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38 """
39 Provides functionality related to CD writer devices.
40
41 @sort: MediaDefinition, MediaCapacity, CdWriter,
42 MEDIA_CDRW_74, MEDIA_CDR_74, MEDIA_CDRW_80, MEDIA_CDR_80
43
44 @var MEDIA_CDRW_74: Constant representing 74-minute CD-RW media.
45 @var MEDIA_CDR_74: Constant representing 74-minute CD-R media.
46 @var MEDIA_CDRW_80: Constant representing 80-minute CD-RW media.
47 @var MEDIA_CDR_80: Constant representing 80-minute CD-R media.
48
49 @author: Kenneth J. Pronovici <pronovic@ieee.org>
50 """
51
52
53
54
55
56
57 import os
58 import re
59 import logging
60 import tempfile
61 import time
62
63
64 from CedarBackup2.util import resolveCommand, executeCommand
65 from CedarBackup2.util import convertSize, displayBytes, encodePath
66 from CedarBackup2.util import UNIT_SECTORS, UNIT_BYTES, UNIT_KBYTES, UNIT_MBYTES
67 from CedarBackup2.writers.util import validateDevice, validateScsiId, validateDriveSpeed
68 from CedarBackup2.writers.util import IsoImage
69
70
71
72
73
74
75 logger = logging.getLogger("CedarBackup2.log.writers.cdwriter")
76
77 MEDIA_CDRW_74 = 1
78 MEDIA_CDR_74 = 2
79 MEDIA_CDRW_80 = 3
80 MEDIA_CDR_80 = 4
81
82 CDRECORD_COMMAND = [ "cdrecord", ]
83 EJECT_COMMAND = [ "eject", ]
84 MKISOFS_COMMAND = [ "mkisofs", ]
181
262
269 """
270 Simple value object to hold image properties for C{DvdWriter}.
271 """
273 self.newDisc = False
274 self.tmpdir = None
275 self.mediaLabel = None
276 self.entries = None
277
278
279
280
281
282
283 -class CdWriter(object):
284
285
286
287
288
289 """
290 Class representing a device that knows how to write CD media.
291
292 Summary
293 =======
294
295 This is a class representing a device that knows how to write CD media. It
296 provides common operations for the device, such as ejecting the media,
297 writing an ISO image to the media, or checking for the current media
298 capacity. It also provides a place to store device attributes, such as
299 whether the device supports writing multisession discs, etc.
300
301 This class is implemented in terms of the C{eject} and C{cdrecord}
302 programs, both of which should be available on most UN*X platforms.
303
304 Image Writer Interface
305 ======================
306
307 The following methods make up the "image writer" interface shared
308 with other kinds of writers (such as DVD writers)::
309
310 __init__
311 initializeImage()
312 addImageEntry()
313 writeImage()
314 setImageNewDisc()
315 retrieveCapacity()
316 getEstimatedImageSize()
317
318 Only these methods will be used by other Cedar Backup functionality
319 that expects a compatible image writer.
320
321 The media attribute is also assumed to be available.
322
323 Media Types
324 ===========
325
326 This class knows how to write to two different kinds of media, represented
327 by the following constants:
328
329 - C{MEDIA_CDR_74}: 74-minute CD-R media (650 MB capacity)
330 - C{MEDIA_CDRW_74}: 74-minute CD-RW media (650 MB capacity)
331 - C{MEDIA_CDR_80}: 80-minute CD-R media (700 MB capacity)
332 - C{MEDIA_CDRW_80}: 80-minute CD-RW media (700 MB capacity)
333
334 Most hardware can read and write both 74-minute and 80-minute CD-R and
335 CD-RW media. Some older drives may only be able to write CD-R media.
336 The difference between the two is that CD-RW media can be rewritten
337 (erased), while CD-R media cannot be.
338
339 I do not support any other configurations for a couple of reasons. The
340 first is that I've never tested any other kind of media. The second is
341 that anything other than 74 or 80 minute is apparently non-standard.
342
343 Device Attributes vs. Media Attributes
344 ======================================
345
346 A given writer instance has two different kinds of attributes associated
347 with it, which I call device attributes and media attributes. Device
348 attributes are things which can be determined without looking at the
349 media, such as whether the drive supports writing multisession disks or
350 has a tray. Media attributes are attributes which vary depending on the
351 state of the media, such as the remaining capacity on a disc. In
352 general, device attributes are available via instance variables and are
353 constant over the life of an object, while media attributes can be
354 retrieved through method calls.
355
356 Talking to Hardware
357 ===================
358
359 This class needs to talk to CD writer hardware in two different ways:
360 through cdrecord to actually write to the media, and through the
361 filesystem to do things like open and close the tray.
362
363 Historically, CdWriter has interacted with cdrecord using the scsiId
364 attribute, and with most other utilities using the device attribute.
