performance: add buffer for semantic error callback (#1628)

* add debounced buffer for semantic error callback

A lot of wasted effort doing the operations immediately.

* Minimize debounce delay in tests

* LESS test debounce delay

* Use CI flag to disable delay as well

* Raise test harness semantic validation async waiting period

* MOAR delay....

Author: ponelat

package.json

@@ -33,7 +33,7 @@
     "test": "npm run just-test-in-node && npm run lint-errors",
     "test-in-node": "npm run lint-errors && npm run just-test-in-node",
     "just-test": "karma start --config karma.conf.js",
-    "just-test-in-node": "mocha --recursive --compilers js:babel-core/register test",
+    "just-test-in-node": "NODE_ENV=test mocha --recursive --compilers js:babel-core/register test",
     "just-test-in-node-watch": "npm run just-test-in-node -- -w",
     "serve-static": "http-server -i -a 0.0.0.0 -p 3001",
     "prestart": "npm install",

src/plugins/validate-semantic/actions.js

@@ -1,7 +1,34 @@
 import forEach from "lodash/forEach"
+import debounce from "lodash/debounce"
 
 export const SOURCE = "semantic"
 
+// the test system does not tolerate slowness!
+const { NODE_ENV, CI } = process.env
+const DEBOUNCE_MS = (NODE_ENV === "test" || CI === "true") ? 0 : 30
+
+// System for buffering/batching errors
+var errorCollector = []
+const debNewSpecErrBatch = debounce(() => {
+  const system = errorCollector.system // Just a reference to the "latest" system
+  try {
+    errorCollector.forEach(obj => {
+      obj.line = obj.line || system.fn.AST.getLineNumberForPath(system.specSelectors.specStr(), obj.path)
+      obj.source = SOURCE
+    })
+    system.errActions.newSpecErrBatch(errorCollector)
+    errorCollector = [] // Clear stack
+  } catch(e) {
+    console.error(e)
+  }
+}, DEBOUNCE_MS)
+
+const bufferedNewSpecErrBatch = (system, obj) => {
+  errorCollector.push(obj)
+  errorCollector.system = system
+  debNewSpecErrBatch()
+}
+
 export const all = () => (system) => {
 
   // don't run validation if spec is empty
@@ -13,20 +40,16 @@ export const all = () => (system) => {
     source: SOURCE
   })
 
-  const cb = (obj) => setTimeout(() => {
-    obj.line = obj.line || system.fn.AST.getLineNumberForPath(system.specSelectors.specStr(), obj.path)
-    obj.source = SOURCE
-    system.errActions.newSpecErr(obj)
-  }, 0)
+  const errCb = (obj) => bufferedNewSpecErrBatch(system, obj)
 
   forEach(system.validateActions, (fn, name) => {
     if(name.indexOf("validateAsync") === 0) {
-      fn(cb) // Function send messages on its own, it won't be cached ( due to the nature of async operations )
+      fn(errCb) // Function send messages on its own, it won't be cached ( due to the nature of async operations )
     } else if(name.indexOf("validate") === 0) {
       Promise.resolve(fn())
         .then(validationObjs => {
           if(validationObjs) {
-            validationObjs.forEach(cb)
+            validationObjs.forEach(errCb)
           }
         })
     }

test/plugins/validate-semantic/validate-helper.js

@@ -5,6 +5,8 @@ import ValidateBasePlugin from "plugins/validate-base"
 import ValidateSemanticPlugin from "plugins/validate-semantic"
 import ASTPlugin from "plugins/ast"
 
+const DELAY_MS = process.env.CI === "true" ? 100 : 60
+
 export default function validateHelper(spec) {
   return new Promise((resolve) => {
     const system = SwaggerUi({
@@ -26,7 +28,7 @@ export default function validateHelper(spec) {
       ]
     })
     system.validateActions.all()
-    setTimeout(resolve.bind(null, system), 60)
+    setTimeout(resolve.bind(null, system), DELAY_MS)
   })
 
 }