| Thank you for doing that. This explains much. For a while now I have been running a cronjob to commit my profile's sessionstore-backups directory to a git repo every 5 minutes. This is because, occasionally, when Firefox starts, it will load tabs in some kind of limbo state where the page is blank and the title is displayed in the tab--but if I refresh the page, it immediately goes to about:blank, and the original tab is completely lost. When this happens, I can dig the tabs out of the recovery.js or previous.js files with a Python script that dumps the tabs out of the JSON, but if Firefox overwrites those files first, I can't. So the git repo lets me recover them no matter what. What I have noticed is that the git repo grows huge very quickly. Right now my recovery.js file is 2.6 MB (which seems ridiculous for storing a list of URLs and title strings), but the git repo is 4.3 GB. If I run "git gc --aggressive" and wait a long time, it compresses down very well, to a few hundred MB. But it's simply absurd how much data is being stored, and storing useless stuff like images in data URIs explains a lot. |
Like you, I also observed that exactly the people who depend on the tabs to "remain" after the restart are those who are hit by the bugs in the "restoration" and as I've said, I believe the users would more prefer to have "stable" tabs and URLs than the "fully restored sessions in the tabs" when all the tabs fully randomly (for them) disappear. Maybe saving just the tabs and URLs separately from "everything session" would be a good step to the robustness (since it would be much less data and much less chance to get corrupted) and then maybe, pretty please, an option "don't save session data" can be in the about:config too)?
Once there's decision to store just the URLs of the tabs as the separate file, the file can even be organized in a way that just the URL that is changed gets rewritten, therefore making the "complete corruption" of the file impossible and also removing the necessity for Firefox to keep N older versions of the big files (which then eventually still don't help the user like you).