365 This changed somewhat in Cedar Backup 2.9.0.
366
367 When Cedar Backup was first written, the only way to interact with
368 cdrecord was by using a SCSI device id. IDE devices were mapped to
369 pseudo-SCSI devices through the kernel. Later, extended SCSI "methods"
370 arrived, and it became common to see C{ATA:1,0,0} or C{ATAPI:0,0,0} as a
371 way to address IDE hardware. By late 2006, C{ATA} and C{ATAPI} had
372 apparently been deprecated in favor of just addressing the IDE device
373 directly by name, i.e. C{/dev/cdrw}.
374
375 Because of this latest development, it no longer makes sense to require a
376 CdWriter to be created with a SCSI id -- there might not be one. So, the
377 passed-in SCSI id is now optional. Also, there is now a hardwareId
378 attribute. This attribute is filled in with either the SCSI id (if
379 provided) or the device (otherwise). The hardware id is the value that
380 will be passed to cdrecord in the C{dev=} argument.
381
382 Testing
383 =======
384
385 It's rather difficult to test this code in an automated fashion, even if
386 you have access to a physical CD writer drive. It's even more difficult
387 to test it if you are running on some build daemon (think of a Debian
388 autobuilder) which can't be expected to have any hardware or any media
389 that you could write to.
390
391 Because of this, much of the implementation below is in terms of static
392 methods that are supposed to take defined actions based on their
393 arguments. Public methods are then implemented in terms of a series of
394 calls to simplistic static methods. This way, we can test as much as
395 possible of the functionality via testing the static methods, while
396 hoping that if the static methods are called appropriately, things will
397 work properly. It's not perfect, but it's much better than no testing at
398 all.
399
400 @sort: __init__, isRewritable, _retrieveProperties, retrieveCapacity, _getBoundaries,
401 _calculateCapacity, openTray, closeTray, refreshMedia, writeImage,
402 _blankMedia, _parsePropertiesOutput, _parseBoundariesOutput,
403 _buildOpenTrayArgs, _buildCloseTrayArgs, _buildPropertiesArgs,
404 _buildBoundariesArgs, _buildBlankArgs, _buildWriteArgs,
405 device, scsiId, hardwareId, driveSpeed, media, deviceType, deviceVendor,
406 deviceId, deviceBufferSize, deviceSupportsMulti, deviceHasTray, deviceCanEject,
407 initializeImage, addImageEntry, writeImage, setImageNewDisc, getEstimatedImageSize
408 """
409
410
411
412
413
414 - def __init__(self, device, scsiId=None, driveSpeed=None,
415 mediaType=MEDIA_CDRW_74, noEject=False,
416 refreshMediaDelay=0, ejectDelay=0, unittest=False):
417 """
418 Initializes a CD writer object.
419
420 The current user must have write access to the device at the time the
421 object is instantiated, or an exception will be thrown. However, no
422 media-related validation is done, and in fact there is no need for any
423 media to be in the drive until one of the other media attribute-related
424 methods is called.
425
426 The various instance variables such as C{deviceType}, C{deviceVendor},
427 etc. might be C{None}, if we're unable to parse this specific information
428 from the C{cdrecord} output. This information is just for reference.
429
430 The SCSI id is optional, but the device path is required. If the SCSI id
431 is passed in, then the hardware id attribute will be taken from the SCSI
432 id. Otherwise, the hardware id will be taken from the device.
433
434 If cdrecord improperly detects whether your writer device has a tray and
435 can be safely opened and closed, then pass in C{noEject=False}. This
436 will override the properties and the device will never be ejected.
437
438 @note: The C{unittest} parameter should never be set to C{True}
439 outside of Cedar Backup code. It is intended for use in unit testing
440 Cedar Backup internals and has no other sensible purpose.
441
442 @param device: Filesystem device associated with this writer.
443 @type device: Absolute path to a filesystem device, i.e. C{/dev/cdrw}
444
445 @param scsiId: SCSI id for the device (optional).
446 @type scsiId: If provided, SCSI id in the form C{[<method>:]scsibus,target,lun}
447
448 @param driveSpeed: Speed at which the drive writes.
449 @type driveSpeed: Use C{2} for 2x device, etc. or C{None} to use device default.
450
451 @param mediaType: Type of the media that is assumed to be in the drive.
452 @type mediaType: One of the valid media type as discussed above.
453
454 @param noEject: Overrides properties to indicate that the device does not support eject.
455 @type noEject: Boolean true/false
456
457 @param refreshMediaDelay: Refresh media delay to use, if any
458 @type refreshMediaDelay: Number of seconds, an integer >= 0
459
460 @param ejectDelay: Eject delay to use, if any
461 @type ejectDelay: Number of seconds, an integer >= 0
462
463 @param unittest: Turns off certain validations, for use in unit testing.
464 @type unittest: Boolean true/false
465
466 @raise ValueError: If the device is not valid for some reason.
467 @raise ValueError: If the SCSI id is not in a valid form.
468 @raise ValueError: If the drive speed is not an integer >= 1.
469 @raise IOError: If device properties could not be read for some reason.
