Reorganize code

6 files changed, 890 insertions, 0 deletions

diff --git a/src/store/block.rs b/src/store/block.rs
new file mode 100644
index 00000000..e2ef32e0
--- /dev/null
+++ b/src/store/block.rs
@@ -0,0 +1,506 @@
+use std::path::PathBuf;
+use std::sync::Arc;
+use std::time::Duration;
+
+use arc_swap::ArcSwapOption;
+use futures::future::*;
+use futures::select;
+use futures::stream::*;
+use serde::{Deserialize, Serialize};
+use tokio::fs;
+use tokio::prelude::*;
+use tokio::sync::{watch, Mutex, Notify};
+
+use crate::data;
+use crate::data::*;
+use crate::error::Error;
+
+use crate::rpc::membership::System;
+use crate::rpc::rpc_client::*;
+use crate::rpc::rpc_server::*;
+
+use crate::table::table_sharded::TableShardedReplication;
+use crate::table::TableReplication;
+
+use crate::store::block_ref_table::*;
+
+use crate::server::Garage;
+
+pub const INLINE_THRESHOLD: usize = 3072;
+
+const BLOCK_RW_TIMEOUT: Duration = Duration::from_secs(42);
+const NEED_BLOCK_QUERY_TIMEOUT: Duration = Duration::from_secs(5);
+const RESYNC_RETRY_TIMEOUT: Duration = Duration::from_secs(10);
+
+#[derive(Debug, Serialize, Deserialize)]
+pub enum Message {
+	Ok,
+	GetBlock(Hash),
+	PutBlock(PutBlockMessage),
+	NeedBlockQuery(Hash),
+	NeedBlockReply(bool),
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct PutBlockMessage {
+	pub hash: Hash,
+
+	#[serde(with = "serde_bytes")]
+	pub data: Vec<u8>,
+}
+
+impl RpcMessage for Message {}
+
+pub struct BlockManager {
+	pub replication: TableShardedReplication,
+	pub data_dir: PathBuf,
+	pub data_dir_lock: Mutex<()>,
+
+	pub rc: sled::Tree,
+
+	pub resync_queue: sled::Tree,
+	pub resync_notify: Notify,
+
+	pub system: Arc<System>,
+	rpc_client: Arc<RpcClient<Message>>,
+	pub garage: ArcSwapOption<Garage>,
+}
+
+impl BlockManager {
+	pub fn new(
+		db: &sled::Db,
+		data_dir: PathBuf,
+		replication: TableShardedReplication,
+		system: Arc<System>,
+		rpc_server: &mut RpcServer,
+	) -> Arc<Self> {
+		let rc = db
+			.open_tree("block_local_rc")
+			.expect("Unable to open block_local_rc tree");
+		rc.set_merge_operator(rc_merge);
+
+		let resync_queue = db
+			.open_tree("block_local_resync_queue")
+			.expect("Unable to open block_local_resync_queue tree");
+
+		let rpc_path = "block_manager";
+		let rpc_client = system.rpc_client::<Message>(rpc_path);
+
+		let block_manager = Arc::new(Self {
+			replication,
+			data_dir,
+			data_dir_lock: Mutex::new(()),
+			rc,
+			resync_queue,
+			resync_notify: Notify::new(),
+			system,
+			rpc_client,
+			garage: ArcSwapOption::from(None),
+		});
+		block_manager
+			.clone()
+			.register_handler(rpc_server, rpc_path.into());
+		block_manager
+	}
+
+	fn register_handler(self: Arc<Self>, rpc_server: &mut RpcServer, path: String) {
+		let self2 = self.clone();
+		rpc_server.add_handler::<Message, _, _>(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<Self>, msg: &Message) -> Result<Message, Error> {
+		match msg {
+			Message::PutBlock(m) => self.write_block(&m.hash, &m.data).await,
+			Message::GetBlock(h) => self.read_block(h).await,
+			Message::NeedBlockQuery(h) => self.need_block(h).await.map(Message::NeedBlockReply),
+			_ => Err(Error::BadRequest(format!("Unexpected RPC message"))),
+		}
+	}
+
+	pub async fn spawn_background_worker(self: Arc<Self>) {
+		// Launch 2 simultaneous workers for background resync loop preprocessing
+		for i in 0..2usize {
