lightstreamer_rs/

lib.rs

// Copyright (C) 2024 Joaquín Béjar García
// Portions of this file are derived from lightstreamer-client
// Copyright (C) 2024 Daniel López Azaña
// Original project: https://github.com/daniloaz/lightstreamer-client
//
// This file is part of lightstreamer-rs.
//
// lightstreamer-rs is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// lightstreamer-rs is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with lightstreamer-rs. If not, see <https://www.gnu.org/licenses/>.

//! # Lightstreamer Rust Client
//!
//! This project is a Rust implementation of the Lightstreamer TLCP (Text-based Live Connections Protocol). It provides a robust client SDK to interact with Lightstreamer servers, enabling real-time data streaming for financial applications, IoT systems, and other use cases requiring live data updates. While it was initially developed to support the [ig_trading_api](https://github.com/joaquinbejar/ig_trading_api) project, it has evolved into a more comprehensive SDK with broader applicability.
//!
//! ## Attribution
//!
//! This project contains code derived from [lightstreamer-client](https://github.com/daniloaz/lightstreamer-client)
//! by Daniel López Azaña (@daniloaz), originally published under GPL-3.0-only license in February 2024.
//!
//! ## About Lightstreamer
//!
//! Lightstreamer is a high-performance real-time messaging server that provides several key features:
//! - Real-time data streaming with optimized bandwidth usage
//! - Support for various transport mechanisms (WebSockets, HTTP streaming, etc.)
//! - Different subscription modes for various data delivery patterns
//! - Robust connection management with automatic recovery
//! - Scalable architecture for high-volume applications
//!
//! ## Features
//!
//! This Rust client SDK provides the following capabilities:
//!
//! - **Connection Management**:
//!   - Full-duplex WebSocket-based connection mode
//!   - Automatic reconnection with configurable retry policies
//!   - Session recovery after temporary disconnections
//!   - Connection status monitoring and event notifications
//!   - Proxy support for enterprise environments
//!
//! - **Subscription Capabilities**:
//!   - Support for multiple subscription modes (MERGE, DISTINCT, COMMAND, RAW)
//!   - Subscription to individual items or item groups
//!   - Field schema definition for structured data
//!   - Real-time item updates with change detection
//!   - Snapshot support for initial state recovery
//!
//! - **Configuration Options**:
//!   - Extensive connection options (polling intervals, timeouts, etc.)
//!   - Bandwidth control and throttling
//!   - Custom HTTP headers for authentication
//!   - Logging configuration for debugging
//!
//! - **Event Handling**:
//!   - Comprehensive event listener system
//!   - Subscription lifecycle events (subscription, unsubscription)
//!   - Item update notifications with field-level change detection
//!   - Connection status change notifications
//!   - Error handling and reporting
//!
//! ## Implementation Status
//!
//! The current implementation supports most core features of the Lightstreamer protocol, with a focus on the WebSocket transport mechanism and the MERGE subscription mode. While initially developed for specific trading API requirements, the library has expanded to include:
//!
//! - All subscription modes (MERGE, DISTINCT, COMMAND, RAW)
//! - Robust error handling and recovery mechanisms
//! - Comprehensive configuration options
//! - Thread-safe asynchronous operation using Tokio
//!
//! Some advanced features that may be implemented in future versions include:
//!
//! - Message sending capabilities (MPN)
//! - Client-side filtering and frequency limitations
//! - Additional transport mechanisms beyond WebSockets
//! - Enhanced security features
//!
//! ## Installation
//!
//! To use this SDK in your Rust project, add the following dependency to your `Cargo.toml`:
//!
//! ```toml
//! [dependencies]
//! lightstreamer-rs = "0.1.4"
//! ```
//!
//! ## Usage
//!
//! ### Quick Start (Simplified API)
//!
//! For most use cases, use the simplified `SimpleClient` API:
//!
//! ```ignore
//! use lightstreamer_rs::client::{ClientConfig, SimpleClient, SubscriptionParams};
