From 4e9f320b1c774164913b51d8241c1e4a949a29e1 Mon Sep 17 00:00:00 2001
From: Vlad Lazar <vlad@neon.tech>
Date: Fri, 2 Feb 2024 13:48:01 +0000
Subject: [PATCH] pageserver: thread vectored reconstruct to generic layer

---
 pageserver/src/tenant/storage_layer/layer.rs | 51 +++++++++++++++++++-
 1 file changed, 49 insertions(+), 2 deletions(-)

diff --git a/pageserver/src/tenant/storage_layer/layer.rs b/pageserver/src/tenant/storage_layer/layer.rs
index 52c0f8abdc..97c5c2efe7 100644
--- a/pageserver/src/tenant/storage_layer/layer.rs
+++ b/pageserver/src/tenant/storage_layer/layer.rs
@@ -1,5 +1,6 @@
 use anyhow::Context;
 use camino::{Utf8Path, Utf8PathBuf};
+use pageserver_api::keyspace::KeySpace;
 use pageserver_api::models::{
     HistoricLayerInfo, LayerAccessKind, LayerResidenceEventReason, LayerResidenceStatus,
 };
@@ -16,13 +17,14 @@ use crate::config::PageServerConf;
 use crate::context::RequestContext;
 use crate::repository::Key;
 use crate::span::debug_assert_current_span_has_tenant_and_timeline_id;
+use crate::tenant::timeline::GetVectoredError;
 use crate::tenant::{remote_timeline_client::LayerFileMetadata, Timeline};
 
 use super::delta_layer::{self, DeltaEntry};
 use super::image_layer;
 use super::{
     AsLayerDesc, LayerAccessStats, LayerAccessStatsReset, LayerFileName, PersistentLayerDesc,
-    ValueReconstructResult, ValueReconstructState,
+    ValueReconstructResult, ValueReconstructState, ValuesReconstructState,
 };
 
 use utils::generation::Generation;
@@ -262,6 +264,29 @@ impl Layer {
             .with_context(|| format!("get_value_reconstruct_data for layer {self}"))
     }
 
+    pub(crate) async fn get_values_reconstruct_data(
+        &self,
+        keyspace: KeySpace,
+        end_lsn: Lsn,
+        reconstruct_data: &mut ValuesReconstructState,
+        ctx: &RequestContext,
+    ) -> Result<(), GetVectoredError> {
+        let layer = self
+            .0
+            .get_or_maybe_download(true, Some(ctx))
+            .await
+            .map_err(|err| GetVectoredError::Other(anyhow::anyhow!(err)))?;
+
+        self.0
+            .access_stats
+            .record_access(LayerAccessKind::GetValueReconstructData, ctx);
+
+        layer
+            .get_values_reconstruct_data(keyspace, end_lsn, reconstruct_data, &self.0, ctx)
+            .instrument(tracing::debug_span!("get_values_reconstruct_data", layer=%self))
+            .await
+    }
+
     /// Download the layer if evicted.
     ///
     /// Will not error when the layer is already downloaded.
@@ -1177,7 +1202,7 @@ pub(crate) enum EvictionError {
 
 /// Error internal to the [`LayerInner::get_or_maybe_download`]
 #[derive(Debug, thiserror::Error)]
-enum DownloadError {
+pub(crate) enum DownloadError {
     #[error("timeline has already shutdown")]
     TimelineShutdown,
     #[error("no remote storage configured")]
@@ -1337,6 +1362,28 @@ impl DownloadedLayer {
         }
     }
 
+    async fn get_values_reconstruct_data(
+        &self,
+        keyspace: KeySpace,
+        end_lsn: Lsn,
+        reconstruct_data: &mut ValuesReconstructState,
+        owner: &Arc<LayerInner>,
+        ctx: &RequestContext,
+    ) -> Result<(), GetVectoredError> {
+        use LayerKind::*;
+
+        match self.get(owner, ctx).await.map_err(GetVectoredError::from)? {
+            Delta(d) => {
+                d.get_values_reconstruct_data(keyspace, end_lsn, reconstruct_data, ctx)
+                    .await
+            }
+            Image(i) => {
+                i.get_values_reconstruct_data(keyspace, reconstruct_data, ctx)
+                    .await
+            }
+        }
+    }
+
     async fn dump(&self, owner: &Arc<LayerInner>, ctx: &RequestContext) -> anyhow::Result<()> {
         use LayerKind::*;
         match self.get(owner, ctx).await? {