otterbook_core 0.1.3

A high-performance, lock-free price level implementation for limit order books in Rust. This library provides the building blocks for creating efficient trading systems with support for multiple order types and concurrent access patterns.
Documentation
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use crate::{OrderBook, OrderBookError};
use pricelevel::{OrderId, OrderType, OrderUpdate, PriceLevel, Side};
use std::sync::Arc;
use tracing::trace;

impl OrderBook {
    /// Update an order's price and/or quantity
    pub fn update_order(
        &self,
        update: OrderUpdate,
    ) -> Result<Option<Arc<OrderType>>, OrderBookError> {
        trace!("Order book {}: Updating order {:?}", self.symbol, update);
        match update {
            OrderUpdate::UpdatePrice {
                order_id,
                new_price,
            } => {
                // Get the order location without locking
                let location = self.order_locations.get(&order_id).map(|val| *val);

                if let Some((old_price, _)) = location {
                    // If price doesn't change, do nothing
                    if old_price == new_price {
                        return Err(OrderBookError::InvalidOperation {
                            message: "Cannot update price to the same value".to_string(),
                        });
                    }

                    // Get the original order without holding locks
                    let original_order = if let Some(order) = self.get_order(order_id) {
                        // Create a copy of the order
                        Arc::try_unwrap(order.clone()).unwrap_or_else(|arc| (*arc))
                    } else {
                        return Ok(None); // Order not found
                    };

                    // Cancel the original order
                    self.cancel_order(order_id)?;

                    // Create a new order with the updated price
                    let mut new_order = original_order;

                    // Update the price based on order type
                    match &mut new_order {
                        OrderType::Standard { price, .. } => *price = new_price,
                        OrderType::IcebergOrder { price, .. } => *price = new_price,
                        OrderType::PostOnly { price, .. } => *price = new_price,
                        OrderType::TrailingStop { price, .. } => *price = new_price,
                        OrderType::PeggedOrder { price, .. } => *price = new_price,
                        OrderType::MarketToLimit { price, .. } => *price = new_price,
                        OrderType::ReserveOrder { price, .. } => *price = new_price,
                    }

                    // Add the updated order
                    let result = self.add_order(new_order)?;
                    Ok(Some(result))
                } else {
                    Ok(None) // Order not found
                }
            }

            OrderUpdate::UpdateQuantity {
                order_id,
                new_quantity,
            } => {
                // Get order location without locking
                let location = self.order_locations.get(&order_id).map(|val| *val);

                if let Some((price, side)) = location {
                    // Get the appropriate price levels map
                    let price_levels = match side {
                        Side::Buy => &self.bids,
                        Side::Sell => &self.asks,
                    };

                    // Use entry() to safely modify the price level without deadlocks
                    let mut result = None;
                    let mut is_empty = false;

                    price_levels.entry(price).and_modify(|price_level| {
                        // Create update operation
                        let update = OrderUpdate::UpdateQuantity {
                            order_id,
                            new_quantity,
                        };

                        // Try to update the order
                        if let Ok(updated_order) = price_level.update_order(update) {
                            result = updated_order;
                            is_empty = price_level.order_count() == 0;
                        }
                    });

                    // If the price level is now empty, remove it
                    if is_empty {
                        price_levels.remove(&price);
                        self.order_locations.remove(&order_id);
                    }

                    Ok(result)
                } else {
                    Ok(None) // Order not found
                }
            }

            OrderUpdate::UpdatePriceAndQuantity {
                order_id,
                new_price,
                new_quantity,
            } => {
                // Get order location without locking
                let location = self.order_locations.get(&order_id).map(|val| *val);

                if let Some((_, _)) = location {
                    // Get the original order without holding locks
                    let original_order = if let Some(order) = self.get_order(order_id) {
                        // Create a copy of the order
                        Arc::try_unwrap(order.clone()).unwrap_or_else(|arc| (*arc))
                    } else {
                        return Ok(None); // Order not found
                    };

                    // Cancel the original order
                    self.cancel_order(order_id)?;

                    // Create a new order with the updated price and quantity
                    let mut new_order = original_order;

                    // Update the price and quantity based on order type
                    match &mut new_order {
                        OrderType::Standard {
                            price, quantity, ..
                        } => {
                            *price = new_price;
                            *quantity = new_quantity;
                        }
                        OrderType::IcebergOrder {
                            price,
                            visible_quantity,
                            ..
                        } => {
                            *price = new_price;
                            *visible_quantity = new_quantity;
                        }
                        OrderType::PostOnly {
                            price, quantity, ..
                        } => {
                            *price = new_price;
                            *quantity = new_quantity;
                        }
                        OrderType::TrailingStop {
                            price, quantity, ..
                        } => {
                            *price = new_price;
                            *quantity = new_quantity;
                        }
                        OrderType::PeggedOrder {
                            price, quantity, ..
                        } => {
                            *price = new_price;
                            *quantity = new_quantity;
                        }
                        OrderType::MarketToLimit {
                            price, quantity, ..
                        } => {
                            *price = new_price;
                            *quantity = new_quantity;
                        }
                        OrderType::ReserveOrder {
                            price,
                            visible_quantity,
                            ..
                        } => {
                            *price = new_price;
                            *visible_quantity = new_quantity;
                        }
                    }

                    // Add the updated order
                    let result = self.add_order(new_order)?;
                    Ok(Some(result))
                } else {
                    Ok(None) // Order not found
                }
            }

            OrderUpdate::Cancel { order_id } => {
                // Get order location without locking
                let location = self.order_locations.get(&order_id).map(|val| *val);

                if let Some((price, side)) = location {
                    // Get the appropriate price levels map
                    let price_levels = match side {
                        Side::Buy => &self.bids,
                        Side::Sell => &self.asks,
                    };

