6 files changed, 468 insertions, 0 deletions
diff --git a/src/util/Cargo.toml b/src/util/Cargo.toml
new file mode 100644
index 00000000..6f61a586
--- /dev/null
+++ b/src/util/Cargo.toml
@@ -0,0 +1,35 @@
+[package]
+name = "garage_util"
+version = "0.1.0"
+authors = ["Alex Auvolat <alex@adnab.me>"]
+edition = "2018"
+
+[lib]
+path = "lib.rs"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+rand = "0.7"
+hex = "0.3"
+sha2 = "0.8"
+err-derive = "0.2.3"
+log = "0.4"
+
+sled = "0.31"
+
+toml = "0.5"
+rmp-serde = "0.14.3"
+serde = { version = "1.0", default-features = false, features = ["derive", "rc"] }
+serde_json = "1.0"
+
+futures = "0.3"
+futures-util = "0.3"
+tokio = { version = "0.2", default-features = false, features = ["rt-core", "rt-threaded", "io-driver", "net", "tcp", "time", "macros", "sync", "signal", "fs"] }
+
+http = "0.2"
+hyper = "0.13"
+rustls = "0.17"
+webpki = "0.21"
+
+
diff --git a/src/util/background.rs b/src/util/background.rs
new file mode 100644
index 00000000..937062dd
--- /dev/null
+++ b/src/util/background.rs
@@ -0,0 +1,124 @@
+use core::future::Future;
+use std::pin::Pin;
+
+use futures::future::join_all;
+use futures::select;
+use futures_util::future::*;
+use std::sync::Arc;
+use tokio::sync::Mutex;
+use tokio::sync::{mpsc, watch, Notify};
+
+use crate::error::Error;
+
+type JobOutput = Result<(), Error>;
+type Job = Pin<Box<dyn Future<Output = JobOutput> + Send>>;
+
+pub struct BackgroundRunner {
+	n_runners: usize,
+	pub stop_signal: watch::Receiver<bool>,
+
+	queue_in: mpsc::UnboundedSender<(Job, bool)>,
+	queue_out: Mutex<mpsc::UnboundedReceiver<(Job, bool)>>,
+	job_notify: Notify,
+
+	workers: Mutex<Vec<tokio::task::JoinHandle<()>>>,
+}
+
+impl BackgroundRunner {
+	pub fn new(n_runners: usize, stop_signal: watch::Receiver<bool>) -> Arc<Self> {
+		let (queue_in, queue_out) = mpsc::unbounded_channel();
+		Arc::new(Self {
+			n_runners,
+			stop_signal,
+			queue_in,
+			queue_out: Mutex::new(queue_out),
+			job_notify: Notify::new(),
+			workers: Mutex::new(Vec::new()),
+		})
+	}
+
+	pub async fn run(self: Arc<Self>) {
+		let mut workers = self.workers.lock().await;
+		for i in 0..self.n_runners {
+			workers.push(tokio::spawn(self.clone().runner(i)));
+		}
+		drop(workers);
+
+		let mut stop_signal = self.stop_signal.clone();
+		while let Some(exit_now) = stop_signal.recv().await {
+			if exit_now {
+				let mut workers = self.workers.lock().await;
+				let workers_vec = workers.drain(..).collect::<Vec<_>>();
+				join_all(workers_vec).await;
+				return;
+			}
+		}
+	}
+
+	pub fn spawn<T>(&self, job: T)
+	where
+		T: Future<Output = JobOutput> + Send + 'static,
+	{
+		let boxed: Job = Box::pin(job);
+		let _: Result<_, _> = self.queue_in.clone().send((boxed, false));
+		self.job_notify.notify();
+	}
+
+	pub fn spawn_cancellable<T>(&self, job: T)
+	where
+		T: Future<Output = JobOutput> + Send + 'static,
+	{
+		let boxed: Job = Box::pin(job);
+		let _: Result<_, _> = self.queue_in.clone().send((boxed, true));
+		self.job_notify.notify();
+	}
+
+	pub async fn spawn_worker<F, T>(&self, name: String, worker: F)
+	where
+		F: FnOnce(watch::Receiver<bool>) -> T + Send + 'static,
+		T: Future<Output = JobOutput> + Send + 'static,
+	{
+		let mut workers = self.workers.lock().await;
+		let stop_signal = self.stop_signal.clone();
