From 3045956ddd2db7d33351aacbcdc5de43b1e26eec Mon Sep 17 00:00:00 2001
From: Joonas Koivunen <joonas@neon.tech>
Date: Mon, 21 Aug 2023 22:30:24 +0300
Subject: [PATCH] refactor(LayerE): use new internal api

---
 pageserver/src/tenant/storage_layer.rs | 24 ++++++++++++------------
 pageserver/src/tenant/timeline.rs      |  2 +-
 2 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/pageserver/src/tenant/storage_layer.rs b/pageserver/src/tenant/storage_layer.rs
index f06f232725..8d369f568c 100644
--- a/pageserver/src/tenant/storage_layer.rs
+++ b/pageserver/src/tenant/storage_layer.rs
@@ -544,7 +544,7 @@ impl LayerE {
     }
 
     pub(crate) async fn evict_and_wait(
-        &self,
+        self: &Arc<Self>,
         _: &RemoteTimelineClient,
     ) -> Result<(), super::timeline::EvictionError> {
         use tokio::sync::broadcast::error::RecvError;
@@ -606,7 +606,7 @@ impl LayerE {
         reconstruct_data: &mut ValueReconstructState,
         ctx: &RequestContext,
     ) -> anyhow::Result<ValueReconstructResult> {
-        let layer = self.get_or_download(Some(ctx)).await?;
+        let layer = self.get_or_maybe_download(true, Some(ctx)).await?;
         self.access_stats
             .record_access(LayerAccessKind::GetValueReconstructData, ctx);
 
@@ -619,7 +619,7 @@ impl LayerE {
         self: &Arc<Self>,
         ctx: &RequestContext,
     ) -> anyhow::Result<Vec<DeltaEntry<ResidentDeltaLayer>>> {
-        let layer = self.get_or_download(Some(ctx)).await?;
+        let layer = self.get_or_maybe_download(true, Some(ctx)).await?;
         self.access_stats
             .record_access(LayerAccessKind::KeyIter, ctx);
 
@@ -632,12 +632,7 @@ impl LayerE {
         self: &Arc<Self>,
         allow_download: bool,
     ) -> anyhow::Result<ResidentLayer> {
-        let downloaded = if !allow_download {
-            self.get()
-                .ok_or_else(|| anyhow::anyhow!("layer {self} is not downloaded"))
-        } else {
-            self.get_or_download(None).await
-        }?;
+        let downloaded = self.get_or_maybe_download(allow_download, None).await?;
 
         Ok(ResidentLayer {
             _downloaded: downloaded,
@@ -645,6 +640,11 @@ impl LayerE {
         })
     }
 
+    pub(crate) async fn get_or_download(self: &Arc<Self>) -> anyhow::Result<()> {
+        self.get_or_maybe_download(true, None).await?;
+        Ok(())
+    }
+
     fn get_or_apply_evictedness(
         guard: Option<heavier_once_cell::Guard<'_, ResidentOrWantedEvicted>>,
         wanted_evicted: &AtomicBool,
@@ -664,11 +664,11 @@ impl LayerE {
     }
 
     /// Cancellation safe.
-    pub(crate) async fn get_or_download(
+    async fn get_or_maybe_download(
         self: &Arc<Self>,
+        allow_download: bool,
         ctx: Option<&RequestContext>,
-    ) -> anyhow::Result<Arc<DownloadedLayer>> {
-        let allow_download = true;
+    ) -> Result<Arc<DownloadedLayer>, DownloadError> {
         let download = move || async move {
             // disable any scheduled but not yet running eviction deletions for this
             self.version.fetch_add(1, Ordering::Relaxed);
diff --git a/pageserver/src/tenant/timeline.rs b/pageserver/src/tenant/timeline.rs
index 1725b6aadd..253202f1a2 100644
--- a/pageserver/src/tenant/timeline.rs
+++ b/pageserver/src/tenant/timeline.rs
@@ -3989,7 +3989,7 @@ impl Timeline {
 
                 js.spawn(
                     async move {
-                        let res = next.get_or_download(None).await;
+                        let res = next.get_or_download().await;
                         (next, res)
                     }
                     .instrument(span),