pito-fetch

Downloads you can trust, in one call. pito-fetch is a small Rust library, part of PITO MD: give it a URL, where the file goes and the file’s sha256. It downloads into a .part file, picks that file up again after a crash or a dropped connection, checks the sha256 and only then renames it into place. A file is there whole and verified, or not at all.

1 GiB downloaded and verified	2.47 s on loopback, in 7.8 MiB of memory
Library code	699 lines of Rust
Dependencies	3 direct (ureq, sha2, thiserror), no OpenSSL or other system library
Clean release build	11.7 s
A downloader built on it	2.5 MB stripped, TLS and root certificates included

Speed and memory says how each number was measured. Works on Linux and macOS (Windows through WSL).

Start here

• Install: add the crate and download your first file.
• Download a file: a Request, a Fetcher and a progress callback.
• Resume and verify: what happens after a crash, a Ctrl-C or a wrong sha256.
• Cancel a download: stop it from another thread and resume it later.
• Handle errors: every FetchError, and what to do with each.
• Two downloads of one file: threads or processes racing for the same file.
• Timeouts and limits: containment, timings, retries, redirects and byte caps.
• Write the sha256 sums: make the sums a manifest pins, and a static manifest with FetchSpec.
• Try it locally: the get and serve examples.
• Formats: the part file, the sha256 strings and the progress values it promises.
• API reference: every public type and function, from cargo doc.
• Changelog.

Licence

The code is MIT licensed, © Catalin Ilinca. The pito-fetch and PITO MD names and their logos are © Catalin Ilinca, all rights reserved, and are not covered by the MIT licence. Source and issues: github.com/gmrdad82/pito-fetch.