+		workers.push(tokio::spawn(async move {
+			if let Err(e) = worker(stop_signal).await {
+				error!("Worker stopped with error: {}, error: {}", name, e);
+			} else {
+				info!("Worker exited successfully: {}", name);
+			}
+		}));
+	}
+
+	async fn runner(self: Arc<Self>, i: usize) {
+		let mut stop_signal = self.stop_signal.clone();
+		loop {
+			let must_exit: bool = *stop_signal.borrow();
+			if let Some(job) = self.dequeue_job(must_exit).await {
+				if let Err(e) = job.await {
+					error!("Job failed: {}", e)
+				}
+			} else {
+				if must_exit {
+					info!("Background runner {} exiting", i);
+					return;
+				}
+				select! {
+					_ = self.job_notify.notified().fuse() => (),
+					_ = stop_signal.recv().fuse() => (),
+				}
+			}
+		}
+	}
+
+	async fn dequeue_job(&self, must_exit: bool) -> Option<Job> {
+		let mut queue = self.queue_out.lock().await;
+		while let Ok((job, cancellable)) = queue.try_recv() {
+			if cancellable && must_exit {
+				continue;
+			} else {
+				return Some(job);
+			}
+		}
+		None
+	}
+}
diff --git a/src/util/config.rs b/src/util/config.rs
new file mode 100644
index 00000000..cb871562
--- /dev/null
+++ b/src/util/config.rs
@@ -0,0 +1,66 @@
+use std::io::Read;
+use std::net::SocketAddr;
+use std::path::PathBuf;
+
+use serde::Deserialize;
+
+use crate::error::Error;
+
+#[derive(Deserialize, Debug, Clone)]
+pub struct Config {
+	pub metadata_dir: PathBuf,
+	pub data_dir: PathBuf,
+
+	pub api_bind_addr: SocketAddr,
+	pub rpc_bind_addr: SocketAddr,
+
+	pub bootstrap_peers: Vec<SocketAddr>,
+
+	#[serde(default = "default_max_concurrent_rpc_requests")]
+	pub max_concurrent_rpc_requests: usize,
+
+	#[serde(default = "default_block_size")]
+	pub block_size: usize,
+
+	#[serde(default = "default_replication_factor")]
+	pub meta_replication_factor: usize,
+
+	#[serde(default = "default_epidemic_factor")]
+	pub meta_epidemic_factor: usize,
+
+	#[serde(default = "default_replication_factor")]
+	pub data_replication_factor: usize,
+
+	pub rpc_tls: Option<TlsConfig>,
+}
+
+#[derive(Deserialize, Debug, Clone)]
+pub struct TlsConfig {
+	pub ca_cert: String,
+	pub node_cert: String,
+	pub node_key: String,
+}
+
+fn default_max_concurrent_rpc_requests() -> usize {
+	12
+}
+fn default_block_size() -> usize {
+	1048576
+}
+fn default_replication_factor() -> usize {
+	3
+}
+fn default_epidemic_factor() -> usize {
+	3
+}
+
+pub fn read_config(config_file: PathBuf) -> Result<Config, Error> {
+	let mut file = std::fs::OpenOptions::new()
+		.read(true)
+		.open(config_file.as_path())?;
+
+	let mut config = String::new();
+	file.read_to_string(&mut config)?;
+
+	Ok(toml::from_str(&config)?)
+}
diff --git a/src/util/data.rs b/src/util/data.rs
new file mode 100644
index 00000000..8f976f71
--- /dev/null
+++ b/src/util/data.rs
@@ -0,0 +1,124 @@
+use rand::Rng;
+use serde::de::{self, Visitor};
+use serde::{Deserialize, Deserializer, Serialize, Serializer};
+use sha2::{Digest, Sha256};
+use std::fmt;
+use std::time::{SystemTime, UNIX_EPOCH};
+
+#[derive(Default, PartialOrd, Ord, Clone, Hash, PartialEq, Copy)]
+pub struct FixedBytes32([u8; 32]);
+
+impl From<[u8; 32]> for FixedBytes32 {
+	fn from(x: [u8; 32]) -> FixedBytes32 {
+		FixedBytes32(x)
+	}
+}
+
+impl std::convert::AsRef<[u8]> for FixedBytes32 {
+	fn as_ref(&self) -> &[u8] {
+		&self.0[..]
