Struct JsonFormat 

pub struct JsonFormat { /* private fields */ }

Available on crate feature json only.

JSON formatter.

The default configuration emits compact JSON Lines. Every string is escaped so the output is valid JSON for any input, and the escaping also covers DEL, C1 controls, U+2028/U+2029 and bidi controls so a record stays on one line even for tools that treat those as line breaks. User keys named timestamp, level, target, message, file or line are written as fields.<name>.

Examples

use log_io::format::{Format, JsonFormat};
use log_io::{Field, Level, Metadata, Record, Value};

let fmt = JsonFormat::new();
let fields = [Field::new("port", 8080_u16), Field::new("level", "spoofed")];
let record = Record::new(Metadata::new(Level::Info, "app"), "started", &fields);

let mut out = String::new();
fmt.write_record(&record, &mut out)?;
assert_eq!(
    out,
    "{\"level\":\"info\",\"target\":\"app\",\"message\":\"started\",\
      \"port\":8080,\"fields.level\":\"spoofed\"}\n"
);

Implementations

impl JsonFormat

pub const fn new() -> Self

New compact JSON formatter. Equivalent to Self::default().

pub const fn pretty(self, enabled: bool) -> Self

Toggle pretty (multi-line, indented) output. Intended for reading by eye; line-oriented ingestion needs the compact form.

pub const fn timestamp_rfc3339(self, enabled: bool) -> Self

Emit timestamps as RFC 3339 strings instead of Unix nanoseconds.

Enabled: "timestamp":"2023-11-14T22:13:20.000000000Z". Disabled (default): "timestamp":1700000000000000000. Note that nanosecond integers exceed 2^53, so consumers that parse JSON numbers as doubles lose sub-microsecond precision; prefer the RFC 3339 form for such consumers.

Trait Implementations

impl Clone for JsonFormat

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for JsonFormat

impl Debug for JsonFormat

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for JsonFormat

fn default() -> Self

Returns the “default value” for a type.

impl Format for JsonFormat

fn write_record(&self, record: &Record<'_>, writer: &mut dyn Write) -> Result

Write record to writer.

fn write_record_generic<W: Write>( &self, record: &Record<'_>, writer: &mut W, ) -> Result

Statically dispatched variant of Format::write_record.