odin-javascript-exercises/node_modules/readable-stream/lib/internal/streams/BufferList.js
2017-12-15 12:56:14 -06:00

74 lines
No EOL
1.8 KiB
JavaScript

'use strict';
/*<replacement>*/
function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
var Buffer = require('safe-buffer').Buffer;
/*</replacement>*/
function copyBuffer(src, target, offset) {
src.copy(target, offset);
}
module.exports = function () {
function BufferList() {
_classCallCheck(this, BufferList);
this.head = null;
this.tail = null;
this.length = 0;
}
BufferList.prototype.push = function push(v) {
var entry = { data: v, next: null };
if (this.length > 0) this.tail.next = entry;else this.head = entry;
this.tail = entry;
++this.length;
};
BufferList.prototype.unshift = function unshift(v) {
var entry = { data: v, next: this.head };
if (this.length === 0) this.tail = entry;
this.head = entry;
++this.length;
};
BufferList.prototype.shift = function shift() {
if (this.length === 0) return;
var ret = this.head.data;
if (this.length === 1) this.head = this.tail = null;else this.head = this.head.next;
--this.length;
return ret;
};
BufferList.prototype.clear = function clear() {
this.head = this.tail = null;
this.length = 0;
};
BufferList.prototype.join = function join(s) {
if (this.length === 0) return '';
var p = this.head;
var ret = '' + p.data;
while (p = p.next) {
ret += s + p.data;
}return ret;
};
BufferList.prototype.concat = function concat(n) {
if (this.length === 0) return Buffer.alloc(0);
if (this.length === 1) return this.head.data;
var ret = Buffer.allocUnsafe(n >>> 0);
var p = this.head;
var i = 0;
while (p) {
copyBuffer(p.data, ret, i);
i += p.data.length;
p = p.next;
}
return ret;
};
return BufferList;
}();