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|
#[cfg(test)]
#[allow(dead_code)]
use async_trait::async_trait;
use growthring::wal::{
WALBytes, WALFile, WALLoader, WALPos, WALRingId, WALStore,
};
use indexmap::{map::Entry, IndexMap};
use rand::Rng;
use std::cell::RefCell;
use std::collections::VecDeque;
use std::collections::{hash_map, HashMap};
use std::convert::TryInto;
use std::rc::Rc;
pub trait FailGen {
fn next_fail(&self) -> bool;
}
struct FileContentEmul(RefCell<Vec<u8>>);
impl FileContentEmul {
pub fn new() -> Self {
FileContentEmul(RefCell::new(Vec::new()))
}
}
impl std::ops::Deref for FileContentEmul {
type Target = RefCell<Vec<u8>>;
fn deref(&self) -> &Self::Target {
&self.0
}
}
/// Emulate the a virtual file handle.
pub struct WALFileEmul<G: FailGen> {
file: Rc<FileContentEmul>,
fgen: Rc<G>,
}
#[async_trait(?Send)]
impl<G: FailGen> WALFile for WALFileEmul<G> {
async fn allocate(&self, offset: WALPos, length: usize) -> Result<(), ()> {
if self.fgen.next_fail() {
return Err(());
}
let offset = offset as usize;
if offset + length > self.file.borrow().len() {
self.file.borrow_mut().resize(offset + length, 0)
}
for v in &mut self.file.borrow_mut()[offset..offset + length] {
*v = 0
}
Ok(())
}
fn truncate(&self, length: usize) -> Result<(), ()> {
if self.fgen.next_fail() {
return Err(());
}
self.file.borrow_mut().resize(length, 0);
Ok(())
}
async fn write(&self, offset: WALPos, data: WALBytes) -> Result<(), ()> {
if self.fgen.next_fail() {
return Err(());
}
let offset = offset as usize;
&self.file.borrow_mut()[offset..offset + data.len()]
.copy_from_slice(&data);
Ok(())
}
fn read(
&self,
offset: WALPos,
length: usize,
) -> Result<Option<WALBytes>, ()> {
if self.fgen.next_fail() {
return Err(());
}
let offset = offset as usize;
let file = self.file.borrow();
if offset + length > file.len() {
Ok(None)
} else {
Ok(Some(
(&file[offset..offset + length]).to_vec().into_boxed_slice(),
))
}
}
}
pub struct WALStoreEmulState {
files: HashMap<String, Rc<FileContentEmul>>,
}
impl WALStoreEmulState {
pub fn new() -> Self {
WALStoreEmulState {
files: HashMap::new(),
}
}
pub fn clone(&self) -> Self {
WALStoreEmulState {
files: self.files.clone(),
}
}
}
/// Emulate the persistent storage state.
pub struct WALStoreEmul<'a, G>
where
G: FailGen,
{
state: RefCell<&'a mut WALStoreEmulState>,
fgen: Rc<G>,
}
impl<'a, G: FailGen> WALStoreEmul<'a, G> {
pub fn new(state: &'a mut WALStoreEmulState, fgen: Rc<G>) -> Self {
let state = RefCell::new(state);
WALStoreEmul { state, fgen }
}
}
#[async_trait(?Send)]
impl<'a, G> WALStore for WALStoreEmul<'a, G>
where
G: 'static + FailGen,
{
type FileNameIter = std::vec::IntoIter<String>;
async fn open_file(
&self,
filename: &str,
touch: bool,
) -> Result<Box<dyn WALFile>, ()> {
if self.fgen.next_fail() {
return Err(());
}
match self.state.borrow_mut().files.entry(filename.to_string()) {
hash_map::Entry::Occupied(e) => Ok(Box::new(WALFileEmul {
file: e.get().clone(),
fgen: self.fgen.clone(),
})),
hash_map::Entry::Vacant(e) => {
if touch {
Ok(Box::new(WALFileEmul {
file: e.insert(Rc::new(FileContentEmul::new())).clone(),
fgen: self.fgen.clone(),
}))
} else {
Err(())
}
}
}
}
async fn remove_file(&self, filename: String) -> Result<(), ()> {
//println!("remove_file(filename={})", filename);
if self.fgen.next_fail() {
return Err(());
}
self.state
.borrow_mut()
.files
.remove(&filename)
.ok_or(())
.and_then(|_| Ok(()))
}
fn enumerate_files(&self) -> Result<Self::FileNameIter, ()> {
if self.fgen.next_fail() {
return Err(());
}
let mut logfiles = Vec::new();
for (fname, _) in self.state.borrow().files.iter() {
logfiles.push(fname.clone())
}
Ok(logfiles.into_iter())
}
}
pub struct SingleFailGen {
cnt: std::cell::Cell<usize>,
fail_point: usize,
}
impl SingleFailGen {
pub fn new(fail_point: usize) -> Self {
SingleFailGen {
cnt: std::cell::Cell::new(0),
fail_point,
}
}
}
impl FailGen for SingleFailGen {
fn next_fail(&self) -> bool {
let c = self.cnt.get();
self.cnt.set(c + 1);
c == self.fail_point
}
}
pub struct ZeroFailGen;
impl FailGen for ZeroFailGen {
fn next_fail(&self) -> bool {
false
}
}
pub struct CountFailGen(std::cell::Cell<usize>);
impl CountFailGen {
pub fn new() -> Self {
CountFailGen(std::cell::Cell::new(0))
}
pub fn get_count(&self) -> usize {
self.0.get()
}
}
impl FailGen for CountFailGen {
fn next_fail(&self) -> bool {
self.0.set(self.0.get() + 1);
false
}
}
/// An ordered list of intervals: `(begin, end, color)*`.
