纯异步nodejs文件夹(目录)复制功能

var async = require("async"); var fs = require("fs"); var path = require("path"); // cursively make dir  function mkdirs(p, mode, f, made) {   if (typeof mode === 'function' || mode === undefined) {     f = mode;     mode = 0777 & (~process.umask());   }   if (!made)     made = null;   var cb = f || function () {};   if (typeof mode === 'string')     mode = parseInt(mode, 8);   p = path.resolve(p);   fs.mkdir(p, mode, function (er) {     if (!er) {       made = made || p;       return cb(null, made);     }     switch (er.code) {     case 'ENOENT':       mkdirs(path.dirname(p), mode, function (er, made) {         if (er) {           cb(er, made);         } else {           mkdirs(p, mode, cb, made);         }       });       break;       // In the case of any other error, just see if there's a dir       // there already. If so, then hooray! If not, then something       // is borked.     default:       fs.stat(p, function (er2, stat) {         // if the stat fails, then that's super weird.         // let the original error be the failure reason.         if (er2 || !stat.isDirectory()) {           cb(er, made);         } else {           cb(null, made)         };       });       break;     }   }); } // single file copy function copyFile(file, toDir, cb) {   async.waterfall([       function (callback) {         fs.exists(toDir, function (exists) {           if (exists) {             callback(null, false);           } else {             callback(null, true);           }         });       }, function (need, callback) {         if (need) {           mkdirs(path.dirname(toDir), callback);         } else {           callback(null, true);         }       }, function (p, callback) {         var reads = fs.createReadStream(file);         var writes = fs.createWriteStream(path.join(path.dirname(toDir), path.basename(file)));         reads.pipe(writes);         //don't forget close the when all the data are read         reads.on("end", function () {           writes.end();           callback(null);         });         reads.on("error", function (err) {           console.log("error occur in reads");           callback(true, err);         });       }     ], cb); } // cursively count the files that need to be copied function _ccoutTask(from, to, cbw) {   async.waterfall([       function (callback) {         fs.stat(from, callback);       },       function (stats, callback) {         if (stats.isFile()) {           cbw.addFile(from, to);           callback(null, []);         } else if (stats.isDirectory()) {           fs.readdir(from, callback);         }       },       function (files, callback) {         if (files.length) {           for (var i = 0; i < files.length; i++) {             _ccoutTask(path.join(from, files[i]), path.join(to, files[i]), cbw.increase());           }         }         callback(null);       }     ], cbw); } // wrap the callback before counting function ccoutTask(from, to, cb) {   var files = [];   var count = 1;   function wrapper(err) {     count--;     if (err || count <= 0) {       cb(err, files)     }   }   wrapper.increase = function () {     count++;     return wrapper;   }   wrapper.addFile = function (file, dir) {     files.push({       file : file,       dir : dir     });   }   _ccoutTask(from, to, wrapper); } function copyDir(from, to, cb) {   if(!cb){    cb=function(){};   }   async.waterfall([       function (callback) {         fs.exists(from, function (exists) {           if (exists) {             callback(null, true);           } else {             console.log(from + " not exists");             callback(true);           }         });       },       function (exists, callback) {         fs.stat(from, callback);       },       function (stats, callback) {         if (stats.isFile()) {           // one file copy           copyFile(from, to, function (err) {             if (err) {               // break the waterfall               callback(true);             } else {               callback(null, []);             }           });         } else if (stats.isDirectory()) {           ccoutTask(from, to, callback);         }       },       function (files, callback) {           // prevent reaching to max file open limit              async.mapLimit(files, 10, function (f, cb) {           copyFile(f.file, f.dir, cb);         }, callback);       }     ], cb); } var start = new Date().getTime(); copyDir("F://gear", "F://gear2", function (err) {   if (err) {     console.log("error ocur");     console.dir(err);   } else {     console.log("copy ok");     console.log("consume time:" + (new Date().getTime() - start))   } });