nei-interface/utils/buffer-helper.js

auto create interface by nei

let BufferHelper = function () {
    this.buffers = [];
    this.size = 0;
    this._status = "changed";
};
  
BufferHelper.prototype.concat = function (buffer) {
    for (var i = 0, l = arguments.length; i < l; i++) {
        this._concat(arguments[i]);
    }
    return this;
};
  
BufferHelper.prototype._concat = function (buffer) {
    this.buffers.push(buffer);
    this.size = this.size + buffer.length;
    this._status = "changed";
    return this;
};
  
BufferHelper.prototype._toBuffer = function () {
    var data = null;
    var buffers = this.buffers;
    switch(buffers.length) {
        case 0:
            data = new Buffer(0);
            break;
        case 1:
            data = buffers[0];
            break;
        default:
            data = new Buffer(this.size);
            for (var i = 0, pos = 0, l = buffers.length; i < l; i++) {
            var buffer = buffers[i];
            buffer.copy(data, pos);
            pos += buffer.length;
            }
            break;
    }
    // Cache the computed result
    this._status = "computed";
    this.buffer = data;
    return data;
};
  
BufferHelper.prototype.toBuffer = function () {
    return this._status === "computed" ? this.buffer : this._toBuffer();
};
  
BufferHelper.prototype.toString = function () {
    return Buffer.prototype.toString.apply(this.toBuffer(), arguments);
};
  
module.exports = BufferHelper;