Database
The database related code is located in ./portalnet/storage.rs.
There are three main database kinds:
| DB Name | Kind | Location | Purpose | Keys | Values |
|---|---|---|---|---|---|
| Main | SQLite | Disk | Data store | Content ID | Content key, content value, content size |
| Memory | HashMap | Memory | Kademlia cache | Content key | Content data bytes |
Main content database
This is an SQLite database that stores content data. For a piece of content, this includes the content ID, content key, content value and the size of the content. It makes assessing the size of the database quicker by avoiding the need to repeatedly compute the size of each content.
Memory content database
This uses is an in-memory hashmap to keep content that may not be required for long term storage. An overlay service uses this database when receiving data from a peer as part of Kademlia-related actions. If required, data is later moved to disk in the main content database.