Re: tronconneuse: how is current_position done?

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Wesley Leggette wrote:
| On Thu, 2005-03-24 at 22:29 +0100, Denis Corbin wrote:
|
| Wesley Leggette wrote:
| |
[...]
|
| when the tronconneuse object is constructed, the underlyling layer is in
| the state where the header_version has been read. So the offset points
| to the first encrypted byte. This value is used when initializing the
| tronconneuse object.
|
|
|> So when using the tronconneuse, say if you want to store an offset into
|> the catalog, do you store the value returned by get_position(), or do
|> you have to add initial_shift to the position?

no, the catalogue always get the value from the get_position() method,
whatever is the underlying object (compresseur, tronconneuse, sar, etc.).

|
|> (Sorry, I just can't get it through my head ;) I can grasp HOW the
|> offset position stored in the catalog is calculated.

the offset is not "calculated" by the catalog object it is stored as
returned by the get_position() method of the inherited generic_file object.

|> I just can't figure
|> out WHERE in the code this calculation occurs.

the calculation occures in the get_position() method of each
generic_file inherited class used in the stack used
(compresseur/tronconneuse/sar/fichier for an example of possible stack).

|> And is this offset
|> position always the same number used when calculating block_num?

block_num is internal to tronconneuse object. It is useful when the
encrypted data does not need the same amount of byte to be stored as
requires the clear corresponding data.

|
|> Thanks,
|> Wesley
|

Cheers,
Denis.
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