   "warn", "warning",
   "err", "error", 
   "sec",
   ]


class MonitorLog(object):
    """
    For watching cluster log messages.  Instantiate an object and keep
    it around while callback is periodically called.  Construct with
    'level' to monitor 'level' messages (one of MONITOR_LEVELS).
    arg will be passed to the callback.

    callback will be called with:
        arg (given to __init__)
        line (the full line, including timestamp, who, level, msg)
        who (which entity issued the log message)
        timestamp_sec (sec of a struct timespec)
        timestamp_nsec (sec of a struct timespec)
        seq (sequence number)
        level (string representing the level of the log message)
        msg (the message itself)
    callback's return value is ignored
    """

    def monitor_log_callback(self, arg, line, who, sec, nsec, seq, level, msg):
        """
        Local callback wrapper, in case we decide to do something
        """
        self.callback(arg, line, who, sec, nsec, seq, level, msg)
        return 0

    def __init__(self, cluster, level, callback, arg):
        if level not in MONITOR_LEVELS:
            raise LogicError("invalid monitor level " + level)
        if not callable(callback):
            raise LogicError("callback must be a callable function")
        self.level = level
        self.callback = callback
        self.arg = arg
        callback_factory = CFUNCTYPE(c_int,    # return type (really void)
                                     c_void_p, # arg
                                     c_char_p, # line
                                     c_char_p, # who
                                     c_uint64, # timestamp_sec
                                     c_uint64, # timestamp_nsec
                                     c_ulong,  # seq
                                     c_char_p, # level
                                     c_char_p) # msg
        self.internal_callback = callback_factory(self.monitor_log_callback)

        r = run_in_thread(cluster.librados.rados_monitor_log,
                          (cluster.cluster, level, self.internal_callback, arg))
        if r:
            raise make_ex(r, 'error calling rados_monitor_log')