solana/bucket_map/src/bucket_storage.rs

417 lines
13 KiB
Rust

use {
crate::{bucket_stats::BucketStats, MaxSearch},
memmap2::MmapMut,
rand::{thread_rng, Rng},
solana_measure::measure::Measure,
std::{
fs::{remove_file, OpenOptions},
io::{Seek, SeekFrom, Write},
path::PathBuf,
sync::{
atomic::{AtomicU64, Ordering},
Arc,
},
},
};
/*
1 2
2 4
3 8
4 16
5 32
6 64
7 128
8 256
9 512
10 1,024
11 2,048
12 4,096
13 8,192
14 16,384
23 8,388,608
24 16,777,216
*/
pub const DEFAULT_CAPACITY_POW2: u8 = 5;
/// A Header UID of 0 indicates that the header is unlocked
const UID_UNLOCKED: Uid = 0;
pub(crate) type Uid = u64;
#[repr(C)]
struct Header {
lock: u64,
}
impl Header {
/// try to lock this entry with 'uid'
/// return true if it could be locked
fn try_lock(&mut self, uid: Uid) -> bool {
if self.lock == UID_UNLOCKED {
self.lock = uid;
true
} else {
false
}
}
/// mark this entry as unlocked
fn unlock(&mut self, expected: Uid) {
assert_eq!(expected, self.lock);
self.lock = UID_UNLOCKED;
}
/// uid that has locked this entry or None if unlocked
fn uid(&self) -> Option<Uid> {
if self.lock == UID_UNLOCKED {
None
} else {
Some(self.lock)
}
}
/// true if this entry is unlocked
fn is_unlocked(&self) -> bool {
self.lock == UID_UNLOCKED
}
}
pub struct BucketStorage {
path: PathBuf,
mmap: MmapMut,
pub cell_size: u64,
pub capacity_pow2: u8,
pub count: Arc<AtomicU64>,
pub stats: Arc<BucketStats>,
pub max_search: MaxSearch,
}
#[derive(Debug)]
pub enum BucketStorageError {
AlreadyAllocated,
}
impl Drop for BucketStorage {
fn drop(&mut self) {
let _ = remove_file(&self.path);
}
}
impl BucketStorage {
pub fn new_with_capacity(
drives: Arc<Vec<PathBuf>>,
num_elems: u64,
elem_size: u64,
capacity_pow2: u8,
max_search: MaxSearch,
stats: Arc<BucketStats>,
count: Arc<AtomicU64>,
) -> Self {
let cell_size = elem_size * num_elems + std::mem::size_of::<Header>() as u64;
let (mmap, path) = Self::new_map(&drives, cell_size as usize, capacity_pow2, &stats);
Self {
path,
mmap,
cell_size,
count,
capacity_pow2,
stats,
max_search,
}
}
pub fn max_search(&self) -> u64 {
self.max_search as u64
}
pub fn new(
drives: Arc<Vec<PathBuf>>,
num_elems: u64,
elem_size: u64,
max_search: MaxSearch,
stats: Arc<BucketStats>,
count: Arc<AtomicU64>,
) -> Self {
Self::new_with_capacity(
drives,
num_elems,
elem_size,
DEFAULT_CAPACITY_POW2,
max_search,
stats,
count,
)
}
/// return ref to header of item 'ix' in mmapped file
fn header_ptr(&self, ix: u64) -> &Header {
let ix = (ix * self.cell_size) as usize;
let hdr_slice: &[u8] = &self.mmap[ix..ix + std::mem::size_of::<Header>()];
unsafe {
let hdr = hdr_slice.as_ptr() as *const Header;
hdr.as_ref().unwrap()
}
}
/// return ref to header of item 'ix' in mmapped file
#[allow(clippy::mut_from_ref)]
fn header_mut_ptr(&self, ix: u64) -> &mut Header {
let ix = (ix * self.cell_size) as usize;
let hdr_slice: &[u8] = &self.mmap[ix..ix + std::mem::size_of::<Header>()];
unsafe {
let hdr = hdr_slice.as_ptr() as *mut Header;
hdr.as_mut().unwrap()
}
}
/// return uid allocated at index 'ix' or None if vacant
pub fn uid(&self, ix: u64) -> Option<Uid> {
assert!(ix < self.capacity(), "bad index size");
self.header_ptr(ix).uid()
}
/// true if the entry at index 'ix' is free (as opposed to being allocated)
pub fn is_free(&self, ix: u64) -> bool {
// note that the terminology in the implementation is locked or unlocked.
