httpdt

A datetime library for HTTP clients and servers.

Generates timestamps for use in the HTTP Date header, the only format required for implementation of HTTP.

Calculates with a focus on clarity from SystemTime, with no external dependencies, and provides for updates to previously generated datetimes for speed.

Available via crates.io:

cargo add httpdt@0.1.0

Why?

For a smaller surface area and better understanding of the underlying logic when implementing a client or server. No need to audit a more extensive datetime crate to generate a single relatively straightforward output.

How?

Instantiate a Datetime struct with the new method, then get the current timestamp for the 'Date' header field with for_header:

use httpdt::Datetime;

let timestamp = Datetime::new()?
  .for_header();

To reduce computation, an initial instance can be used as the basis for successive new timestamps via the now method:

use httpdt::Datetime;

let dt = Datetime::new()?;

let ts_initial = dt
  .for_header();
// ...
let ts_updated = dt
  .now()?
  .for_header();

The default method provides a Datetime instance corresponding to the Unix epoch, the raw method the number of seconds since the epoch.

Docs

The documentation is available at docs.rs. It can be built and viewed locally in the browser with the following command:

cargo doc --open

Making changes

Running the tests after making changes and adding tests to cover new behaviour is recommended.

Tests

The unit tests and documentation example can be run with the following command:

cargo test

The unit test cases for each component are in the test module at the base of the corresponding source file.

Development plan

The following are the expected next steps in the development of the code base. The general medium-term aim is a clear, robust and efficient datetime resource for fuller HTTP implementations. Pull requests are welcome for these and other potential improvements.

• implement a top-level error type
• revisit cross-component integer typing
• document and expose the individual components
• handle timezones, allowing for generation of server log entries in Common Log Format
• revise SystemTime-dependent testing
• extend test modules