Struct Log 

pub struct Log {
    pub level: LogLevel,
    pub format: String,
    pub args: Vec<Rc<dyn Encoder>>,
    pub metadata: Vec<(String, Rc<dyn Encoder>)>,
    pub pending: bool,
}

A structure to represent log messages.

Fields

level: LogLevel

specifies the log level of the message

format: String

format string for the simple message, uses Erlang formatter syntax

args: Vec<Rc<dyn Encoder>>

arguments for the format string

metadata: Vec<(String, Rc<dyn Encoder>)>

metadata for the log message

pending: bool

used to catch unsent messages that accidentally get dropped

Implementations

impl Log

pub fn new(level: LogLevel, format: &str) -> Self

Create a new Log builder.

Once created, a log message must be sent explicitly.

To prevent creating a log message but erroneously failing to send it, a panic is raised if a message is dropped without being sent.

If a message is legitimately created but not sent, use the cancel function.

Example

use rustler_logger::*;

let log = Log::new(LogLevel::Info, "Hello, ~s!")
    .arg("world")
    .send();

pub fn arg(self, arg: impl Encoder + 'static) -> Self

Builder-style method to put an argument into a log message.

Example

use rustler_logger::*;

let log = Log::new(LogLevel::Info, "Hello, ~s!")
    .arg("world")
    .send();

pub fn opt_arg(self, arg: Option<impl Encoder + 'static>) -> Self

Builder-style method to put an optional argument into a log message.

If the value is Some(arg), arg will be unwrapped and included in the log message. If the value is None, the key will not be included.

Example

use rustler_logger::*;

let log = Log::new(LogLevel::Info, "Hello, ~s!")
    .opt_arg(Some("world"))
    .send();

pub fn opt_arg_else( self, some_arg: Option<impl Encoder + 'static>, none_arg: impl Encoder + 'static, ) -> Self

Builder-style method to put an optional argument into a log message, or a default value if the argument is None.

Example

use rustler_logger::*;

let log = Log::new(LogLevel::Info, "Hello, ~s!")
    .opt_arg_else(Some("world"), "unknown")
    .send();

pub fn meta(self, key: &str, value: impl Encoder + 'static) -> Self

Builder-style method to put a key-value-pair into a log message.

Example

use rustler_logger::*;

let log = Log::new(LogLevel::Info, "Hello, {}!")
    .arg("world")
    .meta("user_id", 123)
    .send();

pub fn opt_meta(self, key: &str, value: Option<impl Encoder + 'static>) -> Self

Builder-style method to put an optional key-value-pair into a log message.

If the value is None, the key will not be included in the log message.

Example

use rustler_logger::*;

let quota: Option<u64> = None;
let uid: Option<u64> = Some(1003);

let log = Log::new(LogLevel::Info, "Hello, {}!")
    .arg("world")
    .opt_meta("quota", quota)
    .opt_meta("uid", uid)
    .send();

pub fn send(self)

Sends the constructed log message.

Example

use rustler_logger::*;

let log = Log::new(LogLevel::Info, "Hello, {}!")
    .arg("world")
    .meta("user_id", 123)
    .send();

pub fn cancel(self)

Cancel a log message that has not been sent yet.

If a message is constructed but not sent, it must be cancelled to prevent a panic. This panic occurs so that log messages won’t be constructed but then accidentally not sent.

Example

use rustler_logger::*;

let log = Log::new(LogLevel::Info, "Hello, ~s!")
    .arg("world");

log.cancel();

Trait Implementations

impl Clone for Log

fn clone(&self) -> Log

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Drop for Log

fn drop(&mut self)

Panic if a log message is dropped without being sent or cancelled.