2178d6a70c
A maintainable, extensible BitTorrent client (C11, Linux/io_uring) targeting 10 GbE saturation. All torrent functionality is built from scratch; liburing is the only linked third-party dependency on the data path. Implements Phases 1-7 of the roadmap: - core: page-aligned buffer pool, MPMC/Treiber queues, bitfields, worker pool - crypto: SHA-1/256 (SHA-NI + scalar), Merkle (BEP-52), RC4 (MSE) - bencode/metainfo: zero-copy parser, v1/v2/hybrid .torrent + magnet - peer: sans-IO wire codec, MSE/PE handshake state machine, BEP-10, ut_metadata, PEX - piece/storage: block-level multi-peer engine, rarest-first + endgame, per-file completion events + single-file relocate (move-as-you-finish) - tracker/dht: HTTP + UDP (BEP-15) trackers, BEP-5 KRPC iterative lookup - platform: io_uring reactor (SQPOLL, registered buffers, SEND_ZC) - surface: versioned RPC, native plugin ABI, sandboxed Lua scripting, nautd/nautctl Verified against libtorrent (single/multi/hybrid, MSE, magnet-via-DHT, swarm); unit + interop tests green; ASan/UBSan/TSan clean. Scripting reference in docs/scripting.md. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
63 lines
2.8 KiB
C
63 lines
2.8 KiB
C
/* buf.h — page-aligned, refcounted buffer pool.
|
|
*
|
|
* This is the spine of the zero-copy data path. One physical buffer is filled
|
|
* by recv (io_uring registered buffer), decrypted in place, hashed in place by
|
|
* a worker thread, then written to disk via O_DIRECT or sent via SEND_ZC — the
|
|
* same pages throughout, never memcpy'd.
|
|
*
|
|
* Ownership model (ABA-free without tagging):
|
|
* - naut_buf_get() pops from the freelist and is SINGLE-CONSUMER: only the
|
|
* pool's owning reactor thread may call it.
|
|
* - naut_buf_put()/naut_buf_ref() are MULTI-PRODUCER: any thread (e.g. a hash
|
|
* worker that finished with a buffer) may call them. put() pushes back onto
|
|
* the freelist only on the 1->0 refcount transition.
|
|
* Because only the owner pops, a buffer in flight is never re-pushed by another
|
|
* thread, so the Treiber-stack pop has no ABA hazard.
|
|
*/
|
|
#ifndef NAUT_BUF_H
|
|
#define NAUT_BUF_H
|
|
|
|
#include "naut/common.h"
|
|
|
|
typedef struct naut_bufpool naut_bufpool;
|
|
|
|
typedef struct naut_buf {
|
|
_Atomic uint32_t refcnt; /* live references; 0 => on freelist */
|
|
uint32_t len; /* bytes of valid payload in data[] */
|
|
uint32_t cap; /* == pool block_size */
|
|
uint32_t idx; /* index within the pool (for registered bufs)*/
|
|
struct naut_buf *fnext; /* freelist link (owner-thread access only) */
|
|
naut_bufpool *pool;
|
|
uint8_t *data; /* page-aligned, cap bytes */
|
|
} naut_buf;
|
|
|
|
/* block_size must be a multiple of NAUT_PAGE (O_DIRECT alignment).
|
|
* If use_hugepages, the data slab is mmap'd with MAP_HUGETLB (falls back to
|
|
* normal pages if unavailable). */
|
|
naut_bufpool *naut_bufpool_create(uint32_t block_size, uint32_t block_count,
|
|
bool use_hugepages);
|
|
naut_bufpool *naut_bufpool_create_on_node(uint32_t block_size,
|
|
uint32_t block_count,
|
|
bool use_hugepages,
|
|
int numa_node);
|
|
void naut_bufpool_destroy(naut_bufpool *p);
|
|
|
|
/* Owner thread only. Returns NULL when exhausted (caller applies backpressure).
|
|
* Returned buffer has refcnt==1 and len==0. */
|
|
naut_buf *naut_buf_get(naut_bufpool *p) NAUT_MUST_USE;
|
|
|
|
/* Any thread. */
|
|
NAUT_INLINE void naut_buf_ref(naut_buf *b) {
|
|
atomic_fetch_add_explicit(&b->refcnt, 1, memory_order_relaxed);
|
|
}
|
|
void naut_buf_put(naut_buf *b);
|
|
|
|
/* Introspection (approximate under concurrency). */
|
|
uint32_t naut_bufpool_capacity(const naut_bufpool *p);
|
|
uint32_t naut_bufpool_available(const naut_bufpool *p);
|
|
|
|
/* Base of the contiguous data slab + total bytes — used to register the whole
|
|
* region with io_uring as a single fixed-buffer area. */
|
|
void *naut_bufpool_slab(const naut_bufpool *p, size_t *out_bytes);
|
|
|
|
#endif /* NAUT_BUF_H */
|