Add decmpfs LZBitmap support

[eternalbits]

Hello

In the long list you have here, perhaps a reference to the bitmap that is possibly used to draw the entire layout is missing.
I'm talking about what appears right at the end of sm_datazone, there the whole bitmap appears.

I can help with bitmap identification if you're interested.
Rui

[joachimmetz]

I can help with bitmap identification if you're interested.

Sure, feel free t send a PR. Note that merging it can take a while seeing other priorities on my end.

[eternalbits]

Hello, thank you very much for your attention!

I am part of the Virtual Disk Compact and Copy application that has been studying compression by apfs. It is a pity that Apple does not make more data available that allows to be more useful in compression.

I leave here a result in an Excel workbook. The most relevant parts are the Spaceman sheet and the Space0, Space1 and Space2 sheets. I note that in this way the entire disk is represented in the form of a bitmap.

Catalina.xlsx

All the best,
Rui

[joachimmetz]

@eternalbits thanks, I'll have a closer look when time permits

[P5-2005]

Hello, thank you very much for your attention!

I am part of the Virtual Disk Compact and Copy application that has been studying compression by apfs. It is a pity that Apple does not make more data available that allows to be more useful in compression.

I leave here a result in an Excel workbook. The most relevant parts are the Spaceman sheet and the Space0, Space1 and Space2 sheets. I note that in this way the entire disk is represented in the form of a bitmap.

Catalina.xlsx

All the best, Rui

i think this will be more interesting, take a look : https://github.com/eafer/libzbitmap

[joachimmetz]

@P5-2005 thanks that is less cryptic than the original report