# safe-buffer [![travis][travis-image]][travis-url] [![npm][npm-image]][npm-url] [![downloads][downloads-image]][downloads-url] [![javascript style guide][standard-image]][standard-url]
[travis-image]: https://img.shields.io/travis/feross/safe-buffer/master.svg
[travis-url]: https://travis-ci.org/feross/safe-buffer
[npm-image]: https://img.shields.io/npm/v/safe-buffer.svg
[npm-url]: https://npmjs.org/package/safe-buffer
[downloads-image]: https://img.shields.io/npm/dm/safe-buffer.svg
[downloads-url]: https://npmjs.org/package/safe-buffer
[standard-image]: https://img.shields.io/badge/code_style-standard-brightgreen.svg
[standard-url]: https://standardjs.com
#### Safer Node.js Buffer API
**Use the new Node.js Buffer APIs (`Buffer.from`, `Buffer.alloc`,
`Buffer.allocUnsafe`, `Buffer.allocUnsafeSlow`) in all versions of Node.js.**
**Uses the built-in implementation when available.**
## install
```
npm install safe-buffer
```
## usage
The goal of this package is to provide a safe replacement for the node.js `Buffer`.
It's a drop-in replacement for `Buffer`. You can use it by adding one `require` line to
the top of your node.js modules:
```js
var Buffer = require('safe-buffer').Buffer
// Existing buffer code will continue to work without issues:
new Buffer('hey', 'utf8')
new Buffer([1, 2, 3], 'utf8')
new Buffer(obj)
new Buffer(16) // create an uninitialized buffer (potentially unsafe)
// But you can use these new explicit APIs to make clear what you want:
Buffer.from('hey', 'utf8') // convert from many types to a Buffer
Buffer.alloc(16) // create a zero-filled buffer (safe)
Buffer.allocUnsafe(16) // create an uninitialized buffer (potentially unsafe)
```
## api
### Class Method: Buffer.from(array)
<!-- YAML
added: v3.0.0
-->
* `array` {Array}
Allocates a new `Buffer` using an `array` of octets.
```js
const buf = Buffer.from([0x62,0x75,0x66,0x66,0x65,0x72]);
// creates a new Buffer containing ASCII bytes
// ['b','u','f','f','e','r']
```
A `TypeError` will be thrown if `array` is not an `Array`.
### Class Method: Buffer.from(arrayBuffer[, byteOffset[, length]])
<!-- YAML
added: v5.10.0
-->
* `arrayBuffer` {ArrayBuffer} The `.buffer` property of a `TypedArray` or
a `new ArrayBuffer()`
* `byteOffset` {Number} Default: `0`
* `length` {Number} Default: `arrayBuffer.length - byteOffset`
When passed a reference to the `.buffer` property of a `TypedArray` instance,
the newly created `Buffer` will share the same allocated memory as the
TypedArray.
```js
const arr = new Uint16Array(2);
arr[0] = 5000;
arr[1] = 4000;
const buf = Buffer.from(arr.buffer); // shares the memory with arr;
console.log(buf);
// Prints: <Buffer 88 13 a0 0f>
// changing the TypedArray changes the Buffer also
arr[1] = 6000;
console.log(buf);
// Prints: <Buffer 88 13 70 17>
```
The optional `byteOffset` and `length` arguments specify a memory range within
the `arrayBuffer` that will be shared by the `Buffer`.
```js
const ab = new ArrayBuffer(10);
const buf = Buffer.from(ab, 0, 2);
console.log(buf.length);
// Prints: 2
```
A `TypeError` will be thrown if `arrayBuffer` is not an `ArrayBuffer`.
### Class Method: Buffer.from(buffer)
<!-- YAML
added: v3.0.0
-->
* `buffer` {Buffer}
Copies the passed `buffer` data onto a new `Buffer` instance.
```js
const buf1 = Buffer.from('buffer');
const buf2 = Buffer.from(buf1);
buf1[0] = 0x61;
console.log(buf1.toString());
// 'auffer'
console.log(buf2.toString());
// 'buffer' (copy is not changed)
```
A `TypeError` will be thrown if `buffer` is not a `Buffer`.
### Class Method: Buffer.from(str[, encoding])
<!-- YAML
added: v5.10.0
-->
* `str` {String} String to encode.
