commit
a2fa60fa31
|
@ -1,44 +1,44 @@
|
|||
//! The `historian` crate provides a microservice for generating a Proof-of-History.
|
||||
//! It logs EventData items on behalf of its users. It continuously generates
|
||||
//! new hashes, only stopping to check if it has been sent an EventData item. It
|
||||
//! tags each EventData with an Event and sends it back. The Event includes the
|
||||
//! EventData, the latest hash, and the number of hashes since the last event.
|
||||
//! The resulting Event stream represents ordered events in time.
|
||||
//! It logs Event items on behalf of its users. It continuously generates
|
||||
//! new hashes, only stopping to check if it has been sent an Event item. It
|
||||
//! tags each Event with an Entry and sends it back. The Entry includes the
|
||||
//! Event, the latest hash, and the number of hashes since the last event.
|
||||
//! The resulting stream of entries represents ordered events in time.
|
||||
|
||||
use std::thread::JoinHandle;
|
||||
use std::sync::mpsc::{Receiver, Sender};
|
||||
use event::{Event, EventData};
|
||||
use log::{Entry, Event};
|
||||
|
||||
pub struct Historian {
|
||||
pub sender: Sender<EventData>,
|
||||
pub receiver: Receiver<Event>,
|
||||
pub thread_hdl: JoinHandle<(Event, EventThreadExitReason)>,
|
||||
pub sender: Sender<Event>,
|
||||
pub receiver: Receiver<Entry>,
|
||||
pub thread_hdl: JoinHandle<(Entry, ExitReason)>,
|
||||
}
|
||||
|
||||
#[derive(Debug, PartialEq, Eq)]
|
||||
pub enum EventThreadExitReason {
|
||||
pub enum ExitReason {
|
||||
RecvDisconnected,
|
||||
SendDisconnected,
|
||||
}
|
||||
|
||||
fn drain_queue(
|
||||
receiver: &Receiver<EventData>,
|
||||
sender: &Sender<Event>,
|
||||
fn log_events(
|
||||
receiver: &Receiver<Event>,
|
||||
sender: &Sender<Entry>,
|
||||
num_hashes: u64,
|
||||
end_hash: u64,
|
||||
) -> Result<u64, (Event, EventThreadExitReason)> {
|
||||
) -> Result<u64, (Entry, ExitReason)> {
|
||||
use std::sync::mpsc::TryRecvError;
|
||||
let mut num_hashes = num_hashes;
|
||||
loop {
|
||||
match receiver.try_recv() {
|
||||
Ok(data) => {
|
||||
let e = Event {
|
||||
Ok(event) => {
|
||||
let entry = Entry {
|
||||
end_hash,
|
||||
num_hashes,
|
||||
data,
|
||||
event,
|
||||
};
|
||||
if let Err(_) = sender.send(e.clone()) {
|
||||
return Err((e, EventThreadExitReason::SendDisconnected));
|
||||
if let Err(_) = sender.send(entry.clone()) {
|
||||
return Err((entry, ExitReason::SendDisconnected));
|
||||
}
|
||||
num_hashes = 0;
|
||||
}
|
||||
|
@ -46,24 +46,24 @@ fn drain_queue(
|
|||
return Ok(num_hashes);
|
||||
}
|
||||
Err(TryRecvError::Disconnected) => {
|
||||
let e = Event {
|
||||
let entry = Entry {
|
||||
end_hash,
|
||||
num_hashes,
|
||||
data: EventData::Tick,
|
||||
event: Event::Tick,
|
||||
};
|
||||
return Err((e, EventThreadExitReason::RecvDisconnected));
|
||||
return Err((entry, ExitReason::RecvDisconnected));
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// A background thread that will continue tagging received EventData messages and
|
||||
/// sending back Event messages until either the receiver or sender channel is closed.
|
||||
pub fn event_stream(
|
||||
/// A background thread that will continue tagging received Event messages and
|
||||
/// sending back Entry messages until either the receiver or sender channel is closed.
