node.js 复制文件夹
思路:
1、callback 驱动
2、递归所有需要复制文件
3、在一定阀值下并发复制文件
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 | 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)) } }); |