simple_redis

Simple and resilient redis client.


Keywords
pubsub, database, cache, redis, redis-client, rust, rust-library
License
Apache-2.0

Documentation

simple_redis

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Simple and resilient redis client for rust.

Overview

This library provides a very basic, simple API for the most common redis operations.
While not as comprehensive or flexible as redis-rs, it does provide a simpler api for most common use cases and operations as well as automatic and resilient internal connection and subscription (pubsub) handling.
In addition, the entire API is accessible via simple client interface and there is no need to manage multiple entities such as connection or pubsub in parallel.

Connection Resiliency

Connection resiliency is managed by verifying the internally managed connection before every operation against the redis server.
In case of any connection issue, a new connection will be allocated to ensure the operation is invoked on a valid connection only.
However, this comes at a small performance cost of PING operation to the redis server.

//! In redis-rs, connections are no longer usable in case the connection is broken and if operations are invoked on the client directly, it will basically open a new connection for every operation which is very costly.

Subscription Resiliency

Subscription resiliency is ensured by recreating the internal pubsub and issuing new subscription requests automatically in case of any error while fetching a message from the subscribed channels.

redis-rs doesn't provide any such automatic resiliency and re-subscription capabilities.

Usage

Initialization and Simple Operations

fn main() {
    match simple_redis::create("redis://127.0.0.1:6379/") {
        Ok(mut client) => {
            println!("Created Redis Client");

            match client.set("my_key", "my_value") {
                Err(error) => println!("Unable to set value in Redis: {}", error),
                _ => println!("Value set in Redis"),
            };

            match client.get_string("my_key") {
                Ok(value) => println!("Read value from Redis: {}", value),
                Err(error) => println!("Unable to get value from Redis: {}", error),
            };

            match client.set("my_numeric_key", 255.5) {
                Err(error) => println!("Unable to set value in Redis: {}", error),
                _ => println!("Value set in Redis"),
            };

            match client.get::<f32>("my_numeric_key") {
                Ok(value) => println!("Read value from Redis: {}", value),
                Err(error) => println!("Unable to get value from Redis: {}", error),
            };

            match client.hgetall("my_map") {
                Ok(map) => match map.get("my_field") {
                    Some(value) => println!("Got field value from map: {}", value),
                    None => println!("Map field is empty"),
                },
                Err(error) => println!("Unable to read map from Redis: {}", error),
            };

            // run some command that is not built in the library
            match client.run_command::<String>("ECHO", vec!["testing"]) {
                Ok(value) => assert_eq!(value, "testing"),
                _ => panic!("test error"),
            };

            // publish messages
            let result = client.publish("news_channel", "test message");
            assert!(result.is_ok());
        }
        Err(error) => println!("Unable to create Redis client: {}", error),
    }
}

Subscription Flow

use simple_redis::{Interrupts, Message};

fn main() {
    match simple_redis::create("redis://127.0.0.1:6379/") {
        Ok(mut client) => {
            println!("Created Redis Client");

            let mut result = client.subscribe("important_notifications");
            assert!(result.is_ok());
            result = client.psubscribe("*_notifications");
            assert!(result.is_ok());

            // fetch messages from all subscriptions
            let mut polling_counter: usize = 0;
            client
                .fetch_messages(
                    &mut |message: Message| -> bool {
                        let payload: String = message.get_payload().unwrap();
                        println!("Got message: {}", payload);

                        // continue fetching
                        false
                    },
                    // interrupts enable you to break the fetching blocking call
                    &mut || -> Interrupts {
                        let mut interrupts = Interrupts::new();
                        interrupts.next_polling_time = Some(150);

                        polling_counter = polling_counter + 1;
                        if polling_counter > 3 {
                            interrupts.stop = true;
                        }

                        interrupts
                    },
                )
                .unwrap();
        }
        Err(error) => println!("Unable to create Redis client: {}", error),
    }
}

Closing Connection

fn main() {
    match simple_redis::create("redis://127.0.0.1:6379/") {
        Ok(mut client) => {
            println!("Created Redis Client");

            match client.set("my_key", "my_value") {
                Err(error) => println!("Unable to set value in Redis: {}", error),
                _ => println!("Value set in Redis"),
            };

            match client.quit() {
                Err(error) => println!("Error: {}", error),
                _ => println!("Connection Closed."),
            }
        }
        Err(error) => println!("Unable to create Redis client: {}", error),
    }
}

Installation

In order to use this library, just add it as a dependency:

[dependencies]
simple_redis = "^0.6.3"

API Documentation

See full docs at: API Docs

Contributing

See contributing guide

Release History

See Changelog

License

Developed by Sagie Gur-Ari and licensed under the Apache 2 open source license.