From 53b884ec2bdc126e98d6e7fca07a4699594fa702 Mon Sep 17 00:00:00 2001
From: Fabien O'Carroll <fabien@allou.is>
Date: Wed, 15 May 2019 13:28:10 +0200
Subject: [PATCH] Refactored json-schema to use one instance of ajv (#10746)

refs https://github.com/TryGhost/Team/issues/211

Previous code was creating a new ajv instance for each call, as well as
loading the schemas, which are cached. This was causing a memory leak as
ajv caches all schemas.

We've replaced it with one instance of ajv, and conditionally
loading/compiling the schemas if they haven't been seen before.
---
 .../v2/utils/validators/utils/json-schema.js  | 21 ++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/core/server/api/v2/utils/validators/utils/json-schema.js b/core/server/api/v2/utils/validators/utils/json-schema.js
index 1db3ed9e3f..b355239ddc 100644
--- a/core/server/api/v2/utils/validators/utils/json-schema.js
+++ b/core/server/api/v2/utils/validators/utils/json-schema.js
@@ -3,15 +3,22 @@ const Ajv = require('ajv');
 const stripKeyword = require('./strip-keyword');
 const common = require('../../../../../lib/common');
 
-const validate = (schema, definitions, data) => {
-    const ajv = new Ajv({
-        allErrors: true,
-        useDefaults: true
-    });
+const ajv = new Ajv({
+    allErrors: true,
+    useDefaults: true
+});
 
-    stripKeyword(ajv);
+stripKeyword(ajv);
 
-    const validation = ajv.addSchema(definitions).compile(schema);
+const getValidation = (schema, def) => {
+    if (!ajv.getSchema(def.$id)) {
+        ajv.addSchema(def);
+    }
+    return ajv.getSchema(schema.$id) || ajv.compile(schema);
+};
+
+const validate = (schema, definition, data) => {
+    const validation = getValidation(schema, definition);
 
     validation(data);