Caching and logging

README.md

@@ -26,6 +26,8 @@ will attempt to look for a `.babelrc-browser` file. If neither of those files ex
 the `package.json` for a `babel` property.
 
 You can specify different file extensions with the `extensions` option in the transform's config (shown below).
+Files are cached in memory by default. You can use `memoryCachedExtensions` to remove caching on some files if you prefer.
+To save memory the cache is flushed after `idleCacheFlushTimeout` (default: 10 minutes).
 
 ```javascript
 require('lasso').configure({
@@ -34,7 +36,9 @@ require('lasso').configure({
             {
                 transform: 'lasso-babel-transform',
                 config: {
-                    extensions: ['.js', '.es6'] // Enabled file extensions. Default: ['.js', '.es6']
+                    extensions: ['.marko', '.js', '.es6'], // Enabled file extensions. Default: ['.js', '.es6']
+                    memoryCachedExtensions: ['.js', '.es6'], // Enabled memory caching for these file extensions. Default: same of 'extensions'
+                    idleCacheFlushTimeout: 20 * 60 * 1000, // FLushese the cache to save memory after 20 mins. Default 10 minutes.
                 }
             }
         ]
@@ -73,7 +77,7 @@ be transpiled by Babel. For example:
 
 _my-module/.babelrc:_
 
-```
+```javascript
 {
     "exclude": ["excluded/**"],
     "presets": [ "@babel/preset-env" ]
@@ -83,7 +87,7 @@ _my-module/.babelrc:_
 As mentioned above, you can also opt to use the `babel` property to the `package.json`.
 
 _my-module/package.json:_
-```
+```javascript
 {
     "name": "my-module",
     ...
@@ -99,3 +103,15 @@ You will need to install any Babel plugins enabled in your babel config. For exa
 npm install @babel/preset-env --save
 ```
 
+## Debugging
+
+Add this at the beginning of your main file:
+
+```javascript
+require('raptor-logging').configure({
+    loggers: {
+        'lasso-babel-transform': 'DEBUG', // or Info
+        'lasso-babel-transform/cache': 'DEBUG'
+    }
+});
+```

package.json

@@ -1,6 +1,6 @@
 {
   "name": "lasso-babel-transform",
-  "version": "3.0.1",
+  "version": "3.1.0",
   "description": "Lasso.js transform that uses Babel to transpile ES6 code to ES5.",
   "main": "src/index.js",
   "scripts": {
@@ -23,6 +23,7 @@
   "dependencies": {
     "lasso-caching-fs": "^1.0.1",
     "lasso-package-root": "^1.0.0",
+    "raptor-logging": "^1.0.0",
     "strip-json-comments": "^2.0.1"
   },
   "devDependencies": {

src/index.js

@@ -6,6 +6,10 @@ const stripJsonComments = require('strip-json-comments');
 const lassoPackageRoot = require('lasso-package-root');
 const readOptions = { encoding: 'utf8' };
 
+const logger = require('raptor-logging').logger('lasso-babel-transform');
+const loggerCache = require('raptor-logging').logger('lasso-babel-transform/cache');
+const caches = new WeakMap();
+
 let babel;
 
 function getBabel() {
@@ -20,17 +24,37 @@ function readAndParse(path) {
         fs.readFileSync(path, readOptions)));
 }
 
+let cacheNumber = 0;
 module.exports = {
     id: __filename,
     stream: false,
     createTransform(transformConfig) {
 
