laminar-core 0.13.1

Core streaming engine for LaminarDB - reactor, operators, and state management
Documentation

laminar-core

Core streaming engine for LaminarDB -- reactor, operators, state stores, and streaming infrastructure.

Overview

This is the Ring 0 crate containing all latency-critical components. Everything here is designed for sub-microsecond execution with zero heap allocations on the hot path.

Key Modules

Module Purpose
reactor Single-threaded event loop, CPU-pinned
operator Windows (tumbling, sliding, hopping, session), joins (stream, ASOF, temporal, lookup), changelog, lag/lead, ranking
state StateStore trait, InMemoryStateStore (FxHashMap), ChangelogAwareStore wrapper
time Event time processing, watermarks (partitioned, keyed, alignment groups)
streaming Ring buffer, SPSC/MPSC channels, source/sink abstractions, checkpoint manager
dag DAG pipeline topology, multicast routing, executor, checkpointing
subscription Reactive push-based subscriptions: events, notifications, registry, dispatcher
tpc Thread-per-core runtime: SPSC queues, key router, core handles, backpressure
sink Exactly-once transactional sink, epoch adapter
mv Cascading materialized views
compiler JIT compiler: EventRow, Cranelift expressions, pipeline extraction/compilation, cache
alloc Zero-allocation enforcement (bump/arena allocators)
numa NUMA-aware memory allocation
io_uring io_uring integration, three-ring I/O architecture
budget Task budget enforcement

Feature Flags

Flag Purpose
jit Cranelift JIT compilation for Ring 0 query execution
allocation-tracking Panic on heap allocation in marked sections
io-uring Linux 5.10+ io_uring integration
hwloc Enhanced NUMA topology discovery
xdp Linux eBPF/XDP network optimization

Ring Placement

This crate operates in Ring 0 (Hot Path). All code must:

  • Make zero heap allocations
  • Use no locks (SPSC queues for communication)
  • Avoid system calls on the fast path
  • Stay within task budget limits

Benchmarks

cargo bench -p laminar-core --bench state_bench       # State lookup latency
cargo bench -p laminar-core --bench throughput_bench   # Throughput per core
cargo bench -p laminar-core --bench latency_bench      # p99 latency
cargo bench -p laminar-core --bench window_bench       # Window operations
cargo bench -p laminar-core --bench dag_bench          # DAG pipeline
cargo bench -p laminar-core --bench join_bench         # Join throughput