smaller startup.blend #42083

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Lawrence D'Oliveiro · 2014-10-05T08:08:19+02:00

2014-10-05 08:08:19 +02:00

Not sure if this is technically a bug, but...

I notice that startup.blend includes 64 blocks of type MTex that don’t seem to be referenced anywhere. Loading the startup file into Blender and then saving it without making any changes removes these blocks.

Enclosed startup.blend is a copy of startup.blend from the current Blender source tree after processing through my experimental blendhack script to remove the unreferenced blocks. I also saved it with 32-bit rather than 64-bit pointers, which knocks about another 50K off the size.

I also note the potential for information leaks in the current procedure for saving .blend files; for example, fixed-length fields containing null-terminated strings retain traces of previous values after the terminating null. And the saving of in-memory addresses can give hints about the configuration of the system on which the file was saved.

Not sure if this is technically a bug, but... I notice that `startup.blend` includes 64 blocks of type `MTex` that don’t seem to be referenced anywhere. Loading the startup file into Blender and then saving it without making any changes removes these blocks. Enclosed [startup.blend](https://archive.blender.org/developer/F115037/startup.blend) is a copy of `startup.blend` from the current Blender source tree after processing through my experimental [blendhack ](https://github.com/ldo/blendhack) script to remove the unreferenced blocks. I also saved it with 32-bit rather than 64-bit pointers, which knocks about another 50K off the size. I also note the potential for information leaks in the current procedure for saving `.blend` files; for example, fixed-length fields containing null-terminated strings retain traces of previous values after the terminating null. And the saving of in-memory addresses can give hints about the configuration of the system on which the file was saved.

Lawrence D'Oliveiro commented

2014-10-05 08:08:19 +02:00

Changed status to: 'Open'

Lawrence D'Oliveiro commented

2014-10-05 08:08:19 +02:00

Added subscriber: @ldo

Campbell Barton was assigned by Bastien Montagne

2014-10-05 09:15:03 +02:00

Bastien Montagne commented

2014-10-05 09:15:03 +02:00

Added subscriber: @mont29

Bastien Montagne commented

2014-10-05 09:15:03 +02:00

Campbell, you handle startup file iirc?

Campbell Barton commented

2014-10-06 15:23:37 +02:00

Having small startup.blend is good of course but we can do this next time we require some update to the blend file in master.

Removing unreferenced blocks is good, but won't blender do this on save?

Further, if we use blendhack - this should be documented as being the new way to create/clean/prepare startup.blend files... but before that would want to see some good justification to use it, and some review of the code.

Why (for example) does blender allow so many unused blocks in startup.blend to begin with? - is this some error in Blender we should resolve?

Having small startup.blend is good of course but we can do this next time we require some update to the blend file in master. Removing unreferenced blocks is good, but won't blender do this on save? Further, if we use `blendhack` - this should be documented as being the new way to create/clean/prepare startup.blend files... but before that would want to see some good justification to use it, and some review of the code. Why (for example) does blender allow so many unused blocks in startup.blend to begin with? - is this some error in Blender we should resolve?

Lawrence D'Oliveiro commented

2014-10-07 00:37:18 +02:00

I don’t know what your procedure is for creating startup.blend in the source tree: isn’t that done with Blender itself? Who created the startup.blend that is currently there? (It seems to date from Blender 2.67.) Like I said, if I load and save that startup file, Blender does get rid of those unused blocks.

I feel that in general there should be an equivalent text representation for .blend files, perhaps in JSON form. This would make it easier to keep track of changes to them. It might not be practical for general use, but could be handy here in the source tree.

blendhack is still very much experimental and buggy. Do you see uses for it in the Blender development effort? I was pleased to be able to get as far as writing .blend files that Blender would open without crashing. :)

I don’t know what your procedure is for creating `startup.blend` in the source tree: isn’t that done with Blender itself? Who created the `startup.blend` that is currently there? (It seems to date from Blender 2.67.) Like I said, if I load and save that startup file, Blender does get rid of those unused blocks. I feel that in general there should be an equivalent text representation for `.blend` files, perhaps in JSON form. This would make it easier to keep track of changes to them. It might not be practical for general use, but could be handy here in the source tree. `blendhack` is still very much experimental and buggy. Do you see uses for it in the Blender development effort? I was pleased to be able to get as far as writing `.blend` files that Blender would open without crashing. :)

Campbell Barton commented

2014-10-23 12:55:07 +02:00

@ldo, we just re-save startup.blend from Blender when updates are needed.

Recently we've been changing preferences in-code, to avoid re-saving a new blend file for every minor change, so we only update startup.blend when we add a new screen or change window layout for example.

Since the re-save will resolve the problem. (which we'll likely do anyway, there are some changes for the movie-clip editor screen planned...), Im not sure its worth to keep this patch open.

@ldo, we just re-save `startup.blend` from Blender when updates are needed. Recently we've been changing preferences in-code, to avoid re-saving a new blend file for every minor change, so we only update startup.blend when we add a new screen or change window layout for example. Since the re-save will resolve the problem. (which we'll likely do anyway, there are some changes for the movie-clip editor screen planned...), Im not sure its worth to keep this patch open.

Lawrence D'Oliveiro commented

2014-10-24 00:15:40 +02:00

OK. I might submit a proposal later for maintaining startup.blend in text form in the source tree—when I have my script working a bit more reliably. Hopefully the advantages of a text format should be obvious: easier to compare for differences and accept patches for. Not sure if JSON will do the trick—need to be able to record references from one block to another.

In the meantime, might I suggest using a 32-bit build of Blender to save a new startup.blend? That should knock about 44K off its size.

OK. I might submit a proposal later for maintaining `startup.blend` in text form in the source tree—when I have my script working a bit more reliably. Hopefully the advantages of a text format should be obvious: easier to compare for differences and accept patches for. Not sure if JSON will do the trick—need to be able to record references from one block to another. In the meantime, might I suggest using a 32-bit build of Blender to save a new `startup.blend`? That should knock about 44K off its size.

Campbell Barton removed their assignment 2016-08-11 06:38:03 +02:00

Campbell Barton commented

2016-08-11 06:38:03 +02:00

Removed subscriber: @ideasman42

Lawrence D'Oliveiro commented

2017-08-27 07:56:57 +02:00

As mentioned in #52387, the size saving doesn’t seem so significant with larger files. Also the issue with unreferenced MTex blocks is no longer present with the current startup.blend.

As mentioned in #52387, the size saving doesn’t seem so significant with larger files. Also the issue with unreferenced `MTex` blocks is no longer present with the current `startup.blend`.

Hans Goudey closed this issue

2024-03-03 04:13:56 +01:00

Blender Bot added

and removed

labels 2024-03-03 04:13:59 +01:00

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