470 """
471 self._image = None
472 self._device = validateDevice(device, unittest)
473 self._scsiId = validateScsiId(scsiId)
474 self._driveSpeed = validateDriveSpeed(driveSpeed)
475 self._media = MediaDefinition(mediaType)
476 self._noEject = noEject
477 self._refreshMediaDelay = refreshMediaDelay
478 self._ejectDelay = ejectDelay
479 if not unittest:
480 (self._deviceType,
481 self._deviceVendor,
482 self._deviceId,
483 self._deviceBufferSize,
484 self._deviceSupportsMulti,
485 self._deviceHasTray,
486 self._deviceCanEject) = self._retrieveProperties()
487
488
489
490
491
492
494 """
495 Property target used to get the device value.
496 """
497 return self._device
498
500 """
501 Property target used to get the SCSI id value.
502 """
503 return self._scsiId
504
506 """
507 Property target used to get the hardware id value.
508 """
509 if self._scsiId is None:
510 return self._device
511 return self._scsiId
512
514 """
515 Property target used to get the drive speed.
516 """
517 return self._driveSpeed
518
524
526 """
527 Property target used to get the device type.
528 """
529 return self._deviceType
530
532 """
533 Property target used to get the device vendor.
534 """
535 return self._deviceVendor
536
538 """
539 Property target used to get the device id.
540 """
541 return self._deviceId
542
544 """
545 Property target used to get the device buffer size.
546 """
547 return self._deviceBufferSize
548
550 """
551 Property target used to get the device-support-multi flag.
552 """
553 return self._deviceSupportsMulti
554
556 """
557 Property target used to get the device-has-tray flag.
558 """
559 return self._deviceHasTray
560
562 """
563 Property target used to get the device-can-eject flag.
564 """
565 return self._deviceCanEject
566
572
574 """
575 Property target used to get the configured eject delay, in seconds.
576 """
577 return self._ejectDelay
578
579 device = property(_getDevice, None, None, doc="Filesystem device name for this writer.")
580 scsiId = property(_getScsiId, None, None, doc="SCSI id for the device, in the form C{[<method>:]scsibus,target,lun}.")
581 hardwareId = property(_getHardwareId, None, None, doc="Hardware id for this writer, either SCSI id or device path.")
582 driveSpeed = property(_getDriveSpeed, None, None, doc="Speed at which the drive writes.")
583 media = property(_getMedia, None, None, doc="Definition of media that is expected to be in the device.")
584 deviceType = property(_getDeviceType, None, None, doc="Type of the device, as returned from C{cdrecord -prcap}.")
585 deviceVendor = property(_getDeviceVendor, None, None, doc="Vendor of the device, as returned from C{cdrecord -prcap}.")
586 deviceId = property(_getDeviceId, None, None, doc="Device identification, as returned from C{cdrecord -prcap}.")
587 deviceBufferSize = property(_getDeviceBufferSize, None, None, doc="Size of the device's write buffer, in bytes.")
588 deviceSupportsMulti = property(_getDeviceSupportsMulti, None, None, doc="Indicates whether device supports multisession discs.")
589 deviceHasTray = property(_getDeviceHasTray, None, None, doc="Indicates whether the device has a media tray.")
590 deviceCanEject = property(_getDeviceCanEject, None, None, doc="Indicates whether the device supports ejecting its media.")
591 refreshMediaDelay = property(_getRefreshMediaDelay, None, None, doc="Refresh media delay, in seconds.")
592 ejectDelay = property(_getEjectDelay, None, None, doc="Eject delay, in seconds.")
593
594
595
596
597
598
600 """Indicates whether the media is rewritable per configuration."""
601 return self._media.rewritable
602
604 """
605 Retrieves properties for a device from C{cdrecord}.
606
607 The results are returned as a tuple of the object device attributes as
608 returned from L{_parsePropertiesOutput}: C{(deviceType, deviceVendor,
609 deviceId, deviceBufferSize, deviceSupportsMulti, deviceHasTray,
610 deviceCanEject)}.
611
612 @return: Results tuple as described above.
613 @raise IOError: If there is a problem talking to the device.
614 """
615 args = CdWriter._buildPropertiesArgs(self.hardwareId)
616 command = resolveCommand(CDRECORD_COMMAND)
617 (result, output) = executeCommand(command, args, returnOutput=True, ignoreStderr=True)
618 if result != 0:
619 raise IOError("Error (%d) executing cdrecord command to get properties." % result)
620 return CdWriter._parsePropertiesOutput(output)
621
623 """
624 Retrieves capacity for the current media in terms of a C{MediaCapacity}
625 object.
626
627 If C{entireDisc} is passed in as C{True} the capacity will be for the
628 entire disc, as if it were to be rewritten from scratch. If the drive
629 does not support writing multisession discs or if C{useMulti} is passed
630 in as C{False}, the capacity will also be as if the disc were to be
631 rewritten from scratch, but the indicated boundaries value will be
632 C{None}. The same will happen if the disc cannot be read for some
633 reason. Otherwise, the capacity (including the boundaries) will
634 represent whatever space remains on the disc to be filled by future
635 sessions.
