Module postgres 

PostgreSQL LISTEN/NOTIFY coordination for distributed WarpDrive instances

This module provides distributed coordination using PostgreSQL’s LISTEN/NOTIFY feature. Multiple WarpDrive instances can coordinate cache invalidation, circuit breaker state, rate limits, and health status.

Architecture

• PgPool: Connection pool for PostgreSQL operations
• PgListener: Long-lived connection for receiving NOTIFY events
• PgNotifier: Publishes NOTIFY events to channels
• PgNotification: Typed notification message with JSON payload

Example

use warpdrive::postgres::{PgPool, PgListener, PgNotifier};
use warpdrive::config::Config;

let config = Config::from_env()?;
let pool = PgPool::from_config(&config).await?;

// Start listening for cache invalidations
let channels = vec!["warpdrive:cache:invalidate".to_string()];
let mut listener = PgListener::new(&pool, channels).await?;

// Publish a notification
let notifier = PgNotifier::new(pool.clone());
notifier.notify("warpdrive:cache:invalidate", &serde_json::json!({
    "key": "user:123"
})).await?;

// Receive notification
use futures::StreamExt;
while let Some(notification) = listener.stream().next().await {
    println!("Received: {:?}", notification);
}

Structs

PgListener

PostgreSQL LISTEN handler for receiving NOTIFY events

PgNotification

Notification received from PostgreSQL LISTEN

PgNotifier

PostgreSQL NOTIFY publisher for sending notifications

PgPool

PostgreSQL connection pool for distributed coordination

Enums

PgError

Errors that can occur during PostgreSQL operations