1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311
//! A steamy river of uring. Fast IO using io_uring. //! //! io_uring is going to change everything. It will speed up your //! disk usage by like 300%. Go ahead, run the `O_DIRECT` example //! and compare that to using a threadpool or anything //! you want. It's not gonna come close! //! //! Starting in linux 5.5, it also has support for tcp accept. //! This is gonna shred everything out there!!! //! //! But there's a few snags. Mainly, it's a little misuse-prone. //! But Rust is pretty nice for specifying proofs about //! memory usage in the type system. And we don't even have //! to get too squirley. Check out the `write_at` implementation, //! for example. It just says that the Completion, the underlying //! uring, the file being used, the buffer being used, etc... //! will all be in scope at the same time while the Completion //! is in-use. //! //! This library aims to be misuse-resistant. //! Most of the other io_uring libraries make //! it really easy to blow your legs off with //! use-after-frees. `rio` uses standard Rust //! lifetime specification to make use-after-frees //! fail to compile. Also, if a `Completion` //! that was pinned to the lifetime of a uring //! and backing buffer is dropped, it //! waits for its backing operation to complete //! before returning from Drop, to further //! prevent use-after-frees. use-after-frees //! are not expressible when using `rio`. //! //! # Examples //! //! This won't compile: //! //! ```compile_fail //! let rio = rio::new().unwrap(); //! let file = std::fs::File::open("use_after_free").unwrap(); //! let out_buf = vec![42; 666]; //! //! let completion = rio.write_at(&file, &out_buf, 0).unwrap(); //! //! // At this very moment, the kernel has a pointer to that there slice. //! // It also has the raw file descriptor of the file. //! // It's fixin' to write the data from that memory into the file. //! // But if we freed it, it would be a bug, //! // and the kernel would write potentially scandalous data //! // into the file instead. //! //! // any of the next 3 lines would cause compilation to fail... //! drop(out_io_slice); //! drop(file); //! drop(rio); //! //! // this is both a Future and a normal blocking promise thing. //! // If you're using async, just call `.await` on it instead //! // of `.wait()` //! completion.wait(); //! //! // now it's safe to drop those things in any order. //! ``` //! //! //! Really shines with O_DIRECT: //! //! ```no_run //! use std::{ //! fs::OpenOptions, //! io::{IoSlice, Result}, //! os::unix::fs::OpenOptionsExt, //! }; //! //! const CHUNK_SIZE: u64 = 4096 * 256; //! //! // `O_DIRECT` requires all reads and writes //! // to be aligned to the block device's block //! // size. 4096 might not be the best, or even //! // a valid one, for yours! //! #[repr(align(4096))] //! struct Aligned([u8; CHUNK_SIZE as usize]); //! //! fn main() -> Result<()> { //! // start the ring //! let ring = rio::new().expect("create uring"); //! //! // open output file, with `O_DIRECT` set //! let file = OpenOptions::new() //! .read(true) //! .write(true) //! .create(true) //! .truncate(true) //! .custom_flags(libc::O_DIRECT) //! .open("file") //! .expect("open file"); //! //! // create output buffer //! let out_buf = Aligned([42; CHUNK_SIZE as usize]); //! let out_slice = out_buf.0.as_ref(); //! //! let mut completions = vec![]; //! //! for i in 0..(4 * 1024) { //! let at = i * CHUNK_SIZE; //! //! let completion = ring.write_at( //! &file, //! &out_slice, //! at, //! ); //! completions.push(completion); //! } //! //! for completion in completions.into_iter() { //! completion.wait()?; //! } //! //! Ok(()) //! } //! ``` #![doc( html_logo_url = "https://raw.githubusercontent.com/spacejam/sled/master/art/tree_face_anti-transphobia.png" )] #![cfg_attr(test, deny(warnings))] #![deny( missing_docs, future_incompatible, nonstandard_style, rust_2018_idioms, missing_copy_implementations, trivial_casts, trivial_numeric_casts, unsafe_code, unused_qualifications )] #![deny( clippy::cast_lossless, clippy::cast_possible_truncation, clippy::cast_possible_wrap, clippy::cast_precision_loss, clippy::cast_sign_loss, clippy::checked_conversions, clippy::decimal_literal_representation, clippy::doc_markdown, clippy::empty_enum, clippy::explicit_into_iter_loop, clippy::explicit_iter_loop, clippy::expl_impl_clone_on_copy, clippy::fallible_impl_from, clippy::filter_map, clippy::filter_map_next, clippy::find_map, clippy::float_arithmetic, clippy::get_unwrap, clippy::if_not_else, clippy::inline_always, clippy::invalid_upcast_comparisons, clippy::items_after_statements, clippy::map_flatten, clippy::match_same_arms, clippy::maybe_infinite_iter, clippy::mem_forget, clippy::missing_const_for_fn, clippy::module_name_repetitions, clippy::multiple_crate_versions, clippy::multiple_inherent_impl, clippy::mut_mut, clippy::needless_borrow, clippy::needless_continue, clippy::needless_pass_by_value, clippy::non_ascii_literal, clippy::option_map_unwrap_or, clippy::option_map_unwrap_or_else, clippy::path_buf_push_overwrite, clippy::print_stdout, clippy::pub_enum_variant_names, clippy::redundant_closure_for_method_calls, clippy::replace_consts, clippy::result_map_unwrap_or_else, clippy::shadow_reuse, clippy::shadow_same, clippy::shadow_unrelated, clippy::single_match_else, clippy::string_add, clippy::string_add_assign, clippy::type_repetition_in_bounds, clippy::unicode_not_nfc, clippy::unimplemented, clippy::unseparated_literal_suffix, clippy::used_underscore_binding, clippy::wildcard_dependencies, clippy::wildcard_enum_match_arm, clippy::wrong_pub_self_convention )] use std::io; mod completion; mod histogram; mod lazy; mod metrics; #[cfg(target_os = "linux")] mod io_uring; #[cfg(target_os = "linux")] pub use io_uring::{Config, Ordering, Rio, Uring}; pub use completion::Completion; use { completion::{pair, Filler}, histogram::Histogram, lazy::Lazy, metrics::{Measure, M}, }; /// Create a new IO system. pub fn new() -> io::Result<Rio> { Config::default().start() } /// Encompasses various types of IO structures that /// can be operated on as if they were a libc::iovec pub trait AsIoVec { /// Returns the address of this object. fn into_new_iovec(&self) -> libc::iovec; } impl<A: ?Sized + AsRef<[u8]>> AsIoVec for A { fn into_new_iovec(&self) -> libc::iovec { let self_ref: &[u8] = self.as_ref(); let self_ptr: *const [u8] = self_ref; libc::iovec { iov_base: self_ptr as *mut _, iov_len: self_ref.len(), } } } /// We use this internally as a way of communicating /// that for certain operations, we cannot accept a /// reference into read-only memory, like for reads. /// /// If your compilation fails because of something /// related to this, it's because you are trying /// to use memory as a destination for a read /// that could never actually be written to anyway, /// which the compiler may place in read-only /// memory in your process that cannot be written /// to by anybody. /// /// # Examples /// /// This will cause the following code to break, /// which would have caused an IO error anyway /// due to trying to write to static read-only /// memory: /// /// ```compile_fail /// let ring = rio::new().unwrap(); /// let file = std::fs::File::open("failure").unwrap(); /// /// // the following buffer is placed in /// // static, read-only memory and would /// // never be valid to write to /// let buffer: &[u8] = b"this is read-only"; /// /// // this fails to compile, because &[u8] /// // does not implement `AsIoVecMut`: /// ring.read_at(&file, &buffer, 0).unwrap(); /// ``` /// /// which can be fixed by making it a mutable /// slice: /// /// ```no_run /// let ring = rio::new().unwrap(); /// let file = std::fs::File::open("failure").unwrap(); /// /// // the following buffer is placed in /// // readable and writable memory, due to /// // its mutability /// let buffer: &mut [u8] = &mut [0; 42]; /// /// // this now works /// ring.read_at(&file, &buffer, 0).wait(); /// ``` pub trait AsIoVecMut {} impl<A: ?Sized + AsMut<[u8]>> AsIoVecMut for A {} /// A trait for describing transformations from the /// `io_uring_cqe` type into an expected meaningful /// high-level result. pub trait FromCqe { /// Describes a conversion from a successful /// `io_uring_cqe` to a desired output type. fn from_cqe(cqe: io_uring::io_uring_cqe) -> Self; } impl FromCqe for usize { fn from_cqe(cqe: io_uring::io_uring_cqe) -> usize { use std::convert::TryFrom; usize::try_from(cqe.res).unwrap() } } impl FromCqe for () { fn from_cqe(_: io_uring::io_uring_cqe) {} }