use std::collections::{BTreeMap, HashMap}; use std::sync::Arc; use std::time::Duration; use log::warn; use arc_swap::ArcSwapOption; use futures::stream::*; use serde::{Deserialize, Serialize}; use serde_bytes::ByteBuf; use garage_util::data::*; use garage_util::error::Error; use garage_rpc::membership::System; use garage_rpc::ring::Ring; use garage_rpc::rpc_client::*; use garage_rpc::rpc_server::*; use crate::schema::*; use crate::table_sync::*; const TABLE_RPC_TIMEOUT: Duration = Duration::from_secs(10); pub struct Table { pub instance: F, pub replication: R, pub name: String, pub(crate) rpc_client: Arc>>, pub system: Arc, pub store: sled::Tree, pub syncer: ArcSwapOption>, } #[derive(Serialize, Deserialize)] pub(crate) enum TableRPC { Ok, ReadEntry(F::P, F::S), ReadEntryResponse(Option), // Read range: read all keys in partition P, possibly starting at a certain sort key offset ReadRange(F::P, Option, Option, usize), Update(Vec>), SyncRPC(SyncRPC), } impl RpcMessage for TableRPC {} pub trait TableReplication: Send + Sync { // See examples in table_sharded.rs and table_fullcopy.rs // To understand various replication methods // Which nodes to send reads from fn read_nodes(&self, hash: &Hash, system: &System) -> Vec; fn read_quorum(&self) -> usize; // Which nodes to send writes to fn write_nodes(&self, hash: &Hash, system: &System) -> Vec; fn write_quorum(&self) -> usize; fn max_write_errors(&self) -> usize; fn epidemic_writes(&self) -> bool; // Which are the nodes that do actually replicate the data fn replication_nodes(&self, hash: &Hash, ring: &Ring) -> Vec; fn split_points(&self, ring: &Ring) -> Vec; } impl Table where F: TableSchema + 'static, R: TableReplication + 'static, { // =============== PUBLIC INTERFACE FUNCTIONS (new, insert, get, etc) =============== pub async fn new( instance: F, replication: R, system: Arc, db: &sled::Db, name: String, rpc_server: &mut RpcServer, ) -> Arc { let store = db.open_tree(&name).expect("Unable to open DB tree"); let rpc_path = format!("table_{}", name); let rpc_client = system.rpc_client::>(&rpc_path); let table = Arc::new(Self { instance, replication, name, rpc_client, system, store, syncer: ArcSwapOption::from(None), }); table.clone().register_handler(rpc_server, rpc_path); let syncer = TableSyncer::launch(table.clone()).await; table.syncer.swap(Some(syncer)); table } pub async fn insert(&self, e: &F::E) -> Result<(), Error> { let hash = e.partition_key().hash(); let who = self.replication.write_nodes(&hash, &self.system); //eprintln!("insert who: {:?}", who); let e_enc = Arc::new(ByteBuf::from(rmp_to_vec_all_named(e)?)); let rpc = TableRPC::::Update(vec![e_enc]); self.rpc_client .try_call_many( &who[..], rpc, RequestStrategy::with_quorum(self.replication.write_quorum()) .with_timeout(TABLE_RPC_TIMEOUT), ) .await?; Ok(()) } pub async fn insert_many(&self, entries: &[F::E]) -> Result<(), Error> { let mut call_list = HashMap::new(); for entry in entries.iter() { let hash = entry.partition_key().hash(); let who = self.replication.write_nodes(&hash, &self.system); let e_enc = Arc::new(ByteBuf::from(rmp_to_vec_all_named(entry)?)); for node in who { if !call_list.contains_key(&node) { call_list.insert(node, vec![]); } call_list.get_mut(&node).unwrap().push(e_enc.clone()); } } let call_futures = call_list.drain().map(|(node, entries)| async move { let rpc = TableRPC::::Update(entries); let resp = self.rpc_client.call(node, rpc, TABLE_RPC_TIMEOUT).await?; Ok::<_, Error>((node, resp)) }); let mut resps = call_futures.collect::>(); let mut errors = vec![]; while let Some(resp) = resps.next().await { if let Err(e) = resp { errors.push(e); } } if errors.len() > self.replication.max_write_errors() { Err(Error::Message("Too many errors".into())) } else { Ok(()) } } pub async fn get( self: &Arc, partition_key: &F::P, sort_key: &F::S, ) -> Result, Error> { let hash = partition_key.hash(); let who = self.replication.read_nodes(&hash, &self.system); //eprintln!("get who: {:?}", who); let rpc = TableRPC::::ReadEntry(partition_key.clone(), sort_key.clone()); let resps = self .rpc_client .try_call_many( &who[..], rpc, RequestStrategy::with_quorum(self.replication.read_quorum()) .with_timeout(TABLE_RPC_TIMEOUT) .interrupt_after_quorum(true), ) .await?; let mut ret = None; let mut not_all_same = false; for resp in resps { if let TableRPC::ReadEntryResponse(value) = resp { if let Some(v_bytes) = value { let v = self.decode_entry(v_bytes.as_slice())?; ret = match ret { None => Some(v), Some(mut x) => { if x != v { not_all_same = true; x.merge(&v); } Some(x) } } } } else { return Err(Error::Message(format!