cargo_util/
du.rs

1//! A simple disk usage estimator.
2
3use anyhow::{Context, Result};
4use ignore::overrides::OverrideBuilder;
5use ignore::{WalkBuilder, WalkState};
6use std::path::Path;
7use std::sync::{Arc, Mutex};
8
9/// Determines the disk usage of all files in the given directory.
10///
11/// The given patterns are gitignore style patterns relative to the given
12/// path. If there are patterns, it will only count things matching that
13/// pattern. `!` can be used to exclude things. See [`OverrideBuilder::add`]
14/// for more info.
15///
16/// This is a primitive implementation that doesn't handle hard links, and
17/// isn't particularly fast (for example, not using `getattrlistbulk` on
18/// macOS). It also only uses actual byte sizes instead of block counts (and
19/// thus vastly undercounts directories with lots of small files). It would be
20/// nice to improve this or replace it with something better.
21pub fn du(path: &Path, patterns: &[&str]) -> Result<u64> {
22    du_inner(path, patterns).with_context(|| format!("failed to walk `{}`", path.display()))
23}
24
25fn du_inner(path: &Path, patterns: &[&str]) -> Result<u64> {
26    let mut builder = OverrideBuilder::new(path);
27    for pattern in patterns {
28        builder.add(pattern)?;
29    }
30    let overrides = builder.build()?;
31
32    let mut builder = WalkBuilder::new(path);
33    builder
34        .overrides(overrides)
35        .hidden(false)
36        .parents(false)
37        .ignore(false)
38        .git_global(false)
39        .git_ignore(false)
40        .git_exclude(false);
41    let walker = builder.build_parallel();
42
43    // Platforms like PowerPC don't support AtomicU64, so we use a Mutex instead.
44    //
45    // See:
46    // - https://github.com/rust-lang/cargo/pull/12981
47    // - https://github.com/rust-lang/rust/pull/117916#issuecomment-1812635848
48    let total = Arc::new(Mutex::new(0u64));
49
50    // A slot used to indicate there was an error while walking.
51    //
52    // It is possible that more than one error happens (such as in different
53    // threads). The error returned is arbitrary in that case.
54    let err = Arc::new(Mutex::new(None));
55    walker.run(|| {
56        Box::new(|entry| {
57            match entry {
58                Ok(entry) => match entry.metadata() {
59                    Ok(meta) => {
60                        if meta.is_file() {
61                            let mut lock = total.lock().unwrap();
62                            *lock += meta.len();
63                        }
64                    }
65                    Err(e) => {
66                        *err.lock().unwrap() = Some(e.into());
67                        return WalkState::Quit;
68                    }
69                },
70                Err(e) => {
71                    *err.lock().unwrap() = Some(e.into());
72                    return WalkState::Quit;
73                }
74            }
75            WalkState::Continue
76        })
77    });
78
79    if let Some(e) = err.lock().unwrap().take() {
80        return Err(e);
81    }
82
83    let total = *total.lock().unwrap();
84    Ok(total)
85}