+        const logInfoEnabled = logger.isInfoEnabled();
+        const logDebugEnabled = logger.isDebugEnabled();
+        const loggerCacheDebugEnabled = loggerCache.isDebugEnabled();
+
         let extensions = transformConfig.extensions;
 
         if (!extensions) {
             extensions = ['.js', '.es6'];
         }
 
+        logger.info('These extensions will be transformed: ' + JSON.stringify(extensions));
+
+        let memoryCachedExtensions = transformConfig.memoryCachedExtensions === undefined && extensions || [];
+
+        logger.info('These extensions will be CACHED: ' + JSON.stringify(memoryCachedExtensions));
+
+
+        const idleCacheFlushTimeout = transformConfig.idleCacheFlushTimeout || 10 * 60 * 1000;
+        if(!idleCacheFlushTimeout) { 
+            logger.info('The cache will NOT be flushed');
+        } else {
+            logger.info('The cache will be flush after ' + idleCacheFlushTimeout + ' ms of inactivity.');
+        }
+
+
         extensions = extensions.reduce((lookup, ext) => {
             if (ext.charAt(0) !== '.') {
                 ext = '.' + ext;
@@ -39,14 +63,57 @@ module.exports = {
             return lookup;
         }, {});
 
+        memoryCachedExtensions = memoryCachedExtensions.reduce((lookup, ext) => {
+            if (ext.charAt(0) !== '.') {
+                ext = '.' + ext;
+            }
+            lookup[ext] = true;
+            return lookup;
+        }, {});
+
         return function lassoBabelTransform(code, lassoContext) {
             let filename = lassoContext.filename;
+            const ext = path.extname(filename);
 
-            if (!filename || !extensions.hasOwnProperty(path.extname(filename))) {
+            let relativeFilename = filename;
+            if (loggerCacheDebugEnabled || logInfoEnabled) relativeFilename = path.relative(process.cwd(), filename);
+
+            if (!filename || !extensions.hasOwnProperty(ext)) {
                 // This shouldn't be the case
                 return code;
             }
 
+            const shouldMemoryCache = memoryCachedExtensions.hasOwnProperty(ext);
+
+            let lasso = lassoContext.lasso;
+            let cache;
+            if (shouldMemoryCache) {
+                cache = caches.get(lasso); 
+                if (!cache) {
+                    logger.debug('Creating a new cache');
+                    cacheNumber++;
+                    cache = { cacheNumber }; // Save the number of caches being created
+                    caches.set(lasso, cache);
+                }
+
+                if (idleCacheFlushTimeout) {
+                    if (cache.timerId) clearTimeout(cache.timerId);
+                    cache.timerId = setTimeout(() => {
+                        loggerCache.debug('CACHE (#' + cache.cacheNumber + ') was FLUSHED after '  + idleCacheFlushTimeout + ' ms of inactivity.');
+                        caches.delete(lasso);
+                    }, idleCacheFlushTimeout);
+                }
+
+                if (cache) {
+                    let cachedCode = cache[filename];
+
+                    if (cachedCode) {
+                        if (loggerCacheDebugEnabled) loggerCache.debug('CACHE HIT (#' + cache.cacheNumber + '): ' + relativeFilename);
+                        return cachedCode;
+                    }
+                }
+            }
+
             let babelOptions = transformConfig.babelOptions;
 
             if (!babelOptions) {
@@ -104,15 +171,27 @@ module.exports = {
             babelOptions.filename = filename;
             babelOptions.babelrc = false;
             let babel = getBabel();
+            let resultCode;
 
-            let result = babel.transformSync(code, babelOptions);
+            const start = Date.now();
+            const result = babel.transformSync(code, babelOptions);
+            const ms = Date.now()  - start;
             if(result == null) {
               // "ignore" and "only" disable ALL babel processing of a file
               // e.g. => .babelrc = { "only": ["included/**"] }
               // transform('excluded/foo.js') will return null
-              return code;
+              if (logDebugEnabled) logger.debug('File "' + relativeFilename + '" was NOT compiled ( ' + ms + ' ms)');
+              resultCode = code;
+            } else {
+              if (logInfoEnabled)  logger.info('File "' + relativeFilename + '" was COMPILED ( ' + ms + ' ms)');
+              resultCode = result.code;
+            }
+
+            if (cache) {
+                cache[filename] = resultCode;
+                if (loggerCacheDebugEnabled) loggerCache.debug('File "' + relativeFilename + '" was CACHED(#' + cache.cacheNumber + ')');
             }
-            return result.code;
+            return resultCode;
         };
     }
 };