636
637 @param entireDisc: Indicates whether to return capacity for entire disc.
638 @type entireDisc: Boolean true/false
639
640 @param useMulti: Indicates whether a multisession disc should be assumed, if possible.
641 @type useMulti: Boolean true/false
642
643 @return: C{MediaCapacity} object describing the capacity of the media.
644 @raise IOError: If the media could not be read for some reason.
645 """
646 boundaries = self._getBoundaries(entireDisc, useMulti)
647 return CdWriter._calculateCapacity(self._media, boundaries)
648
650 """
651 Gets the ISO boundaries for the media.
652
653 If C{entireDisc} is passed in as C{True} the boundaries will be C{None},
654 as if the disc were to be rewritten from scratch. If the drive does not
655 support writing multisession discs, the returned value will be C{None}.
656 The same will happen if the disc can't be read for some reason.
657 Otherwise, the returned value will be represent the boundaries of the
658 disc's current contents.
659
660 The results are returned as a tuple of (lower, upper) as needed by the
661 C{IsoImage} class. Note that these values are in terms of ISO sectors,
662 not bytes. Clients should generally consider the boundaries value
663 opaque, however.
664
665 @param entireDisc: Indicates whether to return capacity for entire disc.
666 @type entireDisc: Boolean true/false
667
668 @param useMulti: Indicates whether a multisession disc should be assumed, if possible.
669 @type useMulti: Boolean true/false
670
671 @return: Boundaries tuple or C{None}, as described above.
672 @raise IOError: If the media could not be read for some reason.
673 """
674 if not self._deviceSupportsMulti:
675 logger.debug("Device does not support multisession discs; returning boundaries None.")
676 return None
677 elif not useMulti:
678 logger.debug("Use multisession flag is False; returning boundaries None.")
679 return None
680 elif entireDisc:
681 logger.debug("Entire disc flag is True; returning boundaries None.")
682 return None
683 else:
684 args = CdWriter._buildBoundariesArgs(self.hardwareId)
685 command = resolveCommand(CDRECORD_COMMAND)
686 (result, output) = executeCommand(command, args, returnOutput=True, ignoreStderr=True)
687 if result != 0:
688 logger.debug("Error (%d) executing cdrecord command to get capacity.", result)
689 logger.warn("Unable to read disc (might not be initialized); returning boundaries of None.")
690 return None
691 boundaries = CdWriter._parseBoundariesOutput(output)
692 if boundaries is None:
693 logger.debug("Returning disc boundaries: None")
694 else:
695 logger.debug("Returning disc boundaries: (%d, %d)", boundaries[0], boundaries[1])
696 return boundaries
697
698 @staticmethod
700 """
701 Calculates capacity for the media in terms of boundaries.
702
703 If C{boundaries} is C{None} or the lower bound is 0 (zero), then the
704 capacity will be for the entire disc minus the initial lead in.
705 Otherwise, capacity will be as if the caller wanted to add an additional
706 session to the end of the existing data on the disc.
707
708 @param media: MediaDescription object describing the media capacity.
709 @param boundaries: Session boundaries as returned from L{_getBoundaries}.
710
711 @return: C{MediaCapacity} object describing the capacity of the media.
712 """
713 if boundaries is None or boundaries[1] == 0:
714 logger.debug("Capacity calculations are based on a complete disc rewrite.")
715 sectorsAvailable = media.capacity - media.initialLeadIn
716 if sectorsAvailable < 0: sectorsAvailable = 0.0
717 bytesUsed = 0.0
718 bytesAvailable = convertSize(sectorsAvailable, UNIT_SECTORS, UNIT_BYTES)
719 else:
720 logger.debug("Capacity calculations are based on a new ISO session.")
721 sectorsAvailable = media.capacity - boundaries[1] - media.leadIn
722 if sectorsAvailable < 0: sectorsAvailable = 0.0
723 bytesUsed = convertSize(boundaries[1], UNIT_SECTORS, UNIT_BYTES)
724 bytesAvailable = convertSize(sectorsAvailable, UNIT_SECTORS, UNIT_BYTES)
725 logger.debug("Used [%s], available [%s].", displayBytes(bytesUsed), displayBytes(bytesAvailable))
726 return MediaCapacity(bytesUsed, bytesAvailable, boundaries)
727
728
729
730
731
732
734 """
735 Initializes the writer's associated ISO image.
736
737 This method initializes the C{image} instance variable so that the caller
738 can use the C{addImageEntry} method. Once entries have been added, the
739 C{writeImage} method can be called with no arguments.
740
741 @param newDisc: Indicates whether the disc should be re-initialized
742 @type newDisc: Boolean true/false.
