├── .gitignore
├── LICENSE
├── README.md
├── example.js
├── index.js
└── package.json


/.gitignore:
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1 | node_modules
2 | 


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/LICENSE:
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 1 | The MIT License (MIT)
 2 | 
 3 | Copyright (c) 2018 Mathias Buus
 4 | 
 5 | Permission is hereby granted, free of charge, to any person obtaining a copy
 6 | of this software and associated documentation files (the "Software"), to deal
 7 | in the Software without restriction, including without limitation the rights
 8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 9 | copies of the Software, and to permit persons to whom the Software is
10 | furnished to do so, subject to the following conditions:
11 | 
12 | The above copyright notice and this permission notice shall be included in
13 | all copies or substantial portions of the Software.
14 | 
15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
21 | THE SOFTWARE.
22 | 


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/README.md:
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 1 | # random-access-latency
 2 | 
 3 | A [random-access-storage](https://github.com/random-access-storage/random-access-storage) instance that wraps another one and adds latency
 4 | 
 5 | ```sh
 6 | npm install random-access-latency
 7 | ```
 8 | 
 9 | ## Usage
10 | 
11 | ```js
12 | const ral = require('random-access-latency')
13 | const ram = require('random-access-memory')
14 | 
15 | // use ral to wrap another storage instance and add latency
16 | 
17 | // add between 50 and 100ms latency to each operation
18 | const storage = ral([50, 100], ram())
19 | 
20 | // should have latency
21 | storage.write(42, Buffer.from('hi'), function () {
22 |   storage.read(42, 2, console.log)
23 | })
24 | ```
25 | 
26 | ## API
27 | 
28 | #### `storage = ral(latency, otherStorage)`
29 | 
30 | Wrap another store in random-access-storage instance that adds latency to all operations.
31 | If `latency` is an array a random latency is picked between the first and second number in the array.
32 | 
33 | ## License
34 | 
35 | MIT
36 | 


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/example.js:
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 1 | const ral = require('random-access-latency')
 2 | const ram = require('random-access-memory')
 3 | 
 4 | // use ral to wrap another storage instance and add latency
 5 | 
 6 | const storage = ral([50, 100], ram()) // add between 50 and 100ms latency to each operation
 7 | 
 8 | // should have latency
 9 | storage.write(42, Buffer.from('hi'), function () {
10 |   storage.read(42, 2, console.log)
11 | })
12 | 


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/index.js:
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 1 | const ras = require('random-access-storage')
 2 | 
 3 | module.exports = function (latency, other) {
 4 |   if (!Array.isArray(latency)) latency = [latency, latency]
 5 | 
 6 |   const delta = latency[1] - latency[0]
 7 | 
 8 |   return ras({
 9 |     read: run(0),
10 |     write: run(1),
11 |     del: run(2),
12 |     stat: run(3)
13 |   })
14 | 
15 |   function run (type) {
16 |     return function (req) {
17 |       const timeout = Math.round(Math.random() * delta + latency[0])
18 |       setTimeout(() => fwd(type, req), timeout)
19 |     }
20 |   }
21 | 
22 |   function fwd (type, req) {
23 |     const cb = req.callback.bind(req)
24 | 
25 |     switch (type) {
26 |       case 0: return other.read(req.offset, req.size, cb)
27 |       case 1: return other.write(req.offset, req.data, cb)
28 |       case 2: return other.del(req.offset, req.size, cb)
29 |       case 3: return other.stat(cb)
30 |     }
31 |   }
32 | }
33 | 


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/package.json:
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 1 | {
 2 |   "name": "random-access-latency",
 3 |   "version": "1.0.0",
 4 |   "description": "A random-access-storage instance that wraps another one and adds latency",
 5 |   "main": "index.js",
 6 |   "scripts": {
 7 |     "test": "standard"
 8 |   },
 9 |   "dependencies": {
10 |     "random-access-storage": "^1.1.1"
11 |   },
12 |   "devDependencies": {
13 |     "standard": "^11.0.1"
14 |   },
15 |   "repository": {
16 |     "type": "git",
17 |     "url": "https://github.com/random-access-storage/random-access-latency.git"
18 |   },
19 |   "author": "Mathias Buus (@mafintosh)",
20 |   "license": "MIT",
21 |   "bugs": {
22 |     "url": "https://github.com/random-access-storage/random-access-latency/issues"
23 |   },
24 |   "homepage": "https://github.com/random-access-storage/random-access-latency"
25 | }
26 | 


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