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authorAlex Auvolat <alex@adnab.me>2021-03-18 19:27:02 +0100
committerAlex Auvolat <alex@adnab.me>2021-03-18 19:27:02 +0100
commit4348bde180887f5185ca6da6024476e8e8fb2fe6 (patch)
tree8a35f0e4229d15665af7673eebcaa1b3d75a73cb /src/table/data.rs
parent5b659b28ce6bef15072d2fc93f777aa8ff73b2d8 (diff)
parent4eb16e886388f35d2bdee52b16922421004cf132 (diff)
downloadgarage-4348bde180887f5185ca6da6024476e8e8fb2fe6.tar.gz
garage-4348bde180887f5185ca6da6024476e8e8fb2fe6.zip
Merge branch 'dev-0.2'
Diffstat (limited to 'src/table/data.rs')
-rw-r--r--src/table/data.rs254
1 files changed, 254 insertions, 0 deletions
diff --git a/src/table/data.rs b/src/table/data.rs
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+use core::borrow::Borrow;
+use std::sync::Arc;
+
+use log::warn;
+use serde_bytes::ByteBuf;
+use sled::Transactional;
+use tokio::sync::Notify;
+
+use garage_util::data::*;
+use garage_util::error::*;
+
+use garage_rpc::membership::System;
+
+use crate::crdt::CRDT;
+use crate::replication::*;
+use crate::schema::*;
+
+pub struct TableData<F: TableSchema, R: TableReplication> {
+ system: Arc<System>,
+
+ pub name: String,
+ pub(crate) instance: F,
+ pub(crate) replication: R,
+
+ pub store: sled::Tree,
+
+ pub(crate) merkle_tree: sled::Tree,
+ pub(crate) merkle_todo: sled::Tree,
+ pub(crate) merkle_todo_notify: Notify,
+ pub(crate) gc_todo: sled::Tree,
+}
+
+impl<F, R> TableData<F, R>
+where
+ F: TableSchema,
+ R: TableReplication,
+{
+ pub fn new(system: Arc<System>, name: String, instance: F, replication: R, db: &sled::Db) -> Arc<Self> {
+ let store = db
+ .open_tree(&format!("{}:table", name))
+ .expect("Unable to open DB tree");
+
+ let merkle_tree = db
+ .open_tree(&format!("{}:merkle_tree", name))
+ .expect("Unable to open DB Merkle tree tree");
+ let merkle_todo = db
+ .open_tree(&format!("{}:merkle_todo", name))
+ .expect("Unable to open DB Merkle TODO tree");
+
+ let gc_todo = db
+ .open_tree(&format!("{}:gc_todo", name))
+ .expect("Unable to open DB tree");
+
+ Arc::new(Self {
+ system,
+ name,
+ instance,
+ replication,
+ store,
+ merkle_tree,
+ merkle_todo,
+ merkle_todo_notify: Notify::new(),
+ gc_todo,
+ })
+ }
+
+ // Read functions
+
+ pub fn read_entry(&self, p: &F::P, s: &F::S) -> Result<Option<ByteBuf>, Error> {
+ let tree_key = self.tree_key(p, s);
+ if let Some(bytes) = self.store.get(&tree_key)? {
+ Ok(Some(ByteBuf::from(bytes.to_vec())))
+ } else {
+ Ok(None)
+ }
+ }
+
+ pub fn read_range(
+ &self,
+ p: &F::P,
+ s: &Option<F::S>,
+ filter: &Option<F::Filter>,
+ limit: usize,
+ ) -> Result<Vec<Arc<ByteBuf>>, Error> {
+ let partition_hash = p.hash();
+ let first_key = match s {
+ None => partition_hash.to_vec(),
+ Some(sk) => self.tree_key(p, sk),
+ };
+ let mut ret = vec![];
+ for item in self.store.range(first_key..) {
+ let (key, value) = item?;
+ if &key[..32] != partition_hash.as_slice() {
+ break;
+ }
+ let keep = match filter {
+ None => true,
+ Some(f) => {
+ let entry = self.decode_entry(value.as_ref())?;
+ F::matches_filter(&entry, f)
+ }
+ };
+ if keep {
+ ret.push(Arc::new(ByteBuf::from(value.as_ref())));
+ }
+ if ret.len() >= limit {
+ break;
+ }
+ }
+ Ok(ret)
+ }
+
+ // Mutation functions
+ // When changing this code, take care of propagating modifications correctly:
+ // - When an entry is modified or deleted, call the updated() function
+ // on the table instance
+ // - When an entry is modified or deleted, add it to the merkle updater's todo list.
+ // This has to be done atomically with the modification for the merkle updater
+ // to maintain consistency. The merkle updater must then be notified with todo_notify.