743
744 @param tmpdir: Temporary directory to use if needed
745 @type tmpdir: String representing a directory path on disk
746
747 @param mediaLabel: Media label to be applied to the image, if any
748 @type mediaLabel: String, no more than 25 characters long
749 """
750 self._image = _ImageProperties()
751 self._image.newDisc = newDisc
752 self._image.tmpdir = encodePath(tmpdir)
753 self._image.mediaLabel = mediaLabel
754 self._image.entries = {}
755
756 - def addImageEntry(self, path, graftPoint):
757 """
758 Adds a filepath entry to the writer's associated ISO image.
759
760 The contents of the filepath -- but not the path itself -- will be added
761 to the image at the indicated graft point. If you don't want to use a
762 graft point, just pass C{None}.
763
764 @note: Before calling this method, you must call L{initializeImage}.
765
766 @param path: File or directory to be added to the image
767 @type path: String representing a path on disk
768
769 @param graftPoint: Graft point to be used when adding this entry
770 @type graftPoint: String representing a graft point path, as described above
771
772 @raise ValueError: If initializeImage() was not previously called
773 """
774 if self._image is None:
775 raise ValueError("Must call initializeImage() before using this method.")
776 if not os.path.exists(path):
777 raise ValueError("Path [%s] does not exist." % path)
778 self._image.entries[path] = graftPoint
779
781 """
782 Resets (overrides) the newDisc flag on the internal image.
783 @param newDisc: New disc flag to set
784 @raise ValueError: If initializeImage() was not previously called
785 """
786 if self._image is None:
787 raise ValueError("Must call initializeImage() before using this method.")
788 self._image.newDisc = newDisc
789
790
792 """
793 Gets the estimated size of the image associated with the writer.
794 @return: Estimated size of the image, in bytes.
795 @raise IOError: If there is a problem calling C{mkisofs}.
796 @raise ValueError: If initializeImage() was not previously called
797 """
798 if self._image is None:
799 raise ValueError("Must call initializeImage() before using this method.")
800 image = IsoImage()
801 for path in self._image.entries.keys():
802 image.addEntry(path, self._image.entries[path], override=False, contentsOnly=True)
803 return image.getEstimatedSize()
804
805
806
807
808
809
811 """
812 Opens the device's tray and leaves it open.
813
814 This only works if the device has a tray and supports ejecting its media.
815 We have no way to know if the tray is currently open or closed, so we
816 just send the appropriate command and hope for the best. If the device
817 does not have a tray or does not support ejecting its media, then we do
818 nothing.
819
820 If the writer was constructed with C{noEject=True}, then this is a no-op.
821
822 Starting with Debian wheezy on my backup hardware, I started seeing
823 consistent problems with the eject command. I couldn't tell whether
824 these problems were due to the device management system or to the new
825 kernel (3.2.0). Initially, I saw simple eject failures, possibly because
826 I was opening and closing the tray too quickly. I worked around that
827 behavior with the new ejectDelay flag.
828
829 Later, I sometimes ran into issues after writing an image to a disc:
830 eject would give errors like "unable to eject, last error: Inappropriate
831 ioctl for device". Various sources online (like Ubuntu bug #875543)
832 suggested that the drive was being locked somehow, and that the
833 workaround was to run 'eject -i off' to unlock it. Sure enough, that
834 fixed the problem for me, so now it's a normal error-handling strategy.
835
836 @raise IOError: If there is an error talking to the device.
837 """
838 if not self._noEject:
839 if self._deviceHasTray and self._deviceCanEject:
840 args = CdWriter._buildOpenTrayArgs(self._device)
841 result = executeCommand(EJECT_COMMAND, args)[0]
842 if result != 0:
843 logger.debug("Eject failed; attempting kludge of unlocking the tray before retrying.")
844 self.unlockTray()
845 result = executeCommand(EJECT_COMMAND, args)[0]
846 if result != 0:
847 raise IOError("Error (%d) executing eject command to open tray (failed even after unlocking tray)." % result)
848 logger.debug("Kludge was apparently successful.")
849 if self.ejectDelay is not None:
850 logger.debug("Per configuration, sleeping %d seconds after opening tray.", self.ejectDelay)
851 time.sleep(self.ejectDelay)
852
863
865 """
866 Closes the device's tray.
867
868 This only works if the device has a tray and supports ejecting its media.
869 We have no way to know if the tray is currently open or closed, so we
870 just send the appropriate command and hope for the best. If the device
871 does not have a tray or does not support ejecting its media, then we do
872 nothing.
873
874 If the writer was constructed with C{noEject=True}, then this is a no-op.
875
876 @raise IOError: If there is an error talking to the device.
877 """
878 if not self._noEject:
879 if self._deviceHasTray and self._deviceCanEject:
880 args = CdWriter._buildCloseTrayArgs(self._device)
881 command = resolveCommand(EJECT_COMMAND)
882 result = executeCommand(command, args)[0]
883 if result != 0:
884 raise IOError("Error (%d) executing eject command to close tray." % result)
885
912
913 - def writeImage(self, imagePath=None, newDisc=False, writeMulti=True):
914 """
915 Writes an ISO image to the media in the device.
916
917 If C{newDisc} is passed in as C{True}, we assume that the entire disc
918 will be overwritten, and the media will be blanked before writing it if
919 possible (i.e. if the media is rewritable).
