From 401881264c91f191ea4535968b6d1f146fd6906d Mon Sep 17 00:00:00 2001
From: mulugetam <mulugeta.mammo@intel.com>
Date: Thu, 20 Apr 2023 11:49:25 -0700
Subject: [PATCH] Use lowercase letters for zstd, zstdnodict compression
 codecs. (#7231)

Signed-off-by: Mulugeta Mammo <mulugeta.mammo@intel.com>
Signed-off-by: Shivansh Arora <hishiv@amazon.com>
---
 .../codec/customcodecs/CustomCodecPlugin.java  |  4 ++--
 .../customcodecs/Lucene95CustomCodec.java      | 18 ++++++++++++++++--
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/sandbox/plugins/custom-codecs/src/main/java/org/opensearch/index/codec/customcodecs/CustomCodecPlugin.java b/sandbox/plugins/custom-codecs/src/main/java/org/opensearch/index/codec/customcodecs/CustomCodecPlugin.java
index ed2eb962050d4..9d36184bf81af 100644
--- a/sandbox/plugins/custom-codecs/src/main/java/org/opensearch/index/codec/customcodecs/CustomCodecPlugin.java
+++ b/sandbox/plugins/custom-codecs/src/main/java/org/opensearch/index/codec/customcodecs/CustomCodecPlugin.java
@@ -14,8 +14,8 @@
 /**
  * A plugin that implements custom codecs. Supports these codecs:
  * <ul>
- * <li>ZSTD
- * <li>ZSTDNODICT
+ * <li>zstd
+ * <li>zstdnodict
  * </ul>
  *
  * @opensearch.internal
diff --git a/sandbox/plugins/custom-codecs/src/main/java/org/opensearch/index/codec/customcodecs/Lucene95CustomCodec.java b/sandbox/plugins/custom-codecs/src/main/java/org/opensearch/index/codec/customcodecs/Lucene95CustomCodec.java
index 652306e59559b..ad9e5cd3374fa 100644
--- a/sandbox/plugins/custom-codecs/src/main/java/org/opensearch/index/codec/customcodecs/Lucene95CustomCodec.java
+++ b/sandbox/plugins/custom-codecs/src/main/java/org/opensearch/index/codec/customcodecs/Lucene95CustomCodec.java
@@ -12,6 +12,8 @@
 import org.apache.lucene.codecs.FilterCodec;
 import org.apache.lucene.codecs.lucene95.Lucene95Codec;
 
+import java.util.Locale;
+
 abstract class Lucene95CustomCodec extends FilterCodec {
     public static final int DEFAULT_COMPRESSION_LEVEL = 6;
 
@@ -23,13 +25,25 @@ public enum Mode {
 
     private final StoredFieldsFormat storedFieldsFormat;
 
-    /** new codec for a given compression algorithm and default compression level */
+    /**
+     * Creates a new compression codec with the default compression level.
+     *
+     * @param mode The compression codec (ZSTD or ZSTDNODICT).
+     */
     public Lucene95CustomCodec(Mode mode) {
         this(mode, DEFAULT_COMPRESSION_LEVEL);
     }
 
+    /**
+     * Creates a new compression codec with the given compression level. We use
+     * lowercase letters when registering the codec so that we remain consistent with
+     * the other compression codecs: default, lucene_default, and best_compression.
+     *
+     * @param mode The compression codec (ZSTD or ZSTDNODICT).
+     * @parama compressionLevel The compression level.
+     */
     public Lucene95CustomCodec(Mode mode, int compressionLevel) {
-        super(mode.name(), new Lucene95Codec());
+        super(mode.name().toLowerCase(Locale.ROOT), new Lucene95Codec());
         this.storedFieldsFormat = new Lucene95CustomStoredFieldsFormat(mode, compressionLevel);
     }