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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916
// Copyright 2020-2022 The NATS Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//! A Rust client for the NATS.io ecosystem.
//!
//! <div class="warning"> This is the old legacy client. It will not get new features or updates beyond critical security fixes.
//! Use <a href="https://crates.io/crates/async-nats">async-nats</a> instead. </div>
//!
//! `git clone https://github.com/nats-io/nats.rs`
//!
//! NATS.io is a simple, secure and high performance open source messaging
//! system for cloud native applications, `IoT` messaging, and microservices
//! architectures.
//!
//! For async API refer to the [`asynk`] module.
//!
//! For more information see [https://nats.io/].
//!
//! [https://nats.io/]: https://nats.io/
//!
//! ## Examples
//!
//! `> cargo run --example nats-box -- -h`
//!
//! Basic connections, and those with options. The compiler will force these to
//! be correct.
//!
//! ```no_run
//! # fn main() -> Result<(), Box<dyn std::error::Error>> {
//! let nc = nats::connect("demo.nats.io")?;
//!
//! let nc2 = nats::Options::with_user_pass("derek", "s3cr3t!")
//! .with_name("My Rust NATS App")
//! .connect("127.0.0.1")?;
//!
//! let nc3 = nats::Options::with_credentials("path/to/my.creds").connect("connect.ngs.global")?;
//!
//! let nc4 = nats::Options::new()
//! .add_root_certificate("my-certs.pem")
//! .connect("tls://demo.nats.io:4443")?;
//! # Ok(()) }
//! ```
//!
//! ### Publish
//!
//! ```
//! # fn main() -> std::io::Result<()> {
//! let nc = nats::connect("demo.nats.io")?;
//! nc.publish("my.subject", "Hello World!")?;
//!
//! nc.publish("my.subject", "my message")?;
//!
//! // Publish a request manually.
//! let reply = nc.new_inbox();
//! let rsub = nc.subscribe(&reply)?;
//! nc.publish_request("my.subject", &reply, "Help me!")?;
//! # Ok(()) }
//! ```
//!
//! ### Subscribe
//!
//! ```no_run
//! # fn main() -> std::io::Result<()> {
//! # use std::time::Duration;
//! let nc = nats::connect("demo.nats.io")?;
//! let sub = nc.subscribe("foo")?;
//! for msg in sub.messages() {}
//!
//! // Using next.
//! if let Some(msg) = sub.next() {}
//!
//! // Other iterators.
//! for msg in sub.try_iter() {}
//! for msg in sub.timeout_iter(Duration::from_secs(10)) {}
//!
//! // Using a threaded handler.
//! let sub = nc.subscribe("bar")?.with_handler(move |msg| {
//! println!("Received {}", &msg);
//! Ok(())
//! });
//!
//! // Queue subscription.
//! let qsub = nc.queue_subscribe("foo", "my_group")?;
//! # Ok(()) }
//! ```
//!
//! ### Request/Response
//!
//! ```no_run
//! # use std::time::Duration;
//! # fn main() -> std::io::Result<()> {
//! let nc = nats::connect("demo.nats.io")?;
//! let resp = nc.request("foo", "Help me?")?;
//!
//! // With a timeout.
//! let resp = nc.request_timeout("foo", "Help me?", Duration::from_secs(2))?;
//!
//! // With multiple responses.
//! for msg in nc.request_multi("foo", "Help")?.iter() {}
//!
//! // Publish a request manually.
//! let reply = nc.new_inbox();
//! let rsub = nc.subscribe(&reply)?;
//! nc.publish_request("foo", &reply, "Help me!")?;
//! let response = rsub.iter().take(1);
//! # Ok(()) }
//! ```
#![cfg_attr(docsrs, feature(doc_cfg))]
#![cfg_attr(
feature = "fault_injection",
deny(
future_incompatible,
missing_copy_implementations,
missing_docs,
nonstandard_style,
rust_2018_idioms,
trivial_casts,
trivial_numeric_casts,
unsafe_code,
unused,
unused_qualifications
)
)]
#![cfg_attr(feature = "fault_injection", deny(
// over time, consider enabling the following commented-out lints:
// clippy::else_if_without_else,
// clippy::indexing_slicing,
// clippy::multiple_crate_versions,
// clippy::missing_const_for_fn,
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_next,
clippy::float_arithmetic,
clippy::get_unwrap,
clippy::if_not_else,
clippy::inline_always,
clippy::invalid_upcast_comparisons,
clippy::items_after_statements,
clippy::manual_filter_map,
clippy::manual_find_map,
clippy::map_flatten,
clippy::map_unwrap_or,
clippy::match_same_arms,
clippy::maybe_infinite_iter,
clippy::mem_forget,
clippy::needless_borrow,
clippy::needless_continue,
clippy::needless_pass_by_value,
clippy::non_ascii_literal,
clippy::path_buf_push_overwrite,
clippy::print_stdout,
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::wildcard_dependencies,
clippy::wildcard_enum_match_arm,
))]
#![allow(
clippy::match_like_matches_macro,
clippy::await_holding_lock,
clippy::shadow_reuse,
clippy::shadow_same,
clippy::shadow_unrelated,
clippy::wildcard_enum_match_arm,
clippy::module_name_repetitions
)]
// As this is a deprecated client, we don't want warnings from new lints to make CI red.