+	}
+}
+
+impl Eq for FixedBytes32 {}
+
+impl fmt::Debug for FixedBytes32 {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+		write!(f, "{}…", hex::encode(&self.0[..8]))
+	}
+}
+
+struct FixedBytes32Visitor;
+impl<'de> Visitor<'de> for FixedBytes32Visitor {
+	type Value = FixedBytes32;
+
+	fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+		formatter.write_str("a byte slice of size 32")
+	}
+
+	fn visit_bytes<E: de::Error>(self, value: &[u8]) -> Result<Self::Value, E> {
+		if value.len() == 32 {
+			let mut res = [0u8; 32];
+			res.copy_from_slice(value);
+			Ok(res.into())
+		} else {
+			Err(E::custom(format!(
+				"Invalid byte string length {}, expected 32",
+				value.len()
+			)))
+		}
+	}
+}
+
+impl<'de> Deserialize<'de> for FixedBytes32 {
+	fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<FixedBytes32, D::Error> {
+		deserializer.deserialize_bytes(FixedBytes32Visitor)
+	}
+}
+
+impl Serialize for FixedBytes32 {
+	fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+		serializer.serialize_bytes(&self.0[..])
+	}
+}
+
+impl FixedBytes32 {
+	pub fn as_slice(&self) -> &[u8] {
+		&self.0[..]
+	}
+	pub fn as_slice_mut(&mut self) -> &mut [u8] {
+		&mut self.0[..]
+	}
+	pub fn to_vec(&self) -> Vec<u8> {
+		self.0.to_vec()
+	}
+}
+
+pub type UUID = FixedBytes32;
+pub type Hash = FixedBytes32;
+
+pub fn hash(data: &[u8]) -> Hash {
+	let mut hasher = Sha256::new();
+	hasher.input(data);
+	let mut hash = [0u8; 32];
+	hash.copy_from_slice(&hasher.result()[..]);
+	hash.into()
+}
+
+pub fn gen_uuid() -> UUID {
+	rand::thread_rng().gen::<[u8; 32]>().into()
+}
+
+pub fn now_msec() -> u64 {
+	SystemTime::now()
+		.duration_since(UNIX_EPOCH)
+		.expect("Fix your clock :o")
+		.as_millis() as u64
+}
+
+// RMP serialization with names of fields and variants
+
+pub fn rmp_to_vec_all_named<T>(val: &T) -> Result<Vec<u8>, rmp_serde::encode::Error>
+where
+	T: Serialize + ?Sized,
+{
+	let mut wr = Vec::with_capacity(128);
+	let mut se = rmp_serde::Serializer::new(&mut wr)
+		.with_struct_map()
+		.with_string_variants();
+	val.serialize(&mut se)?;
+	Ok(wr)
+}
+
+pub fn debug_serialize<T: Serialize>(x: T) -> String {
+	match serde_json::to_string(&x) {
+		Ok(ss) => {
+			if ss.len() > 100 {
+				ss[..100].to_string()
+			} else {
+				ss
+			}
+		}
+		Err(e) => format!("<JSON serialization error: {}>", e),
+	}
+}
diff --git a/src/util/error.rs b/src/util/error.rs
new file mode 100644
index 00000000..f73d6915
--- /dev/null
+++ b/src/util/error.rs
@@ -0,0 +1,112 @@
+use err_derive::Error;
+use hyper::StatusCode;
+use std::io;
+
+use crate::data::*;
+
+#[derive(Debug, Error)]
+pub enum RPCError {
+	#[error(display = "Node is down: {:?}.", _0)]
+	NodeDown(UUID),
+	#[error(display = "Timeout: {}", _0)]
+	Timeout(#[error(source)] tokio::time::Elapsed),
+	#[error(display = "HTTP error: {}", _0)]
+	HTTP(#[error(source)] http::Error),
+	#[error(display = "Hyper error: {}", _0)]
+	Hyper(#[error(source)] hyper::Error),
+	#[error(display = "Messagepack encode error: {}", _0)]
+	RMPEncode(#[error(source)] rmp_serde::encode::Error),
