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Adds Bloom Filter example using RedisBloom. (#1835)

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* Adds Bloom Filter example using RedisBloom.

* Update bloom-filter.js

Co-authored-by: Leibale Eidelman <leibale1998@gmail.com>
This commit is contained in:
Simon Prickett
2022-01-15 16:47:47 +00:00
committed by GitHub
parent e4601b6960
commit 06cb63756c
2 changed files with 93 additions and 13 deletions
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This folder contains example scripts showing how to use Node Redis in different scenarios.
| File Name | Description |
|-----------------------------|----------------------------------------------------------------------------------------------------------------|
| `blocking-list-pop.js` | Block until an element is pushed to a list |
| `command-with-modifiers.js` | Define a script that allows to run a command with several modifiers |
| `connect-as-acl-user.js` | Connect to Redis 6 using an ACL user |
| `lua-multi-incr.js` | Define a custom lua script that allows you to perform INCRBY on multiple keys |
| `managing-json.js` | Store, retrieve and manipulate JSON data atomically with [RedisJSON](https://redisjson.io/) |
| `search-hashes.js` | Uses [RediSearch](https://redisearch.io) to index and search data in hashes |
| `search-json.js` | Uses [RediSearch](https://redisearch.io/) and [RedisJSON](https://redisjson.io/) to index and search JSON data |
| `set-scan.js` | An example script that shows how to use the SSCAN iterator functionality |
| `stream-producer.js` | Adds entries to a [Redis Stream](https://redis.io/topics/streams-intro) using the `XADD` command |
| `stream-consumer.js` | Reads entries from a [Redis Stream](https://redis.io/topics/streams-intro) using the blocking `XREAD` command |
| `topk.js` | Use the [RedisBloom](https://redisbloom.io) TopK to track the most frequently seen items. |
| File Name | Description |
|-----------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------|
| `blocking-list-pop.js` | Block until an element is pushed to a list |
| `bloom-filter.js` | Space efficient set membership checks with a [Bloom Filter](https://en.wikipedia.org/wiki/Bloom_filter) using [RedisBloom](https://redisbloom.io) |
| `command-with-modifiers.js` | Define a script that allows to run a command with several modifiers |
| `connect-as-acl-user.js` | Connect to Redis 6 using an ACL user |
| `lua-multi-incr.js` | Define a custom lua script that allows you to perform INCRBY on multiple keys |
| `managing-json.js` | Store, retrieve and manipulate JSON data atomically with [RedisJSON](https://redisjson.io/) |
| `search-hashes.js` | Uses [RediSearch](https://redisearch.io) to index and search data in hashes |
| `search-json.js` | Uses [RediSearch](https://redisearch.io/) and [RedisJSON](https://redisjson.io/) to index and search JSON data |
| `set-scan.js` | An example script that shows how to use the SSCAN iterator functionality |
| `stream-producer.js` | Adds entries to a [Redis Stream](https://redis.io/topics/streams-intro) using the `XADD` command |
| `stream-consumer.js` | Reads entries from a [Redis Stream](https://redis.io/topics/streams-intro) using the blocking `XREAD` command |
| `topk.js` | Use the [RedisBloom](https://redisbloom.io) TopK to track the most frequently seen items. |
## Contributing

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examples/bloom-filter.js Normal file
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// This example demonstrates the use of the Bloom Filter
// in the RedisBloom module (https://redisbloom.io/)
import { createClient } from 'redis';
async function bloomFilter() {
const client = createClient();
await client.connect();
// Delete any pre-existing Bloom Filter.
await client.del('mybloom');
// Reserve a Bloom Filter with configurable error rate and capacity.
// https://oss.redis.com/redisbloom/Bloom_Commands/#bfreserve
try {
await client.bf.reserve('mybloom', 0.01, 1000);
console.log('Reserved Bloom Filter.');
} catch (e) {
if (e.message.endsWith('item exists')) {
console.log('Bloom Filter already reserved.');
} else {
console.log('Error, maybe RedisBloom is not installed?:');
console.log(e);
}
}
// Add items to Bloom Filter individually with BF.ADD command.
await Promise.all([
client.bf.add('mybloom', 'leibale'),
client.bf.add('mybloom', 'simon'),
client.bf.add('mybloom', 'guy'),
client.bf.add('mybloom', 'suze'),
client.bf.add('mybloom', 'brian'),
client.bf.add('mybloom', 'steve'),
client.bf.add('mybloom', 'kyle'),
client.bf.add('mybloom', 'josefin'),
client.bf.add('mybloom', 'alex'),
client.bf.add('mybloom', 'nava'),
]);
// Add multiple items to Bloom Filter at once with BF.MADD command.
await client.bf.mAdd('mybloom', [
'kaitlyn',
'rachel'
]);
console.log('Added members to Bloom Filter.');
// Check whether a member exists with the BF.EXISTS command.
const simonExists = await client.bf.exists('mybloom', 'simon');
console.log(`simon ${simonExists ? 'may' : 'does not'} exist in the Bloom Filter.`);
// Check whether multiple members exist with the BF.MEXISTS command:
const [ lanceExists, leibaleExists ] = await client.bf.mExists('mybloom', [
'lance',
'leibale'
]);
console.log(`lance ${lanceExists ? 'may' : 'does not'} exist in the Bloom Filter.`);
console.log(`leibale ${leibaleExists ? 'may' : 'does not'} exist in the Bloom Filter.`);
// Get stats for the Bloom Filter with the BF.INFO command:
const info = await client.bf.info('mybloom');
// info looks like this:
//
// {
// capacity: 1000,
// size: 1531,
// numberOfFilters: 1,
// numberOfInsertedItems: 12,
// expansionRate: 2
// }
console.log(info);
await client.quit();
}
bloomFilter();