AJV constructed on every call

[gnichola]

I am using v5.4.6 and an open api spec 3.1.0., and on app luanch I initialize the validtor like so

// 2. Add the OpenApiValidator middleware
app.use(
	OpenApiValidator.middleware({
		apiSpec,
		validateResponses: true 	// default false
		// 3. Provide the path to the controllers directory
		// operationHandlers: path.join(__dirname), // default false
	}),
);

I then made the same endpoint call 3 times. Each time, I see ajv being constructed, the apiSpec is reparsed and validated and the entire spec is re-added to ajv via:

    if ((_a = openApiSpec.components) === null || _a === void 0 ? void 0 : _a.schemas) {
        Object.entries(openApiSpec.components.schemas).forEach(([id, schema]) => {
            ajv.addSchema(openApiSpec.components.schemas[id], `#/components/schemas/${id}`);
        });

Since ajv is a new instance every time, the addSchema call endups up returning undefined for let sch = this._cache.get(schema);

I have not come across anything in the docs that would indicate a way to prevent this continual reload, but I am hoping I missed something.

[cdimascio]

@gnichola the ajv instances are not created per request. createAjv is called a handful of times when the server initializes. For instance it initializes ajv, creating an instance for the schema preprocessor, the request validator, the request body validator, and the response validator since each have different validation settings and rules. additionally, multipart handler also creates an instance. we should be able to remove the multi-part validator (by reusing the request validator and potentially there is opportunity to also re-use it for the preprocessor).

in any case, while there may be opportunity to avoid a couple instantiations, they only affect server start, they do not apply per request.

[cdimascio]

PR #1062 provides improved caching