920
921 If C{writeMulti} is passed in as C{True}, then a multisession disc will
922 be written if possible (i.e. if the drive supports writing multisession
923 discs).
924
925 if C{imagePath} is passed in as C{None}, then the existing image
926 configured with C{initializeImage} will be used. Under these
927 circumstances, the passed-in C{newDisc} flag will be ignored.
928
929 By default, we assume that the disc can be written multisession and that
930 we should append to the current contents of the disc. In any case, the
931 ISO image must be generated appropriately (i.e. must take into account
932 any existing session boundaries, etc.)
933
934 @param imagePath: Path to an ISO image on disk, or C{None} to use writer's image
935 @type imagePath: String representing a path on disk
936
937 @param newDisc: Indicates whether the entire disc will overwritten.
938 @type newDisc: Boolean true/false.
939
940 @param writeMulti: Indicates whether a multisession disc should be written, if possible.
941 @type writeMulti: Boolean true/false
942
943 @raise ValueError: If the image path is not absolute.
944 @raise ValueError: If some path cannot be encoded properly.
945 @raise IOError: If the media could not be written to for some reason.
946 @raise ValueError: If no image is passed in and initializeImage() was not previously called
947 """
948 if imagePath is None:
949 if self._image is None:
950 raise ValueError("Must call initializeImage() before using this method with no image path.")
951 try:
952 imagePath = self._createImage()
953 self._writeImage(imagePath, writeMulti, self._image.newDisc)
954 finally:
955 if imagePath is not None and os.path.exists(imagePath):
956 try: os.unlink(imagePath)
957 except: pass
958 else:
959 imagePath = encodePath(imagePath)
960 if not os.path.isabs(imagePath):
961 raise ValueError("Image path must be absolute.")
962 self._writeImage(imagePath, writeMulti, newDisc)
963
964
966 """
967 Creates an ISO image based on configuration in self._image.
968 @return: Path to the newly-created ISO image on disk.
969 @raise IOError: If there is an error writing the image to disk.
970 @raise ValueError: If there are no filesystem entries in the image
971 @raise ValueError: If a path cannot be encoded properly.
972 """
973 path = None
974 capacity = self.retrieveCapacity(entireDisc=self._image.newDisc)
975 image = IsoImage(self.device, capacity.boundaries)
976 image.volumeId = self._image.mediaLabel
977 for key in self._image.entries.keys():
978 image.addEntry(key, self._image.entries[key], override=False, contentsOnly=True)
979 size = image.getEstimatedSize()
980 logger.info("Image size will be %s.", displayBytes(size))
981 available = capacity.bytesAvailable
982 logger.debug("Media capacity: %s", displayBytes(available))
983 if size > available:
984 logger.error("Image [%s] does not fit in available capacity [%s].", displayBytes(size), displayBytes(available))
985 raise IOError("Media does not contain enough capacity to store image.")
986 try:
987 (handle, path) = tempfile.mkstemp(dir=self._image.tmpdir)
988 try: os.close(handle)
989 except: pass
990 image.writeImage(path)
991 logger.debug("Completed creating image [%s].", path)
992 return path
993 except Exception, e:
994 if path is not None and os.path.exists(path):
995 try: os.unlink(path)
996 except: pass
997 raise e
998
999 - def _writeImage(self, imagePath, writeMulti, newDisc):
1000 """
1001 Write an ISO image to disc using cdrecord.
1002 The disc is blanked first if C{newDisc} is C{True}.
1003 @param imagePath: Path to an ISO image on disk
1004 @param writeMulti: Indicates whether a multisession disc should be written, if possible.
1005 @param newDisc: Indicates whether the entire disc will overwritten.
1006 """
1007 if newDisc:
1008 self._blankMedia()
1009 args = CdWriter._buildWriteArgs(self.hardwareId, imagePath, self._driveSpeed, writeMulti and self._deviceSupportsMulti)
1010 command = resolveCommand(CDRECORD_COMMAND)
1011 result = executeCommand(command, args)[0]
1012 if result != 0:
1013 raise IOError("Error (%d) executing command to write disc." % result)
1014 self.refreshMedia()
1015
1028
1029
1030
1031
1032
1033
1034 @staticmethod
1036 """
1037 Parses the output from a C{cdrecord} properties command.
1038
1039 The C{output} parameter should be a list of strings as returned from
1040 C{executeCommand} for a C{cdrecord} command with arguments as from
1041 C{_buildPropertiesArgs}. The list of strings will be parsed to yield
1042 information about the properties of the device.
1043
1044 The output is expected to be a huge long list of strings. Unfortunately,
1045 the strings aren't in a completely regular format. However, the format
1046 of individual lines seems to be regular enough that we can look for
1047 specific values. Two kinds of parsing take place: one kind of parsing
1048 picks out out specific values like the device id, device vendor, etc.
