From e1e24ca6c06581aa1b282f4ff64d2dc0af56298a Mon Sep 17 00:00:00 2001
From: Mark Paluch <mpaluch@paluch.biz>
Date: Fri, 25 Feb 2022 10:14:32 +0100
Subject: [PATCH] Rename `ReadFrom.NEAREST` to `LOWEST_LATENCY` to clarify its
 functionality #1997

Introduce LOWEST_LATENCY and deprecate NEAREST.
---
 src/main/java/io/lettuce/core/ReadFrom.java   | 23 +++++++++++++++----
 .../java/io/lettuce/core/ReadFromImpl.java    |  6 +++--
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/src/main/java/io/lettuce/core/ReadFrom.java b/src/main/java/io/lettuce/core/ReadFrom.java
index 1c89420bad..1b216b6f2d 100644
--- a/src/main/java/io/lettuce/core/ReadFrom.java
+++ b/src/main/java/io/lettuce/core/ReadFrom.java
@@ -88,9 +88,24 @@ public abstract class ReadFrom {
     public static final ReadFrom SLAVE = REPLICA;
 
     /**
-     * Setting to read from the nearest node.
+     * Setting to read from the node with the lowest latency during topology discovery. Note that latency measurements are
+     * momentary snapshots that can change in rapid succession. Requires dynamic refresh sources to obtain topologies and
+     * latencies from all nodes in the cluster.
+     *
+     * @since 6.1.7
+     */
+    public static final ReadFrom LOWEST_LATENCY = new ReadFromImpl.ReadFromLowestCommandLatency();
+
+    /**
+     * Setting to read from the node with the lowest latency during topology discovery. Note that latency measurements are
+     * momentary snapshots that can change in rapid succession. Requires dynamic refresh sources to obtain topologies and
+     * latencies from all nodes in the cluster.
+     *
+     * @deprecated since 6.1.7 as we're renaming this setting to {@link #LOWEST_LATENCY} for more clarity what this setting
+     *             actually represents.
      */
-    public static final ReadFrom NEAREST = new ReadFromImpl.ReadFromNearest();
+    @Deprecated
+    public static final ReadFrom NEAREST = LOWEST_LATENCY;
 
     /**
      * Setting to read from any node.
@@ -198,8 +213,8 @@ public static ReadFrom valueOf(String name) {
             return REPLICA_PREFERRED;
         }
 
-        if (name.equalsIgnoreCase("nearest")) {
-            return NEAREST;
+        if (name.equalsIgnoreCase("nearest") || name.equalsIgnoreCase("lowestLatency")) {
+            return LOWEST_LATENCY;
         }
 
         if (name.equalsIgnoreCase("any")) {
diff --git a/src/main/java/io/lettuce/core/ReadFromImpl.java b/src/main/java/io/lettuce/core/ReadFromImpl.java
index 63724b46da..487138cf9b 100644
--- a/src/main/java/io/lettuce/core/ReadFromImpl.java
+++ b/src/main/java/io/lettuce/core/ReadFromImpl.java
@@ -94,9 +94,11 @@ static final class ReadFromReplicaPreferred extends OrderedPredicateReadFromAdap
     }
 
     /**
-     * Read from nearest node.
+     * Read from the node with the lowest latency during topology discovery. Note that latency measurements are momentary
+     * snapshots that can change in rapid succession. Requires dynamic refresh sources to obtain topologies and latencies from
+     * all nodes in the cluster.
      */
-    static final class ReadFromNearest extends ReadFrom {
+    static final class ReadFromLowestCommandLatency extends ReadFrom {
 
         @Override
         public List<RedisNodeDescription> select(Nodes nodes) {