1 #ifndef IO_URING_ENGINE_H
2 #define IO_URING_ENGINE_H 1
8 #include <sys/socket.h>
10 #include <linux/stat.h>
19 IOUringEngine(size_t slop_bytes);
20 void submit_read(int fd, size_t len, off_t offset, std::function<void(std::string_view)> cb);
22 // NOTE: We just do the stat() to get the data into the dentry cache for fast access,
23 // or to check whether the file exists. Thus, the callback has only an OK/not OK boolean.
24 void submit_stat(const char *path, std::function<void(bool ok)> cb);
25 bool get_supports_stat() { return supports_stat; }
28 size_t get_waiting_reads() const { return pending_reads + queued_reads.size(); }
32 void submit_read_internal(io_uring_sqe *sqe, int fd, size_t len, off_t offset, std::function<void(std::string_view)> cb);
33 void submit_stat_internal(io_uring_sqe *sqe, char *path, std::function<void(bool)> cb);
37 size_t pending_reads = 0; // Number of requests we have going in the ring.
38 bool using_uring, supports_stat = false;
39 const size_t slop_bytes;
45 std::function<void(std::string_view)> cb;
47 std::queue<QueuedRead> queued_reads;
50 char *pathname; // Owned by us.
51 std::function<void(bool)> cb;
53 std::queue<QueuedStat> queued_stats;
61 std::function<void(std::string_view)> read_cb;
62 std::function<void(bool)> stat_cb;
81 // 256 simultaneous requests should be ample, for slow and fast media alike.
82 static constexpr size_t queue_depth = 256;
85 #endif // !defined(IO_URING_ENGINE_H)