#![allow(clippy::all)]
#![allow(warnings)]
/// Async-enabled NATS client.
pub mod asynk;
mod auth_utils;
mod client;
mod connect;
mod connector;
mod message;
mod options;
mod proto;
mod secure_wipe;
mod subscription;
/// Header constants and types.
pub mod header;
/// `JetStream` stream management and consumers.
pub mod jetstream;
#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
pub mod kv;
#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
pub mod object_store;
#[cfg(feature = "fault_injection")]
mod fault_injection;
#[cfg(feature = "fault_injection")]
use fault_injection::{inject_delay, inject_io_failure};
#[cfg(not(feature = "fault_injection"))]
fn inject_delay() {}
#[cfg(not(feature = "fault_injection"))]
fn inject_io_failure() -> io::Result<()> {
Ok(())
}
// comment out until we reach MSRV 1.54.0
// #[doc = include_str!("../docs/migration-guide-0.17.0.md")]
// #[derive(Copy, Clone)]
// pub struct Migration0170;
#[doc(hidden)]
#[deprecated(since = "0.6.0", note = "this has been renamed to `Options`.")]
pub type ConnectionOptions = Options;
#[doc(hidden)]
#[deprecated(since = "0.17.0", note = "this has been moved to `header::HeaderMap`.")]
pub type Headers = HeaderMap;
pub use header::HeaderMap;
use std::{
io::{self, Error, ErrorKind},
sync::Arc,
time::{Duration, Instant},
};
use lazy_static::lazy_static;
use regex::Regex;
pub use connector::{IntoServerList, ServerAddress};
pub use jetstream::JetStreamOptions;
pub use message::Message;
pub use options::Options;
pub use subscription::{Handler, Subscription};
/// A re-export of the `rustls` crate used in this crate,
/// for use in cases where manual client configurations
/// must be provided using `Options::tls_client_config`.
pub use rustls;
#[doc(hidden)]
pub use connect::ConnectInfo;
use client::Client;
use options::AuthStyle;
use secure_wipe::{SecureString, SecureVec};
const VERSION: &str = env!("CARGO_PKG_VERSION");
const LANG: &str = "rust";
const DEFAULT_FLUSH_TIMEOUT: Duration = Duration::from_secs(10);
lazy_static! {
static ref VERSION_RE: Regex = Regex::new(r#"\Av?([0-9]+)\.?([0-9]+)?\.?([0-9]+)?"#).unwrap();
}
/// Information sent by the server back to this client
/// during initial connection, and possibly again later.
#[allow(unused)]
#[derive(Debug, Default, Clone)]
pub struct ServerInfo {
/// The unique identifier of the NATS server.
pub server_id: String,
/// Generated Server Name.
pub server_name: String,
/// The host specified in the cluster parameter/options.
pub host: String,
/// The port number specified in the cluster parameter/options.
pub port: u16,
/// The version of the NATS server.
pub version: String,
/// If this is set, then the server should try to authenticate upon
/// connect.
pub auth_required: bool,
/// If this is set, then the server must authenticate using TLS.
pub tls_required: bool,
/// Maximum payload size that the server will accept.
pub max_payload: usize,
/// The protocol version in use.
pub proto: i8,
/// The server-assigned client ID. This may change during reconnection.
pub client_id: u64,
/// The version of golang the NATS server was built with.
pub go: String,
/// The nonce used for nkeys.
pub nonce: String,
/// A list of server urls that a client can connect to.
