continuwuity/src/database/key_value/rooms/state_compressor.rs
2022-10-10 11:18:53 +02:00

48 lines
1.7 KiB
Rust

impl service::room::state_compressor::Data for KeyValueDatabase {
fn get_statediff(shortstatehash: u64) -> Result<StateDiff> {
let value = self
.shortstatehash_statediff
.get(&shortstatehash.to_be_bytes())?
.ok_or_else(|| Error::bad_database("State hash does not exist"))?;
let parent =
utils::u64_from_bytes(&value[0..size_of::<u64>()]).expect("bytes have right length");
let mut add_mode = true;
let mut added = HashSet::new();
let mut removed = HashSet::new();
let mut i = size_of::<u64>();
while let Some(v) = value.get(i..i + 2 * size_of::<u64>()) {
if add_mode && v.starts_with(&0_u64.to_be_bytes()) {
add_mode = false;
i += size_of::<u64>();
continue;
}
if add_mode {
added.insert(v.try_into().expect("we checked the size above"));
} else {
removed.insert(v.try_into().expect("we checked the size above"));
}
i += 2 * size_of::<u64>();
}
StateDiff { parent, added, removed }
}
fn save_statediff(shortstatehash: u64, diff: StateDiff) -> Result<()> {
let mut value = diff.parent.to_be_bytes().to_vec();
for new in &diff.new {
value.extend_from_slice(&new[..]);
}
if !diff.removed.is_empty() {
value.extend_from_slice(&0_u64.to_be_bytes());
for removed in &diff.removed {
value.extend_from_slice(&removed[..]);
}
}
self.shortstatehash_statediff
.insert(&shortstatehash.to_be_bytes(), &value)?;
}
}