etag
Create simple HTTP ETags
This module generates HTTP ETags (as defined in RFC 7232) for use in HTTP responses.
Installation
This is a Node.js module available through the
npm registry. Installation is done using the
npm install command:
$ npm install etag
API
var etag = require('etag')
etag(entity, [options])
Generate a strong ETag for the given entity. This should be the complete
body of the entity. Strings, Buffers, and fs.Stats are accepted. By
default, a strong ETag is generated except for fs.Stats, which will
generate a weak ETag (this can be overwritten by options.weak).
res.setHeader('ETag', etag(body))
Options
etag accepts these properties in the options object.
weak
Specifies if the generated ETag will include the weak validator mark (that
is, the leading W/). The actual entity tag is the same. The default value
is false, unless the entity is fs.Stats, in which case it is true.
Testing
$ npm test
Benchmark
$ npm run-script bench
> etag@1.8.0 bench nodejs-etag
> node benchmark/index.js
http_parser@2.7.0
node@6.9.1
v8@5.1.281.84
uv@1.9.1
zlib@1.2.8
ares@1.10.1-DEV
icu@57.1
modules@48
openssl@1.0.2j
> node benchmark/body0-100b.js
100B body
4 tests completed.
* buffer - strong x 498,600 ops/sec ±0.82% (191 runs sampled)
* buffer - weak x 496,249 ops/sec ±0.59% (179 runs sampled)
string - strong x 466,298 ops/sec ±0.88% (186 runs sampled)
string - weak x 464,298 ops/sec ±0.84% (184 runs sampled)
> node benchmark/body1-1kb.js
1KB body
4 tests completed.
* buffer - strong x 346,535 ops/sec ±0.32% (189 runs sampled)
* buffer - weak x 344,958 ops/sec ±0.52% (185 runs sampled)
string - strong x 259,672 ops/sec ±0.82% (191 runs sampled)
string - weak x 260,931 ops/sec ±0.76% (190 runs sampled)
> node benchmark/body2-5kb.js
5KB body
4 tests completed.
* buffer - strong x 136,510 ops/sec ±0.62% (189 runs sampled)
* buffer - weak x 136,604 ops/sec ±0.51% (191 runs sampled)
string - strong x 80,903 ops/sec ±0.84% (192 runs sampled)
string - weak x 82,785 ops/sec ±0.50% (193 runs sampled)
> node benchmark/body3-10kb.js
10KB body
4 tests completed.
* buffer - strong x 78,650 ops/sec ±0.31% (193 runs sampled)
* buffer - weak x 78,685 ops/sec ±0.41% (193 runs sampled)
string - strong x 43,999 ops/sec ±0.43% (193 runs sampled)
string - weak x 44,081 ops/sec ±0.45% (192 runs sampled)
> node benchmark/body4-100kb.js
100KB body
4 tests completed.
buffer - strong x 8,860 ops/sec ±0.66% (191 runs sampled)
* buffer - weak x 9,030 ops/sec ±0.26% (193 runs sampled)
string - strong x 4,838 ops/sec ±0.16% (194 runs sampled)
string - weak x 4,800 ops/sec ±0.52% (192 runs sampled)
> node benchmark/stats.js
stat
4 tests completed.
* real - strong x 1,468,073 ops/sec ±0.32% (191 runs sampled)
* real - weak x 1,446,852 ops/sec ±0.64% (190 runs sampled)
fake - strong x 635,707 ops/sec ±0.33% (194 runs sampled)
fake - weak x 627,708 ops/sec ±0.36% (192 runs sampled)