//! use lightstreamer_rs::subscription::SubscriptionMode;
//!
//! #[tokio::main]
//! async fn main() -> Result<(), Box<dyn std::error::Error>> {
//!     // 1. Create configuration
//!     let config = ClientConfig::new("http://push.lightstreamer.com/lightstreamer")
//!         .adapter_set("DEMO");
//!
//!     // 2. Create client
//!     let client = SimpleClient::new(config)?;
//!
//!     // 3. Subscribe and get channel receiver
//!     let params = SubscriptionParams::new(
//!         SubscriptionMode::Merge,
//!         vec!["item1".to_string(), "item2".to_string()],
//!         vec!["last_price".to_string(), "time".to_string()],
//!     ).data_adapter("QUOTE_ADAPTER");
//!
//!     let mut receiver = client.subscribe(params).await?;
//!
//!     // 4. Process updates asynchronously
//!     tokio::spawn(async move {
//!         while let Some(update) = receiver.recv().await {
//!             println!("Price: {:?}", update.get_value("last_price"));
//!         }
//!     });
//!
//!     // 5. Connect and run
//!     client.connect().await?;
//!     
//!     Ok(())
//! }
//! ```
//!
//! ### Advanced Usage (Full API)
//!
//! Here's a comprehensive example of how to use the Lightstreamer Rust Client SDK:
//!
//! ```ignore
//! // This example shows how to use the Lightstreamer Rust client
//! use lightstreamer_rs::client::{LightstreamerClient, Transport};
//! use lightstreamer_rs::subscription::{Subscription, SubscriptionMode, SubscriptionListener, ItemUpdate};
//! use std::sync::Arc;
//! use tokio::sync::Notify;
//! use std::time::Duration;
//!
//! // Define a custom subscription listener
//! struct MySubscriptionListener;
//!
//! impl SubscriptionListener for MySubscriptionListener {
//!     fn on_subscription(&self) {
//!         info!("Subscription confirmed by the server");
//!     }
//!     
//!     fn on_item_update(&self, update: ItemUpdate) {
//!         info!("Received update for item: {}", update.get_item_name());
//!         for field in update.get_fields() {
//!             if let Some(value) = update.get_value(field) {
//!                 info!("  {} = {}", field, value);
//!             }
//!         }
//!     }
//! }
//!
//! async fn example() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
//!     // Create a new LightstreamerClient instance
//!     let result = LightstreamerClient::new(
//!         Some("ws://your-lightstreamer-server.com"),  // Server address
//!         Some("YOUR_ADAPTER_SET"),                   // Adapter set
//!         None,                                       // User (optional)
//!         None,                                       // Password (optional)
//!     );
//!     
//!     let mut client = match result {
//!         Ok(client) => client,
//!         Err(e) => return Err(e),
//!     };
//!     
//!     // Configure the connection details if needed
//!     client.connection_details.set_user("YOUR_USERNAME");
//!     client.connection_details.set_password("YOUR_PASSWORD");
//!     
//!     // Configure connection options if needed
//!     client.connection_options.set_content_length(50000000);
//!     client.connection_options.set_keepalive_interval(5);
//!     client.connection_options.set_forced_transport(Some(Transport::WsStreaming));
//!     
//!     // Create a shutdown signal for graceful termination
//!     let shutdown_signal = Arc::new(Notify::new());
//!     
//!     // Connect to the Lightstreamer server
//!     if let Err(e) = client.connect(shutdown_signal.clone()).await {
//!         return Err(e);
//!     }
//!     
//!     // Create a subscription
//!     let subscription_result = Subscription::new(
//!         SubscriptionMode::Merge,
//!         Some(vec!["item1".to_string(), "item2".to_string()]),
//!         Some(vec!["field1".to_string(), "field2".to_string()]),
//!     );
//!     
//!     let subscription = match subscription_result {
//!         Ok(sub) => sub,
//!         Err(e) => return Err(e),
//!     };
//!     
//!     // Add a listener to the subscription (optional)
//!     let listener = Box::new(MySubscriptionListener);
//!     subscription.add_listener(listener);
//!     
//!     // Get the subscription sender from the client
//!     // Note: This method might not exist in the current API, check the documentation
