index.js
function md5(buffer) {
    var hash = crypto.createHash('md5');
    return hash.update(buffer).digest('hex').slice(0, 10);
}
function md5(buffer) {
    var hash = crypto.createHash('md5');
    return hash.update(buffer).digest('hex').slice(0, 10);
}
function md5 ( buffer ) { var hash = crypto . createHash ( 'md5' ) ; return hash . update ( buffer ) . digest ( 'hex' ) . slice ( 0 , 10 ) ; }
计算 md5

@inner
@param {Buffer} buffer
@return {string}
计算 md5