feat: Cache parsed SQL in Event class

This reduces the number of times we need to parse the SQL, which is
expensive, and improves sequence diagram load times by ~24%

Author: ahtrotta

packages/models/src/event.js

@@ -19,6 +19,8 @@ function alias(obj, prop, alias) {
 // This class supercedes `CallTree` and `CallNode`. Events are stored in a flat
 // array and can also be traversed like a tree via `parent` and `children`.
 export default class Event {
+  static parsedSqlCache = {};
+
   static contentType(...messages) {
     const msg = messages.find((message) => (message?.headers || {})['Content-Type']);
     if (!msg) {
@@ -526,10 +528,19 @@ export default class Event {
 
     let properties;
     if (sqlQuery) {
-      const sqlNormalized = abstractSqlAstJSON(sqlQuery, this.sql.database_type)
-        // Collapse repeated variable literals and parameter tokens (e.g. '?, ?' in an IN clause)
-        .split(/{"type":"variable"}(?:,{"type":"variable"})*/g)
-        .join(`{"type":"variable"}`);
+      let sqlNormalized;
+      const cacheKey = `${this.sql.database_type}:${sqlQuery}`;
+      if (!Event.parsedSqlCache[cacheKey]) {
+        sqlNormalized = abstractSqlAstJSON(sqlQuery, this.sql.database_type)
+          // Collapse repeated variable literals and parameter tokens (e.g. '?, ?' in an IN clause)
+          .split(/{"type":"variable"}(?:,{"type":"variable"})*/g)
+          .join(`{"type":"variable"}`);
+
+        Event.parsedSqlCache[cacheKey] = sqlNormalized;
+      } else {
+        sqlNormalized = Event.parsedSqlCache[cacheKey];
+      }
+
       properties = {
         event_type: 'sql',
         sql_normalized: sqlNormalized,

packages/models/tests/unit/event.spec.js

@@ -101,12 +101,21 @@ describe('Event', () => {
         });
       });
       describe('stableProperties', () => {
-        it('sql_normalized', () => {
+        it('sql_normalized and cached', () => {
+          const expectedSqlNormalized =
+            '{"type":"statement","variant":"list","statement":[{"type":"statement","variant":"select","result":[{"type":"function","name":{"type":"identifier","variant":"function","name":"count"},"args":{"type":"identifier","variant":"star","name":"*"}}],"from":{"type":"identifier","variant":"table","name":"spree_stores"}}]}';
+
           verifyJSON(sqlEvent.gatherStableProperties(), {
             event_type: 'sql',
-            sql_normalized:
-              '{"type":"statement","variant":"list","statement":[{"type":"statement","variant":"select","result":[{"type":"function","name":{"type":"identifier","variant":"function","name":"count"},"args":{"type":"identifier","variant":"star","name":"*"}}],"from":{"type":"identifier","variant":"table","name":"spree_stores"}}]}',
+            sql_normalized: expectedSqlNormalized,
           });
+
+          const expectedSqlKey = `${sqlEvent.sql.database_type}:${sqlEvent.sqlQuery}`;
+          const expectedSqlCache = {
+            [expectedSqlKey]: expectedSqlNormalized,
+          };
+
+          expect(Event.parsedSqlCache).toEqual(expectedSqlCache);
         });
         it('sql_normalized with query parameters', () => {
           const sql = {