diff options
Diffstat (limited to 'src/main.rs')
| -rw-r--r-- | src/main.rs | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/src/main.rs b/src/main.rs new file mode 100644 index 0000000..e7d70b3 --- /dev/null +++ b/src/main.rs @@ -0,0 +1,228 @@ +use std::io::{self, Result, Write}; +use std::collections::{HashSet, HashMap}; +use crate::errors::*; + +mod errors; + +fn sortuniq<T: Ord>(mut vec: Vec<T>) -> Vec<T> { + if vec.len() == 0 { + return vec; + } + + vec.sort(); + + let mut last_added_at = 0; + for i in 1..vec.len() { + if vec[i] != vec[last_added_at] { + vec.swap(i, last_added_at + 1); + last_added_at += 1; + } + } + + assert!(last_added_at + 1 <= vec.len()); + vec.resize_with(last_added_at + 1, || panic!("")); + vec +} + +#[allow(dead_code)] +fn deduplicate<T: std::hash::Hash + Eq + Copy>(mut vec: Vec<T>) -> Vec<T> { + if vec.len() == 0 { + return vec; + } + + let mut seen = HashSet::new(); + seen.insert(vec[0]); + + let mut last_added_at = 0; + for i in 1..vec.len() { + if !seen.contains(&vec[i]) { + seen.insert(vec[i]); + vec.swap(i, last_added_at + 1); + last_added_at += 1; + } + } + + assert!(last_added_at + 1 <= vec.len()); + vec.resize_with(last_added_at + 1, || panic!("")); + vec +} + +struct RefInfo<'repo> { + reference: git2::Reference<'repo>, + commit: git2::Commit<'repo>, +} + +#[derive(Debug, Clone)] +enum HistoryNode { + Genesis(git2::Oid), + Merge(git2::Oid, Vec<usize>), + Reference(git2::Oid, Vec<usize>), +} + +impl HistoryNode { + fn oid(&self) -> git2::Oid { + match self { + &HistoryNode::Genesis(oid) => oid, + &HistoryNode::Merge(oid, _) => oid, + &HistoryNode::Reference(oid, _) => oid, + } + } +} + +struct HistoryCache<F: Fn(&git2::Oid) -> bool> { + nodes: Vec<HistoryNode>, + cache: HashMap<git2::Oid, usize>, + is_reference: F, +} + +impl<F: Fn(&git2::Oid) -> bool> HistoryCache<F> { + fn new(is_reference: F) -> Self { + HistoryCache { + nodes: Vec::new(), + cache: HashMap::new(), + is_reference + } + } + + fn node_for(&self, key: usize) -> Option<&HistoryNode> { + self.nodes.get(key) + } + + fn build_history(&mut self, commit: &git2::Commit) -> usize { + let oid = commit.id(); + + if let Some(&key) = self.cache.get(&oid) { + return key; + } + + // eprintln!("build_history: inspecting {} {}", &oid.to_string()[0..8], commit.summary().expect("no summary?")); + + let parents = commit.parents().collect::<Vec<_>>(); + macro_rules! build_recursive { + () => {{ + let list = parents.iter().map(|c| self.build_history(c)).collect::<Vec<_>>(); + let list = self.simplify_merge(&list); + sortuniq(list) + }} + } + + let key = self.nodes.len(); + self.nodes.push(HistoryNode::Genesis(git2::Oid::zero())); // reserve the place + + let node = if (self.is_reference)(&oid) { + HistoryNode::Reference(oid, build_recursive!()) + } else if parents.len() == 1 { + return self.build_history(&parents[0]); + } else if parents.len() == 0 { + HistoryNode::Genesis(oid) + } else { + HistoryNode::Merge(oid, build_recursive!()) + }; + + self.nodes[key] = node; + self.cache.insert(oid, key); + key + } + + fn simplify_merge(&self, parents: &Vec<usize>) -> Vec<usize> { + let mut result: Vec<usize> = Vec::new(); + + for &parent in parents { + match &self.nodes[parent] { + HistoryNode::Genesis(_) => result.push(parent), + HistoryNode::Reference(_, _) => result.push(parent), + HistoryNode::Merge(_, ps) => result.append(&mut self.simplify_merge(ps)), + } + } + + result + } +} + +fn write_dot<W: Write, F: Fn(&git2::Oid) -> bool>(stream: &mut W, history: &mut HistoryCache<F>, seen: &mut HashSet<usize>, refmap: &HashMap<git2::Oid, RefInfo>, key: usize) -> Result<()> { + if !seen.insert(key) { + return Ok(()); + } + + let next_keys; + + match history.node_for(key).unwrap() { + HistoryNode::Genesis(oid) => { + writeln!(stream, "\t\"{}\" [label=\"G\"];", oid)?; + next_keys = Vec::new(); + }, + HistoryNode::Reference(oid, parents) => { + writeln!(stream, "\t\"{}\" [label=\"{}\"];", oid, refmap.get(oid).unwrap().reference.shorthand().expect("Reference name not valid utf8"))?; + // writeln!(stream, "\t\"{}\" [label=\"R\"];", oid)?; + for &parent in parents { + let node = history.node_for(parent).unwrap(); + writeln!(stream, "\t\"{}\" -> \"{}\";", node.oid(), oid)?; + } + next_keys = parents.clone(); + }, + HistoryNode::Merge(oid, parents) => { + writeln!(stream, "\t\"{}\" [label=\"\"];", oid)?; + for &parent in parents { + let node = history.node_for(parent).unwrap(); + writeln!(stream, "\t\"{}\" -> \"{}\";", node.oid(), oid)?; + } + next_keys = parents.clone(); + }, + } + + for key in next_keys { + write_dot(stream, history, seen, refmap, key)?; + } + + Ok(()) +} + +fn main() -> Result<()> { + let args = std::env::args().collect::<Vec<_>>(); + if args.len() != 2 { + eprintln!("Usage: {} <repo-dir>", args[0]); + std::process::exit(1); + } + + let repo = git2::Repository::open(&args[1]).to_io_result()?; + + let mut refmap: HashMap<git2::Oid, RefInfo> = HashMap::new(); + + for reference in repo.references().to_io_result()? { + let reference = reference.to_io_result()?; + if reference.is_tag() || reference.is_remote() { + let reference = reference.resolve().to_io_result()?; + match reference.peel_to_commit() { + Ok(commit) => { + let oid = reference.target().expect("Resolved reference is not a direct reference?"); + refmap.insert(oid, RefInfo { reference, commit }); + // println!("{} {}", + // reference.name().expect("Invalid utf8 in reference name"), + // commit.id()); + } + Err(_) => {}, + } + } + } + + let mut history_cache = HistoryCache::new(|oid| refmap.contains_key(oid)); + + for (_oid, info) in &refmap { + let _key = history_cache.build_history(&info.commit); + // println!("{}: {:?}", oid, history_cache.node_for(key)); + } + + let mut keys_done = HashSet::new(); + println!("digraph G {{"); + println!("\trankdir=\"BT\";"); + // println!("\tnode [shape=point]"); + println!("\tedge [arrowhead=none]"); + println!("\tsep=\"+100\";"); + for (_oid, info) in &refmap { + let key = history_cache.build_history(&info.commit); + write_dot(&mut io::stdout(), &mut history_cache, &mut keys_done, &refmap, key)?; + } + println!("}}"); + + Ok(()) +} |