rust/neon
1
0
Fork 0
mirror of https://github.com/neondatabase/neon.git synced 2026-01-14 08:52:56 +00:00
Code Issues Packages Projects Releases Wiki Activity

Use dashmap in page cache

Browse Source
This commit is contained in:
Bojan Serafimov
2022-10-19 17:16:02 -04:00
parent bc5ec43056
commit 47d29613a7
3 changed files with 33 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
Cargo.lock generated
View File

@@ -894,6 +894,19 @@ dependencies = [
"syn",
]
[[package]]
name = "dashmap"
version = "5.4.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "907076dfda823b0b36d2a1bb5f90c96660a5bbcd7729e10727f07858f22c4edc"
dependencies = [
"cfg-if",
"hashbrown",
"lock_api",
"once_cell",
"parking_lot_core 0.9.3",
]
[[package]]
name = "data-encoding"
version = "2.3.2"
@@ -2141,6 +2154,7 @@ dependencies = [
"criterion",
"crossbeam-utils",
"daemonize",
"dashmap",
"etcd_broker",
"fail",
"futures",

1
pageserver/Cargo.toml
View File

@@ -67,6 +67,7 @@ remote_storage = { path = "../libs/remote_storage" }
workspace_hack = { version = "0.1", path = "../workspace_hack" }
close_fds = "0.3.2"
walkdir = "2.3.2"
dashmap = "5.4.0"
[dev-dependencies]
criterion = "0.4"

42
pageserver/src/page_cache.rs
View File

@@ -36,8 +36,9 @@
//! mapping is automatically removed and the slot is marked free.
//!
use dashmap::mapref::entry::Entry;
use dashmap::DashMap;
use std::{
collections::{hash_map::Entry, HashMap},
convert::TryInto,
sync::{
atomic::{AtomicU8, AtomicUsize, Ordering},
@@ -168,18 +169,11 @@ impl Slot {
pub struct PageCache {
/// This contains the mapping from the cache key to buffer slot that currently
/// contains the page, if any.
///
/// TODO: This is protected by a single lock. If that becomes a bottleneck,
/// this HashMap can be replaced with a more concurrent version, there are
/// plenty of such crates around.
///
/// If you add support for caching different kinds of objects, each object kind
/// can have a separate mapping map, next to this field.
materialized_page_map: RwLock<HashMap<MaterializedPageHashKey, Vec<Version>>>,
materialized_page_map: DashMap<MaterializedPageHashKey, Vec<Version>>,
ephemeral_page_map: RwLock<HashMap<(u64, u32), usize>>,
ephemeral_page_map: DashMap<(u64, u32), usize>,
immutable_page_map: RwLock<HashMap<(u64, u32), usize>>,
immutable_page_map: DashMap<(u64, u32), usize>,
/// The actual buffers with their metadata.
slots: Box<[Slot]>,
@@ -616,7 +610,7 @@ impl PageCache {
fn search_mapping(&self, cache_key: &mut CacheKey) -> Option<usize> {
match cache_key {
CacheKey::MaterializedPage { hash_key, lsn } => {
let map = self.materialized_page_map.read().unwrap();
let map = &self.materialized_page_map;
let versions = map.get(hash_key)?;
let version_idx = match versions.binary_search_by_key(lsn, |v| v.lsn) {
@@ -629,11 +623,11 @@ impl PageCache {
Some(version.slot_idx)
}
CacheKey::EphemeralPage { file_id, blkno } => {
let map = self.ephemeral_page_map.read().unwrap();
let map = &self.ephemeral_page_map;
Some(*map.get(&(*file_id, *blkno))?)
}
CacheKey::ImmutableFilePage { file_id, blkno } => {
let map = self.immutable_page_map.read().unwrap();
let map = &self.immutable_page_map;
Some(*map.get(&(*file_id, *blkno))?)
}
}
@@ -646,7 +640,7 @@ impl PageCache {
fn search_mapping_for_write(&self, key: &CacheKey) -> Option<usize> {
match key {
CacheKey::MaterializedPage { hash_key, lsn } => {
let map = self.materialized_page_map.read().unwrap();
let map = &self.materialized_page_map;
let versions = map.get(hash_key)?;
if let Ok(version_idx) = versions.binary_search_by_key(lsn, |v| v.lsn) {
@@ -656,11 +650,11 @@ impl PageCache {
}
}
CacheKey::EphemeralPage { file_id, blkno } => {
let map = self.ephemeral_page_map.read().unwrap();
let map = &self.ephemeral_page_map;
Some(*map.get(&(*file_id, *blkno))?)
}
CacheKey::ImmutableFilePage { file_id, blkno } => {
let map = self.immutable_page_map.read().unwrap();
let map = &self.immutable_page_map;
Some(*map.get(&(*file_id, *blkno))?)
}
}
@@ -675,7 +669,7 @@ impl PageCache {
hash_key: old_hash_key,
lsn: old_lsn,
} => {
let mut map = self.materialized_page_map.write().unwrap();
let map = &self.materialized_page_map;
if let Entry::Occupied(mut old_entry) = map.entry(old_hash_key.clone()) {
let versions = old_entry.get_mut();
@@ -690,12 +684,12 @@ impl PageCache {
}
}
CacheKey::EphemeralPage { file_id, blkno } => {
let mut map = self.ephemeral_page_map.write().unwrap();
let map = &self.ephemeral_page_map;
map.remove(&(*file_id, *blkno))
.expect("could not find old key in mapping");
}
CacheKey::ImmutableFilePage { file_id, blkno } => {
let mut map = self.immutable_page_map.write().unwrap();
let map = &self.immutable_page_map;
map.remove(&(*file_id, *blkno))
.expect("could not find old key in mapping");
}
@@ -713,8 +707,8 @@ impl PageCache {
hash_key: new_key,
lsn: new_lsn,
} => {
let mut map = self.materialized_page_map.write().unwrap();
let versions = map.entry(new_key.clone()).or_default();
let map = &self.materialized_page_map;
let mut versions = map.entry(new_key.clone()).or_default();
match versions.binary_search_by_key(new_lsn, |v| v.lsn) {
Ok(version_idx) => Some(versions[version_idx].slot_idx),
Err(version_idx) => {
@@ -730,7 +724,7 @@ impl PageCache {
}
}
CacheKey::EphemeralPage { file_id, blkno } => {
let mut map = self.ephemeral_page_map.write().unwrap();
let map = &self.ephemeral_page_map;
match map.entry((*file_id, *blkno)) {
Entry::Occupied(entry) => Some(*entry.get()),
Entry::Vacant(entry) => {
@@ -740,7 +734,7 @@ impl PageCache {
}
}
CacheKey::ImmutableFilePage { file_id, blkno } => {
let mut map = self.immutable_page_map.write().unwrap();
let map = &self.immutable_page_map;
match map.entry((*file_id, *blkno)) {
Entry::Occupied(entry) => Some(*entry.get()),
Entry::Vacant(entry) => {