From e708c4e22c9584f9517444cd1664b73e2a18d598 Mon Sep 17 00:00:00 2001
From: Christian Schwarz <christian@neon.tech>
Date: Tue, 31 Jan 2023 11:49:15 +0100
Subject: [PATCH] replace btreemap with vec

This is PR https://github.com/neondatabase/neon/pull/3496
---
 libs/pageserver_api/src/models.rs | 11 +++++------
 pageserver/src/tenant/timeline.rs | 12 ++++++------
 2 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/libs/pageserver_api/src/models.rs b/libs/pageserver_api/src/models.rs
index a0deba2eaf..155cfbba92 100644
--- a/libs/pageserver_api/src/models.rs
+++ b/libs/pageserver_api/src/models.rs
@@ -1,5 +1,4 @@
 use std::{
-    collections::BTreeSet,
     fmt,
     num::{NonZeroU64, NonZeroUsize},
     ops::Range,
@@ -232,14 +231,14 @@ pub struct TimelineInfo {
     pub state: TimelineState,
 }
 
-#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize)]
 pub struct LayerMapInfo {
-    pub in_memory_layers: BTreeSet<InMemoryLayerInfo>,
-    pub historic_layers: BTreeSet<HistoricLayerInfo>,
+    pub in_memory_layers: Vec<InMemoryLayerInfo>,
+    pub historic_layers: Vec<HistoricLayerInfo>,
 }
 
+#[derive(Debug, Clone, Serialize)]
 #[serde_as]
-#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Copy, Clone, Serialize, Deserialize)]
 #[serde(tag = "kind")]
 pub enum InMemoryLayerInfo {
     Open {
@@ -254,8 +253,8 @@ pub enum InMemoryLayerInfo {
     },
 }
 
+#[derive(Debug, Clone, Serialize)]
 #[serde_as]
-#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Serialize, Deserialize)]
 #[serde(tag = "kind")]
 pub enum HistoricLayerInfo {
     Delta {
diff --git a/pageserver/src/tenant/timeline.rs b/pageserver/src/tenant/timeline.rs
index 0fd2808239..557b1ca749 100644
--- a/pageserver/src/tenant/timeline.rs
+++ b/pageserver/src/tenant/timeline.rs
@@ -17,7 +17,7 @@ use tokio_util::sync::CancellationToken;
 use tracing::*;
 
 use std::cmp::{max, min, Ordering};
-use std::collections::{BTreeSet, HashMap};
+use std::collections::HashMap;
 use std::fs;
 use std::ops::{Deref, Range};
 use std::path::{Path, PathBuf};
@@ -821,18 +821,18 @@ impl Timeline {
     }
 
     pub fn layer_map_info(&self) -> LayerMapInfo {
-        let mut in_memory_layers = BTreeSet::new();
+        let mut in_memory_layers = Vec::new();
         let layer_map = self.layers.read().unwrap();
         if let Some(open_layer) = &layer_map.open_layer {
-            in_memory_layers.insert(open_layer.info());
+            in_memory_layers.push(open_layer.info());
         }
         for frozen_layer in &layer_map.frozen_layers {
-            in_memory_layers.insert(frozen_layer.info());
+            in_memory_layers.push(frozen_layer.info());
         }
 
-        let mut historic_layers = BTreeSet::new();
+        let mut historic_layers = Vec::new();
         for historic_layer in layer_map.iter_historic_layers() {
-            historic_layers.insert(historic_layer.info());
+            historic_layers.push(historic_layer.info());
         }
 
         LayerMapInfo {