                    // Use entry() to safely modify the price level
                    let mut result = None;
                    let mut is_empty = false;

                    price_levels.entry(price).and_modify(|price_level| {
                        // Create cancel operation
                        let update = OrderUpdate::Cancel { order_id };

                        // Try to cancel the order
                        if let Ok(cancelled_order) = price_level.update_order(update) {
                            result = cancelled_order;
                            is_empty = price_level.order_count() == 0;
                        }
                    });

                    // If we cancelled an order, remove it from tracking
                    if result.is_some() {
                        self.order_locations.remove(&order_id);

                        // If price level is empty, remove it
                        if is_empty {
                            price_levels.remove(&price);
                        }
                    }

                    Ok(result)
                } else {
                    Ok(None) // Order not found
                }
            }

            OrderUpdate::Replace {
                order_id,
                price,
                quantity,
                side,
            } => {
                // Get the original order without holding locks
                let original_opt = self.get_order(order_id);

                if let Some(original) = original_opt {
                    // Extract what we need from the original order
                    let timestamp = original.timestamp();
                    let time_in_force = original.time_in_force();

                    // Check which order type we need to create
                    let new_order = match &*original {
                        OrderType::Standard { .. } => OrderType::Standard {
                            id: order_id,
                            price,
                            quantity,
                            side,
                            timestamp,
                            time_in_force,
                        },
                        OrderType::IcebergOrder {
                            hidden_quantity, ..
                        } => OrderType::IcebergOrder {
                            id: order_id,
                            price,
                            visible_quantity: quantity,
                            hidden_quantity: *hidden_quantity,
                            side,
                            timestamp,
                            time_in_force,
                        },
                        OrderType::PostOnly { .. } => OrderType::PostOnly {
                            id: order_id,
                            price,
                            quantity,
                            side,
                            timestamp,
                            time_in_force,
                        },
                        OrderType::ReserveOrder {
                            hidden_quantity,
                            replenish_threshold,
                            replenish_amount,
                            auto_replenish,
                            ..
                        } => OrderType::ReserveOrder {
                            id: order_id,
                            price,
                            visible_quantity: quantity,
                            hidden_quantity: *hidden_quantity,
                            side,
                            timestamp,
                            time_in_force,
                            replenish_threshold: *replenish_threshold,
                            replenish_amount: *replenish_amount,
                            auto_replenish: *auto_replenish,
                        },
                        // Add cases for other order types if needed
                        _ => {
                            return Err(OrderBookError::InvalidOperation {
                                message: "Replace operation not supported for this order type"
                                    .to_string(),
                            });
                        }
                    };

                    // Cancel the original order
                    self.cancel_order(order_id)?;

                    // Add the new order
                    let result = self.add_order(new_order)?;
                    Ok(Some(result))
                } else {
                    Ok(None) // Original order not found
                }
            }
        }
    }

    /// Cancel an order by ID
    pub fn cancel_order(
        &self,
        order_id: OrderId,
    ) -> Result<Option<Arc<OrderType>>, OrderBookError> {
        // Primero encontramos la ubicación de la orden (precio y lado) sin bloquear
        let location = self.order_locations.get(&order_id).map(|val| *val);

        if let Some((price, side)) = location {
            // Obtener el mapa de niveles de precio apropiado
            let price_levels = match side {
                Side::Buy => &self.bids,
                Side::Sell => &self.asks,
            };

            // Crear la actualización para cancelar
            let update = OrderUpdate::Cancel { order_id };

            // Utilizar entry() para modificar el nivel de precio de manera segura
            let mut result = None;
            let mut empty_level = false;

            price_levels.entry(price).and_modify(|price_level| {
                // Intentar cancelar la orden
                if let Ok(cancelled) = price_level.update_order(update) {
                    result = cancelled;

                    // Verificar si el nivel quedó vacío
                    empty_level = price_level.order_count() == 0;
                }
            });

            // Si obtuvimos un resultado y la orden fue cancelada
            if result.is_some() {
                // Eliminar la orden del mapa de ubicaciones
                self.order_locations.remove(&order_id);

                // Si el nivel quedó vacío, eliminarlo
                if empty_level {
                    price_levels.remove(&price);
                }
            }

            Ok(result)
        } else {
            // La orden no se encontró
            Ok(None)
        }
    }

    /// Add a new order to the book
    pub fn add_order(&self, order: OrderType) -> Result<Arc<OrderType>, OrderBookError> {
        trace!(
            "Order book {}: Adding order {} at price {}",
            self.symbol,
            order.id(),
            order.price()
        );
        let price = order.price();
        let side = order.side();

        // Check if the order has expired before adding
        if self.has_expired(&order) {
            return Err(OrderBookError::InvalidOperation {
                message: "Order has already expired".to_string(),
            });
        }

        // For post-only orders, check for price crossing
        if order.is_post_only() && self.will_cross_market(price, side) {
            let opposite_price = match side {
                Side::Buy => self.best_ask().unwrap(),
                Side::Sell => self.best_bid().unwrap(),
            };

            return Err(OrderBookError::PriceCrossing {
                price,
                side,
                opposite_price,
            });
        }

        // Handle immediate-or-cancel and fill-or-kill orders
        if order.is_immediate() {
            return self.handle_immediate_order(order);
        }

        // Standard limit order processing
        let price_levels = match side {
            Side::Buy => &self.bids,
            Side::Sell => &self.asks,
        };

        // Get or create the price level
        let price_level = price_levels
            .entry(price)
            .or_insert_with(|| Arc::new(PriceLevel::new(price)));

        // Add the order to the price level
        let order_arc = price_level.add_order(order);

        // Track the order's location
        self.order_locations.insert(order_arc.id(), (price, side));

        Ok(order_arc)
    }
}