+ // - When an entry is updated to be a tombstone, add it to the gc_todo tree
+
+ pub(crate) fn update_many<T: Borrow<ByteBuf>>(&self, entries: &[T]) -> Result<(), Error> {
+ for update_bytes in entries.iter() {
+ self.update_entry(update_bytes.borrow().as_slice())?;
+ }
+ Ok(())
+ }
+
+ pub(crate) fn update_entry(&self, update_bytes: &[u8]) -> Result<(), Error> {
+ let update = self.decode_entry(update_bytes)?;
+ let tree_key = self.tree_key(update.partition_key(), update.sort_key());
+
+ let changed = (&self.store, &self.merkle_todo).transaction(|(store, mkl_todo)| {
+ let (old_entry, new_entry) = match store.get(&tree_key)? {
+ Some(prev_bytes) => {
+ let old_entry = self
+ .decode_entry(&prev_bytes)
+ .map_err(sled::transaction::ConflictableTransactionError::Abort)?;
+ let mut new_entry = old_entry.clone();
+ new_entry.merge(&update);
+ (Some(old_entry), new_entry)
+ }
+ None => (None, update.clone()),
+ };
+
+ if Some(&new_entry) != old_entry.as_ref() {
+ let new_bytes = rmp_to_vec_all_named(&new_entry)
+ .map_err(Error::RMPEncode)
+ .map_err(sled::transaction::ConflictableTransactionError::Abort)?;
+ let new_bytes_hash = blake2sum(&new_bytes[..]);
+ mkl_todo.insert(tree_key.clone(), new_bytes_hash.as_slice())?;
+ store.insert(tree_key.clone(), new_bytes)?;
+ Ok(Some((old_entry, new_entry, new_bytes_hash)))
+ } else {
+ Ok(None)
+ }
+ })?;
+
+ if let Some((old_entry, new_entry, new_bytes_hash)) = changed {
+ let is_tombstone = new_entry.is_tombstone();
+ self.instance.updated(old_entry, Some(new_entry));
+ self.merkle_todo_notify.notify_one();
+ if is_tombstone {
+ // We are only responsible for GC'ing this item if we are the
+ // "leader" of the partition, i.e. the first node in the
+ // set of nodes that replicates this partition.
+ // This avoids GC loops and does not change the termination properties
+ // of the GC algorithm, as in all cases GC is suspended if
+ // any node of the partition is unavailable.
+ let pk_hash = Hash::try_from(&tree_key[..32]).unwrap();
+ let nodes = self.replication.write_nodes(&pk_hash);
+ if nodes.first() == Some(&self.system.id) {
+ self.gc_todo.insert(&tree_key, new_bytes_hash.as_slice())?;
+ }
+ }
+ }
+
+ Ok(())
+ }
+
+ pub(crate) fn delete_if_equal(self: &Arc<Self>, k: &[u8], v: &[u8]) -> Result<bool, Error> {
+ let removed = (&self.store, &self.merkle_todo).transaction(|(store, mkl_todo)| {
+ if let Some(cur_v) = store.get(k)? {
+ if cur_v == v {
+ store.remove(k)?;
+ mkl_todo.insert(k, vec![])?;
+ return Ok(true);
+ }
+ }
+ Ok(false)
+ })?;
+
+ if removed {
+ let old_entry = self.decode_entry(v)?;
+ self.instance.updated(Some(old_entry), None);
+ self.merkle_todo_notify.notify_one();
+ }
+ Ok(removed)
+ }
+
+ pub(crate) fn delete_if_equal_hash(
+ self: &Arc<Self>,
+ k: &[u8],
+ vhash: Hash,
+ ) -> Result<bool, Error> {
+ let removed = (&self.store, &self.merkle_todo).transaction(|(store, mkl_todo)| {
+ if let Some(cur_v) = store.get(k)? {
+ if blake2sum(&cur_v[..]) == vhash {
+ store.remove(k)?;
+ mkl_todo.insert(k, vec![])?;
+ return Ok(Some(cur_v));
+ }
+ }
+ Ok(None)
+ })?;
+
+ if let Some(old_v) = removed {
+ let old_entry = self.decode_entry(&old_v[..])?;
+ self.instance.updated(Some(old_entry), None);
+ self.merkle_todo_notify.notify_one();
+ Ok(true)
+ } else {
+ Ok(false)
+ }
+ }
+
+ // ---- Utility functions ----
+
+ pub(crate) fn tree_key(&self, p: &F::P, s: &F::S) -> Vec<u8> {
+ let mut ret = p.hash().to_vec();
+ ret.extend(s.sort_key());
+ ret
+ }
+
+ pub(crate) fn decode_entry(&self, bytes: &[u8]) -> Result<F::E, Error> {
+ match rmp_serde::decode::from_read_ref::<_, F::E>(bytes) {
+ Ok(x) => Ok(x),
+ Err(e) => match F::try_migrate(bytes) {
+ Some(x) => Ok(x),
+ None => {
+ warn!("Unable to decode entry of {}: {}", self.name, e);
+ for line in hexdump::hexdump_iter(bytes) {
+ debug!("{}", line);
+ }
+ Err(e.into())
+ }
+ },
+ }
+ }
+
+ pub fn gc_todo_len(&self) -> usize {
+ self.gc_todo.len()
+ }
+}