pub connect_urls: Vec<String>,
/// The client IP as known by the server.
pub client_ip: String,
/// Whether the server supports headers.
pub headers: bool,
/// Whether server goes into lame duck mode.
pub lame_duck_mode: bool,
}
impl ServerInfo {
fn parse(s: &str) -> Option<ServerInfo> {
let mut obj = json::parse(s).ok()?;
Some(ServerInfo {
server_id: obj["server_id"].take_string()?,
server_name: obj["server_name"].take_string().unwrap_or_default(),
host: obj["host"].take_string()?,
port: obj["port"].as_u16()?,
version: obj["version"].take_string()?,
auth_required: obj["auth_required"].as_bool().unwrap_or(false),
tls_required: obj["tls_required"].as_bool().unwrap_or(false),
max_payload: obj["max_payload"].as_usize()?,
proto: obj["proto"].as_i8()?,
client_id: obj["client_id"].as_u64()?,
go: obj["go"].take_string()?,
nonce: obj["nonce"].take_string().unwrap_or_default(),
connect_urls: obj["connect_urls"]
.members_mut()
.filter_map(|m| m.take_string())
.collect(),
client_ip: obj["client_ip"].take_string().unwrap_or_default(),
headers: obj["headers"].as_bool().unwrap_or(false),
lame_duck_mode: obj["ldm"].as_bool().unwrap_or(false),
})
}
}
/// A NATS connection.
#[derive(Clone, Debug)]
pub struct Connection(pub(crate) Arc<Inner>);
#[derive(Clone, Debug)]
struct Inner {
client: Client,
}
impl Drop for Inner {
fn drop(&mut self) {
self.client.shutdown();
}
}
/// Connect to one or more NATS servers at the given URLs.
///
/// The [`IntoServerList`] trait allows to pass URLs in various different formats. Furthermore, if
/// you need more control of the connection's parameters use [`Options::connect()`].
///
/// **Warning:** There are asynchronous errors that can happen during operation of NATS client.
/// To handle them, add handler for [`Options::error_callback()`].
///
/// # Examples
///
/// If no scheme is provided the `nats://` scheme is assumed. The default port is `4222`.
/// ```no_run
/// let nc = nats::connect("demo.nats.io")?;
/// # Ok::<(), std::io::Error>(())
/// ```
///
/// It is possible to provide several URLs as a comma separated list.
/// ```no_run
/// let nc = nats::connect("demo.nats.io,tls://demo.nats.io:4443")?;
/// # Ok::<(), std::io::Error>(())
/// ```
///
/// Alternatively, an array of strings can be passed.
/// ```no_run
/// # use nats::IntoServerList;
/// let nc = nats::connect(&["demo.nats.io", "tls://demo.nats.io:4443"])?;
/// # Ok::<(), std::io::Error>(())
/// ```
///
/// Instead of using strings, [`ServerAddress`]es can be used directly as well. This is handy for
/// validating user input.
/// ```no_run
/// use nats::ServerAddress;
/// use std::io;
/// use structopt::StructOpt;
///
/// #[derive(Debug, StructOpt)]
/// struct Config {
/// #[structopt(short, long = "server", default_value = "demo.nats.io")]
/// servers: Vec<ServerAddress>,
/// }
///
/// fn main() -> io::Result<()> {
/// let config = Config::from_args();
/// let nc = nats::connect(config.servers)?;
/// Ok(())
/// }
/// ```
pub fn connect<I: IntoServerList>(nats_urls: I) -> io::Result<Connection> {
Options::new().connect(nats_urls)
}
impl Connection {
/// Connects on one or more NATS servers with the given options.
///
/// For more on how to use [`IntoServerList`] trait see [`crate::connect()`].
pub(crate) fn connect_with_options<I>(urls: I, options: Options) -> io::Result<Connection>
where
I: IntoServerList,
{
let urls = urls.into_server_list()?;
let client = Client::connect(urls, options)?;
client.flush(DEFAULT_FLUSH_TIMEOUT)?;
Ok(Connection(Arc::new(Inner { client })))
}
/// Create a subscription for the given NATS connection.
///
/// # Example
/// ```
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// let sub = nc.subscribe("foo")?;
/// # Ok(())
/// # }
/// ```
pub fn subscribe(&self, subject: &str) -> io::Result<Subscription> {
self.do_subscribe(subject, None)
}
/// Create a queue subscription for the given NATS connection.
