Crate libstrophe

libstrophe - ergonomic wrapper for Rust

This library provides high level ergonomic bindings for libstrophe, an XMPP client library.

Documentation

The documentation for this library covers only Rust specific bits and refers to original library documentation in most other cases.

Workflow

The general workflow is quite similar to what you get with the C library. The topmost object is Context. It contains platform-specific bits like logging and memory allocation. Plus an event loop used to keep things going. This crate wraps logging with the facilities provided by log crate (provided the default rust-log feature is enabled). Memory allocation is also handled by Rust native means. When a Connection is created it will temporarily consume the Context. After all the setup is done, call one of the connect_*() methods to retrieve the Context back. In this manner a single Context can be used for multiple Connections consequently. When you’re done with setting up Connections for the Context, use run() or run_once() methods to start the event loop rolling.

Safety

This crate tries to be as safe as possible. Yet it’s not always possible to guarantee that when wrapping a C library. The following assumptions are made which might not necessarily be true and thus might introduce unsafety:

• Context event loop methods are borrowing self immutably considering it immutable (or more specifically having interior mutability)

The main objects in this crate are marked as Send and it should be indeed be safe to send them between threads. Yet, no major investigation of the library source code has been performed to ensure that this is true.

Initialization and shutdown

You don’t need to call the initialization function, it’s done automatically when creating a Context. Yet you might want to call the shutdown() function when your application terminates. Be aware though that the initialization can be called only once in the program lifetime so you won’t be able to use the library properly after you called shutdown().

Callbacks

The crate has the ability to store callbacks taking ownership of them so you can pass closures and not care about storing them externally. There are some things to note about it though. It’s not always possible to know whether the underlying library accepted the callback. The crate will keep the closure internally in either case, though it may not ever be called by the library. You can still remove the callback with the corresponding *handler_delete() or *handler_clear() method.

Due to the way the C libstrophe library is implemented and how Rust optimizes monomorphization, your callbacks must actually be compiled to different function with separate addresses when you pass them to the same handler setup method. So if you want to pass 2 callbacks hander_add ensure that their code is unique and rust didn’t merge them into a single function behind the scenes. You can test whether 2 callbacks are same or not with the Connection::*handlers_same() family of functions. If it returns true then you will only be able to pass one of them to the corresponding handler function, the other will be silently ignored.

Due to the fact that the crate uses userdata to pass the actual user callback, it’s not possible to use userdata inside the callbacks for your own data. So if you need to have a state between callback invocations you must use closures.

Because the main objects are marked as Send and we store callbacks inside them, all callbacks must also be Send.

Examples

let connection_handler = |ctx: &libstrophe::Context,
                          _conn: &mut libstrophe::Connection,
                          _evt: libstrophe::ConnectionEvent| {
   ctx.stop();
};

let ctx = libstrophe::Context::new_with_default_logger();
let mut conn = libstrophe::Connection::new(ctx);
conn.set_jid("example@127.0.0.1");
conn.set_pass("password");
let mut ctx = conn.connect_client(None, None, connection_handler).unwrap();
ctx.run();
libstrophe::shutdown();

For more complete examples see this crate examples directory and libstrophe examples.

Crate features

The following features are provided:

• rust-log - enabled by default, makes the crate integrate into Rust logging facilities
• libstrophe-0_9_3 - enabled by default, enables functions specific to libstrophe-0.9.3
• libstrophe-0_10_0 - enabled by default, enables functions specific to libstrophe-0.10
• libstrophe-0_11_0 - enabled by default, enables functions specific to libstrophe-0.11
• libstrophe-0_12_0 - enabled by default, enables functions specific to libstrophe-0.12
• libstrophe-0_13 - enabled by default, enables functions specific to libstrophe-0.13
• libstrophe-0_14 - enabled by default, enables functions specific to libstrophe-0.14
• buildtime_bindgen - forces regeneration of the bindings instead of relying on the pre-generated sources

Modules

jid

Structs

AllocContext

Internal Context that only specifies allocation functions and uses null logger. Needed to not pass Context to e.g. Stanza because it uses only allocation functions from Context.

ConnectClientError

Connection

Proxy to the underlying sys::xmpp_conn_t struct.

ConnectionFlags

Context

Proxy to the underlying sys::xmpp_ctx_t struct.

HandlerId

IdHandlerId

Logger

Wrapper around the underlying sys::xmpp_log_t struct.

OwnedStreamError

Owned version of StreamError. stanza is guarded by Mutex to make the error type Sync.

SMState

Stream Management state of a connection object

SerializedSmState

SerializedSmStateRef

Stanza

Proxy to the underlying sys::xmpp_stanza_t struct.

StanzaMutRef

Wrapper for mutable reference to Stanza, implements Deref and DerefMut to Stanza

StanzaRef

Wrapper for constant reference to Stanza, implements Deref to Stanza

StreamError

Error of the stream. Inspect the typ for the specific error type. text contains additional text information about the error. stanza is the original error stanza sent by the server, most probably you don’t need to process it because data from it is already in typ and text.

TimedHandlerId

TlsCert

Enums

CertElement

CertFailResult

ConnectionError

ConnectionEvent

Error

ErrorType

HandlerResult

LogLevel

OwnedConnectionError

QueueElement

SockoptResult

ToTextError

Functions

XMPP_STANZA_NAME_IN_NS

Helper function for Stanza::get_child_by_path XMPP_STANZA_NAME_IN_NS

shutdown

xmpp_shutdown

version_check

xmpp_version_check

Type Aliases

Result

std::result::Result with the crate’s Error