Module zero_copy

The zero_copy module contains all the zero-copy-related data structures used in the system. Zero-copy market data structures for ultra-fast binary parsing

This module provides zerocopy-enabled structures for direct memory mapping of binary market data from exchanges, eliminating parsing overhead.

Bytemuck Usage Strategy

We use a hybrid approach with bytemuck for maximum safety:

1. Non-generic structs (ZeroCopyPriceLevel, ZeroCopyTrade, MessageHeader):

   • Use bytemuck’s Pod and Zeroable derives for safe zero-copy operations
   • All methods use bytemuck’s safe APIs (bytes_of, try_from_bytes)

2. Generic structs (ZeroCopyOrderBookUpdate):

   • Cannot derive Pod/Zeroable due to const generic limitations
   • Bytemuck doesn’t support arrays [T; N] with generic N
   • Maintain minimal unsafe code with comprehensive safety documentation
   • Use parse_message_generic() instead of parse_message()

This approach maximizes safety while maintaining the flexibility of const generics for compile-time configurable buffer sizes.

Re-exports

pub use ZeroCopyOrderBookUpdate10 as DefaultZeroCopyOrderBookUpdate;

Structs

MessageHeader

Zero-copy message header for length-prefixed protocols

ZeroCopyOrderBookUpdate

Zero-copy order book update with const generic array sizing

ZeroCopyPriceLevel

Zero-copy price level structure

ZeroCopyTrade

Zero-copy trade message

Functions

parse_message

Parse a message from a buffer with proper alignment checks

parse_message_generic

Parse a message from a buffer for types that can’t implement Pod

parse_message_mut

Parse a mutable message from a buffer with proper alignment checks

Type Aliases

ZeroCopyOrderBookUpdate5

Type alias for a zero-copy order book update with 5 levels per side.

ZeroCopyOrderBookUpdate10

Type alias for a zero-copy order book update with 10 levels per side.

ZeroCopyOrderBookUpdate20

Type alias for a zero-copy order book update with 20 levels per side.