+			let bm2 = self.clone();
+			let background = self.system.background.clone();
+			tokio::spawn(async move {
+				tokio::time::delay_for(Duration::from_secs(10)).await;
+				background
+					.spawn_worker(format!("block resync worker {}", i), move |must_exit| {
+						bm2.resync_loop(must_exit)
+					})
+					.await;
+			});
+		}
+	}
+
+	pub async fn write_block(&self, hash: &Hash, data: &[u8]) -> Result<Message, Error> {
+		let _lock = self.data_dir_lock.lock().await;
+
+		let mut path = self.block_dir(hash);
+		fs::create_dir_all(&path).await?;
+
+		path.push(hex::encode(hash));
+		if fs::metadata(&path).await.is_ok() {
+			return Ok(Message::Ok);
+		}
+
+		let mut f = fs::File::create(path).await?;
+		f.write_all(data).await?;
+		drop(f);
+
+		Ok(Message::Ok)
+	}
+
+	pub async fn read_block(&self, hash: &Hash) -> Result<Message, Error> {
+		let path = self.block_path(hash);
+
+		let mut f = match fs::File::open(&path).await {
+			Ok(f) => f,
+			Err(e) => {
+				// Not found but maybe we should have had it ??
+				self.put_to_resync(hash, 0)?;
+				return Err(Into::into(e));
+			}
+		};
+		let mut data = vec![];
+		f.read_to_end(&mut data).await?;
+		drop(f);
+
+		if data::hash(&data[..]) != *hash {
+			let _lock = self.data_dir_lock.lock().await;
+			warn!("Block {:?} is corrupted. Deleting and resyncing.", hash);
+			fs::remove_file(path).await?;
+			self.put_to_resync(&hash, 0)?;
+			return Err(Error::CorruptData(*hash));
+		}
+
+		Ok(Message::PutBlock(PutBlockMessage { hash: *hash, data }))
+	}
+
+	pub async fn need_block(&self, hash: &Hash) -> Result<bool, Error> {
+		let needed = self
+			.rc
+			.get(hash.as_ref())?
+			.map(|x| u64_from_bytes(x.as_ref()) > 0)
+			.unwrap_or(false);
+		if needed {
+			let path = self.block_path(hash);
+			let exists = fs::metadata(&path).await.is_ok();
+			Ok(!exists)
+		} else {
+			Ok(false)
+		}
+	}
+
+	fn block_dir(&self, hash: &Hash) -> PathBuf {
+		let mut path = self.data_dir.clone();
+		path.push(hex::encode(&hash.as_slice()[0..1]));
+		path.push(hex::encode(&hash.as_slice()[1..2]));
+		path
+	}
+	fn block_path(&self, hash: &Hash) -> PathBuf {
+		let mut path = self.block_dir(hash);
+		path.push(hex::encode(hash.as_ref()));
+		path
+	}
+
+	pub fn block_incref(&self, hash: &Hash) -> Result<(), Error> {
+		let old_rc = self.rc.get(&hash)?;
+		self.rc.merge(&hash, vec![1])?;
+		if old_rc.map(|x| u64_from_bytes(&x[..]) == 0).unwrap_or(true) {
+			self.put_to_resync(&hash, BLOCK_RW_TIMEOUT.as_millis() as u64)?;
+		}
+		Ok(())
+	}
+
+	pub fn block_decref(&self, hash: &Hash) -> Result<(), Error> {
+		let new_rc = self.rc.merge(&hash, vec![0])?;
+		if new_rc.map(|x| u64_from_bytes(&x[..]) == 0).unwrap_or(true) {
+			self.put_to_resync(&hash, 0)?;
+		}
+		Ok(())
+	}
+
+	fn put_to_resync(&self, hash: &Hash, delay_millis: u64) -> Result<(), Error> {
+		let when = now_msec() + delay_millis;
+		trace!("Put resync_queue: {} {:?}", when, hash);
+		let mut key = u64::to_be_bytes(when).to_vec();
+		key.extend(hash.as_ref());
+		self.resync_queue.insert(key, hash.as_ref())?;
+		self.resync_notify.notify();
+		Ok(())
+	}
+
+	async fn resync_loop(
+		self: Arc<Self>,
+		mut must_exit: watch::Receiver<bool>,
+	) -> Result<(), Error> {
+		let mut n_failures = 0usize;
+		while !*must_exit.borrow() {
+			if let Some((time_bytes, hash_bytes)) = self.resync_queue.pop_min()? {