|
||||
pub fn create_logger(
|
||||
start_hash: u64,
|
||||
receiver: Receiver<EventData>,
|
||||
sender: Sender<Event>,
|
||||
) -> JoinHandle<(Event, EventThreadExitReason)> {
|
||||
receiver: Receiver<Event>,
|
||||
sender: Sender<Entry>,
|
||||
) -> JoinHandle<(Entry, ExitReason)> {
|
||||
use std::collections::hash_map::DefaultHasher;
|
||||
use std::hash::{Hash, Hasher};
|
||||
use std::thread;
|
||||
|
@ -72,9 +72,9 @@ pub fn event_stream(
|
|||
let mut hasher = DefaultHasher::new();
|
||||
let mut num_hashes = 0;
|
||||
loop {
|
||||
match drain_queue(&receiver, &sender, num_hashes, end_hash) {
|
||||
match log_events(&receiver, &sender, num_hashes, end_hash) {
|
||||
Ok(n) => num_hashes = n,
|
||||
Err(e) => return e,
|
||||
Err(err) => return err,
|
||||
}
|
||||
end_hash.hash(&mut hasher);
|
||||
end_hash = hasher.finish();
|
||||
|
@ -86,9 +86,9 @@ pub fn event_stream(
|
|||
impl Historian {
|
||||
pub fn new(start_hash: u64) -> Self {
|
||||
use std::sync::mpsc::channel;
|
||||
let (sender, event_data_receiver) = channel();
|
||||
let (event_sender, receiver) = channel();
|
||||
let thread_hdl = event_stream(start_hash, event_data_receiver, event_sender);
|
||||
let (sender, event_receiver) = channel();
|
||||
let (entry_sender, receiver) = channel();
|
||||
let thread_hdl = create_logger(start_hash, event_receiver, entry_sender);
|
||||
Historian {
|
||||
sender,
|
||||
receiver,
|
||||
|
@ -100,39 +100,39 @@ impl Historian {
|
|||
#[cfg(test)]
|
||||
mod tests {
|
||||
use super::*;
|
||||
use event::*;
|
||||
use log::*;
|
||||
|
||||
#[test]
|
||||
fn test_historian() {
|
||||
let hist = Historian::new(0);
|
||||
|
||||
let data = EventData::Tick;
|
||||
hist.sender.send(data.clone()).unwrap();
|
||||
let e0 = hist.receiver.recv().unwrap();
|
||||
assert_eq!(e0.data, data);
|
||||
let event = Event::Tick;
|
||||
hist.sender.send(event.clone()).unwrap();
|
||||
let entry0 = hist.receiver.recv().unwrap();
|
||||
assert_eq!(entry0.event, event);
|
||||
|
||||
let data = EventData::UserDataKey(0xdeadbeef);
|
||||
hist.sender.send(data.clone()).unwrap();
|
||||
let e1 = hist.receiver.recv().unwrap();
|
||||
assert_eq!(e1.data, data);
|
||||
let event = Event::UserDataKey(0xdeadbeef);
|
||||
hist.sender.send(event.clone()).unwrap();
|
||||
let entry1 = hist.receiver.recv().unwrap();
|
||||
assert_eq!(entry1.event, event);
|
||||
|
||||
drop(hist.sender);
|
||||
assert_eq!(
|
||||
hist.thread_hdl.join().unwrap().1,
|
||||
EventThreadExitReason::RecvDisconnected
|
||||
ExitReason::RecvDisconnected
|
||||
);
|
||||
|
||||
verify_slice(&[e0, e1], 0);
|
||||
verify_slice(&[entry0, entry1], 0);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_historian_closed_sender() {
|
||||
let hist = Historian::new(0);
|
||||
drop(hist.receiver);
|
||||
hist.sender.send(EventData::Tick).unwrap();
|
||||
hist.sender.send(Event::Tick).unwrap();
|
||||
assert_eq!(
|
||||
hist.thread_hdl.join().unwrap().1,
|
||||
EventThreadExitReason::SendDisconnected
|
||||
ExitReason::SendDisconnected
|
||||
);
|
||||
}
|
||||
}
|
||||
|
|
|
@ -1,5 +1,5 @@
|
|||
#![cfg_attr(feature = "unstable", feature(test))]
|
||||
pub mod event;
|
||||
pub mod log;
|
||||
pub mod historian;
|
||||
extern crate itertools;
|
||||
extern crate rayon;
|
||||
|
|
|
@ -1,10 +1,10 @@
|
|||
//! The `event` crate provides the foundational data structures for Proof-of-History
|
||||
//! The `log` crate provides the foundational data structures for Proof-of-History,
|
||||
//! an ordered log of events in time.