+	#[error(display = "Messagepack decode error: {}", _0)]
+	RMPDecode(#[error(source)] rmp_serde::decode::Error),
+	#[error(display = "Too many errors: {:?}", _0)]
+	TooManyErrors(Vec<String>),
+}
+
+#[derive(Debug, Error)]
+pub enum Error {
+	#[error(display = "IO error: {}", _0)]
+	Io(#[error(source)] io::Error),
+
+	#[error(display = "Hyper error: {}", _0)]
+	Hyper(#[error(source)] hyper::Error),
+
+	#[error(display = "HTTP error: {}", _0)]
+	HTTP(#[error(source)] http::Error),
+
+	#[error(display = "Invalid HTTP header value: {}", _0)]
+	HTTPHeader(#[error(source)] http::header::ToStrError),
+
+	#[error(display = "TLS error: {}", _0)]
+	TLS(#[error(source)] rustls::TLSError),
+
+	#[error(display = "PKI error: {}", _0)]
+	PKI(#[error(source)] webpki::Error),
+
+	#[error(display = "Sled error: {}", _0)]
+	Sled(#[error(source)] sled::Error),
+
+	#[error(display = "Messagepack encode error: {}", _0)]
+	RMPEncode(#[error(source)] rmp_serde::encode::Error),
+	#[error(display = "Messagepack decode error: {}", _0)]
+	RMPDecode(#[error(source)] rmp_serde::decode::Error),
+	#[error(display = "JSON error: {}", _0)]
+	JSON(#[error(source)] serde_json::error::Error),
+	#[error(display = "TOML decode error: {}", _0)]
+	TomlDecode(#[error(source)] toml::de::Error),
+
+	#[error(display = "Timeout: {}", _0)]
+	RPCTimeout(#[error(source)] tokio::time::Elapsed),
+
+	#[error(display = "Tokio join error: {}", _0)]
+	TokioJoin(#[error(source)] tokio::task::JoinError),
+
+	#[error(display = "RPC call error: {}", _0)]
+	RPC(#[error(source)] RPCError),
+
+	#[error(display = "Remote error: {} (status code {})", _0, _1)]
+	RemoteError(String, StatusCode),
+
+	#[error(display = "Bad request: {}", _0)]
+	BadRequest(String),
+
+	#[error(display = "Not found")]
+	NotFound,
+
+	#[error(display = "Corrupt data: does not match hash {:?}", _0)]
+	CorruptData(Hash),
+
+	#[error(display = "{}", _0)]
+	Message(String),
+}
+
+impl Error {
+	pub fn http_status_code(&self) -> StatusCode {
+		match self {
+			Error::BadRequest(_) => StatusCode::BAD_REQUEST,
+			Error::NotFound => StatusCode::NOT_FOUND,
+			Error::RPC(_) => StatusCode::SERVICE_UNAVAILABLE,
+			_ => StatusCode::INTERNAL_SERVER_ERROR,
+		}
+	}
+}
+
+impl From<sled::TransactionError<Error>> for Error {
+	fn from(e: sled::TransactionError<Error>) -> Error {
+		match e {
+			sled::TransactionError::Abort(x) => x,
+			sled::TransactionError::Storage(x) => Error::Sled(x),
+		}
+	}
+}
+
+impl<T> From<tokio::sync::watch::error::SendError<T>> for Error {
+	fn from(_e: tokio::sync::watch::error::SendError<T>) -> Error {
+		Error::Message(format!("Watch send error"))
+	}
+}
+
+impl<T> From<tokio::sync::mpsc::error::SendError<T>> for Error {
+	fn from(_e: tokio::sync::mpsc::error::SendError<T>) -> Error {
+		Error::Message(format!("MPSC send error"))
+	}
+}
diff --git a/src/util/lib.rs b/src/util/lib.rs
new file mode 100644
index 00000000..0bf09bf6
--- /dev/null
+++ b/src/util/lib.rs
@@ -0,0 +1,7 @@
+#[macro_use]
+extern crate log;
+
+pub mod background;
+pub mod config;
+pub mod data;
+pub mod error;