transport

import "github.com/luxfi/zap/transport"

Package transport is the pluggable GPU-aware ZAP transport.

Three transports are implemented:

default — standard Go net (CPU parsing). Always available. uma — Apple Silicon / NVIDIA Grace unified-memory. cgo + darwin. Network packets land in shared RAM; GPU kernels read them at GPU memory speed without a copy. gpudirect — NVIDIA + Mellanox CX-6/7 (GPUDirect RDMA). cgo + linux. NIC DMA into VRAM, ZAP parsed by GPU kernel, no CPU touch. dpdk — Linux DPDK + GPU-mapped hugepages. cgo + linux. Kernel-bypass packet ingestion, GPU reads from mapped huge- pages. Best for non-Mellanox NICs.

All four implement the same Transport interface. Pick() chooses the best available implementation at runtime, honoring a caller-supplied preference and falling through gracefully when a preferred path is unavailable. There is no gpu build tag — cgo is the only gate, and the OS gate selects which native transports can compile in.

Functions

Registered

func Registered() []string

Registered returns the list of transports that this binary can attempt to instantiate (i.e. the platform-and-build-tag matrix). Used by tools like zap-info and the boot-time diagnostic in lqd.

Types

Buffer

Buffer is one slab of managed memory handed out by a BufferAllocator. For the UMA transport on Linux+CUDA, the underlying pointer is cudaMallocManaged memory — the same bytes the GPU sees. Calling Bytes() gives a Go slice that shares the storage; calling DevicePtr() gives the raw device pointer for CUDA kernel launches.

Release returns the buffer to its allocator. Double-Release is a no-op (allocators detect and ignore it).

BufferAllocator

BufferAllocator hands out managed buffers. Transports that can deliver GPU-resident bytes (UMA Linux+CUDA, UMA Darwin+Metal) implement this; transports that can't (default TCP) return ErrNotAvailable from AllocBuffer so the caller knows to fall back to heap allocation.

Capacity in bytes is the operator-configurable pool size (default 4 GiB); allocations from a full pool block until a buffer is Released.

Capabilities

Capabilities describes what a Transport implementation supports.

Transport

Transport is the wire-level surface multichain gossip uses to ship sealed MultiChainBlocks between validators. The interface is sized for one ZAP message per Send/Recv — batching happens above this layer.

func Pick(preferred string) (Transport, error)