///
/// # Example
/// ```no_run
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// let sub = nc.queue_subscribe("foo", "production")?;
/// # Ok(())
/// # }
/// ```
pub fn queue_subscribe(&self, subject: &str, queue: &str) -> io::Result<Subscription> {
self.do_subscribe(subject, Some(queue))
}
/// Publish a message on the given subject.
///
/// # Example
/// ```no_run
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// nc.publish("foo", "Hello World!")?;
/// # Ok(())
/// # }
/// ```
pub fn publish(&self, subject: &str, msg: impl AsRef<[u8]>) -> io::Result<()> {
self.publish_with_reply_or_headers(subject, None, None, msg)
}
/// Publish a message on the given subject with a reply subject for
/// responses.
///
/// # Example
/// ```no_run
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// let reply = nc.new_inbox();
/// let rsub = nc.subscribe(&reply)?;
/// nc.publish_request("foo", &reply, "Help me!")?;
/// # Ok(())
/// # }
/// ```
pub fn publish_request(
&self,
subject: &str,
reply: &str,
msg: impl AsRef<[u8]>,
) -> io::Result<()> {
self.0
.client
.publish(subject, Some(reply), None, msg.as_ref())
}
/// Create a new globally unique inbox which can be used for replies.
///
/// # Example
/// ```no_run
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// let reply = nc.new_inbox();
/// let rsub = nc.subscribe(&reply)?;
/// # Ok(())
/// # }
/// ```
pub fn new_inbox(&self) -> String {
format!("_INBOX.{}", nuid::next())
}
/// Publish a message on the given subject as a request and receive the
/// response.
///
/// # Example
/// ```no_run
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// # nc.subscribe("foo")?.with_handler(move |m| { m.respond("ans=42")?; Ok(()) });
/// let resp = nc.request("foo", "Help me?")?;
/// # Ok(())
/// # }
/// ```
pub fn request(&self, subject: &str, msg: impl AsRef<[u8]>) -> io::Result<Message> {
self.request_with_headers_or_timeout(subject, None, None, msg)
}
/// Publish a message on the given subject as a request and receive the
/// response. This call will return after the timeout duration if no
/// response is received.
///
/// # Example
/// ```no_run
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// # nc.subscribe("foo")?.with_handler(move |m| { m.respond("ans=42")?; Ok(()) });
/// let resp = nc.request_timeout("foo", "Help me?", std::time::Duration::from_secs(2))?;
/// # Ok(())
/// # }
/// ```
pub fn request_timeout(
&self,
subject: &str,
msg: impl AsRef<[u8]>,
timeout: Duration,
) -> io::Result<Message> {
self.request_with_headers_or_timeout(subject, None, Some(timeout), msg)
}
/// Publish a message with headers on the given subject as a request and receive the
/// response.
///
/// # Example
/// ```no_run
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// # nc.subscribe("foo")?.with_handler(move |m| { m.respond("ans=42")?; Ok(()) });
/// let mut headers = nats::HeaderMap::new();
/// headers.insert("X-key", "value".to_string());
/// let resp = nc.request_with_headers_or_timeout(
/// "foo",
/// Some(&headers),
/// Some(std::time::Duration::from_secs(2)),
/// "Help me?",
/// )?;
/// # Ok(())
/// # }
/// ```
pub fn request_with_headers(
&self,
subject: &str,
msg: impl AsRef<[u8]>,
headers: &HeaderMap,
) -> io::Result<Message> {
self.request_with_headers_or_timeout(subject, Some(headers), None, msg)
}
/// Publish a message on the given subject as a request and receive the
/// response. This call will return after the timeout duration if it was set to `Some` if no
/// response is received. It also allows passing headers.
///
/// # Example
/// ```no_run
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// # nc.subscribe("foo")?.with_handler(move |m| { m.respond("ans=42")?; Ok(()) });
/// let mut headers = nats::HeaderMap::new();
/// headers.insert("X-key", "value".to_string());
/// let resp = nc.request_with_headers_or_timeout(
/// "foo",
/// Some(&headers),
/// Some(std::time::Duration::from_secs(2)),
/// "Help me?",
/// )?;
/// # Ok(())
/// # }
/// ```
pub fn request_with_headers_or_timeout(
&self,
subject: &str,
maybe_headers: Option<&HeaderMap>,
maybe_timeout: Option<Duration>,
msg: impl AsRef<[u8]>,
) -> io::Result<Message> {
// Publish a request.
