Module span 

Distributed tracing spans for tracking units of work.

This module provides the core span implementation for distributed tracing. Spans represent units of work within a trace and can be nested to show relationships between different operations.

Key Concepts

• Span: A unit of work within a trace, with a name and optional attributes
• Span Context: The trace and span IDs that identify a span within a trace
• Span Guards: RAII guards that automatically handle span entry/exit
• Current Span: Thread-local tracking of the currently active span

Basic Usage

use veecle_telemetry::{CurrentSpan, span};

// Create and enter a span
let span = span!("operation", user_id = 123);
let _guard = span.entered();

// Add events to the current span
CurrentSpan::add_event("checkpoint", &[]);

// Span is automatically exited when guard is dropped

Span Lifecycle

1. Creation: Spans are created with a name and optional attributes
2. Entry: Spans are entered to make them the current active span
3. Events: Events and attributes can be added to active spans
4. Exit: Spans are exited when no longer active
5. Close: Spans are closed when their work is complete

Nesting

Spans can be nested to show relationships:

use veecle_telemetry::span;

let parent = span!("parent_operation");
let _parent_guard = parent.entered();

// This span will automatically be a child of the parent
let child = span!("child_operation");
let _child_guard = child.entered();

Structs

CurrentSpan

Utilities for working with the currently active span.

PhantomNotSend 🔒

Technically, SpanGuard can implement both Send and Sync safely. It doesn’t, because it has a PhantomNotSend field, specifically added in order to make it !Send.

Span

A distributed tracing span representing a unit of work.

SpanGuard

Exits and drops the span when this is dropped.

SpanGuardInner 🔒

SpanGuardRef

Exits the span when dropped.

SpanGuardRefInner 🔒

Constants

CURRENT_SPAN 🔒

PhantomNotSend 🔒