etag
创建简单的HTTP ETags
该模块生成HTTP ETags（如RFC 7232中定义）用于 HTTP响应。
安装
这是一个 node . js 模块可通过
npm注册表． 安装是使用
npm install 命令：
$ npm install etag
API
var etag = require('etag')
etag(实体,[选项])
为给定实体生成一个强ETag。这应该是完整的
实体的主体。字符串, Buffer年代, fs.Stats 被接受。通过
默认情况下，生成一个强ETag，除了 fs.Stats，这将
生成一个弱ETag(它可以被 options.weak）.
res.setHeader('ETag', etag(body))
选项
etag 在options对象中接受这些属性。
弱
指定生成的ETag是否包含弱验证器标记(即
是领头的 W/）. 实际的实体标记是相同的。默认值
是 false，除非 entity 是 fs.Stats，在这种情况下，它是 true。
测试
$ npm test
基准
$ npm run-script bench
> [email protected] bench nodejs-etag
> node benchmark/index.js
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
modules@48
[email protected]
> node benchmark/body0-100b.js
100B body
4 tests completed.
buffer - strong x 258,647 ops/sec ±1.07% (180 runs sampled)
buffer - weak x 263,812 ops/sec ±0.61% (184 runs sampled)
string - strong x 259,955 ops/sec ±1.19% (185 runs sampled)
string - weak x 264,356 ops/sec ±1.09% (184 runs sampled)
> node benchmark/body1-1kb.js
1KB body
4 tests completed.
buffer - strong x 189,018 ops/sec ±1.12% (182 runs sampled)
buffer - weak x 190,586 ops/sec ±0.81% (186 runs sampled)
string - strong x 144,272 ops/sec ±0.96% (188 runs sampled)
string - weak x 145,380 ops/sec ±1.43% (187 runs sampled)
> node benchmark/body2-5kb.js
5KB body
4 tests completed.
buffer - strong x 92,435 ops/sec ±0.42% (188 runs sampled)
buffer - weak x 92,373 ops/sec ±0.58% (189 runs sampled)
string - strong x 48,850 ops/sec ±0.56% (186 runs sampled)
string - weak x 49,380 ops/sec ±0.56% (190 runs sampled)
> node benchmark/body3-10kb.js
10KB body
4 tests completed.
buffer - strong x 55,989 ops/sec ±0.93% (188 runs sampled)
buffer - weak x 56,148 ops/sec ±0.55% (190 runs sampled)
string - strong x 27,345 ops/sec ±0.43% (188 runs sampled)
string - weak x 27,496 ops/sec ±0.45% (190 runs sampled)
> node benchmark/body4-100kb.js
100KB body
4 tests completed.
buffer - strong x 7,083 ops/sec ±0.22% (190 runs sampled)
buffer - weak x 7,115 ops/sec ±0.26% (191 runs sampled)
string - strong x 3,068 ops/sec ±0.34% (190 runs sampled)
string - weak x 3,096 ops/sec ±0.35% (190 runs sampled)
> node benchmark/stats.js
stat
4 tests completed.
real - strong x 871,642 ops/sec ±0.34% (189 runs sampled)
real - weak x 867,613 ops/sec ±0.39% (190 runs sampled)
fake - strong x 401,051 ops/sec ±0.40% (189 runs sampled)
fake - weak x 400,100 ops/sec ±0.47% (188 runs sampled)