("Invalid return value to read"))); } } if let Some(ret_entry) = &ret { if not_all_same { let self2 = self.clone(); let ent2 = ret_entry.clone(); self.system .background .spawn_cancellable(async move { self2.repair_on_read(&who[..], ent2).await }); } } Ok(ret) } pub async fn get_range( self: &Arc, partition_key: &F::P, begin_sort_key: Option, filter: Option, limit: usize, ) -> Result, Error> { let hash = partition_key.hash(); let who = self.replication.read_nodes(&hash, &self.system); let rpc = TableRPC::::ReadRange(partition_key.clone(), begin_sort_key, filter, limit); let resps = self .rpc_client .try_call_many( &who[..], rpc, RequestStrategy::with_quorum(self.replication.read_quorum()) .with_timeout(TABLE_RPC_TIMEOUT) .interrupt_after_quorum(true), ) .await?; let mut ret = BTreeMap::new(); let mut to_repair = BTreeMap::new(); for resp in resps { if let TableRPC::Update(entries) = resp { for entry_bytes in entries.iter() { let entry = self.decode_entry(entry_bytes.as_slice())?; let entry_key = self.tree_key(entry.partition_key(), entry.sort_key()); match ret.remove(&entry_key) { None => { ret.insert(entry_key, Some(entry)); } Some(Some(mut prev)) => { let must_repair = prev != entry; prev.merge(&entry); if must_repair { to_repair.insert(entry_key.clone(), Some(prev.clone())); } ret.insert(entry_key, Some(prev)); } Some(None) => unreachable!(), } } } } if !to_repair.is_empty() { let self2 = self.clone(); self.system.background.spawn_cancellable(async move { for (_, v) in to_repair.iter_mut() { self2.repair_on_read(&who[..], v.take().unwrap()).await?; } Ok(()) }); } let ret_vec = ret .iter_mut() .take(limit) .map(|(_k, v)| v.take().unwrap()) .collect::>(); Ok(ret_vec) } // =============== UTILITY FUNCTION FOR CLIENT OPERATIONS =============== async fn repair_on_read(&self, who: &[UUID], what: F::E) -> Result<(), Error> { let what_enc = Arc::new(ByteBuf::from(rmp_to_vec_all_named(&what)?)); self.rpc_client .try_call_many( &who[..], TableRPC::::Update(vec![what_enc]), RequestStrategy::with_quorum(who.len()).with_timeout(TABLE_RPC_TIMEOUT), ) .await?; Ok(()) } // =============== HANDLERS FOR RPC OPERATIONS (SERVER SIDE) ============== fn register_handler(self: Arc, rpc_server: &mut RpcServer, path: String) { let self2 = self.clone(); rpc_server.add_handler::, _, _>(path, move |msg, _addr| { let self2 = self2.clone(); async move { self2.handle(&msg).await } }); let self2 = self.clone(); self.rpc_client .set_local_handler(self.system.id, move |msg| { let self2 = self2.clone(); async move { self2.handle(&msg).await } }); } async fn handle(self: &Arc, msg: &TableRPC) -> Result, Error> { match msg { TableRPC::ReadEntry(key, sort_key) => { let value = self.handle_read_entry(key, sort_key)?; Ok(TableRPC::ReadEntryResponse(value)) } TableRPC::ReadRange(key, begin_sort_key, filter, limit) => { let values = self.handle_read_range(key, begin_sort_key, filter, *limit)?; Ok(TableRPC::Update(values)) } TableRPC::Update(pairs) => { self.handle_update(pairs).await?; Ok(TableRPC::Ok) } TableRPC::SyncRPC(rpc) => { let syncer = self.syncer.load_full().unwrap(); let response = syncer .handle_rpc(rpc, self.system.background.stop_signal.clone()) .await?; Ok(TableRPC::SyncRPC(response)) } _ => Err(Error::BadRPC(format!("Unexpected table RPC"))), } } fn handle_read_entry(&self, p: &F::P, s: &F::S) -> Result, 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) } } fn handle_read_range( &self, p: &F::P, s: &Option, filter: &Option, limit: usize, ) -> Result>, 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) } pub async fn handle_update(self: &Arc, entries: &[Arc]) -> Result<(), Error> { let syncer = self.syncer.load_full().unwrap(); let mut epidemic_propagate = vec![]; for update_bytes in entries.iter() { let update = self.decode_entry(update_bytes.as_slice())?; let tree_key = self.tree_key(update.partition_key(), update.sort_key()); let (old_entry, new_entry) = self.store.transaction(|db| { let (old_entry, new_entry) = match db.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()), }; let new_bytes = rmp_to_vec_all_named(&new_entry) .map_err(Error::RMPEncode) .map_err(sled::transaction::ConflictableTransactionError::Abort)?; db.insert(tree_key.clone(), new_bytes)?; Ok((old_entry, new_entry)) })?; if old_entry.as_ref() != Some(&new_entry) { if self.replication.epidemic_writes() { epidemic_propagate.push(new_entry.clone()); } self.instance.updated(old_entry, Some(new_entry)); syncer.invalidate(&tree_key[..]); } } if epidemic_propagate.len() > 0 { let self2 = self.clone(); self.system .background .spawn_cancellable(async move { self2.insert_many(&epidemic_propagate[..]).await }); } Ok(()) } pub(crate) fn delete_if_equal(self: &Arc, k: &[u8], v: &[u8]) -> Result { let removed = self.store.transaction(|txn| { if let Some(cur_v) = self.store.get(k)? { if cur_v == v { txn.remove(v)?; return Ok(true); } } Ok(false) })?; if removed { let old_entry = self.decode_entry(v)?; self.instance.updated(Some(old_entry), None); self.syncer.load_full().unwrap().invalidate(k); } Ok(removed) } fn tree_key(&self, p: &F::P, s: &F::S) -> Vec { let mut ret = p.hash().to_vec(); ret.extend(s.sort_key()); ret } fn decode_entry(&self, bytes: &[u8]) -> Result { 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()) } }, } } }