use std::{
io::{BufRead, BufReader},
path::{Path, PathBuf},
};
use crate::{file, File, Graph, MAX_COMMITS};
#[derive(thiserror::Error, Debug)]
#[allow(missing_docs)]
pub enum Error {
#[error("{}", .path.display())]
File {
#[source]
err: file::Error,
path: PathBuf,
},
#[error("Commit-graph files mismatch: '{}' uses hash {hash1:?}, but '{}' uses hash {hash2:?}", .path1.display(), .path2.display())]
HashVersionMismatch {
path1: PathBuf,
hash1: gix_hash::Kind,
path2: PathBuf,
hash2: gix_hash::Kind,
},
#[error("Did not find any files that look like commit graphs at '{}'", .0.display())]
InvalidPath(PathBuf),
#[error("Could not open commit-graph file at '{}'", .path.display())]
Io {
#[source]
err: std::io::Error,
path: PathBuf,
},
#[error(
"Commit-graph files contain {0} commits altogether, but only {} commits are allowed",
MAX_COMMITS
)]
TooManyCommits(u64),
}
impl Graph {
pub fn at(path: &Path) -> Result<Self, Error> {
Self::try_from(path)
}
pub fn from_commit_graphs_dir(path: &Path) -> Result<Self, Error> {
let commit_graphs_dir = path;
let chain_file_path = commit_graphs_dir.join("commit-graph-chain");
let chain_file = std::fs::File::open(&chain_file_path).map_err(|e| Error::Io {
err: e,
path: chain_file_path.clone(),
})?;
let mut files = Vec::new();
for line in BufReader::new(chain_file).lines() {
let hash = line.map_err(|e| Error::Io {
err: e,
path: chain_file_path.clone(),
})?;
let graph_file_path = commit_graphs_dir.join(format!("graph-{hash}.graph"));
files.push(File::at(&graph_file_path).map_err(|e| Error::File {
err: e,
path: graph_file_path.clone(),
})?);
}
Self::new(files)
}
pub fn from_file(path: &Path) -> Result<Self, Error> {
let file = File::at(path).map_err(|e| Error::File {
err: e,
path: path.to_owned(),
})?;
Self::new(vec![file])
}
pub fn from_info_dir(info_dir: &Path) -> Result<Self, Error> {
Self::from_file(&info_dir.join("commit-graph"))
.or_else(|_| Self::from_commit_graphs_dir(&info_dir.join("commit-graphs")))
}
pub fn new(files: Vec<File>) -> Result<Self, Error> {
let num_commits: u64 = files.iter().map(|f| u64::from(f.num_commits())).sum();
if num_commits > u64::from(MAX_COMMITS) {
return Err(Error::TooManyCommits(num_commits));
}
for window in files.windows(2) {
let f1 = &window[0];
let f2 = &window[1];
if f1.object_hash() != f2.object_hash() {
return Err(Error::HashVersionMismatch {
path1: f1.path().to_owned(),
hash1: f1.object_hash(),
path2: f2.path().to_owned(),
hash2: f2.object_hash(),
});
}
}
Ok(Self { files })
}
}
impl TryFrom<&Path> for Graph {
type Error = Error;
fn try_from(path: &Path) -> Result<Self, Self::Error> {
if path.is_file() {
Self::from_file(path)
} else if path.is_dir() {
if path.join("commit-graph-chain").is_file() {
Self::from_commit_graphs_dir(path)
} else {
Self::from_info_dir(path)
}
} else {
Err(Error::InvalidPath(path.to_owned()))
}
}
}