1049 The other kind of parsing just sets a boolean flag C{True} if a matching
1050 line is found. All of the parsing is done with regular expressions.
1051
1052 Right now, pretty much nothing in the output is required and we should
1053 parse an empty document successfully (albeit resulting in a device that
1054 can't eject, doesn't have a tray and doesnt't support multisession
1055 discs). I had briefly considered erroring out if certain lines weren't
1056 found or couldn't be parsed, but that seems like a bad idea given that
1057 most of the information is just for reference.
1058
1059 The results are returned as a tuple of the object device attributes:
1060 C{(deviceType, deviceVendor, deviceId, deviceBufferSize,
1061 deviceSupportsMulti, deviceHasTray, deviceCanEject)}.
1062
1063 @param output: Output from a C{cdrecord -prcap} command.
1064
1065 @return: Results tuple as described above.
1066 @raise IOError: If there is problem parsing the output.
1067 """
1068 deviceType = None
1069 deviceVendor = None
1070 deviceId = None
1071 deviceBufferSize = None
1072 deviceSupportsMulti = False
1073 deviceHasTray = False
1074 deviceCanEject = False
1075 typePattern = re.compile(r"(^Device type\s*:\s*)(.*)(\s*)(.*$)")
1076 vendorPattern = re.compile(r"(^Vendor_info\s*:\s*'\s*)(.*?)(\s*')(.*$)")
1077 idPattern = re.compile(r"(^Identifikation\s*:\s*'\s*)(.*?)(\s*')(.*$)")
1078 bufferPattern = re.compile(r"(^\s*Buffer size in KB:\s*)(.*?)(\s*$)")
1079 multiPattern = re.compile(r"^\s*Does read multi-session.*$")
1080 trayPattern = re.compile(r"^\s*Loading mechanism type: tray.*$")
1081 ejectPattern = re.compile(r"^\s*Does support ejection.*$")
1082 for line in output:
1083 if typePattern.search(line):
1084 deviceType = typePattern.search(line).group(2)
1085 logger.info("Device type is [%s].", deviceType)
1086 elif vendorPattern.search(line):
1087 deviceVendor = vendorPattern.search(line).group(2)
1088 logger.info("Device vendor is [%s].", deviceVendor)
1089 elif idPattern.search(line):
1090 deviceId = idPattern.search(line).group(2)
1091 logger.info("Device id is [%s].", deviceId)
1092 elif bufferPattern.search(line):
1093 try:
1094 sectors = int(bufferPattern.search(line).group(2))
1095 deviceBufferSize = convertSize(sectors, UNIT_KBYTES, UNIT_BYTES)
1096 logger.info("Device buffer size is [%d] bytes.", deviceBufferSize)
1097 except TypeError: pass
1098 elif multiPattern.search(line):
1099 deviceSupportsMulti = True
1100 logger.info("Device does support multisession discs.")
1101 elif trayPattern.search(line):
1102 deviceHasTray = True
1103 logger.info("Device has a tray.")
1104 elif ejectPattern.search(line):
1105 deviceCanEject = True
1106 logger.info("Device can eject its media.")
1107 return (deviceType, deviceVendor, deviceId, deviceBufferSize, deviceSupportsMulti, deviceHasTray, deviceCanEject)
1108
1109 @staticmethod
1111 """
1112 Parses the output from a C{cdrecord} capacity command.
1113
1114 The C{output} parameter should be a list of strings as returned from
1115 C{executeCommand} for a C{cdrecord} command with arguments as from
1116 C{_buildBoundaryArgs}. The list of strings will be parsed to yield
1117 information about the capacity of the media in the device.
1118
1119 Basically, we expect the list of strings to include just one line, a pair
1120 of values. There isn't supposed to be whitespace, but we allow it anyway
1121 in the regular expression. Any lines below the one line we parse are
1122 completely ignored. It would be a good idea to ignore C{stderr} when
1123 executing the C{cdrecord} command that generates output for this method,
1124 because sometimes C{cdrecord} spits out kernel warnings about the actual
1125 output.
1126
1127 The results are returned as a tuple of (lower, upper) as needed by the
1128 C{IsoImage} class. Note that these values are in terms of ISO sectors,
1129 not bytes. Clients should generally consider the boundaries value
1130 opaque, however.
1131
1132 @note: If the boundaries output can't be parsed, we return C{None}.
1133
1134 @param output: Output from a C{cdrecord -msinfo} command.
1135
1136 @return: Boundaries tuple as described above.
1137 @raise IOError: If there is problem parsing the output.
1138 """
1139 if len(output) < 1:
1140 logger.warn("Unable to read disc (might not be initialized); returning full capacity.")
1141 return None
1142 boundaryPattern = re.compile(r"(^\s*)([0-9]*)(\s*,\s*)([0-9]*)(\s*$)")
1143 parsed = boundaryPattern.search(output[0])
1144 if not parsed:
1145 raise IOError("Unable to parse output of boundaries command.")
