C-Command Software Forum

Option to compress libraries


Is it possible to compress libraries (instead of encrypting them)? Does encryption include compression?

Also, is it possible to make a library spotlight searchable (DEVONthink introduced this feature recently)?

I am looking at EagleFiler to archive my email (DEVONthink which I use for my paperless office is not very good at that imho). I like the fact that actual email are kept archived (and not RTFd exports).

Thank you,

You can certainly compress an EagleFiler library—it’s just a folder—but it’s not possible to access it in EagleFiler without decompressing it first.


Libraries have always been Spotlight-searchable, since they’re stored as regular files/folders.

Sorry for the lack of clarity, let me reformulate my compression question.

Let’s take the example of email backup (which is ultimately what is of interest for me): emails are .emlx files, mostly plain text with the attachments uuencoded inside the files.

When I use EagleFiler to archive, these files are essentially moved from Apple Mail library to EagleFiler database (which is a folder and metadata files). The good side: I get to keep the original emlx file and it’s spotlight searchable.

However, lots of emails (still) contain BMP images (despite my complains) and a lot of text. Both (especially the BMP payload) are easy to compress and to save on disk space. I’d like to keep the emlx files as: .emlx.zip inside the archive database (it’s an archive so it can be somewhat slower of access). Obviously I don’t want to compress each file individually and decompress each file to access the DB. I’d like avoiding having to decompress a potentially large DB to be able to access it also.

Given that you already have encryption built in, it means that you must have a mechanism to transform the emlx files (decrypt) that are stored in the database. Also, usually to save on encryption time and to strengten the encryption, most program actually compress files before encrypting them. Hence my request for on-the-fly compression of databases :). Do you have something like that on your roadmap? How does your encryption actually work? When the database is encrypted, what about spotlight and your search function?

Thank you.

That’s not correct. Under normal use, when you import mail into EagleFiler, it converts it to mbox format. There are no emlx files in the library, although EagleFiler will auto-generate them when you ask it to open particular messages in Mail.

No. I may add support for compressed mbox files, however.

EagleFiler’s encryption uses the same technology as Apple’s FileVault. It basically creates a mini-vault for your library. As far as I know, this does not use compression—at least the data doesn’t seem to take up any less space. The EagleFiler database, the files, and all the indexes are all encrypted. If you have Spotlight enabled, its indexes for the library are also encrypted.

Thank you for the answers.

I was looking at the encrypted DB and I see you are using a sparseimage (as opposed to a sparsebundle). Wouldn’t that be problematic with Time Machine current implementation?

Indeed, the data in an encrypted DB doesn’t seem to be compressed (adding few megabytes of very compresible data grows the DB by several megabytes).

I’ll probably make that an option at some point. Sparse images do work with Time Machine; they just aren’t as space-efficient as sparse bundles. This matters a lot when you have a huge image, like with FileVault, and somewhat less so with a smaller image like an EagleFiler library. If you need a sparse bundle now, you could convert your sparse image using hdiutil from Terminal. (Note: this would make it incompatible with Mac OS X 10.4.)

EagleFiler 1.4 adds support for sprase bundle images.