diff options
Diffstat (limited to 'node_modules/crc/lib/crc16_xmodem.js')
| -rw-r--r-- | node_modules/crc/lib/crc16_xmodem.js | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/node_modules/crc/lib/crc16_xmodem.js b/node_modules/crc/lib/crc16_xmodem.js new file mode 100644 index 0000000..2bc58a6 --- /dev/null +++ b/node_modules/crc/lib/crc16_xmodem.js @@ -0,0 +1,31 @@ +'use strict'; + +var _buffer = require('buffer'); + +var _define_crc = require('./define_crc'); + +var _define_crc2 = _interopRequireDefault(_define_crc); + +function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; } + +module.exports = (0, _define_crc2.default)('xmodem', function (buf, previous) { + if (!_buffer.Buffer.isBuffer(buf)) buf = (0, _buffer.Buffer)(buf); + + var crc = typeof previous !== 'undefined' ? ~ ~previous : 0x0; + + for (var index = 0; index < buf.length; index++) { + var byte = buf[index]; + var code = crc >>> 8 & 0xFF; + + code ^= byte & 0xFF; + code ^= code >>> 4; + crc = crc << 8 & 0xFFFF; + crc ^= code; + code = code << 5 & 0xFFFF; + crc ^= code; + code = code << 7 & 0xFFFF; + crc ^= code; + } + + return crc; +});
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