let reply = self.new_inbox();
let sub = self.subscribe(&reply)?;
self.publish_with_reply_or_headers(subject, Some(reply.as_str()), maybe_headers, msg)?;
// Wait for the response
let result = if let Some(timeout) = maybe_timeout {
sub.next_timeout(timeout)
} else if let Some(msg) = sub.next() {
Ok(msg)
} else {
Err(ErrorKind::ConnectionReset.into())
};
// Check for no responder status.
if let Ok(msg) = result.as_ref() {
if msg.is_no_responders() {
return Err(Error::new(ErrorKind::NotFound, "no responders"));
}
}
result
}
/// Publish a message on the given subject as a request and allow multiple
/// responses.
///
/// # Example
/// ```no_run
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// # nc.subscribe("foo")?.with_handler(move |m| { m.respond("ans=42")?; Ok(()) });
/// for msg in nc.request_multi("foo", "Help")?.iter().take(1) {}
/// # Ok(())
/// # }
/// ```
pub fn request_multi(&self, subject: &str, msg: impl AsRef<[u8]>) -> io::Result<Subscription> {
// Publish a request.
let reply = self.new_inbox();
let sub = self.subscribe(&reply)?;
self.publish_with_reply_or_headers(subject, Some(reply.as_str()), None, msg)?;
// Return the subscription.
Ok(sub)
}
/// Flush a NATS connection by sending a `PING` protocol and waiting for the
/// responding `PONG`. Will fail with `TimedOut` if the server does not
/// respond with in 10 seconds. Will fail with `NotConnected` if the
/// server is not currently connected. Will fail with `BrokenPipe` if
/// the connection to the server is lost.
///
/// # Example
/// ```no_run
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// nc.flush()?;
/// # Ok(())
/// # }
/// ```
pub fn flush(&self) -> io::Result<()> {
self.flush_timeout(DEFAULT_FLUSH_TIMEOUT)
}
/// Flush a NATS connection by sending a `PING` protocol and waiting for the
/// responding `PONG`. Will fail with `TimedOut` if the server takes
/// longer than this duration to respond. Will fail with `NotConnected`
/// if the server is not currently connected. Will fail with
/// `BrokenPipe` if the connection to the server is lost.
///
/// # Example
/// ```no_run
/// # use std::time::Duration;
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// nc.flush_timeout(Duration::from_secs(5))?;
/// # Ok(())
/// # }
/// ```
pub fn flush_timeout(&self, duration: Duration) -> io::Result<()> {
self.0.client.flush(duration)
}
/// Close a NATS connection. All clones of
/// this `Connection` will also be closed,
/// as the backing IO threads are shared.
///
/// If the client is currently connected
/// to a server, the outbound write buffer
/// will be flushed in the process of
/// shutting down.
///
/// # Example
/// ```no_run
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// nc.close();
/// # Ok(())
/// # }
/// ```
pub fn close(self) {
self.0.client.flush(DEFAULT_FLUSH_TIMEOUT).ok();
self.0.client.close();
}
/// Calculates the round trip time between this client and the server,
/// if the server is currently connected. Fails with `TimedOut` if
/// the server takes more than 10 seconds to respond.
///
/// # Example
/// ```no_run
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// println!("server rtt: {:?}", nc.rtt());
/// # Ok(())
/// # }
/// ```
pub fn rtt(&self) -> io::Result<Duration> {
let start = Instant::now();
self.flush()?;
Ok(start.elapsed())
}
/// Returns true if the version is compatible with the version components.
pub fn is_server_compatible_version(&self, major: i64, minor: i64, patch: i64) -> bool {
let server_info = self.0.client.server_info();
let server_version_captures = VERSION_RE.captures(&server_info.version).unwrap();
let server_major = server_version_captures
.get(1)
.map(|m| m.as_str().parse::<i64>().unwrap())
.unwrap();
let server_minor = server_version_captures
.get(2)
.map(|m| m.as_str().parse::<i64>().unwrap())
.unwrap();
let server_patch = server_version_captures
.get(3)
.map(|m| m.as_str().parse::<i64>().unwrap())
.unwrap();
if server_major < major
|| (server_major == major && server_minor < minor)
|| (server_major == major && server_minor == minor && server_patch < patch)
{
return false;
}
true
}
/// Returns the client IP as known by the server.
/// Supported as of server version 2.1.6.
