bigscene/service/util/copydir.js

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);
}

module.exports = copyDir