Naive attempt at keeping crc cache around between runs

lib/builtins/include.js

@@ -47,7 +47,9 @@ module.exports = function include ( inputdir, outputdir, options, callback ) {
 						sander.mkdirSync( path.dirname( destpath ) );
 
 						try {
-							symlinkOrCopy( filepath, destpath );
+							if ( !sander.existsSync( destpath ) ) {
+								symlinkOrCopy( filepath, destpath );
+							}
 							check();
 						} catch ( e ) {
 							cb( e );

lib/builtins/map.js

@@ -36,7 +36,11 @@ module.exports = function map ( inputdir, outputdir, options ) {
 				// If this mapper only accepts certain extensions, and this isn't
 				// one of them, just copy the file
 				if ( options.accept && !~options.accept.indexOf( ext ) ) {
-					return sander.link( srcpath ).to( destpath );
+					if ( !sander.existsSync( destpath ) ) {
+						return sander.link( srcpath ).to( destpath );
+					} else {
+						return Promise.resolve( true );
+					}
 				}
 
 				return sander.stat( srcpath ).then( function ( stats ) {
@@ -57,6 +61,10 @@ module.exports = function map ( inputdir, outputdir, options ) {
 						previous = options.cache[ filename ];
 
 						if ( previous && compareBuffers( crc, previous.crc ) ) {
+							if ( sander.existsSync( destpath ) ) {
+								return Promise.resolve( true );
+							}
+
 							promises = [ sander.link( previous.codepath ).to( destpath ) ];
 
 							if ( previous.mappath ) {

lib/file/link.js

@@ -11,7 +11,9 @@ module.exports = function () {
 			var dest = resolve.apply( null, arguments );
 
 			return sander.mkdir( path.dirname( dest ) ).then( function () {
-				symlinkOrCopy( src, dest );
+				if ( !sander.existsSync( dest ) ) {
+					symlinkOrCopy( src, dest );
+				}
 			});
 		}
 	};

lib/nodes/Transformer.js

@@ -54,76 +54,84 @@ module.exports = Node.extend({
 			};
 
 			outputdir = path.resolve( session.config.gobbledir, node.id, '' + node.counter++ );
-			node._ready = sander.mkdir( outputdir ).then( function () {
-				return node.input.ready().then( function ( inputdir ) {
-					return queue.add( function ( fulfil, reject ) {
-						var promise, called, callback, start;
-
-						node.emit( 'info', {
-							code: 'TRANSFORM_START',
-							progressIndicator: true,
-							id: node.id
-						});
-
-						start = Date.now();
-
-						callback = function ( err ) {
-							var gobbleError, stack, loc;
-
-							if ( called ) {
-								return;
-							}
-
-							called = true;
-
-							if ( err ) {
-								stack = err.stack || new Error().stack;
-
-								loc = extractLocationInfo( err );
 
-								gobbleError = new GobbleError({
-									message: 'transformation failed',
-									id: node.id,
-									code: 'TRANSFORMATION_FAILED',
-									original: err,
-									stack: stack,
-									file: loc.file,
-									line: loc.line,
-									column: loc.column
-								});
-
-								reject( gobbleError );
-							}
-
-							else {
-								node.emit( 'info', {
-									code: 'TRANSFORM_COMPLETE',
-									id: node.id,
-									duration: Date.now() - start
-								});
-
-								node._cleanup( outputdir );
-								fulfil( outputdir );
+			node._ready = sander.readFile( transformation.cachedir, '.cacheMap' ).then( function ( cache ) {
+				node.options.cache = JSON.parse( cache.toString() );
+			}, function() { return true; } ).then( function () {
+				return sander.mkdir( outputdir ).then( function () {
+					return node.input.ready().then( function ( inputdir ) {
+						return queue.add( function ( fulfil, reject ) {
+							var promise, called, callback, start;
+
+							node.emit( 'info', {
+								code: 'TRANSFORM_START',
+								progressIndicator: true,
+								id: node.id
+							});
+
+							start = Date.now();
+
+							callback = function ( err ) {
+								var gobbleError, stack, loc;
+
+								if ( called ) {
+									return;
+								}
+
+								called = true;
+
+								if ( err ) {
+									stack = err.stack || new Error().stack;
+
+									loc = extractLocationInfo( err );
+
+									gobbleError = new GobbleError({
+										message: 'transformation failed',
+										id: node.id,
+										code: 'TRANSFORMATION_FAILED',
+										original: err,
+										stack: stack,
+										file: loc.file,
+										line: loc.line,
+										column: loc.column
+									});
+
+									reject( gobbleError );
+								}
+
+								else {
+									node.emit( 'info', {
+										code: 'TRANSFORM_COMPLETE',
+										id: node.id,
+										duration: Date.now() - start
+									});
+
+									// stash the cache for future
+									sander.writeFileSync( transformation.cachedir, '.cacheMap', JSON.stringify( node.options.cache || {} ) );
+
+									node._cleanup( outputdir );
+									fulfil( outputdir );
+								}
+							};
+
+							try {
+								promise = node.transformer.call( transformation, inputdir, outputdir, assign({}, node.options ), callback );
+
+								if ( promise && typeof promise.then === 'function' ) {
+									promise.then( function () {
+										callback(); // ensure no argument is passed
+									}).catch( callback );
+								}
+							} catch ( err ) {
+								callback( err );
 							}
-						};
-
-						try {
-							promise = node.transformer.call( transformation, inputdir, outputdir, assign({}, node.options ), callback );
+						});
+					}).catch( function ( err ) {
+						node._abort();
+						queue.abort();
 
-							if ( promise && typeof promise.then === 'function' ) {
-								promise.then( function () {
-									callback(); // ensure no argument is passed
-								}).catch( callback );
-							}
-						} catch ( err ) {
-							callback( err );
-						}
+						throw err;
 					});
-				}).catch( function ( err ) {
-					node._abort();
-					queue.abort();
-
-					throw err;
 				});
 			});
 		}

lib/utils/cleanup.js

@@ -4,7 +4,7 @@ var sander = require( 'sander' ),
 module.exports = function cleanup ( dir ) {
 	return sander.mkdir( dir ).then( function () {
 		return sander.readdir( dir ).then( function ( files ) {
-			var promises = files.map( function ( filename ) {
+			var promises = files.filter( function ( filename ) { return filename.indexOf( '.cache' ) !== -1; }).map( function ( filename ) {
 				return sander.rimraf( dir, filename );
 			});
 

test/scenarios.js

@@ -88,6 +88,7 @@ module.exports = function () {
 						files = files.filter( function ( file ) { return /-foo$/.test( file ); });
 
 						sander.readdir( '.gobble', files[0] ).then( function ( files ) {
+							files = files.filter( function ( file ) { return file.indexOf( '.cache' ) === -1; });
 							assert.deepEqual( files, [ '2' ] );
 							done();
 						});