view rust/hg-core/examples/nodemap/main.rs @ 45144:c93dd9d9f1e6

discovery: change users of `outgoing.missingheads` to `outgoing.ancestorsof`

The attribute `missingheads` was recently renamed to `ancestorsof`, as it,
despite the old name, doesn’t contain the missing heads but the changesets that
were requested (including ancestors) for the outgoing operation.

Changing all the users enables to print a warning if the old name is used.

There is a good chance that some of the users are buggy because of the old name.
Changing them to use the new name makes it more obvious that they are buggy. All
users need to be reviewed for bugs. When sending patches for fixing them, the
change will be more obvious without having to explain again and again the
discrepancy of the old attribute name and what it actually contained.

// Copyright 2019-2020 Georges Racinet <[e-mail]>
//
// This software may be used and distributed according to the terms of the
// GNU General Public License version 2 or any later version.

use clap::*;
use hg::revlog::node::*;
use hg::revlog::nodemap::*;
use hg::revlog::*;
use memmap::MmapOptions;
use rand::Rng;
use std::fs::File;
use std::io;
use std::io::Write;
use std::path::{Path, PathBuf};
use std::str::FromStr;
use std::time::Instant;

mod index;
use index::Index;

fn mmap_index(repo_path: &Path) -> Index {
    let mut path = PathBuf::from(repo_path);
    path.extend([".hg", "store", "00changelog.i"].iter());
    Index::load_mmap(path)
}

fn mmap_nodemap(path: &Path) -> NodeTree {
    let file = File::open(path).unwrap();
    let mmap = unsafe { MmapOptions::new().map(&file).unwrap() };
    let len = mmap.len();
    NodeTree::load_bytes(Box::new(mmap), len)
}

/// Scan the whole index and create the corresponding nodemap file at `path`
fn create(index: &Index, path: &Path) -> io::Result<()> {
    let mut file = File::create(path)?;
    let start = Instant::now();
    let mut nm = NodeTree::default();
    for rev in 0..index.len() {
        let rev = rev as Revision;
        nm.insert(index, index.node(rev).unwrap(), rev).unwrap();
    }
    eprintln!("Nodemap constructed in RAM in {:?}", start.elapsed());
    file.write(&nm.into_readonly_and_added_bytes().1)?;
    eprintln!("Nodemap written to disk");
    Ok(())
}

fn query(index: &Index, nm: &NodeTree, prefix: &str) {
    let start = Instant::now();
    let res = nm.find_hex(index, prefix);
    println!("Result found in {:?}: {:?}", start.elapsed(), res);
}

fn bench(index: &Index, nm: &NodeTree, queries: usize) {
    let len = index.len() as u32;
    let mut rng = rand::thread_rng();
    let nodes: Vec<Node> = (0..queries)
        .map(|_| {
            index
                .node((rng.gen::<u32>() % len) as Revision)
                .unwrap()
                .clone()
        })
        .collect();
    if queries < 10 {
        let nodes_hex: Vec<String> =
            nodes.iter().map(|n| n.encode_hex()).collect();
        println!("Nodes: {:?}", nodes_hex);
    }
    let mut last: Option<Revision> = None;
    let start = Instant::now();
    for node in nodes.iter() {
        last = nm.find_bin(index, node.into()).unwrap();
    }
    let elapsed = start.elapsed();
    println!(
        "Did {} queries in {:?} (mean {:?}), last was {:?} with result {:?}",
        queries,
        elapsed,
        elapsed / (queries as u32),
        nodes.last().unwrap().encode_hex(),
        last
    );
}

fn main() {
    let matches = App::new("Nodemap pure Rust example")
        .arg(
            Arg::with_name("REPOSITORY")
                .help("Path to the repository, always necessary for its index")
                .required(true),
        )
        .arg(
            Arg::with_name("NODEMAP_FILE")
                .help("Path to the nodemap file, independent of REPOSITORY")
                .required(true),
        )
        .subcommand(
            SubCommand::with_name("create")
                .about("Create NODEMAP_FILE by scanning repository index"),
        )
        .subcommand(
            SubCommand::with_name("query")
                .about("Query NODEMAP_FILE for PREFIX")
                .arg(Arg::with_name("PREFIX").required(true)),
        )
        .subcommand(
            SubCommand::with_name("bench")
                .about(
                    "Perform #QUERIES random successful queries on NODEMAP_FILE")
                .arg(Arg::with_name("QUERIES").required(true)),
        )
        .get_matches();

    let repo = matches.value_of("REPOSITORY").unwrap();
    let nm_path = matches.value_of("NODEMAP_FILE").unwrap();

    let index = mmap_index(&Path::new(repo));

    if let Some(_) = matches.subcommand_matches("create") {
        println!("Creating nodemap file {} for repository {}", nm_path, repo);
        create(&index, &Path::new(nm_path)).unwrap();
        return;
    }

    let nm = mmap_nodemap(&Path::new(nm_path));
    if let Some(matches) = matches.subcommand_matches("query") {
        let prefix = matches.value_of("PREFIX").unwrap();
        println!(
            "Querying {} in nodemap file {} of repository {}",
            prefix, nm_path, repo
        );
        query(&index, &nm, prefix);
    }
    if let Some(matches) = matches.subcommand_matches("bench") {
        let queries =
            usize::from_str(matches.value_of("QUERIES").unwrap()).unwrap();
        println!(
            "Doing {} random queries in nodemap file {} of repository {}",
            queries, nm_path, repo
        );
        bench(&index, &nm, queries);
    }
}