+				let time_msec = u64_from_bytes(&time_bytes[0..8]);
+				let now = now_msec();
+				if now >= time_msec {
+					let mut hash = [0u8; 32];
+					hash.copy_from_slice(hash_bytes.as_ref());
+					let hash = Hash::from(hash);
+
+					if let Err(e) = self.resync_iter(&hash).await {
+						warn!("Failed to resync block {:?}, retrying later: {}", hash, e);
+						self.put_to_resync(&hash, RESYNC_RETRY_TIMEOUT.as_millis() as u64)?;
+						n_failures += 1;
+						if n_failures >= 10 {
+							warn!("Too many resync failures, throttling.");
+							tokio::time::delay_for(Duration::from_secs(1)).await;
+						}
+					} else {
+						n_failures = 0;
+					}
+				} else {
+					self.resync_queue.insert(time_bytes, hash_bytes)?;
+					let delay = tokio::time::delay_for(Duration::from_millis(time_msec - now));
+					select! {
+						_ = delay.fuse() => (),
+						_ = self.resync_notify.notified().fuse() => (),
+						_ = must_exit.recv().fuse() => (),
+					}
+				}
+			} else {
+				select! {
+					_ = self.resync_notify.notified().fuse() => (),
+					_ = must_exit.recv().fuse() => (),
+				}
+			}
+		}
+		Ok(())
+	}
+
+	async fn resync_iter(&self, hash: &Hash) -> Result<(), Error> {
+		let path = self.block_path(hash);
+
+		let exists = fs::metadata(&path).await.is_ok();
+		let needed = self
+			.rc
+			.get(hash.as_ref())?
+			.map(|x| u64_from_bytes(x.as_ref()) > 0)
+			.unwrap_or(false);
+
+		if exists != needed {
+			info!(
+				"Resync block {:?}: exists {}, needed {}",
+				hash, exists, needed
+			);
+		}
+
+		if exists && !needed {
+			let garage = self.garage.load_full().unwrap();
+			let active_refs = garage
+				.block_ref_table
+				.get_range(&hash, None, Some(()), 1)
+				.await?;
+			let needed_by_others = !active_refs.is_empty();
+			if needed_by_others {
+				let ring = self.system.ring.borrow().clone();
+				let who = self.replication.replication_nodes(&hash, &ring);
+				let msg = Arc::new(Message::NeedBlockQuery(*hash));
+				let who_needs_fut = who.iter().map(|to| {
+					self.rpc_client
+						.call_arc(*to, msg.clone(), NEED_BLOCK_QUERY_TIMEOUT)
+				});
+				let who_needs = join_all(who_needs_fut).await;
+
+				let mut need_nodes = vec![];
+				for (node, needed) in who.into_iter().zip(who_needs.iter()) {
+					match needed {
+						Ok(Message::NeedBlockReply(needed)) => {
+							if *needed {
+								need_nodes.push(node);
+							}
+						}
+						Err(e) => {
+							return Err(Error::Message(format!(
+								"Should delete block, but unable to confirm that all other nodes that need it have it: {}",
+								e
+							)));
+						}
+						Ok(_) => {
+							return Err(Error::Message(format!(
+								"Unexpected response to NeedBlockQuery RPC"
+							)));
+						}
+					}
+				}
+
+				if need_nodes.len() > 0 {
+					let put_block_message = self.read_block(hash).await?;
+					self.rpc_client
+						.try_call_many(
+							&need_nodes[..],
+							put_block_message,
+							RequestStrategy::with_quorum(need_nodes.len())
+								.with_timeout(BLOCK_RW_TIMEOUT),
+						)
+						.await?;
+				}
+			}
+			fs::remove_file(path).await?;
+			self.resync_queue.remove(&hash)?;
+		}
+
+		if needed && !exists {
+			// TODO find a way to not do this if they are sending it to us
+			// Let's suppose this isn't an issue for now with the BLOCK_RW_TIMEOUT delay
+			// between the RC being incremented and this part being called.