1146 try:
1147 boundaries = ( int(parsed.group(2)), int(parsed.group(4)) )
1148 except TypeError:
1149 raise IOError("Unable to parse output of boundaries command.")
1150 return boundaries
1151
1152
1153
1154
1155
1156
1157 @staticmethod
1159 """
1160 Builds a list of arguments to be passed to a C{eject} command.
1161
1162 The arguments will cause the C{eject} command to open the tray and
1163 eject the media. No validation is done by this method as to whether
1164 this action actually makes sense.
1165
1166 @param device: Filesystem device name for this writer, i.e. C{/dev/cdrw}.
1167
1168 @return: List suitable for passing to L{util.executeCommand} as C{args}.
1169 """
1170 args = []
1171 args.append(device)
1172 return args
1173
1174 @staticmethod
1176 """
1177 Builds a list of arguments to be passed to a C{eject} command.
1178
1179 The arguments will cause the C{eject} command to unlock the tray.
1180
1181 @param device: Filesystem device name for this writer, i.e. C{/dev/cdrw}.
1182
1183 @return: List suitable for passing to L{util.executeCommand} as C{args}.
1184 """
1185 args = []
1186 args.append("-i")
1187 args.append("off")
1188 args.append(device)
1189 return args
1190
1191 @staticmethod
1193 """
1194 Builds a list of arguments to be passed to a C{eject} command.
1195
1196 The arguments will cause the C{eject} command to close the tray and reload
1197 the media. No validation is done by this method as to whether this
1198 action actually makes sense.
1199
1200 @param device: Filesystem device name for this writer, i.e. C{/dev/cdrw}.
1201
1202 @return: List suitable for passing to L{util.executeCommand} as C{args}.
1203 """
1204 args = []
1205 args.append("-t")
1206 args.append(device)
1207 return args
1208
1209 @staticmethod
1211 """
1212 Builds a list of arguments to be passed to a C{cdrecord} command.
1213
1214 The arguments will cause the C{cdrecord} command to ask the device
1215 for a list of its capacities via the C{-prcap} switch.
1216
1217 @param hardwareId: Hardware id for the device (either SCSI id or device path)
1218
1219 @return: List suitable for passing to L{util.executeCommand} as C{args}.
1220 """
1221 args = []
1222 args.append("-prcap")
1223 args.append("dev=%s" % hardwareId)
1224 return args
1225
1226 @staticmethod
1228 """
1229 Builds a list of arguments to be passed to a C{cdrecord} command.
1230
1231 The arguments will cause the C{cdrecord} command to ask the device for
1232 the current multisession boundaries of the media using the C{-msinfo}
1233 switch.
1234
1235 @param hardwareId: Hardware id for the device (either SCSI id or device path)
1236
1237 @return: List suitable for passing to L{util.executeCommand} as C{args}.
1238 """
1239 args = []
1240 args.append("-msinfo")
1241 args.append("dev=%s" % hardwareId)
1242 return args
1243
1244 @staticmethod
1246 """
1247 Builds a list of arguments to be passed to a C{cdrecord} command.
1248
1249 The arguments will cause the C{cdrecord} command to blank the media in
1250 the device identified by C{hardwareId}. No validation is done by this method
1251 as to whether the action makes sense (i.e. to whether the media even can
1252 be blanked).
1253
1254 @param hardwareId: Hardware id for the device (either SCSI id or device path)
1255 @param driveSpeed: Speed at which the drive writes.
1256
1257 @return: List suitable for passing to L{util.executeCommand} as C{args}.
1258 """
1259 args = []
1260 args.append("-v")
1261 args.append("blank=fast")
1262 if driveSpeed is not None:
1263 args.append("speed=%d" % driveSpeed)
1264 args.append("dev=%s" % hardwareId)
1265 return args
1266
1267 @staticmethod
1268 - def _buildWriteArgs(hardwareId, imagePath, driveSpeed=None, writeMulti=True):
1269 """
1270 Builds a list of arguments to be passed to a C{cdrecord} command.
1271
1272 The arguments will cause the C{cdrecord} command to write the indicated
1273 ISO image (C{imagePath}) to the media in the device identified by
1274 C{hardwareId}. The C{writeMulti} argument controls whether to write a
1275 multisession disc. No validation is done by this method as to whether
1276 the action makes sense (i.e. to whether the device even can write
1277 multisession discs, for instance).
1278
1279 @param hardwareId: Hardware id for the device (either SCSI id or device path)
1280 @param imagePath: Path to an ISO image on disk.
1281 @param driveSpeed: Speed at which the drive writes.
1282 @param writeMulti: Indicates whether to write a multisession disc.
1283
1284 @return: List suitable for passing to L{util.executeCommand} as C{args}.
1285 """
1286 args = []
1287 args.append("-v")
1288 if driveSpeed is not None:
1289 args.append("speed=%d" % driveSpeed)
1290 args.append("dev=%s" % hardwareId)
1291 if writeMulti:
1292 args.append("-multi")
1293 args.append("-data")
1294 args.append(imagePath)
1295 return args
1296