#[derive(Clone)]
pub struct PaintStrokes(Vec<(u32, u32, u32)>);
impl PaintStrokes {
pub fn new() -> Self {
PaintStrokes(Vec::new())
}
pub fn to_bytes(&self) -> WALBytes {
let mut res: Vec<u8> = Vec::new();
let is = std::mem::size_of::<u32>();
let len = self.0.len() as u32;
res.resize(is * (1 + 3 * self.0.len()), 0);
let mut rs = &mut res[..];
&mut rs[..is].copy_from_slice(&len.to_le_bytes());
rs = &mut rs[is..];
for (s, e, c) in self.0.iter() {
&mut rs[..is].copy_from_slice(&s.to_le_bytes());
&mut rs[is..is * 2].copy_from_slice(&e.to_le_bytes());
&mut rs[is * 2..is * 3].copy_from_slice(&c.to_le_bytes());
rs = &mut rs[is * 3..];
}
res.into_boxed_slice()
}
pub fn from_bytes(raw: &[u8]) -> Self {
assert!(raw.len() > 4);
assert!(raw.len() & 3 == 0);
let is = std::mem::size_of::<u32>();
let (len_raw, mut rest) = raw.split_at(is);
let len = u32::from_le_bytes(len_raw.try_into().unwrap());
let mut res = Vec::new();
for _ in 0..len {
let (s_raw, rest1) = rest.split_at(is);
let (e_raw, rest2) = rest1.split_at(is);
let (c_raw, rest3) = rest2.split_at(is);
res.push((
u32::from_le_bytes(s_raw.try_into().unwrap()),
u32::from_le_bytes(e_raw.try_into().unwrap()),
u32::from_le_bytes(c_raw.try_into().unwrap()),
));
rest = rest3
}
PaintStrokes(res)
}
pub fn gen_rand<R: rand::Rng>(
max_pos: u32,
max_len: u32,
max_col: u32,
n: usize,
rng: &mut R,
) -> PaintStrokes {
assert!(max_pos > 0);
let mut strokes = Self::new();
for _ in 0..n {
let pos = rng.gen_range(0, max_pos);
let len =
rng.gen_range(1, std::cmp::min(max_len, max_pos - pos + 1));
strokes.stroke(pos, pos + len, rng.gen_range(0, max_col))
}
strokes
}
pub fn stroke(&mut self, start: u32, end: u32, color: u32) {
self.0.push((start, end, color))
}
pub fn into_vec(self) -> Vec<(u32, u32, u32)> {
self.0
}
}
impl growthring::wal::Record for PaintStrokes {
fn serialize(&self) -> WALBytes {
self.to_bytes()
}
}
#[test]
fn test_paint_strokes() {
let mut p = PaintStrokes::new();
for i in 0..3 {
p.stroke(i, i + 3, i + 10)
}
let pr = p.to_bytes();
for ((s, e, c), i) in PaintStrokes::from_bytes(&pr)
.into_vec()
.into_iter()
.zip(0..)