+			let block_data = self.rpc_get_block(&hash).await?;
+			self.write_block(hash, &block_data[..]).await?;
+		}
+
+		Ok(())
+	}
+
+	pub async fn rpc_get_block(&self, hash: &Hash) -> Result<Vec<u8>, Error> {
+		let who = self.replication.read_nodes(&hash, &self.system);
+		let resps = self
+			.rpc_client
+			.try_call_many(
+				&who[..],
+				Message::GetBlock(*hash),
+				RequestStrategy::with_quorum(1)
+					.with_timeout(BLOCK_RW_TIMEOUT)
+					.interrupt_after_quorum(true),
+			)
+			.await?;
+
+		for resp in resps {
+			if let Message::PutBlock(msg) = resp {
+				return Ok(msg.data);
+			}
+		}
+		Err(Error::Message(format!(
+			"Unable to read block {:?}: no valid blocks returned",
+			hash
+		)))
+	}
+
+	pub async fn rpc_put_block(&self, hash: Hash, data: Vec<u8>) -> Result<(), Error> {
+		let who = self.replication.write_nodes(&hash, &self.system);
+		self.rpc_client
+			.try_call_many(
+				&who[..],
+				Message::PutBlock(PutBlockMessage { hash, data }),
+				RequestStrategy::with_quorum(self.replication.write_quorum())
+					.with_timeout(BLOCK_RW_TIMEOUT),
+			)
+			.await?;
+		Ok(())
+	}
+
+	pub async fn repair_data_store(&self, must_exit: &watch::Receiver<bool>) -> Result<(), Error> {
+		// 1. Repair blocks from RC table
+		let garage = self.garage.load_full().unwrap();
+		let mut last_hash = None;
+		let mut i = 0usize;
+		for entry in garage.block_ref_table.store.iter() {
+			let (_k, v_bytes) = entry?;
+			let block_ref = rmp_serde::decode::from_read_ref::<_, BlockRef>(v_bytes.as_ref())?;
+			if Some(&block_ref.block) == last_hash.as_ref() {
+				continue;
+			}
+			if !block_ref.deleted {
+				last_hash = Some(block_ref.block);
+				self.put_to_resync(&block_ref.block, 0)?;
+			}
+			i += 1;
+			if i & 0xFF == 0 && *must_exit.borrow() {
+				return Ok(());
+			}
+		}
+
+		// 2. Repair blocks actually on disk
+		let mut ls_data_dir = fs::read_dir(&self.data_dir).await?;
+		while let Some(data_dir_ent) = ls_data_dir.next().await {
+			let data_dir_ent = data_dir_ent?;
+			let dir_name = data_dir_ent.file_name();
+			let dir_name = match dir_name.into_string() {
+				Ok(x) => x,
+				Err(_) => continue,
+			};
+			if dir_name.len() != 2 || hex::decode(&dir_name).is_err() {
+				continue;
+			}
+
+			let mut ls_data_dir_2 = match fs::read_dir(data_dir_ent.path()).await {
+				Err(e) => {
+					warn!(
+						"Warning: could not list dir {:?}: {}",
+						data_dir_ent.path().to_str(),
+						e
+					);
+					continue;
+				}
+				Ok(x) => x,
+			};
+			while let Some(file) = ls_data_dir_2.next().await {
+				let file = file?;
+				let file_name = file.file_name();
+				let file_name = match file_name.into_string() {
+					Ok(x) => x,
+					Err(_) => continue,
+				};
+				if file_name.len() != 64 {
+					continue;
+				}
+				let hash_bytes = match hex::decode(&file_name) {
+					Ok(h) => h,