|
||||
|
||||
/// A Proof-of-History is an ordered log of events in time. Each entry contains three
|
||||
/// pieces of data. The 'num_hashes' field is the number of hashes performed since the previous
|
||||
/// entry. The 'end_hash' field is the result of hashing 'end_hash' from the previous entry
|
||||
/// 'num_hashes' times. The 'data' field is an optional foreign key (a hash) pointing to some
|
||||
/// arbitrary data that a client is looking to associate with the entry.
|
||||
/// Each log entry contains three pieces of data. The 'num_hashes' field is the number
|
||||
/// of hashes performed since the previous entry. The 'end_hash' field is the result
|
||||
/// of hashing 'end_hash' from the previous entry 'num_hashes' times. The 'event'
|
||||
/// field points to an Event that took place shortly after 'end_hash' was generated.
|
||||
///
|
||||
/// If you divide 'num_hashes' by the amount of time it takes to generate a new hash, you
|
||||
/// get a duration estimate since the last event. Since processing power increases
|
||||
|
@ -13,32 +13,32 @@
|
|||
/// fastest processor. Duration should therefore be estimated by assuming that the hash
|
||||
/// was generated by the fastest processor at the time the entry was logged.
|
||||
#[derive(Debug, PartialEq, Eq, Clone)]
|
||||
pub struct Event {
|
||||
pub struct Entry {
|
||||
pub num_hashes: u64,
|
||||
pub end_hash: u64,
|
||||
pub data: EventData,
|
||||
pub event: Event,
|
||||
}
|
||||
|
||||
/// When 'data' is Tick, the event represents a simple clock tick, and exists for the
|
||||
/// When 'event' is Tick, the event represents a simple clock tick, and exists for the
|
||||
/// sole purpose of improving the performance of event log verification. A tick can
|
||||
/// be generated in 'num_hashes' hashes and verified in 'num_hashes' hashes. By logging
|
||||
/// a hash alongside the tick, each tick and be verified in parallel using the 'end_hash'
|
||||
/// of the preceding tick to seed its hashing.
|
||||
#[derive(Debug, PartialEq, Eq, Clone)]
|
||||
pub enum EventData {
|
||||
pub enum Event {
|
||||
Tick,
|
||||
UserDataKey(u64),
|
||||
}
|
||||
|
||||
impl Event {
|
||||
/// Creates an Event from the number of hashes 'num_hashes' since the previous event
|
||||
impl Entry {
|
||||
/// Creates a Entry from the number of hashes 'num_hashes' since the previous event
|
||||
/// and that resulting 'end_hash'.
|
||||
pub fn new_tick(num_hashes: u64, end_hash: u64) -> Self {
|
||||
let data = EventData::Tick;
|
||||
Event {
|
||||
let event = Event::Tick;
|
||||
Entry {
|
||||
num_hashes,
|
||||
end_hash,
|
||||
data,
|
||||
event,
|
||||
}
|
||||
}
|
||||
|
||||
|
@ -48,8 +48,8 @@ impl Event {
|
|||
}
|
||||
}
|
||||
|
||||
/// Creates the next Tick Event 'num_hashes' after 'start_hash'.
|
||||
pub fn next_tick(start_hash: u64, num_hashes: u64) -> Event {
|
||||
/// Creates the next Tick Entry 'num_hashes' after 'start_hash'.
|
||||
pub fn next_tick(start_hash: u64, num_hashes: u64) -> Entry {
|
||||
use std::collections::hash_map::DefaultHasher;
|
||||
use std::hash::{Hash, Hasher};
|
||||
let mut end_hash = start_hash;
|
||||
|
@ -58,26 +58,26 @@ pub fn next_tick(start_hash: u64, num_hashes: u64) -> Event {
|
|||
end_hash.hash(&mut hasher);
|
||||
end_hash = hasher.finish();
|
||||
}
|
||||
Event::new_tick(num_hashes, end_hash)
|
||||
Entry::new_tick(num_hashes, end_hash)
|
||||
}
|
||||
|
||||
/// Verifies the hashes and counts of a slice of events are all consistent.
|
||||
pub fn verify_slice(events: &[Event], start_hash: u64) -> bool {
|
||||
pub fn verify_slice(events: &[Entry], start_hash: u64) -> bool {
|
||||
use rayon::prelude::*;
|
||||
let genesis = [Event::new_tick(0, start_hash)];
|
||||
let genesis = [Entry::new_tick(0, start_hash)];
|
||||
let event_pairs = genesis.par_iter().chain(events).zip(events);
|
||||
event_pairs.all(|(x0, x1)| x1.verify(x0.end_hash))
|
||||
}
|
||||
|
||||
/// Verifies the hashes and events serially. Exists only for reference.
