fix(editor): optimize large PL/SQL source rendering

Closes #5171

apps/desktop/src/lib/__tests__/sql/currentStatementFrame.spec.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { currentStatementFrameRangeTo, estimateInlineHintVisualColumns, isWideSqlChar, visualSqlColumns, visualSqlColumnsWithInlineHints } from "@/lib/sql/currentStatementFrame";
+import { currentStatementFrameRangeTo, estimateInlineHintVisualColumns, isWideSqlChar, shouldRebuildCurrentStatementFrame, visualSqlColumns, visualSqlColumnsWithInlineHints } from "@/lib/sql/currentStatementFrame";
 import type { SqlTextRange } from "@/lib/sql/sqlStatementRanges";
 
 describe("currentStatementFrameRangeTo", () => {
@@ -14,6 +14,18 @@ describe("currentStatementFrameRangeTo", () => {
   });
 });
 
+describe("shouldRebuildCurrentStatementFrame", () => {
+  it("reuses frame decorations for pure viewport updates", () => {
+    expect(shouldRebuildCurrentStatementFrame({ docChanged: false, selectionSet: false, configurationChanged: false })).toBe(false);
+  });
+
+  it("rebuilds after document, selection, or configuration updates", () => {
+    expect(shouldRebuildCurrentStatementFrame({ docChanged: true, selectionSet: false, configurationChanged: false })).toBe(true);
+    expect(shouldRebuildCurrentStatementFrame({ docChanged: false, selectionSet: true, configurationChanged: false })).toBe(true);
+    expect(shouldRebuildCurrentStatementFrame({ docChanged: false, selectionSet: false, configurationChanged: true })).toBe(true);
+  });
+});
+
 describe("visualSqlColumns", () => {
   it("counts ASCII as one column, tabs as four, and CJK/fullwidth characters as two", () => {
     expect(visualSqlColumns("A\t中Ｂ")).toBe(1 + 4 + 2 + 2);

apps/desktop/src/lib/__tests__/sql/sqlStatementRanges.spec.ts

@@ -346,6 +346,24 @@ describe("splitSqlStatementRanges", () => {
     expect(rangeSqlTexts(splitSqlStatementRanges(oracleIssue2405PlSql, "oracle"))).toEqual([oracleIssue2405PlSql]);
   });
 
+  it("splits large Dameng package bodies without repeated prefix parsing", () => {
+    const body = Array.from({ length: 3000 }, (_, index) => `    v_value := v_value + ${index % 10};`).join("\n");
+    const packageBody = `CREATE OR REPLACE PACKAGE BODY app.big_pkg AS
+  PROCEDURE run IS
+    v_value NUMBER := 0;
+  BEGIN
+${body}
+  END run;
+END big_pkg;`;
+    const sql = `${packageBody}\n/\nSELECT 1;`;
+    const startedAt = performance.now();
+    const ranges = splitSqlStatementRanges(sql, "dameng");
+    const elapsedMs = performance.now() - startedAt;
+
+    expect(rangeSqlTexts(ranges)).toEqual([packageBody, "SELECT 1"]);
+    expect(elapsedMs).toBeLessThan(1000);
+  });
+
   it("keeps nested GaussDB procedure blocks together", () => {
     expect(rangeSqlTexts(splitSqlStatementRanges(gaussDbNestedProcedure, "gaussdb"))).toEqual([gaussDbNestedProcedure]);
   });