//!     let subscription_sender = client.get_subscriptions()[0].clone();
//!     
//!     // Subscribe and get the subscription ID
//!     let subscription_id_result = LightstreamerClient::subscribe_get_id(
//!         subscription_sender.clone(),
//!         subscription
//!     ).await;
//!     
//!     let subscription_id = match subscription_id_result {
//!         Ok(id) => id,
//!         Err(e) => return Err(e),
//!     };
//!     
//!     info!("Subscribed with ID: {}", subscription_id);
//!     
//!     // Wait for some time (in a real application, you would wait for a shutdown signal)
//!     tokio::time::sleep(Duration::from_secs(5)).await;
//!     
//!     // Unsubscribe before disconnecting
//!     LightstreamerClient::unsubscribe(subscription_sender, subscription_id).await;
//!     
//!     Ok(())
//! }
//! ```
//!
//! ### Handling Client Events
//!
//! You can also add listeners to handle client events:
//!
//! Here's an example of implementing a client listener:
//!
//! ```ignore
//! // Note: ClientListener is a private trait, this is just for illustration
//! use lightstreamer_rs::client::model::ClientStatus;
//!
//! struct MyClientListener;
//!
//! // This is just an example of what the ClientListener trait might look like
//! // The actual implementation is internal to the library
//! trait ClientListener {
//!     fn on_status_change(&self, status: &ClientStatus);
//!     fn on_server_error(&self, error_code: i32, error_message: &str);
//!     fn on_property_change(&self, property: &str);
//! }
//!
//! impl ClientListener for MyClientListener {
//!     fn on_status_change(&self, status: &ClientStatus) {
//!         info!("Client status changed to: {:?}", status);
//!     }
//!     
//!     fn on_server_error(&self, error_code: i32, error_message: &str) {
//!         info!("Server error: {} - {}", error_code, error_message);
//!     }
//!     
//!     fn on_property_change(&self, property: &str) {
//!         info!("Property changed: {}", property);
//!     }
//! }
//!
//! // Then add the listener to your client
//! // client.add_listener(Box::new(MyClientListener));
//! ```
//!
//! ### Channel-Based Update Processing
//!
//! For asynchronous processing of updates in separate tasks, you can use the `ChannelSubscriptionListener`:
//!
//! ```ignore
//! use lightstreamer_rs::subscription::ChannelSubscriptionListener;
//!
//! // Create a channel-based listener
//! let (listener, mut update_receiver) = ChannelSubscriptionListener::create_channel();
//!
//! // Add the listener to your subscription
//! subscription.add_listener(Box::new(listener));
//!
//! // Process updates asynchronously in a separate task
//! tokio::spawn(async move {
//!     while let Some(update) = update_receiver.recv().await {
//!         // Process the update
//!         println!("Item: {:?}", update.get_item_name());
//!         println!("Fields: {:?}", update.get_fields());
//!         
//!         // Perform any async operations
//!         // e.g., save to database, send to another service, etc.
//!     }
//! });
//! ```
//!
//! This approach allows you to:
//! - Decouple update reception from processing
//! - Process updates asynchronously without blocking the Lightstreamer event loop
//! - Easily integrate with other async workflows
//! - Handle backpressure naturally through channel buffering
//!

/// Module containing subscription-related functionality.
///
/// This module provides the necessary types and functions to create and manage subscriptions
/// to Lightstreamer items. It includes the `Subscription` struct, subscription modes,
/// item updates, and subscription listeners.
pub mod subscription;

/// Module containing utility functions and error types.
///
/// This module provides common utilities and error types used throughout the library,
/// including exception types for handling illegal arguments and states.
pub mod utils;

/// Module containing client-related functionality.
///
/// This module provides the main `LightstreamerClient` type and related components for
/// connecting to Lightstreamer servers, managing sessions, and handling client events.
pub mod client;

/// Module containing connection-related functionality.
///
/// This module provides types for managing connection details and options.
pub mod connection;