Type IsoImage
object
--+
|
IsoImage
Represents an ISO filesystem image.
Summary
This object represents an ISO 9660 filesystem image. It is
implemented in terms of the mkisofs
program, which has
been ported to many operating systems and platforms. A "sensible
subset" of the mkisofs
functionality is made
available through the public interface, allowing callers to set a
variety of basic options such as publisher id, application id, etc. as
well as specify exactly which files and directories they want included
in their image.
By default, the image is created using the Rock Ridge protocol
(using the -r
option to mkisofs
) because Rock
Ridge discs are generally more useful on UN*X filesystems than standard
ISO 9660 images. However, callers can fall back to the default
mkisofs
functionality by setting the
useRockRidge
instance variable to False
.
Note, however, that this option is not well-tested.
Where Files and Directories are Placed in the Image
Although this class is implemented in terms of the
mkisofs
program, its standard "image contents"
semantics are slightly different than the original mkisofs
semantics. The difference is that files and directories are added to
the image with some additional information about their source directory
kept intact.
As an example, suppose you add the file /etc/profile
to
your image and you do not configure a graft point. The file
/profile
will be created in the image. The behavior for
directories is similar. For instance, suppose that you add
/etc/X11
to the image and do not configure a graft point.
In this case, the directory /X11
will be created in the
image, even if the original /etc/X11
directory is empty.
This behavior differs from the standard mkisofs
behavior!
If a graft point is configured, it will be used to modify the point
at which a file or directory is added into an image. Using the examples
from above, let's assume you set a graft point of base
when adding /etc/profile
and /etc/X11
to your
image. In this case, the file /base/profile
and the
directory /base/X11
would be added to the image.
I feel that this behavior is more consistent than the original
mkisofs
behavior. However, to be fair, it is not quite as
flexible, and some users might not like it. For this reason, the
contentsOnly
parameter to the addEntry
method can be used to revert to
the original behavior if desired.
Method Summary |
|
__init__ (self,
device,
boundaries,
graftPoint)
Initializes an empty ISO image object. |
|
addEntry (self,
path,
graftPoint,
override,
contentsOnly)
Adds an individual file or directory into the ISO image. |
|
getEstimatedSize (self)
Returns the estimated size (in bytes) of the ISO image. |
|
writeImage (self,
imagePath)
Writes this image to disk using the image path. |
Inherited from object |
|
__delattr__ (...)
x.__delattr__('name') <==> del x.name |
|
__getattribute__ (...)
x.__getattribute__('name') <==> x.name |
|
__hash__ (x)
x.__hash__() <==> hash(x) |
|
__new__ (T,
S,
...)
T.__new__(S, ...) -> a new object with type S, a subtype of T |
|
__reduce__ (...)
helper for pickle |
|
__reduce_ex__ (...)
helper for pickle |
|
__repr__ (x)
x.__repr__() <==> repr(x) |
|
__setattr__ (...)
x.__setattr__('name', value) <==> x.name = value |
|
__str__ (x)
x.__str__() <==> str(x) |
Property Summary |
|
device : Device that image will be written to (device path or SCSI id). |
|
boundaries : Session boundaries as required by mkisofs . |
|
graftPoint : Default image-wide graft point (see addEntry for details). |
|
useRockRidge : Indicates whether to use RockRidge (default is True ). |
|
applicationId : Optionally specifies the ISO header application id value. |
|
biblioFile : Optionally specifies the ISO bibliographic file name. |
|
publisherId : Optionally specifies the ISO header publisher id value. |
|
preparerId : Optionally specifies the ISO header preparer id value. |
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volumeId : Optionally specifies the ISO header volume id value. |
__init__(self,
device=None,
boundaries=None,
graftPoint=None)
(Constructor)
Initializes an empty ISO image object.
Only the most commonly-used configuration items can be set using
this constructor. If you have a need to change the others, do so
immediately after creating your object.
The device and boundaries values are both required in order to write
multisession discs. If either is missing or None , a
multisession disc will not be written. The boundaries tuple is in terms
of ISO sectors, as built by an image writer class and returned in a writer.MediaCapacity object.
-
- Parameters:
device -
Name of the device that the image will be written to
(type=Either be a filesystem path or a SCSI address)
boundaries -
Session boundaries as required by mkisofs
(type=Tuple (last_sess_start,next_sess_start) as
returned from cdrecord -msinfo , or
None )
graftPoint -
Default graft point for this page.
(type=String representing a graft point path (see addEntry ).)
- Overrides:
__builtin__.object.__init__
|
addEntry(self,
path,
graftPoint=None,
override=False,
contentsOnly=False)
Adds an individual file or directory into the ISO image.
The path must exist and must be a file or a directory. By default,
the entry will be placed into the image at the root directory, but this
behavior can be overridden using the graftPoint parameter
or instance variable.
You can use the contentsOnly behavior to revert to the
"original" mkisofs behavior for adding
directories, which is to add only the items within the directory, and
not the directory itself.
-
- Parameters:
path -
File or directory to be added to the image
(type=String representing a path on disk)
graftPoint -
Graft point to be used when adding this entry
(type=String representing a graft point path, as described
above)
override -
Override an existing entry with the same path.
(type=Boolean true/false)
contentsOnly -
Add directory contents only (standard mkisofs
behavior).
(type=Boolean true/false)
- Raises:
ValueError -
If path is not a file or directory, or does not exist.
ValueError -
If the path has already been added, and override is not
set.
ValueError -
If a path cannot be encoded properly.
Notes:
- Things get odd if you try to add a directory to an image that
will be written to a multisession disc, and the same directory already
exists in an earlier session on that disc. Not all of the data gets
written. You really wouldn't want to do this anyway, I guess.
- An exception will be thrown if the path has already been added to the
image, unless the
override parameter is set to
True .
- The method
graftPoints parameter overrides the
object-wide instance variable. If neither the method parameter or
object-wide value is set, the path will be written at the image root. The
graft point behavior is determined by the value which is in effect at
the time this method is called, so you must set the
object-wide value before calling this method for the first time, or your
image may not be consistent.
- You cannot use the local
graftPoint parameter to
"turn off" an object-wide instance variable by setting it to
None . Python's default argument functionality buys us a lot,
but it can't make this method psychic. :)
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getEstimatedSize(self)
Returns the estimated size (in bytes) of the ISO image.
This is implemented via the -print-size option to
mkisofs , so it might take a bit of time to execute.
However, the result is as accurate as we can get, since it takes into
account all of the ISO overhead, the true cost of directories in the
structure, etc, etc.
-
- Returns:
-
Estimated size of the image, in bytes.
- Raises:
IOError -
If there is a problem calling mkisofs .
ValueError -
If there are no filesystem entries in the image
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writeImage(self,
imagePath)
Writes this image to disk using the image path.
-
- Parameters:
imagePath -
Path to write image out as
(type=String representing a path on disk)
- Raises:
IOError -
If there is an error writing the image to disk.
ValueError -
If there are no filesystem entries in the image
ValueError -
If a path cannot be encoded properly.
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device
Device that image will be written to (device path or SCSI id).
-
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boundaries
Session boundaries as required by mkisofs .
-
|
graftPoint
Default image-wide graft point (see addEntry for details).
-
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useRockRidge
Indicates whether to use RockRidge (default is True ).
-
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applicationId
Optionally specifies the ISO header application id value.
-
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biblioFile
Optionally specifies the ISO bibliographic file name.
-
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publisherId
Optionally specifies the ISO header publisher id value.
-
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preparerId
Optionally specifies the ISO header preparer id value.
-
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volumeId
Optionally specifies the ISO header volume id value.
-
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