Browser storage limits and eviction criteria

简单说：同一个域名（含子域名），indexdb最大可用空间为不超过磁盘剩余空间的10%且不大于2GB。（firefox）

https://developer.mozilla.org/en-US/docs/Web/API/IndexedDB_API/Browser_storage_limits_and_eviction_criteria

Storage limits

The maximum browser storage space is dynamic — it is based on your hard drive size. The global limit is calculated as 50% of free disk space. In Firefox, an internal browser tool called the Quota Manager keeps track of how much disk space each origin is using up, and deletes data if necessary.

So if the free space on your hard drive is 500 GB, then the total storage for a browser is 250 GB. If this is exceeded, a process called origin eviction comes into play, deleting an entire origin's worth of data until the storage amount goes under the limit again. There is no trimming effect put in place to delete parts of origins — deleting one database of an origin could cause problems with inconsistency.

There's also another limit called group limit — this is defined as 20% of the global limit, but it has a minimum of 10 MB and a maximum of 2 GB. Each origin is part of a group (group of origins). There's one group for each eTLD+1 domain. For example:

• mozilla.org — group1, origin1
• www.mozilla.org — group1, origin2
• joe.blogs.mozilla.org — group1, origin3
• firefox.com — group2, origin4

In this group, mozilla.org, www.mozilla.org, and joe.blogs.mozilla.org can aggregately use a maximum of 20% of the global limit. firefox.com has a separate maximum of 20%.