* `encoding` {String} Encoding to use, Default: `'utf8'`
Creates a new `Buffer` containing the given JavaScript string `str`. If
provided, the `encoding` parameter identifies the character encoding.
If not provided, `encoding` defaults to `'utf8'`.
```js
const buf1 = Buffer.from('this is a tést');
console.log(buf1.toString());
// prints: this is a tést
console.log(buf1.toString('ascii'));
// prints: this is a tC)st
const buf2 = Buffer.from('7468697320697320612074c3a97374', 'hex');
console.log(buf2.toString());
// prints: this is a tést
```
A `TypeError` will be thrown if `str` is not a string.
### Class Method: Buffer.alloc(size[, fill[, encoding]])
<!-- YAML
added: v5.10.0
-->
* `size` {Number}
* `fill` {Value} Default: `undefined`
* `encoding` {String} Default: `utf8`
Allocates a new `Buffer` of `size` bytes. If `fill` is `undefined`, the
`Buffer` will be *zero-filled*.
```js
const buf = Buffer.alloc(5);
console.log(buf);
// <Buffer 00 00 00 00 00>
```
The `size` must be less than or equal to the value of
`require('buffer').kMaxLength` (on 64-bit architectures, `kMaxLength` is
`(2^31)-1`). Otherwise, a [`RangeError`][] is thrown. A zero-length Buffer will
be created if a `size` less than or equal to 0 is specified.
If `fill` is specified, the allocated `Buffer` will be initialized by calling
`buf.fill(fill)`. See [`buf.fill()`][] for more information.
```js
const buf = Buffer.alloc(5, 'a');
console.log(buf);
// <Buffer 61 61 61 61 61>
```
If both `fill` and `encoding` are specified, the allocated `Buffer` will be
initialized by calling `buf.fill(fill, encoding)`. For example:
```js
const buf = Buffer.alloc(11, 'aGVsbG8gd29ybGQ=', 'base64');
console.log(buf);
// <Buffer 68 65 6c 6c 6f 20 77 6f 72 6c 64>
```
Calling `Buffer.alloc(size)` can be significantly slower than the alternative
`Buffer.allocUnsafe(size)` but ensures that the newly created `Buffer` instance
contents will *never contain sensitive data*.
A `TypeError` will be thrown if `size` is not a number.
### Class Method: Buffer.allocUnsafe(size)
<!-- YAML
added: v5.10.0
-->
* `size` {Number}
Allocates a new *non-zero-filled* `Buffer` of `size` bytes. The `size` must
be less than or equal to the value of `require('buffer').kMaxLength` (on 64-bit
architectures, `kMaxLength` is `(2^31)-1`). Otherwise, a [`RangeError`][] is
thrown. A zero-length Buffer will be created if a `size` less than or equal to
0 is specified.
The underlying memory for `Buffer` instances created in this way is *not
initialized*. The contents of the newly created `Buffer` are unknown and
*may contain sensitive data*. Use [`buf.fill(0)`][] to initialize such
`Buffer` instances to zeroes.
```js
const buf = Buffer.allocUnsafe(5);
console.log(buf);
// <Buffer 78 e0 82 02 01>
// (octets will be different, every time)
buf.fill(0);
console.log(buf);
// <Buffer 00 00 00 00 00>
```
A `TypeError` will be thrown if `size` is not a number.
Note that the `Buffer` module pre-allocates an internal `Buffer` instance of
size `Buffer.poolSize` that is used as a pool for the fast allocation of new
`Buffer` instances created using `Buffer.allocUnsafe(size)` (and the deprecated
`new Buffer(size)` constructor) only when `size` is less than or equal to
`Buffer.poolSize >> 1` (floor of `Buffer.poolSize` divided by two). The default
value of `Buffer.poolSize` is `8192` but can be modified.
Use of this pre-allocated internal memory pool is a key difference between
calling `Buffer.alloc(size, fill)` vs. `Buffer.allocUnsafe(size).fill(fill)`.
Specifically, `Buffer.alloc(size, fill)` will *never* use the internal Buffer
pool, while `Buffer.allocUnsafe(size).fill(fill)` *will* use the internal
Buffer pool if `size` is less than or equal to half `Buffer.poolSize`. The
difference is subtle but can be important when an application requires the
additional performance that `Buffer.allocUnsafe(size)` provides.