{
assert_eq!(s, i);
assert_eq!(e, i + 3);
assert_eq!(c, i + 10);
}
}
pub struct Canvas {
waiting: HashMap<WALRingId, usize>,
queue: IndexMap<u32, VecDeque<(u32, WALRingId)>>,
canvas: Box<[u32]>,
}
impl Canvas {
pub fn new(size: usize) -> Self {
let mut canvas = Vec::new();
// fill the backgroudn color 0
canvas.resize(size, 0);
let canvas = canvas.into_boxed_slice();
Canvas {
waiting: HashMap::new(),
queue: IndexMap::new(),
canvas,
}
}
pub fn new_reference(&self, ops: &[PaintStrokes]) -> Self {
let mut res = Self::new(self.canvas.len());
for op in ops {
for (s, e, c) in op.0.iter() {
for i in *s..*e {
res.canvas[i as usize] = *c
}
}
}
res
}
fn get_waiting(&mut self, rid: WALRingId) -> &mut usize {
match self.waiting.entry(rid) {
hash_map::Entry::Occupied(e) => e.into_mut(),
hash_map::Entry::Vacant(e) => e.insert(0),
}
}
fn get_queued(&mut self, pos: u32) -> &mut VecDeque<(u32, WALRingId)> {
match self.queue.entry(pos) {
Entry::Occupied(e) => e.into_mut(),
Entry::Vacant(e) => e.insert(VecDeque::new()),
}
}
pub fn prepaint(&mut self, strokes: &PaintStrokes, rid: &WALRingId) {
let rid = *rid;
let mut nwait = 0;
for (s, e, c) in strokes.0.iter() {
for i in *s..*e {
nwait += 1;
self.get_queued(i).push_back((*c, rid))
}
}
*self.get_waiting(rid) = nwait
}
// TODO: allow customized scheduler
/// Schedule to paint one position, randomly. It optionally returns a finished batch write
/// identified by its start position of WALRingId.
pub fn rand_paint<R: rand::Rng>(
&mut self,
rng: &mut R,
) -> Option<(Option<WALRingId>, u32)> {
if self.is_empty() {
return None;
}
let idx = rng.gen_range(0, self.queue.len());
let (pos, _) = self.queue.get_index(idx).unwrap();
let pos = *pos;
Some((self.paint(pos), pos))
}
pub fn clear_queued(&mut self) {
self.queue.clear();
self.waiting.clear();
}
pub fn paint_all(&mut self) {
for (pos, q) in self.queue.iter() {
self.canvas[*pos as usize] = q.back().unwrap().0;
}
self.clear_queued()
}
pub fn is_empty(&self) -> bool {
self.queue.is_empty()
}
pub fn paint(&mut self, pos: u32) -> Option<WALRingId> {
let q = self.queue.get_mut(&pos).unwrap();
let (c, rid) = q.pop_front().unwrap();
if q.is_empty() {
self.queue.remove(&pos);
}
self.canvas[pos as usize] = c;
if let Some(cnt) = self.waiting.get_mut(&rid) {
*cnt -= 1;
if *cnt == 0 {
self.waiting.remove(&rid);
Some(rid)
} else {
None
}
} else {
None
}
}
pub fn is_same(&self, other: &Canvas) -> bool {
self.canvas.cmp(&other.canvas) == std::cmp::Ordering::Equal
}
pub fn print(&self, max_col: usize) {
println!("# begin canvas");
for r in self.canvas.chunks(max_col) {
for c in r.iter() {
print!("{:02x} ", c & 0xff);
}
println!("");
}
println!("# end canvas");
}
}
#[test]
fn test_canvas() {
let mut rng = <rand::rngs::StdRng as rand::SeedableRng>::seed_from_u64(42);
let mut canvas1 = Canvas::new(100);
let mut canvas2 = Canvas::new(100);
let canvas3 = Canvas::new(101);
let dummy = WALRingId::empty_id();
let s1 = PaintStrokes::gen_rand(100, 10, 256, 2, &mut rng);
let s2 = PaintStrokes::gen_rand(100, 10, 256, 2, &mut rng);
assert!(canvas1.is_same(&canvas2));
assert!(!canvas2.is_same(&canvas3));
canvas1.prepaint(&s1, &dummy);
canvas1.prepaint(&s2, &dummy);
canvas2.prepaint(&s1, &dummy);
canvas2.prepaint(&s2, &dummy);
assert!(canvas1.is_same(&canvas2));
canvas1.rand_paint(&mut rng);
assert!(!canvas1.is_same(&canvas2));
while let Some(_) = canvas1.rand_paint(&mut rng) {}
while let Some(_) = canvas2.rand_paint(&mut rng) {}
assert!(canvas1.is_same(&canvas2));
canvas1.print(10);
}
pub struct PaintingSim {
pub block_nbit: u8,
pub file_nbit: u8,
pub file_cache: usize,
/// number of PaintStrokes (WriteBatch)
pub n: usize,
/// number of strokes per PaintStrokes
pub m: usize,
/// number of scheduled ticks per PaintStroke submission
pub k: usize,