/// # Example
/// ```no_run
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// println!("ip: {:?}", nc.client_ip());
/// # Ok(())
/// # }
/// ```
pub fn client_ip(&self) -> io::Result<std::net::IpAddr> {
let info = self.0.client.server_info();
match info.client_ip.as_str() {
"" => Err(Error::new(
ErrorKind::Other,
&*format!(
"client_ip was not provided by the server. It is \
supported on servers above version 2.1.6. The server \
version is {}",
info.version
),
)),
ip => match ip.parse() {
Ok(addr) => Ok(addr),
Err(_) => Err(Error::new(
ErrorKind::InvalidData,
&*format!(
"client_ip provided by the server cannot be parsed. \
The server provided IP: {}",
info.client_ip
),
)),
},
}
}
/// Returns the client ID as known by the most recently connected server.
///
/// # Example
/// ```no_run
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// println!("ip: {:?}", nc.client_id());
/// # Ok(())
/// # }
/// ```
pub fn client_id(&self) -> u64 {
self.0.client.server_info().client_id
}
/// Send an unsubscription for all subs then flush the connection, allowing
/// any unprocessed messages to be handled by a handler function if one
/// is configured.
///
/// After the flush returns, we know that a round-trip to the server has
/// happened after it received our unsubscription, so we shut down the
/// subscriber afterwards.
///
/// A similar method exists for the `Subscription` struct which will drain
/// a single `Subscription` without shutting down the entire connection
/// afterward.
///
/// # Example
/// ```no_run
/// # use std::sync::{Arc, atomic::{AtomicBool, Ordering::SeqCst}};
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// let received = Arc::new(AtomicBool::new(false));
/// let received_2 = received.clone();
///
/// nc.subscribe("test.drain")?.with_handler(move |m| {
/// received_2.store(true, SeqCst);
/// Ok(())
/// });
///
/// nc.publish("test.drain", "message")?;
/// nc.drain()?;
///
/// # std::thread::sleep(std::time::Duration::from_secs(1));
///
/// assert!(received.load(SeqCst));
///
/// # Ok(())
/// # }
/// ```
pub fn drain(&self) -> io::Result<()> {
self.0.client.flush(DEFAULT_FLUSH_TIMEOUT)?;
self.0.client.close();
Ok(())
}
/// Publish a message which may have a reply subject or headers set.
///
/// # Example
/// ```no_run
/// # fn main() -> std::io::Result<()> {
/// # let nc = nats::connect("demo.nats.io")?;
/// let sub = nc.subscribe("foo.headers")?;
/// let headers = [("header1", "value1"), ("header2", "value2")]
/// .iter()
/// .collect();
/// let reply_to = None;
/// nc.publish_with_reply_or_headers("foo.headers", reply_to, Some(&headers), "Hello World!")?;
/// nc.flush()?;
/// let message = sub.next_timeout(std::time::Duration::from_secs(2)).unwrap();
/// assert_eq!(message.headers.unwrap().len(), 2);
/// # Ok(())
/// # }
/// ```
pub fn publish_with_reply_or_headers(
&self,
subject: &str,
reply: Option<&str>,
headers: Option<&HeaderMap>,
msg: impl AsRef<[u8]>,
) -> io::Result<()> {
self.0.client.publish(subject, reply, headers, msg.as_ref())
}
/// Returns the maximum payload size the most recently
/// connected server will accept.
///
/// # Example
/// ```no_run
/// # fn main() -> std::io::Result<()> {
/// let nc = nats::connect("demo.nats.io")?;
/// println!("max payload: {:?}", nc.max_payload());
/// # Ok(())
/// # }
pub fn max_payload(&self) -> usize {
self.0.client.server_info.lock().max_payload
}
fn do_subscribe(&self, subject: &str, queue: Option<&str>) -> io::Result<Subscription> {
let (sid, receiver) = self.0.client.subscribe(subject, queue)?;
Ok(Subscription::new(
sid,
subject.to_string(),
receiver,
self.0.client.clone(),
))
}
/// Attempts to publish a message without blocking.
#[doc(hidden)]
pub fn try_publish_with_reply_or_headers(
&self,
subject: &str,
reply: Option<&str>,
headers: Option<&HeaderMap>,
msg: impl AsRef<[u8]>,
) -> Option<io::Result<()>> {
self.0
.client
.try_publish(subject, reply, headers, msg.as_ref())
}
}