From ac2250c2811aae44979ab71eb753fc2ca916e51b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Chopin?= <seb@chopin.io>
Date: Thu, 8 Dec 2016 18:07:14 +0100
Subject: [PATCH] Optimise generate out of memory when +10000 paths

---
 lib/generate.js | 37 +++++++++++++++++++------------------
 1 file changed, 19 insertions(+), 18 deletions(-)

diff --git a/lib/generate.js b/lib/generate.js
index 7d00286663..8b38b4ebfd 100644
--- a/lib/generate.js
+++ b/lib/generate.js
@@ -19,6 +19,7 @@ const defaults = {
 }
 
 module.exports = function () {
+  const s = Date.now()
   /*
   ** Update loaders config to add router.base path
   */
@@ -66,9 +67,8 @@ module.exports = function () {
     /*
     ** Generate html files from routes
     */
-    var promises = []
+    let routes = []
     this.routes.forEach((route) => {
-      let subRoutes = []
       if (route.path.includes(':') || route.path.includes('*')) {
         const routeParams = this.options.generate.routeParams[route.path]
         if (!routeParams) {
@@ -76,29 +76,28 @@ module.exports = function () {
           return process.exit(1)
         }
         const toPath = pathToRegexp.compile(route.path)
-        routeParams.forEach((params) => {
-          const newRoute = Object.assign({}, route, { path: toPath(params) })
-          subRoutes.push(newRoute)
-        })
+        routes = routes.concat(routeParams.map((params) => {
+          return Object.assign({}, route, { path: toPath(params) })
+        }))
       } else {
-        subRoutes.push(route)
+        routes.push(route)
       }
-      subRoutes.forEach((route) => {
-        var promise = this.renderRoute(route.path)
-        .then(({ html }) => {
-          var path = join(route.path, sep, 'index.html') // /about -> /about/index.html
-          debug('Generate file: ' + path)
-          path = join(distPath, path)
-          // Make sure the sub folders are created
+    })
+    return co(function * () {
+      while (routes.length) {
+        yield routes.splice(0, 500).map((route) => {
           return co(function * () {
+            const { html } = yield self.renderRoute(route.path)
+            var path = join(route.path, sep, 'index.html') // /about -> /about/index.html
+            debug('Generate file: ' + path)
+            path = join(distPath, path)
+            // Make sure the sub folders are created
             yield mkdirp(dirname(path))
             yield writeFile(path, html, 'utf8')
           })
         })
-        promises.push(promise)
-      })
+      }
     })
-    return Promise.all(promises)
   })
   .then((pages) => {
     // Add .nojekyll file to let Github Pages add the _nuxt/ folder
@@ -107,7 +106,9 @@ module.exports = function () {
     return writeFile(nojekyllPath, '')
   })
   .then(() => {
-    debug('HTML Files generated')
+    const duration = Math.round((Date.now() - s) / 100) / 10
+    debug(`HTML Files generated in ${duration}s`)
+    return this
   })
 }