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reorder: get and get_or_apply_evictedness

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This commit is contained in:
Joonas Koivunen
2023-08-29 10:49:13 +03:00
parent c659d0f218
commit 87ecb2e6ca
1 changed files with 27 additions and 27 deletions
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54
pageserver/src/tenant/storage_layer/layer.rs
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@@ -516,33 +516,6 @@ impl LayerInner {
}
}
/// Access the current state without waiting for the file to be downloaded.
///
/// Used by eviction only. Requires that we've initialized to state which is respective to the
/// actual residency state.
fn get(&self) -> Option<Arc<DownloadedLayer>> {
let locked = self.inner.get();
Self::get_or_apply_evictedness(locked, &self.wanted_evicted)
}
fn get_or_apply_evictedness(
guard: Option<heavier_once_cell::Guard<'_, ResidentOrWantedEvicted>>,
wanted_evicted: &AtomicBool,
) -> Option<Arc<DownloadedLayer>> {
if let Some(mut x) = guard {
if let Some(won) = x.get() {
// there are no guarantees that we will always get to observe a concurrent call
// to evict
if wanted_evicted.load(Ordering::Acquire) {
x.downgrade();
}
return Some(won);
}
}
None
}
/// Should be cancellation safe, but cancellation is troublesome together with the spawned
/// download.
async fn get_or_maybe_download(
@@ -754,6 +727,33 @@ impl LayerInner {
}
}
/// Access the current state without waiting for the file to be downloaded.
///
/// Requires that we've initialized to state which is respective to the
/// actual residency state.
fn get(&self) -> Option<Arc<DownloadedLayer>> {
let locked = self.inner.get();
Self::get_or_apply_evictedness(locked, &self.wanted_evicted)
}
fn get_or_apply_evictedness(
guard: Option<heavier_once_cell::Guard<'_, ResidentOrWantedEvicted>>,
wanted_evicted: &AtomicBool,
) -> Option<Arc<DownloadedLayer>> {
if let Some(mut x) = guard {
if let Some(won) = x.get() {
// there are no guarantees that we will always get to observe a concurrent call
// to evict
if wanted_evicted.load(Ordering::Acquire) {
x.downgrade();
}
return Some(won);
}
}
None
}
async fn needs_download(&self) -> Result<Option<NeedsDownload>, std::io::Error> {
match tokio::fs::metadata(&self.path).await {
Ok(m) => Ok(self.is_file_present_and_good_size(&m).err()),