+					Err(_) => continue,
+				};
+				let mut hash = [0u8; 32];
+				hash.copy_from_slice(&hash_bytes[..]);
+				self.put_to_resync(&hash.into(), 0)?;
+
+				if *must_exit.borrow() {
+					return Ok(());
+				}
+			}
+		}
+		Ok(())
+	}
+}
+
+fn u64_from_bytes(bytes: &[u8]) -> u64 {
+	assert!(bytes.len() == 8);
+	let mut x8 = [0u8; 8];
+	x8.copy_from_slice(bytes);
+	u64::from_be_bytes(x8)
+}
+
+fn rc_merge(_key: &[u8], old: Option<&[u8]>, new: &[u8]) -> Option<Vec<u8>> {
+	let old = old.map(u64_from_bytes).unwrap_or(0);
+	assert!(new.len() == 1);
+	let new = match new[0] {
+		0 => {
+			if old > 0 {
+				old - 1
+			} else {
+				0
+			}
+		}
+		1 => old + 1,
+		_ => unreachable!(),
+	};
+	if new == 0 {
+		None
+	} else {
+		Some(u64::to_be_bytes(new).to_vec())
+	}
+}
diff --git a/src/store/block_ref_table.rs b/src/store/block_ref_table.rs
new file mode 100644
index 00000000..c8a2a2a1
--- /dev/null
+++ b/src/store/block_ref_table.rs
@@ -0,0 +1,68 @@
+use async_trait::async_trait;
+use serde::{Deserialize, Serialize};
+use std::sync::Arc;
+
+use crate::background::*;
+use crate::data::*;
+use crate::error::Error;
+
+use crate::table::*;
+
+use crate::store::block::*;
+
+#[derive(PartialEq, Clone, Debug, Serialize, Deserialize)]
+pub struct BlockRef {
+	// Primary key
+	pub block: Hash,
+
+	// Sort key
+	pub version: UUID,
+
+	// Keep track of deleted status
+	pub deleted: bool,
+}
+
+impl Entry<Hash, UUID> for BlockRef {
+	fn partition_key(&self) -> &Hash {
+		&self.block
+	}
+	fn sort_key(&self) -> &UUID {
+		&self.version
+	}
+
+	fn merge(&mut self, other: &Self) {
+		if other.deleted {
+			self.deleted = true;
+		}
+	}
+}
+
+pub struct BlockRefTable {
+	pub background: Arc<BackgroundRunner>,
+	pub block_manager: Arc<BlockManager>,
+}
+
+#[async_trait]
+impl TableSchema for BlockRefTable {
+	type P = Hash;
+	type S = UUID;
+	type E = BlockRef;
+	type Filter = ();
+
+	async fn updated(&self, old: Option<Self::E>, new: Option<Self::E>) -> Result<(), Error> {
+		let block = &old.as_ref().or(new.as_ref()).unwrap().block;
+		let was_before = old.as_ref().map(|x| !x.deleted).unwrap_or(false);
+		let is_after = new.as_ref().map(|x| !x.deleted).unwrap_or(false);
+		if is_after && !was_before {
+			self.block_manager.block_incref(block)?;
+		}
+		if was_before && !is_after {
+			self.block_manager.block_decref(block)?;
+		}
+		Ok(())
+	}
+
+	fn matches_filter(entry: &Self::E, _filter: &Self::Filter) -> bool {
+		!entry.deleted
+	}
+}
diff --git a/src/store/bucket_table.rs b/src/store/bucket_table.rs
new file mode 100644
index 00000000..5604049c
--- /dev/null
+++ b/src/store/bucket_table.rs
@@ -0,0 +1,82 @@
+use async_trait::async_trait;
+use serde::{Deserialize, Serialize};
+
+use crate::error::Error;
+use crate::table::*;
+
+#[derive(PartialEq, Clone, Debug, Serialize, Deserialize)]
+pub struct Bucket {
+	// Primary key
+	pub name: String,
