garage/src/model/version_table.rs
2020-07-07 13:59:22 +02:00

146 lines
2.9 KiB
Rust

use async_trait::async_trait;
use serde::{Deserialize, Serialize};
use std::sync::Arc;
use garage_util::background::BackgroundRunner;
use garage_util::data::*;
use garage_util::error::Error;
use garage_table::table_sharded::*;
use garage_table::*;
use crate::block_ref_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,
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,
}
impl Version {
pub fn new(
uuid: UUID,
bucket: String,
key: String,
deleted: bool,
blocks: Vec<VersionBlock>,
) -> Self {
let mut ret = Self {
uuid,
deleted,
blocks: vec![],
bucket,
key,
};
for b in blocks {
ret.add_block(b)
.expect("Twice the same VersionBlock in Version constructor");
}
ret
}
/// Adds a block if it wasn't already present
pub fn add_block(&mut self, new: VersionBlock) -> Result<(), ()> {
match self
.blocks
.binary_search_by(|b| b.cmp_key().cmp(&new.cmp_key()))
{
Err(i) => {
self.blocks.insert(i, new);
Ok(())
}
Ok(_) => Err(()),
}
}
pub fn blocks(&self) -> &[VersionBlock] {
&self.blocks[..]
}
}
#[derive(PartialEq, Clone, Debug, Serialize, Deserialize)]
pub struct VersionBlock {
pub part_number: u64,
pub offset: u64,
pub hash: Hash,
pub size: u64,
}
impl VersionBlock {
fn cmp_key(&self) -> (u64, u64) {
(self.part_number, self.offset)
}
}
impl Entry<Hash, EmptyKey> for Version {
fn partition_key(&self) -> &Hash {
&self.uuid
}
fn sort_key(&self) -> &EmptyKey {
&EmptyKey
}
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.cmp_key().cmp(&bi.cmp_key()))
{
Ok(_) => (),
Err(pos) => {
self.blocks.insert(pos, bi.clone());
}
}
}
}
}
}
pub struct VersionTable {
pub background: Arc<BackgroundRunner>,
pub block_ref_table: Arc<Table<BlockRefTable, TableShardedReplication>>,
}
#[async_trait]
impl TableSchema for VersionTable {
type P = Hash;
type S = EmptyKey;
type E = Version;
type Filter = ();
async fn updated(&self, old: Option<Self::E>, new: Option<Self::E>) -> Result<(), Error> {
let block_ref_table = self.block_ref_table.clone();
if let (Some(old_v), Some(new_v)) = (old, new) {
// Propagate deletion of version blocks
if new_v.deleted && !old_v.deleted {
let deleted_block_refs = old_v
.blocks
.iter()
.map(|vb| BlockRef {
block: vb.hash,
version: old_v.uuid,
deleted: true,
})
.collect::<Vec<_>>();
block_ref_table.insert_many(&deleted_block_refs[..]).await?;
}
}
Ok(())
}
fn matches_filter(entry: &Self::E, _filter: &Self::Filter) -> bool {
!entry.deleted
}
}