Trait MessageFormatter 

pub trait MessageFormatter:
    Send
    + Sync
    + Default {
    // Required methods
    fn format_io(
        &mut self,
        message: &Message,
        write: &mut (dyn Write + Send + Sync),
    ) -> Result<(), ServiceError>;
    fn format_fmt(
        &mut self,
        message: &Message,
        write: &mut (dyn Write + Send + Sync),
    ) -> Result<(), ServiceError>;
}

Trait defining the behavior for formatting log messages.

Implementations are responsible for defining the layout (timestamp, level, content) and writing the result to an I/O sink.

Required Methods

fn format_io( &mut self, message: &Message, write: &mut (dyn Write + Send + Sync), ) -> Result<(), ServiceError>

Formats and writes the message to the provided I/O sink.

Implementation Requirements

• Atomicity: To ensure log integrity in concurrent environments, implementations should minimize the number of calls to the writer. Using a single write! macro or a buffered approach is highly recommended.
• Thread Safety: The writer is guaranteed to be Send + Sync. However, some global sinks (like std::io::stdout()) may not support explicit locking while maintaining these bounds.

Errors

Returns ServiceError if formatting fails or the writer encounters an I/O error.

fn format_fmt( &mut self, message: &Message, write: &mut (dyn Write + Send + Sync), ) -> Result<(), ServiceError>

Formats a message specifically for fmt-based destinations.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl MessageFormatter for CloudWatchCoutMessageFormatter

Available on crate feature awscout only.

impl MessageFormatter for AtemporalMessageFormatter

impl MessageFormatter for StandardMessageFormatter