Persistent cache (#426)

* Persistent cache

Cache transform results in `~/.cache/bankai` using
[browserify-persist-fs](https://github.com/martinheidegger/browserify-persist-fs).

This should not be merged until browserify/module-deps#127
is, since currently this does not work great with watchify (if I
understand the linked PR correctly).

Anyway, on the `./example` folder in this repo, results:

```bash
$ time npm run build # cold run
npm run build  13.79s user 0.35s system 159% cpu 8.843 total
$ time npm run build # warm run
npm run build  9.64s user 0.30s system 170% cpu 5.818 total
```

This is already a pretty big win, but on a larger app it should be
much much more noticeable still.

* Add babelify and preset to persistent cache key

* Move persistent cache creation to separate file so we can run gc on build

Author: apollosoftdev

lib/graph-script.js

@@ -16,6 +16,7 @@ var tinyify = require('tinyify')
 var glslify = require('glslify')
 var brfs = require('brfs')
 
+var createPersistentCache = require('./persistent-cache')
 var ttyError = require('./tty-error')
 var exorcise = require('./exorcise')
 
@@ -44,7 +45,7 @@ function node (state, createEdge) {
   var self = this
   var entry = state.metadata.entry
   var fullPaths = Boolean(state.metadata.fullPaths)
-  var b = browserify(browserifyOpts([entry], fullPaths))
+  var b = browserify(browserifyOpts([entry], fullPaths, createPersistentCache(state)))
   var shouldMinify = !state.metadata.watch
 
   if (state.metadata.watch) {
@@ -56,6 +57,8 @@ function node (state, createEdge) {
     })
   }
 
+  // When adding a transform or plugin, also add it to the `getCacheId` function below!
+
   b.ignore('sheetify/insert')
   b.transform(sheetify)
   b.transform(glslify)
@@ -155,13 +158,14 @@ function node (state, createEdge) {
   }
 }
 
-function browserifyOpts (entries, fullPaths) {
+function browserifyOpts (entries, fullPaths, persistentCache) {
   assert.ok(Array.isArray(entries), 'browserifyOpts: entries should be an array')
   return {
     debug: true,
     fullPaths: fullPaths,
     entries: entries,
     packageCache: {},
-    cache: {}
+    cache: {},
+    persistentCache: persistentCache
   }
 }

lib/persistent-cache.js

@@ -0,0 +1,32 @@
+var path = require('path')
+var os = require('os')
+var browserifyPersistFs = require('browserify-persist-fs')
+
+module.exports = function (state) {
+  var cacheDir = path.join(os.homedir(), '.cache', 'bankai')
+  return browserifyPersistFs(cacheDir, getCacheId(state))
+}
+
+function getCacheId (state) {
+  return {
+    watch: state.metadata.watch,
+    entry: state.metadata.entry,
+    transforms: [
+      'sheetify',
+      'glslify',
+      'tfilter',
+      'brfs',
+      'yo-yoify',
+      'css-extract',
+      'tinyify',
+      'split-require',
+      // TODO should probably add custom .babelrc here too if we can
+      'babelify',
+      'babel-preset-env'
+    ].map(version)
+  }
+
+  function version (mod) {
+    return require(mod + '/package.json').version
+  }
+}

package.json

@@ -25,6 +25,7 @@
     "brfs": "^1.4.4",
     "brotli": "^1.3.2",
     "browserify": "^16.0.0",
+    "browserify-persist-fs": "^1.2.1",
     "buffer-graph": "^4.0.0",
     "clean-css": "^4.1.9",
     "concat-stream": "^1.6.0",