whistle/lib/util/file-mgr.js

var fs = require('fs');
var iconv = require('iconv-lite');
var Buffer = require('safe-buffer').Buffer;
var config = require('../config');
var isUtf8 = require('./is-utf8');

var UTF8_RE = /^utf-?8$/i;
var isWin32 = process.platform === 'win32';
var MAX_SIZE = 1024 * 1024 * 64;
var CRLF = Buffer.from('\r\n');
var RSLASH_RE = /\\/g;
var noop = function (_) {
  return _;
};

function toBuffer(buf, charset) {
  if (buf == null || Buffer.isBuffer(buf)) {
    return buf;
  }
  buf += '';
  if (charset && typeof charset === 'string' && !UTF8_RE.test(charset)) {
    try {
      charset = charset.toLowerCase();
      if (charset === 'base64') {
        return Buffer.from(buf, 'base64');
      }
      return iconv.encode(buf, charset);
    } catch (e) {}
  }
  return Buffer.from(buf);
}

function convertSlash(filePath) {
  filePath = config.getHomePath(filePath);
  return isWin32 ? filePath : filePath.replace(RSLASH_RE, '/');
}

function decode(buf) {
  if (!Buffer.isBuffer(buf)) {
    return buf ? String(buf) : '';
  }
  if (!isUtf8(buf)) {
    try {
      return iconv.decode(buf, 'GB18030');
    } catch (e) {}
  }
  return String(buf);
}

function isString(path) {
  return path && typeof path === 'string';
}

function readSingleFile(path, callback) {
  if (!isString(path)) {
    return callback();
  }
  var stream = fs.createReadStream(convertSlash(path));
  var done, buf;
  var execCallback = function (err) {
    if (done) {
      return;
    }
    done = true;
    stream.close();
    callback(err ? null : buf);
  };
  stream.on('data', function (data) {
    if (done) {
      return;
    }
    buf = buf ? Buffer.concat([buf, data]) : data;
    if (buf.length > MAX_SIZE) {
      execCallback();
    }
  });
  stream.on('error', execCallback);
  stream.on('end', execCallback);
}

function getFileMap(list) {
  if (Array.isArray(list)) {
    list = list.join('|');
  }
  if (!isString(list)) {
    return '';
  }
  var fileMap = {};
  list = list.split('|');
  list.forEach(function (file) {
    fileMap[file || ''] = 1;
  });
  return fileMap;
}

function readFileMap(list, callback, isText) {
  var fileMap = getFileMap(list);
  if (!fileMap) {
    return callback('');
  }
  var files = Object.keys(fileMap);
  var len = files.length;
  files.forEach(function (file) {
    readSingleFile(file, function (data) {
      fileMap[file || ''] = isText ? decode(data) : data;
      if (--len <= 0) {
        callback(fileMap);
      }
    });
  });
}

function joinData(list, isText, charset) {
  if (!list || !list.length) {
    return '';
  }
  if (isText) {
    return list.filter(noop).join('\r\n');
  }
  var result = [];
  list.forEach(function (buf) {
    if (buf) {
      buf = toBuffer(buf, charset);
      result.push(buf, CRLF);
    }
  });
  result.pop();
  return result.length ? Buffer.concat(result) : '';
}

function readFileFromMap(path, fileMap, isText) {
  if (!isString(path)) {
    return '';
  }
  path = path.split('|');
  return joinData(
    path.map(function (file) {
      return fileMap[file || ''];
    }),
    isText
  );
}

function readFileList(list, callback, isText) {
  readFileMap(
    list,
    function (fileMap) {
      if (!fileMap) {
        return callback('');
      }
      var result = [];
      list.forEach(function (file) {
        result.push(readFileFromMap(file, fileMap, isText));
      });
      callback(result);
    },
    isText
  );
}

function readFile(path, callback) {
  if (!isString(path)) {
    return callback();
  }
  readFileList(path.split('|'), function (result) {
    callback(joinData(result));
  });
}

function readFilesText(list, callback) {
  readFileList(list, callback, true);
}

function readFileText(path, callback) {
  if (!isString(path)) {
    return callback();
  }
  readFilesText(
    path.split('|'),
    function (result) {
      callback(joinData(result, true));
    },
    true
  );
}

exports.toBuffer = toBuffer;
exports.joinData = joinData;
exports.decode = decode;
exports.readFile = readFile;
exports.readFileList = readFileList;
exports.readFileText = readFileText;
exports.readFilesText = readFilesText;
exports.convertSlash = convertSlash;