// but our api is allocate/free
self.header_ptr(ix).is_unlocked()
}
/// caller knows id is not empty
pub fn uid_unchecked(&self, ix: u64) -> Uid {
self.uid(ix).unwrap()
}
/// 'is_resizing' true if caller is resizing the index (so don't increment count)
/// 'is_resizing' false if caller is adding an item to the index (so increment count)
pub fn allocate(&self, ix: u64, uid: Uid, is_resizing: bool) -> Result<(), BucketStorageError> {
assert!(ix < self.capacity(), "allocate: bad index size");
assert!(UID_UNLOCKED != uid, "allocate: bad uid");
let mut e = Err(BucketStorageError::AlreadyAllocated);
//debug!("ALLOC {} {}", ix, uid);
if self.header_mut_ptr(ix).try_lock(uid) {
e = Ok(());
if !is_resizing {
self.count.fetch_add(1, Ordering::Relaxed);
}
}
e
}
pub fn free(&mut self, ix: u64, uid: Uid) {
assert!(ix < self.capacity(), "bad index size");
assert!(UID_UNLOCKED != uid, "free: bad uid");
self.header_mut_ptr(ix).unlock(uid);
self.count.fetch_sub(1, Ordering::Relaxed);
}
pub fn get<T: Sized>(&self, ix: u64) -> &T {
assert!(ix < self.capacity(), "bad index size");
let start = (ix * self.cell_size) as usize + std::mem::size_of::<Header>();
let end = start + std::mem::size_of::<T>();
let item_slice: &[u8] = &self.mmap[start..end];
unsafe {
let item = item_slice.as_ptr() as *const T;
&*item
}
}
pub fn get_empty_cell_slice<T: Sized>(&self) -> &[T] {
let len = 0;
let item_slice: &[u8] = &self.mmap[0..0];
unsafe {
let item = item_slice.as_ptr() as *const T;
std::slice::from_raw_parts(item, len as usize)
}
}
pub fn get_cell_slice<T: Sized>(&self, ix: u64, len: u64) -> &[T] {
assert!(ix < self.capacity(), "bad index size");
let ix = self.cell_size * ix;
let start = ix as usize + std::mem::size_of::<Header>();
let end = start + std::mem::size_of::<T>() * len as usize;
//debug!("GET slice {} {}", start, end);
let item_slice: &[u8] = &self.mmap[start..end];
unsafe {
let item = item_slice.as_ptr() as *const T;
std::slice::from_raw_parts(item, len as usize)
}
}
#[allow(clippy::mut_from_ref)]
pub fn get_mut<T: Sized>(&self, ix: u64) -> &mut T {
assert!(ix < self.capacity(), "bad index size");
let start = (ix * self.cell_size) as usize + std::mem::size_of::<Header>();
let end = start + std::mem::size_of::<T>();
let item_slice: &[u8] = &self.mmap[start..end];
unsafe {
let item = item_slice.as_ptr() as *mut T;
&mut *item
}
}
#[allow(clippy::mut_from_ref)]
pub fn get_mut_cell_slice<T: Sized>(&self, ix: u64, len: u64) -> &mut [T] {
assert!(ix < self.capacity(), "bad index size");
let ix = self.cell_size * ix;
let start = ix as usize + std::mem::size_of::<Header>();
let end = start + std::mem::size_of::<T>() * len as usize;
//debug!("GET mut slice {} {}", start, end);
let item_slice: &[u8] = &self.mmap[start..end];
unsafe {
let item = item_slice.as_ptr() as *mut T;
std::slice::from_raw_parts_mut(item, len as usize)
}
}
fn new_map(
drives: &[PathBuf],
cell_size: usize,
capacity_pow2: u8,
stats: &BucketStats,
) -> (MmapMut, PathBuf) {
let mut measure_new_file = Measure::start("measure_new_file");
let capacity = 1u64 << capacity_pow2;
let r = thread_rng().gen_range(0, drives.len());
let drive = &drives[r];
let pos = format!("{}", thread_rng().gen_range(0, u128::MAX),);
let file = drive.join(pos);
let mut data = OpenOptions::new()
.read(true)
.write(true)
.create(true)
.open(file.clone())
.map_err(|e| {
panic!(
"Unable to create data file {} in current dir({:?}): {:?}",
file.display(),
std::env::current_dir(),
e
);
})
.unwrap();
// Theoretical performance optimization: write a zero to the end of
// the file so that we won't have to resize it later, which may be
// expensive.
