30% faster startup and faster validation (#159)

Author: mcollina

build-schema-validator.js

@@ -0,0 +1,21 @@
+'use strict'
+
+const Ajv = require('ajv')
+const fs = require('fs')
+const path = require('path')
+const pack = require('ajv-pack')
+
+const ajv = new Ajv({
+  sourceCode: true // this option is required by ajv-pack
+})
+
+const validate = ajv.compile(require('ajv/lib/refs/json-schema-draft-07.json'))
+
+let moduleCode = `// This file is autogenerated by ${path.basename(__filename)}, do not edit
+
+function nop () { return true }
+
+${pack(ajv, validate).replace(/root\.refVal\[0\]/gm, 'nop')}
+`
+
+fs.writeFileSync(path.join(__dirname, 'schema-validator.js'), moduleCode)

index.js

@@ -2,22 +2,7 @@
 
 var Ajv = require('ajv')
 var merge = require('deepmerge')
-
-// This Ajv instance is used to validate that the passed schema
-// is valid json schema. We reuse the instance to avoid having to
-// pay the ajv creation cost more than once.
-var ajv = new Ajv({
-  // Ignore any unknown formats as they aren't used.
-  unknownFormats: 'ignore',
-
-  // Ignoring unknown formats emits warnings, but we don't need to hear about
-  // them.
-  logger: {
-    log: console.log,
-    warn: function () {},
-    error: console.error
-  }
-})
+var validate = require('./schema-validator')
 
 var uglify = null
 var isLong
@@ -34,9 +19,29 @@ var addComma = `
   addComma = true
 `
 
+function isValidSchema (schema, name) {
+  if (!validate(schema)) {
+    if (name) {
+      name = `"${name}" `
+    } else {
+      name = ''
+    }
+    const first = validate.errors[0]
+    const err = new Error(`${name}schema is invalid: data${first.dataPath} ${first.message}`)
+    err.errors = isValidSchema.errors
+    throw err
+  }
+}
+
 function build (schema, options) {
   options = options || {}
-  isValidSchema(schema, options.schema)
+  isValidSchema(schema)
+  if (options.schema) {
+    for (let key of Object.keys(options.schema)) {
+      isValidSchema(options.schema[key], key)
+    }
+  }
+
   /* eslint no-new-func: "off" */
   var code = `
     'use strict'
@@ -985,21 +990,6 @@ function loadUglify () {
   }
 }
 
-function isValidSchema (schema, externalSchema) {
-  if (externalSchema) {
-    Object.keys(externalSchema).forEach(key => {
-      try {
-        ajv.addSchema(externalSchema[key], key)
-      } catch (err) {
-        err.message = '"' + key + '" ' + err.message
-        throw err
-      }
-    })
-  }
-  ajv.compile(schema)
-  ajv.removeSchema()
-}
-
 function isEmpty (schema) {
   for (var key in schema) {
     if (schema.hasOwnProperty(key)) return false

package.json

@@ -31,6 +31,7 @@
   },
   "homepage": "https://github.com/fastify/fast-json-stringify#readme",
   "devDependencies": {
+    "ajv-pack": "^0.3.1",
     "benchmark": "^2.1.4",
     "is-my-json-valid": "^2.19.0",
     "long": "^4.0.0",
@@ -45,5 +46,10 @@
   "dependencies": {
     "ajv": "^6.8.1",
     "deepmerge": "^3.0.0"
+  },
+  "standard": {
+    "ignore": [
+      "schema-validator.js"
+    ]
   }
 }