+
+	// Timestamp and deletion
+	// Upon version increment, all info is replaced
+	pub timestamp: u64,
+	pub deleted: bool,
+
+	// Authorized keys
+	pub authorized_keys: Vec<AllowedKey>,
+}
+
+#[derive(PartialEq, Clone, Debug, Serialize, Deserialize)]
+pub struct AllowedKey {
+	pub access_key_id: String,
+	pub timestamp: u64,
+	pub allowed_read: bool,
+	pub allowed_write: bool,
+}
+
+impl Entry<EmptyKey, String> for Bucket {
+	fn partition_key(&self) -> &EmptyKey {
+		&EmptyKey
+	}
+	fn sort_key(&self) -> &String {
+		&self.name
+	}
+
+	fn merge(&mut self, other: &Self) {
+		if other.timestamp < self.timestamp {
+			*self = other.clone();
+			return;
+		}
+		if self.timestamp > other.timestamp {
+			return;
+		}
+		for ak in other.authorized_keys.iter() {
+			match self
+				.authorized_keys
+				.binary_search_by(|our_ak| our_ak.access_key_id.cmp(&ak.access_key_id))
+			{
+				Ok(i) => {
+					let our_ak = &mut self.authorized_keys[i];
+					if ak.timestamp > our_ak.timestamp {
+						our_ak.timestamp = ak.timestamp;
+						our_ak.allowed_read = ak.allowed_read;
+						our_ak.allowed_write = ak.allowed_write;
+					}
+				}
+				Err(i) => {
+					self.authorized_keys.insert(i, ak.clone());
+				}
+			}
+		}
+	}
+}
+
+pub struct BucketTable;
+
+#[async_trait]
+impl TableSchema for BucketTable {
+	type P = EmptyKey;
+	type S = String;
+	type E = Bucket;
+	type Filter = ();
+
+	async fn updated(&self, _old: Option<Self::E>, _new: Option<Self::E>) -> Result<(), Error> {
+		Ok(())
+	}
+
+	fn matches_filter(entry: &Self::E, _filter: &Self::Filter) -> bool {
+		!entry.deleted
+	}
+}
diff --git a/src/store/mod.rs b/src/store/mod.rs
new file mode 100644
index 00000000..afadc9bb
--- /dev/null
+++ b/src/store/mod.rs
@@ -0,0 +1,5 @@
+pub mod block;
+pub mod block_ref_table;
+pub mod bucket_table;
+pub mod object_table;
+pub mod version_table;
diff --git a/src/store/object_table.rs b/src/store/object_table.rs
new file mode 100644
index 00000000..97de0cdb
--- /dev/null
+++ b/src/store/object_table.rs
@@ -0,0 +1,134 @@
+use async_trait::async_trait;
+use serde::{Deserialize, Serialize};
+use std::sync::Arc;
+
+use crate::background::BackgroundRunner;
+use crate::data::*;
+use crate::error::Error;
+
+use crate::table::table_sharded::*;
+use crate::table::*;
+
+use crate::store::version_table::*;
+
+#[derive(PartialEq, Clone, Debug, Serialize, Deserialize)]
+pub struct Object {
+	// Primary key
+	pub bucket: String,
+
+	// Sort key
+	pub key: String,
+
+	// Data
+	pub versions: Vec<Box<ObjectVersion>>,
+}
+
+#[derive(PartialEq, Clone, Debug, Serialize, Deserialize)]
+pub struct ObjectVersion {
+	pub uuid: UUID,
+	pub timestamp: u64,
+
+	pub mime_type: String,
+	pub size: u64,
+	pub is_complete: bool,
+
+	pub data: ObjectVersionData,
+}
+
+#[derive(PartialEq, Clone, Debug, Serialize, Deserialize)]
+pub enum ObjectVersionData {
