From b7cb9f43b815e910675fe31754b9ec362a50d207 Mon Sep 17 00:00:00 2001
From: Joonas Koivunen <joonas@neon.tech>
Date: Tue, 22 Aug 2023 00:34:49 +0300
Subject: [PATCH] remove Layer::is_incremental, and so on

---
 pageserver/src/tenant/storage_layer.rs                |  6 ------
 pageserver/src/tenant/storage_layer/delta_layer.rs    |  8 --------
 pageserver/src/tenant/storage_layer/image_layer.rs    | 10 ----------
 pageserver/src/tenant/storage_layer/inmemory_layer.rs |  9 ---------
 pageserver/src/tenant/storage_layer/remote_layer.rs   |  5 -----
 5 files changed, 38 deletions(-)

diff --git a/pageserver/src/tenant/storage_layer.rs b/pageserver/src/tenant/storage_layer.rs
index 53fc49e710..5ddead45c2 100644
--- a/pageserver/src/tenant/storage_layer.rs
+++ b/pageserver/src/tenant/storage_layer.rs
@@ -344,12 +344,6 @@ impl LayerAccessStats {
 /// are used in (timeline).
 #[async_trait::async_trait]
 pub trait Layer: std::fmt::Debug + std::fmt::Display + Send + Sync + 'static {
-    /// Does this layer only contain some data for the key-range (incremental),
-    /// or does it contain a version of every page? This is important to know
-    /// for garbage collecting old layers: an incremental layer depends on
-    /// the previous non-incremental layer.
-    fn is_incremental(&self) -> bool;
-
     ///
     /// Return data needed to reconstruct given page at LSN.
     ///
diff --git a/pageserver/src/tenant/storage_layer/delta_layer.rs b/pageserver/src/tenant/storage_layer/delta_layer.rs
index 339b966d5d..0c1180554d 100644
--- a/pageserver/src/tenant/storage_layer/delta_layer.rs
+++ b/pageserver/src/tenant/storage_layer/delta_layer.rs
@@ -254,10 +254,6 @@ impl Layer for DeltaLayer {
         self.get_value_reconstruct_data(key, lsn_range, reconstruct_state, ctx)
             .await
     }
-
-    fn is_incremental(&self) -> bool {
-        self.is_incremental()
-    }
 }
 /// Boilerplate to implement the Layer trait, always use layer_desc for persistent layers.
 impl std::fmt::Display for DeltaLayer {
@@ -390,10 +386,6 @@ impl DeltaLayer {
         self.layer_desc().lsn_range.clone()
     }
 
-    pub(crate) fn is_incremental(&self) -> bool {
-        self.layer_desc().is_incremental
-    }
-
     pub(crate) fn local_path(&self) -> Option<PathBuf> {
         Some(self.path())
     }
diff --git a/pageserver/src/tenant/storage_layer/image_layer.rs b/pageserver/src/tenant/storage_layer/image_layer.rs
index 51b998615a..4596e7ba9d 100644
--- a/pageserver/src/tenant/storage_layer/image_layer.rs
+++ b/pageserver/src/tenant/storage_layer/image_layer.rs
@@ -185,11 +185,6 @@ impl Layer for ImageLayer {
         self.get_value_reconstruct_data(key, lsn_range, reconstruct_state, ctx)
             .await
     }
-
-    /// Boilerplate to implement the Layer trait, always use layer_desc for persistent layers.
-    fn is_incremental(&self) -> bool {
-        self.is_incremental()
-    }
 }
 
 /// Boilerplate to implement the Layer trait, always use layer_desc for persistent layers.
@@ -283,11 +278,6 @@ impl ImageLayer {
         self.layer_desc().lsn_range.clone()
     }
 
-    /// Boilerplate to implement the Layer trait, always use layer_desc for persistent layers.
-    pub(crate) fn is_incremental(&self) -> bool {
-        self.layer_desc().is_incremental
-    }
-
     pub(crate) fn local_path(&self) -> Option<PathBuf> {
         Some(self.path())
     }
diff --git a/pageserver/src/tenant/storage_layer/inmemory_layer.rs b/pageserver/src/tenant/storage_layer/inmemory_layer.rs
index fe4cd37df7..b639852e9f 100644
--- a/pageserver/src/tenant/storage_layer/inmemory_layer.rs
+++ b/pageserver/src/tenant/storage_layer/inmemory_layer.rs
@@ -111,11 +111,6 @@ impl InMemoryLayer {
         self.start_lsn..self.end_lsn_or_max()
     }
 
-    pub(crate) fn is_incremental(&self) -> bool {
-        // in-memory layer is always considered incremental.
-        true
-    }
-
     /// debugging function to print out the contents of the layer
     ///
     /// this is likely completly unused
@@ -218,10 +213,6 @@ impl InMemoryLayer {
 
 #[async_trait::async_trait]
 impl Layer for InMemoryLayer {
-    fn is_incremental(&self) -> bool {
-        self.is_incremental()
-    }
-
     async fn get_value_reconstruct_data(
         &self,
         key: Key,
diff --git a/pageserver/src/tenant/storage_layer/remote_layer.rs b/pageserver/src/tenant/storage_layer/remote_layer.rs
index 95586e2ecd..f1bdcc18eb 100644
--- a/pageserver/src/tenant/storage_layer/remote_layer.rs
+++ b/pageserver/src/tenant/storage_layer/remote_layer.rs
@@ -94,11 +94,6 @@ impl Layer for RemoteLayer {
 
         Ok(())
     }
-
-    /// Boilerplate to implement the Layer trait, always use layer_desc for persistent layers.
-    fn is_incremental(&self) -> bool {
-        self.layer_desc().is_incremental
-    }
 }
 
 /// Boilerplate to implement the Layer trait, always use layer_desc for persistent layers.