### Class Method: Buffer.allocUnsafeSlow(size)
<!-- YAML
added: v5.10.0
-->
* `size` {Number}
Allocates a new *non-zero-filled* and non-pooled `Buffer` of `size` bytes. The
`size` must be less than or equal to the value of
`require('buffer').kMaxLength` (on 64-bit architectures, `kMaxLength` is
`(2^31)-1`). Otherwise, a [`RangeError`][] is thrown. A zero-length Buffer will
be created if a `size` l
没有合适的资源?快使用搜索试试~ 我知道了~
温馨提示
软件开发设计:应用软件开发、系统软件开发、移动应用开发、网站开发C++、Java、python、web、C#等语言的项目开发与学习资料 硬件与设备:单片机、EDA、proteus、RTOS、包括计算机硬件、服务器、网络设备、存储设备、移动设备等 操作系统:LInux、树莓派、安卓开发、微机操作系统、网络操作系统、分布式操作系统等。此外,还有嵌入式操作系统、智能操作系统等。 网络与通信:数据传输、信号处理、网络协议、网络与通信硬件、网络安全网络与通信是一个非常广泛的领域,它涉及到计算机科学、电子工程、数学等多个学科的知识。 云计算与大数据:包括云计算平台、大数据分析、人工智能、机器学习等,云计算是一种基于互联网的计算方式,通过这种方式,共享的软硬件资源和信息可以按需提供给计算机和其他设备。
资源推荐
资源详情
资源评论
收起资源包目录
vue+node外卖项目.zip (388个子文件)
mime.cmd 254B
normalize.css 7KB
.editorconfig 399B
.eslintignore 5B
.eslintrc 647B
.eslintrc 422B
.eslintrc 180B
.gitignore 231B
index.html 611B
favicon.ico 4KB
meat.jpg 108KB
bread.jpg 81KB
rice.jpg 55KB
fish.jpg 27KB
sbcs-data-generated.js 31KB
parse.js 27KB
response.js 26KB
qs.js 24KB
stringify.js 24KB
index.js 23KB
dbcs-codec.js 21KB
ipaddr.js 19KB
tests.js 15KB
index.js 15KB
application.js 14KB
request.js 12KB
index.js 10KB
index.js 10KB
ipaddr.min.js 10KB
utf7.js 9KB
extend-node.js 8KB
parse.js 8KB
dbcs-data.js 8KB
stringify.js 8KB
index.js 6KB
index.js 6KB
utils.js 6KB
internal.js 6KB
index.js 6KB
node.js 6KB
index.js 6KB
utils.js 6KB
index.js 6KB
urlencoded.js 6KB
index.js 5KB
mediaType.js 5KB
index.js 5KB
index.js 5KB
utils.js 5KB
utf16.js 5KB
json.js 5KB
index.js 5KB
browser.js 5KB
sbcs-data.js 5KB
index.js 4KB
debug.js 4KB
route.js 4KB
index.js 4KB
read.js 4KB
index.js 4KB
index.js 4KB
encoding.js 3KB
index.js 3KB
language.js 3KB
streams.js 3KB
index.js 3KB
index.js 3KB
view.js 3KB
layer.js 3KB
charset.js 3KB
index.js 3KB
index.js 3KB
index.js 3KB
index.js 3KB
index.js 3KB
mime.js 3KB
index.js 3KB
index.js 3KB
index.js 2KB
express.js 2KB
test.js 2KB
text.js 2KB
callsite-tostring.js 2KB
sbcs-codec.js 2KB
safer.js 2KB
index.js 2KB
raw.js 2KB
karma.conf.js 2KB
index.js 2KB
index.js 2KB
index.js 1KB
index.js 1KB
dangerous.js 1KB
index.js 1KB
index.js 1KB
index.js 1KB
build.js 1KB
index.js 1KB
index.js 1KB
array-flatten.js 1KB
共 388 条
- 1
- 2
- 3
- 4
资源评论
妄北y
- 粉丝: 1w+
- 资源: 1万+
上传资源 快速赚钱
- 我的内容管理 展开
- 我的资源 快来上传第一个资源
- 我的收益 登录查看自己的收益
- 我的积分 登录查看自己的积分
- 我的C币 登录后查看C币余额
- 我的收藏
- 我的下载
- 下载帮助
安全验证
文档复制为VIP权益,开通VIP直接复制
信息提交成功