garage/src/version_table.rs
2020-04-12 22:24:53 +02:00

87 lines
1.9 KiB
Rust

use async_trait::async_trait;
use serde::{Deserialize, Serialize};
use std::sync::Arc;
use crate::background::BackgroundRunner;
use crate::data::*;
use crate::table::*;
#[derive(PartialEq, Clone, Debug, Serialize, Deserialize)]
pub struct Version {
// Primary key
pub uuid: UUID,
// Actual data: the blocks for this version
pub deleted: bool,
pub blocks: Vec<VersionBlock>,
// Back link to bucket+key so that we can figure if
// this was deleted later on
pub bucket: String,
pub key: String,
}
#[derive(PartialEq, Clone, Debug, Serialize, Deserialize)]
pub struct VersionBlock {
pub offset: u64,
pub hash: Hash,
}
impl Entry<Hash, EmptySortKey> for Version {
fn partition_key(&self) -> &Hash {
&self.uuid
}
fn sort_key(&self) -> &EmptySortKey {
&EmptySortKey
}
fn merge(&mut self, other: &Self) {
if other.deleted {
self.deleted = true;
self.blocks.clear();
} else if !self.deleted {
for bi in other.blocks.iter() {
match self.blocks.binary_search_by(|x| x.offset.cmp(&bi.offset)) {
Ok(_) => (),
Err(pos) => {
self.blocks.insert(pos, bi.clone());
}
}
}
}
}
}
pub struct VersionTable {
pub background: Arc<BackgroundRunner>,
pub block_ref_table: Arc<Table<BlockRefTable>>,
}
#[async_trait]
impl TableSchema for VersionTable {
type P = Hash;
type S = EmptySortKey;
type E = Version;
async fn updated(&self, old: Option<Self::E>, new: Self::E) {
let block_ref_table = self.block_ref_table.clone();
self.background.spawn(async move {
// Propagate deletion of version blocks
if let Some(old_v) = old {
if new.deleted && !old_v.deleted {
let deleted_block_refs = old_v
.blocks
.iter()
.map(|vb| BlockRef {
block: vb.hash.clone(),
version: old_v.uuid.clone(),
deleted: true,
})
.collect::<Vec<_>>();
block_ref_table.insert_many(&deleted_block_refs[..]).await?;
}
}
Ok(())
});
}
}