Crate fast_time 

Provides efficient mechanisms to capture the current timestamp and measure elapsed time.

This crate offers a Clock that can provide timestamps with low overhead, making it suitable for high-frequency querying scenarios like metrics collection and logging. The clock prioritizes efficiency over absolute precision, making it ideal for applications that need to capture thousands of timestamps per second.

Key Features

• Low overhead: Optimized for rapid, repeated timestamp capture on supported platforms
• Monotonic timestamps: Guarantees that timestamps always increase
• Cross-platform: Works on all platforms, with optimizations for Windows and Linux
• Standard library compatibility: Converts to/from std::time::Instant

Trade-offs

On optimized platforms (Windows, Linux):

• May lag behind wall-clock time by a few milliseconds
• May not reflect explicit wall clock adjustments (e.g., NTP synchronization)
• Optimized for frequency over precision

On other platforms, performance is equivalent to std::time::Instant.

Hot loop performance comparison (optimized platforms)

Platform	fast_time	std::time
Windows	2 ns	25 ns
Linux	6 ns	19 ns

Basic Usage

use fast_time::Clock;

let mut clock = Clock::new();
let start = clock.now();

// Do some work...
std::thread::sleep(std::time::Duration::from_millis(10));

let elapsed = start.elapsed(&mut clock);
println!("Operation took: {:?}", elapsed);

High-frequency timestamp collection

use std::time::Duration;

use fast_time::Clock;

let mut clock = Clock::new();
let mut timestamps = Vec::new();

// Collect many timestamps rapidly
for _ in 0..1000 {
    timestamps.push(clock.now());
}

// Measure elapsed time between first and last
let total_time = timestamps
    .last()
    .unwrap()
    .saturating_duration_since(*timestamps.first().unwrap());

println!(
    "Collected {} timestamps in {:?}",
    timestamps.len(),
    total_time
);

Supported platforms

This crate provides optimized implementations for:

• Windows
• Linux

On other platforms, the crate functions as a lightweight wrapper around the Rust standard library’s Instant type, ensuring the crate compiles on all platforms without requiring platform-specific optimizations.

Structs

Clock

A clock that can efficiently provide the current time.

Instant

An instant returned by the fast-time clock.