Plugin Architecture

/var/lib/nabustore/plugins/
├── kioxia.sock       ← vendor binary listens here
├── hpe-alletra.sock
└── pure-fb.sock      ← auto-discovered on startup + inotify watch

// GRPCBackend wraps a vendor gRPC process as a BlobBackend.
// The vendor binary need not be written in Go — it only needs to
// implement BlobService as defined in proto/nabustore.proto.
type GRPCBackend struct {
    conn   *grpc.ClientConn
    client pb.BlobServiceClient
}

func NewGRPCBackend(socketPath string) (*GRPCBackend, error) {
    conn, err := grpc.Dial(
        "unix://"+socketPath,
        grpc.WithTransportCredentials(insecure.NewCredentials()),
        grpc.WithBlock(),
    )
    if err != nil {
        return nil, fmt.Errorf("grpc_backend: dial %s: %w", socketPath, err)
    }
    return &GRPCBackend{conn: conn, client: pb.NewBlobServiceClient(conn)}, nil
}

// Put, Get, GetRange, Stat, Delete, List, Capacity, Close
// all delegate to the gRPC client — proto messages already match
// BlobBackend semantics 1:1.

package localfs

import "github.com/nabustore/nabustore/plugin"

func init() {
    plugin.RegisterBackend("localfs", func(cfg map[string]string) (blob.BlobBackend, error) {
        return NewLocalFSBackend(cfg["data_dir"])
    })
}

//go:build spdk

package spdk

import "github.com/nabustore/nabustore/plugin"

func init() {
    plugin.RegisterBackend("spdk", func(cfg map[string]string) (blob.BlobBackend, error) {
        return NewSPDKBackend(cfg["socket"], cfg["bdev"], cfg["core_mask"])
    })
}

package grpcbackend

import "github.com/nabustore/nabustore/plugin"

func init() {
    // The gRPC backend name is the socket path prefix.
    // plugin.OpenBackend("grpc:kioxia", cfg) → dials unix:///var/lib/nabustore/plugins/kioxia.sock
    plugin.RegisterBackend("grpc", func(cfg map[string]string) (blob.BlobBackend, error) {
        return NewGRPCBackend(cfg["socket_path"])
    })
}

//go:build dpdk

package dpdk

import "github.com/nabustore/nabustore/plugin"

func init() {
    plugin.RegisterTransport("dpdk", func(cfg map[string]string) (transport.Transport, error) {
        return NewDPDKTransport(cfg["pci_addr"], cfg["core_mask"], cfg["mem_size"])
    })
}

//go:build isal
// +build isal
//
// CGO linkage: -lisal  (Intel Intelligent Storage Acceleration Library)
// ISA-L must be installed: dnf install isa-l-devel / apt install libisal-dev

package isal

import "github.com/nabustore/nabustore/plugin"

func init() {
    plugin.RegisterEC("isal", func(cfg map[string]string) (ec.Engine, error) {
        data, _ := strconv.Atoi(cfg["data_shards"])
        parity, _ := strconv.Atoi(cfg["parity_shards"])
        return NewISALEngine(data, parity)  // CGO call into gf_vect_mul / ec_encode_data
    })
}

// CXLIndex is a Robin Hood hash map backed by a Linux DAX device.
// No vendor software required — uses the standard kernel cxl_mem driver
// (in from 5.12, production-stable from 6.5).
//
// Detection path:
//   1. /sys/bus/cxl/devices/*  — enumerate CXL DIMMs
//   2. /dev/dax*               — find corresponding DAX character device
//   3. mmap(O_RDWR|MAP_SHARED) — map the DAX range directly
//   4. clflushopt/clwb         — persistence without msync() overhead
//
// The layout on the DAX device is identical to the mmap/file backend
// so a node can be rebooted without re-indexing.

type CXLIndex struct {
    base    *mmapIndex  // shared Robin Hood logic
    dax     *os.File
    numaNode int
}

func New(daxPath string, numaNode int) (*CXLIndex, error) {
    f, err := os.OpenFile(daxPath, os.O_RDWR, 0600)
    if err != nil {
        return nil, fmt.Errorf("cxl_index: open %s: %w", daxPath, err)
    }
    // ... mmap + validate magic header ...
}

package kioxia

import (
    "github.com/nabustore/nabustore/blob"
    "github.com/nabustore/nabustore/plugin"
)

func init() {
    plugin.RegisterBackend("kioxia-xd7p", func(cfg map[string]string) (blob.BlobBackend, error) {
        return NewXD7PBackend(
            cfg["endpoint"],   // e.g. "192.168.1.10:4420"
            cfg["nqn"],        // NVMe Qualified Name for the subsystem
            cfg["ns_id"],      // Namespace ID
        )
    })
}