/// the size of canvas
pub csize: usize,
/// max length of a single stroke
pub stroke_max_len: u32,
/// max color value
pub stroke_max_col: u32,
/// max number of strokes per PaintStroke
pub stroke_max_n: usize,
/// random seed
pub seed: u64,
}
impl PaintingSim {
pub fn run<G: 'static + FailGen>(
&self,
state: &mut WALStoreEmulState,
canvas: &mut Canvas,
loader: WALLoader,
ops: &mut Vec<PaintStrokes>,
ringid_map: &mut HashMap<WALRingId, usize>,
fgen: Rc<G>,
) -> Result<(), ()> {
let mut rng =
<rand::rngs::StdRng as rand::SeedableRng>::seed_from_u64(self.seed);
let mut wal =
loader.load(WALStoreEmul::new(state, fgen.clone()), |_, _| {
if fgen.next_fail() {
Err(())
} else {
Ok(())
}
})?;
for _ in 0..self.n {
let pss = (0..self.m)
.map(|_| {
PaintStrokes::gen_rand(
self.csize as u32,
self.stroke_max_len,
self.stroke_max_col,
rng.gen_range(1, self.stroke_max_n + 1),
&mut rng,
)
})
.collect::<Vec<PaintStrokes>>();
let pss_ = pss.clone();
// write ahead
let rids = wal.grow(pss);
assert_eq!(rids.len(), self.m);
let recs = rids
.into_iter()
.zip(pss_.into_iter())
.map(|(r, ps)| -> Result<_, _> {
ops.push(ps);
let (rec, rid) = futures::executor::block_on(r)?;
ringid_map.insert(rid, ops.len() - 1);
Ok((rec, rid))
})
.collect::<Result<Vec<_>, ()>>()?;
// finish appending to WAL
/*
for rid in rids.iter() {
println!("got ringid: {:?}", rid);
}
*/
// prepare data writes
for (ps, rid) in recs.into_iter() {
canvas.prepaint(&ps, &rid);
}
// run k ticks of the fine-grained scheduler
for _ in 0..rng.gen_range(1, self.k) {
// storage I/O could fail
if fgen.next_fail() {
return Err(());
}
if let Some((fin_rid, _)) = canvas.rand_paint(&mut rng) {
if let Some(rid) = fin_rid {
futures::executor::block_on(wal.peel(&[rid]))?
}
} else {
break;
}
}
}
//canvas.print(40);
assert_eq!(wal.file_pool_in_use(), 0);
Ok(())
}
pub fn get_walloader(&self) -> WALLoader {
let mut loader = WALLoader::new();
loader
.file_nbit(self.file_nbit)
.block_nbit(self.block_nbit)
.cache_size(self.file_cache);
loader
}
pub fn get_nticks(&self, state: &mut WALStoreEmulState) -> usize {
let mut canvas = Canvas::new(self.csize);
let mut ops: Vec<PaintStrokes> = Vec::new();
let mut ringid_map = HashMap::new();
let fgen = Rc::new(CountFailGen::new());
self.run(
state,
&mut canvas,
self.get_walloader(),
&mut ops,
&mut ringid_map,
fgen.clone(),
)
.unwrap();
fgen.get_count()
}
pub fn check(
&self,
state: &mut WALStoreEmulState,
canvas: &mut Canvas,
wal: WALLoader,
ops: &Vec<PaintStrokes>,
ringid_map: &HashMap<WALRingId, usize>,
) -> bool {
if ops.is_empty() {
return true;
}
let mut last_idx = 0;
let mut napplied = 0;
canvas.clear_queued();
wal.load(
WALStoreEmul::new(state, Rc::new(ZeroFailGen)),
|payload, ringid| {
let s = PaintStrokes::from_bytes(&payload);
canvas.prepaint(&s, &ringid);
last_idx = *ringid_map.get(&ringid).unwrap() + 1;
napplied += 1;
Ok(())
},
)
.unwrap();
println!("last = {}/{}, applied = {}", last_idx, ops.len(), napplied);
canvas.paint_all();
// recover complete
let canvas0 = if last_idx > 0 {
let canvas0 = canvas.new_reference(&ops[..last_idx]);
if canvas.is_same(&canvas0) {
None
} else {
Some(canvas0)
}
} else {
let canvas0 = canvas.new_reference(&[]);
if canvas.is_same(&canvas0) {
None
} else {
let i0 = ops.len() - self.m;
let mut canvas0 = canvas0.new_reference(&ops[..i0]);
let mut res = None;
'outer: loop {
if canvas.is_same(&canvas0) {
break;
}
for i in i0..ops.len() {
canvas0.prepaint(&ops[i], &WALRingId::empty_id());
canvas0.paint_all();
if canvas.is_same(&canvas0) {
break 'outer;
}
}
res = Some(canvas0);
break;
}
res
}
};
if let Some(canvas0) = canvas0 {
canvas.print(40);
canvas0.print(40);
false
} else {
true
}
}
pub fn new_canvas(&self) -> Canvas {
Canvas::new(self.csize)
}
}
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