feat: add Idempotency to Postgres (#7750)

src/Adapters/Storage/Postgres/PostgresStorageAdapter.js

@@ -2440,9 +2440,55 @@ export class PostgresStorageAdapter implements StorageAdapter {
       ? fieldNames.map((fieldName, index) => `lower($${index + 3}:name) varchar_pattern_ops`)
       : fieldNames.map((fieldName, index) => `$${index + 3}:name`);
     const qs = `CREATE INDEX IF NOT EXISTS $1:name ON $2:name (${constraintPatterns.join()})`;
-    await conn.none(qs, [indexNameOptions.name, className, ...fieldNames]).catch(error => {
-      throw error;
-    });
+    const setIdempotencyFunction = options.setIdempotencyFunction !== undefined ? options.setIdempotencyFunction : false;
+    if (setIdempotencyFunction) {
+      await this.ensureIdempotencyFunctionExists(options);
+    }
+    await conn.none(qs, [indexNameOptions.name, className, ...fieldNames])
+      .catch(error => {
+        if (
+          error.code === PostgresDuplicateRelationError &&
+          error.message.includes(indexNameOptions.name)
+        ) {
+          // Index already exists. Ignore error.
+        } else if (
+          error.code === PostgresUniqueIndexViolationError &&
+          error.message.includes(indexNameOptions.name)
+        ) {
+          // Cast the error into the proper parse error
+          throw new Parse.Error(
+            Parse.Error.DUPLICATE_VALUE,
+            'A duplicate value for a field with unique values was provided'
+          );
+        } else {
+          throw error;
+        }
+      });
+  }
+
+  async deleteIdempotencyFunction(
+    options?: Object = {}
+  ): Promise<any> {
+    const conn = options.conn !== undefined ? options.conn : this._client;
+    const qs = 'DROP FUNCTION IF EXISTS idempotency_delete_expired_records()';
+    return conn
+      .none(qs)
+      .catch(error => {
+        throw error;
+      });
+  }
+
+  async ensureIdempotencyFunctionExists(
+    options?: Object = {}
+  ): Promise<any> {
+    const conn = options.conn !== undefined ? options.conn : this._client;
+    const ttlOptions = options.ttl !== undefined ? `${options.ttl} seconds` : '60 seconds';
+    const qs = 'CREATE OR REPLACE FUNCTION idempotency_delete_expired_records() RETURNS void LANGUAGE plpgsql AS $$ BEGIN DELETE FROM "_Idempotency" WHERE expire < NOW() - INTERVAL $1; END; $$;';
+    return conn
+      .none(qs, [ttlOptions])
+      .catch(error => {
+        throw error;
+      });
   }
 }