Mercurial > hg
view rust/hg-core/src/requirements.rs @ 45924:a2eda1ff22aa
requirements: move loading to hg-core and add parsing
No functional change, checking comes later.
Differential Revision: https://phab.mercurial-scm.org/D9398
author | Simon Sapin <simon-commits@exyr.org> |
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date | Tue, 24 Nov 2020 17:49:16 +0100 |
parents | |
children | 2ad2745e0be9 |
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use std::io; use std::path::Path; #[derive(Debug)] pub enum RequirementsError { // TODO: include a path? Io(io::Error), /// The `requires` file is corrupted Corrupted, /// The repository requires a feature that we don’t support Unsupported { feature: String, }, } fn parse(bytes: &[u8]) -> Result<Vec<String>, ()> { // The Python code reading this file uses `str.splitlines` // which looks for a number of line separators (even including a couple of // non-ASCII ones), but Python code writing it always uses `\n`. let lines = bytes.split(|&byte| byte == b'\n'); lines .filter(|line| !line.is_empty()) .map(|line| { // Python uses Unicode `str.isalnum` but feature names are all // ASCII if line[0].is_ascii_alphanumeric() { Ok(String::from_utf8(line.into()).unwrap()) } else { Err(()) } }) .collect() } pub fn load(repo_root: &Path) -> Result<Vec<String>, RequirementsError> { match std::fs::read(repo_root.join(".hg").join("requires")) { Ok(bytes) => parse(&bytes).map_err(|()| RequirementsError::Corrupted), // Treat a missing file the same as an empty file. // From `mercurial/localrepo.py`: // > requires file contains a newline-delimited list of // > features/capabilities the opener (us) must have in order to use // > the repository. This file was introduced in Mercurial 0.9.2, // > which means very old repositories may not have one. We assume // > a missing file translates to no requirements. Err(error) if error.kind() == std::io::ErrorKind::NotFound => { Ok(Vec::new()) } Err(error) => Err(RequirementsError::Io(error))?, } }