|
||||
pub fn verify_slice_seq(events: &[Event], start_hash: u64) -> bool {
|
||||
let genesis = [Event::new_tick(0, start_hash)];
|
||||
pub fn verify_slice_seq(events: &[Entry], start_hash: u64) -> bool {
|
||||
let genesis = [Entry::new_tick(0, start_hash)];
|
||||
let mut event_pairs = genesis.iter().chain(events).zip(events);
|
||||
event_pairs.all(|(x0, x1)| x1.verify(x0.end_hash))
|
||||
}
|
||||
|
||||
/// Create a vector of Ticks of length 'len' from 'start_hash' hash and 'num_hashes'.
|
||||
pub fn create_ticks(start_hash: u64, num_hashes: u64, len: usize) -> Vec<Event> {
|
||||
pub fn create_ticks(start_hash: u64, num_hashes: u64, len: usize) -> Vec<Entry> {
|
||||
use itertools::unfold;
|
||||
let mut events = unfold(start_hash, |state| {
|
||||
let event = next_tick(*state, num_hashes);
|
||||
|
@ -93,8 +93,8 @@ mod tests {
|
|||
|
||||
#[test]
|
||||
fn test_event_verify() {
|
||||
assert!(Event::new_tick(0, 0).verify(0)); // base case
|
||||
assert!(!Event::new_tick(0, 0).verify(1)); // base case, bad
|
||||
assert!(Entry::new_tick(0, 0).verify(0)); // base case
|
||||
assert!(!Entry::new_tick(0, 0).verify(1)); // base case, bad
|
||||
assert!(next_tick(0, 1).verify(0)); // inductive step
|
||||
assert!(!next_tick(0, 1).verify(1)); // inductive step, bad
|
||||
}
|
||||
|
@ -104,10 +104,10 @@ mod tests {
|
|||
assert_eq!(next_tick(0, 1).num_hashes, 1)
|
||||
}
|
||||
|
||||
fn verify_slice_generic(verify_slice: fn(&[Event], u64) -> bool) {
|
||||
fn verify_slice_generic(verify_slice: fn(&[Entry], u64) -> bool) {
|
||||
assert!(verify_slice(&vec![], 0)); // base case
|
||||
assert!(verify_slice(&vec![Event::new_tick(0, 0)], 0)); // singleton case 1
|
||||
assert!(!verify_slice(&vec![Event::new_tick(0, 0)], 1)); // singleton case 2, bad
|
||||
assert!(verify_slice(&vec![Entry::new_tick(0, 0)], 0)); // singleton case 1
|
||||
assert!(!verify_slice(&vec![Entry::new_tick(0, 0)], 1)); // singleton case 2, bad
|
||||
assert!(verify_slice(&create_ticks(0, 0, 2), 0)); // inductive step
|
||||
|
||||
let mut bad_ticks = create_ticks(0, 0, 2);
|
||||
|
@ -131,23 +131,23 @@ mod tests {
|
|||
mod bench {
|
||||
extern crate test;
|
||||
use self::test::Bencher;
|
||||
use event;
|
||||
use log::*;
|
||||
|
||||
#[bench]
|
||||
fn event_bench(bencher: &mut Bencher) {
|
||||
let start_hash = 0;
|
||||
let events = event::create_ticks(start_hash, 100_000, 8);
|
||||
let events = create_ticks(start_hash, 100_000, 8);
|
||||
bencher.iter(|| {
|
||||
assert!(event::verify_slice(&events, start_hash));
|
||||
assert!(verify_slice(&events, start_hash));
|
||||
});
|
||||
}
|
||||
|
||||
#[bench]
|
||||
fn event_bench_seq(bencher: &mut Bencher) {
|
||||
let start_hash = 0;
|
||||
let events = event::create_ticks(start_hash, 100_000, 8);
|
||||
let events = create_ticks(start_hash, 100_000, 8);
|
||||
bencher.iter(|| {
|
||||
assert!(event::verify_slice_seq(&events, start_hash));
|
||||
assert!(verify_slice_seq(&events, start_hash));
|
||||
});
|
||||
}
|
||||
}
|
Loading…
Reference in New Issue