From b7de35c7798e9349aed7da5781e0d2b03b76f902 Mon Sep 17 00:00:00 2001
From: huiseong29 <tobestar29@naver.com>
Date: Sat, 19 Sep 2026 01:52:54 +0900
Subject: [PATCH] [ZEPPELIN-6465] Extract magic numbers in
 EmbeddingSearch.saveIndex() into named constants
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

### What is this PR for?
`EmbeddingSearch` declares its tuning values as named `private static final int`
constants near the top of the class (`EMBEDDING_DIM`, `MAX_TEXT_LENGTH`,
`MAX_INDEX_ENTRIES`), but the two truncation limits in `saveIndex()` were left as
bare literals. Each value appeared twice — once in the length check and once in the
`substring(0, ...)` call — so changing only one occurrence would silently let the
check bound and the truncation bound drift apart.

This extracts `2000` and `1000` into `MAX_PERSISTED_TEXT_LENGTH` and
`MAX_PERSISTED_OUTPUT_LENGTH`, following the constant style already used in the class,
and replaces all four usages.

The names deliberately distinguish these persistence limits from the existing
`MAX_TEXT_LENGTH` (1500), which bounds in-memory processing before embedding and is
a different value for a different purpose. Javadoc on the new text constant makes
that distinction explicit.

Values are unchanged, so behavior and the persisted binary format are identical and
`INDEX_VERSION` does not need to move. `loadIndex()` has no corresponding truncation
logic and is untouched.

### What type of PR is it?
Refactoring

### Todos
- [x] - Extract the two truncation limits into named constants
- [x] - Replace all four literal usages in saveIndex()

### What is the Jira issue?
https://issues.apache.org/jira/browse/ZEPPELIN-6465

### How should this be tested?
The EmbeddingSearch tests are gated behind `ZEPPELIN_EMBEDDING_TEST` and require the
embedding model to be installed first:

    bash bin/install-search-model.sh
    ZEPPELIN_EMBEDDING_TEST=true ./mvnw test -pl zeppelin-server -Dtest='*EmbeddingSearch*'

All 12 tests pass. `grep -n "2000\|1000" EmbeddingSearch.java` shows the values only
at the two constant declarations, with no bare literals left in `saveIndex()`.

### Screenshots (if appropriate)
N/A

### Questions:
* Does the license files need to update? No
* Is there breaking changes for older versions? No
* Does this needs documentation? No
---
 .../apache/zeppelin/search/EmbeddingSearch.java | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/zeppelin-server/src/main/java/org/apache/zeppelin/search/EmbeddingSearch.java b/zeppelin-server/src/main/java/org/apache/zeppelin/search/EmbeddingSearch.java
index c95e6fbe704..41b9666bd25 100644
--- a/zeppelin-server/src/main/java/org/apache/zeppelin/search/EmbeddingSearch.java
+++ b/zeppelin-server/src/main/java/org/apache/zeppelin/search/EmbeddingSearch.java
@@ -96,6 +96,15 @@ public class EmbeddingSearch extends SearchService {
    */
   private static final float MIN_SIMILARITY = 0.25f;
   private static final int MAX_TEXT_LENGTH = 1500;
+  /**
+   * Truncation limit applied to the text field when an entry is written to the index file.
+   * Distinct from {@link #MAX_TEXT_LENGTH}, which bounds in-memory processing before embedding.
+   */
+  private static final int MAX_PERSISTED_TEXT_LENGTH = 2000;
+  /**
+   * Truncation limit applied to the output field when an entry is written to the index file.
+   */
+  private static final int MAX_PERSISTED_OUTPUT_LENGTH = 1000;
 
   static final String ID_FIELD = "id";
   private static final String PARAGRAPH = "paragraph";
@@ -868,15 +877,15 @@ private void saveIndex() throws IOException {
           out.writeUTF(e.getKey());
           out.writeUTF(e.getValue().noteName != null ? e.getValue().noteName : "");
           String text = e.getValue().text != null ? e.getValue().text : "";
-          if (text.length() > 2000) {
-            text = text.substring(0, 2000);
+          if (text.length() > MAX_PERSISTED_TEXT_LENGTH) {
+            text = text.substring(0, MAX_PERSISTED_TEXT_LENGTH);
           }
           out.writeUTF(text);
           out.writeUTF(e.getValue().title != null ? e.getValue().title : "");
           out.writeUTF(e.getValue().tables != null ? e.getValue().tables : "");
           String output = e.getValue().output != null ? e.getValue().output : "";
-          if (output.length() > 1000) {
-            output = output.substring(0, 1000);
+          if (output.length() > MAX_PERSISTED_OUTPUT_LENGTH) {
+            output = output.substring(0, MAX_PERSISTED_OUTPUT_LENGTH);
           }
           out.writeUTF(output);
           for (float v : e.getValue().embedding) {