//debug!("GROWING file {}", capacity * cell_size as u64);
data.seek(SeekFrom::Start(capacity * cell_size as u64 - 1))
.unwrap();
data.write_all(&[0]).unwrap();
data.rewind().unwrap();
measure_new_file.stop();
let mut measure_flush = Measure::start("measure_flush");
data.flush().unwrap(); // can we skip this?
measure_flush.stop();
let mut measure_mmap = Measure::start("measure_mmap");
let res = (unsafe { MmapMut::map_mut(&data).unwrap() }, file);
measure_mmap.stop();
stats
.new_file_us
.fetch_add(measure_new_file.as_us(), Ordering::Relaxed);
stats
.flush_file_us
.fetch_add(measure_flush.as_us(), Ordering::Relaxed);
stats
.mmap_us
.fetch_add(measure_mmap.as_us(), Ordering::Relaxed);
res
}
/// copy contents from 'old_bucket' to 'self'
fn copy_contents(&mut self, old_bucket: &Self) {
let mut m = Measure::start("grow");
let old_cap = old_bucket.capacity();
let old_map = &old_bucket.mmap;
let increment = self.capacity_pow2 - old_bucket.capacity_pow2;
let index_grow = 1 << increment;
(0..old_cap as usize).for_each(|i| {
let old_ix = i * old_bucket.cell_size as usize;
let new_ix = old_ix * index_grow;
let dst_slice: &[u8] = &self.mmap[new_ix..new_ix + old_bucket.cell_size as usize];
let src_slice: &[u8] = &old_map[old_ix..old_ix + old_bucket.cell_size as usize];
unsafe {
let dst = dst_slice.as_ptr() as *mut u8;
let src = src_slice.as_ptr() as *const u8;
std::ptr::copy_nonoverlapping(src, dst, old_bucket.cell_size as usize);
};
});
m.stop();
self.stats.resizes.fetch_add(1, Ordering::Relaxed);
self.stats.resize_us.fetch_add(m.as_us(), Ordering::Relaxed);
}
/// allocate a new bucket, copying data from 'bucket'
pub fn new_resized(
drives: &Arc<Vec<PathBuf>>,
max_search: MaxSearch,
bucket: Option<&Self>,
capacity_pow_2: u8,
num_elems: u64,
elem_size: u64,
stats: &Arc<BucketStats>,
) -> Self {
let mut new_bucket = Self::new_with_capacity(
Arc::clone(drives),
num_elems,
elem_size,
capacity_pow_2,
max_search,
Arc::clone(stats),
bucket
.map(|bucket| Arc::clone(&bucket.count))
.unwrap_or_default(),
);
if let Some(bucket) = bucket {
new_bucket.copy_contents(bucket);
}
let sz = new_bucket.capacity();
{
let mut max = new_bucket.stats.max_size.lock().unwrap();
*max = std::cmp::max(*max, sz);
}
new_bucket
}
/// Return the number of cells currently allocated
pub fn capacity(&self) -> u64 {
1 << self.capacity_pow2
}
}
#[cfg(test)]
mod test {
use {super::*, tempfile::tempdir};
#[test]
fn test_bucket_storage() {
let tmpdir = tempdir().unwrap();
let paths: Vec<PathBuf> = vec![tmpdir.path().to_path_buf()];
assert!(!paths.is_empty());
let mut storage =
BucketStorage::new(Arc::new(paths), 1, 1, 1, Arc::default(), Arc::default());
let ix = 0;
let uid = Uid::MAX;
assert!(storage.is_free(ix));
assert!(storage.allocate(ix, uid, false).is_ok());
assert!(storage.allocate(ix, uid, false).is_err());
assert!(!storage.is_free(ix));
assert_eq!(storage.uid(ix), Some(uid));
assert_eq!(storage.uid_unchecked(ix), uid);
storage.free(ix, uid);
assert!(storage.is_free(ix));
assert_eq!(storage.uid(ix), None);
let uid = 1;
assert!(storage.is_free(ix));
assert!(storage.allocate(ix, uid, false).is_ok());
assert!(storage.allocate(ix, uid, false).is_err());
assert!(!storage.is_free(ix));
assert_eq!(storage.uid(ix), Some(uid));
assert_eq!(storage.uid_unchecked(ix), uid);
storage.free(ix, uid);
assert!(storage.is_free(ix));
assert_eq!(storage.uid(ix), None);
}
}