+	DeleteMarker,
+	Inline(#[serde(with = "serde_bytes")] Vec<u8>),
+	FirstBlock(Hash),
+}
+
+impl ObjectVersion {
+	fn cmp_key(&self) -> (u64, &UUID) {
+		(self.timestamp, &self.uuid)
+	}
+}
+
+impl Entry<String, String> for Object {
+	fn partition_key(&self) -> &String {
+		&self.bucket
+	}
+	fn sort_key(&self) -> &String {
+		&self.key
+	}
+
+	fn merge(&mut self, other: &Self) {
+		for other_v in other.versions.iter() {
+			match self
+				.versions
+				.binary_search_by(|v| v.cmp_key().cmp(&other_v.cmp_key()))
+			{
+				Ok(i) => {
+					let mut v = &mut self.versions[i];
+					if other_v.size > v.size {
+						v.size = other_v.size;
+					}
+					if other_v.is_complete && !v.is_complete {
+						v.is_complete = true;
+					}
+				}
+				Err(i) => {
+					self.versions.insert(i, other_v.clone());
+				}
+			}
+		}
+		let last_complete = self
+			.versions
+			.iter()
+			.enumerate()
+			.rev()
+			.filter(|(_, v)| v.is_complete)
+			.next()
+			.map(|(vi, _)| vi);
+
+		if let Some(last_vi) = last_complete {
+			self.versions = self.versions.drain(last_vi..).collect::<Vec<_>>();
+		}
+	}
+}
+
+pub struct ObjectTable {
+	pub background: Arc<BackgroundRunner>,
+	pub version_table: Arc<Table<VersionTable, TableShardedReplication>>,
+}
+
+#[async_trait]
+impl TableSchema for ObjectTable {
+	type P = String;
+	type S = String;
+	type E = Object;
+	type Filter = ();
+
+	async fn updated(&self, old: Option<Self::E>, new: Option<Self::E>) -> Result<(), Error> {
+		let version_table = self.version_table.clone();
+		if let (Some(old_v), Some(new_v)) = (old, new) {
+			// Propagate deletion of old versions
+			for v in old_v.versions.iter() {
+				if new_v
+					.versions
+					.binary_search_by(|nv| nv.cmp_key().cmp(&v.cmp_key()))
+					.is_err()
+				{
+					let deleted_version = Version {
+						uuid: v.uuid,
+						deleted: true,
+						blocks: vec![],
+						bucket: old_v.bucket.clone(),
+						key: old_v.key.clone(),
+					};
+					version_table.insert(&deleted_version).await?;
+				}
+			}
+		}
+		Ok(())
+	}
+
+	fn matches_filter(_entry: &Self::E, _filter: &Self::Filter) -> bool {
+		// TODO
+		true
+	}
+}
diff --git a/src/store/version_table.rs b/src/store/version_table.rs
new file mode 100644
index 00000000..d25a56ca
--- /dev/null
+++ b/src/store/version_table.rs
@@ -0,0 +1,95 @@
+use async_trait::async_trait;
+use serde::{Deserialize, Serialize};
+use std::sync::Arc;
+
+use crate::background::BackgroundRunner;
+use crate::data::*;
+use crate::error::Error;
+
+use crate::table::table_sharded::*;
+use crate::table::*;
+
+use crate::store::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,
+	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, 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.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, 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
+	}
+}