about summary refs log tree commit diff
path: root/tvix/castore/src/import/fs.rs
blob: a87a0278da4dccc205bd1b93ae39159fe4a67397 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
use std::os::unix::fs::MetadataExt;
use std::os::unix::fs::PermissionsExt;
use std::path::Path;

use futures::stream::BoxStream;
use tracing::instrument;
use walkdir::DirEntry;
use walkdir::WalkDir;

use crate::blobservice::BlobService;
use crate::directoryservice::DirectoryService;
use crate::proto::node::Node;

use super::ingest_entries;
use super::upload_blob_at_path;
use super::Error;
use super::IngestionEntry;

///! Imports that deal with a real filesystem.

/// Ingests the contents at a given path into the tvix store, interacting with a [BlobService] and
/// [DirectoryService]. It returns the root node or an error.
///
/// It does not follow symlinks at the root, they will be ingested as actual symlinks.
#[instrument(skip(blob_service, directory_service), fields(path), err)]
pub async fn ingest_path<BS, DS, P>(
    blob_service: BS,
    directory_service: DS,
    path: P,
) -> Result<Node, Error>
where
    P: AsRef<Path> + std::fmt::Debug,
    BS: BlobService + Clone,
    DS: AsRef<dyn DirectoryService>,
{
    let entry_stream = walk_path_for_ingestion(blob_service, path.as_ref());
    ingest_entries(directory_service, entry_stream).await
}

/// Walk the filesystem at a given path and returns a stream of ingestion entries.
///
/// This is how [`ingest_path`] assembles the set of entries to pass on [`ingest_entries`].
/// This low-level function can be used if additional filtering or processing is required on the
/// entries.
///
/// It does not follow symlinks at the root, they will be ingested as actual symlinks.
///
/// This function will walk the filesystem using `walkdir` and will consume
/// `O(#number of entries)` space.
#[instrument(fields(path), skip(blob_service))]
fn walk_path_for_ingestion<'a, BS>(
    blob_service: BS,
    path: &'a Path,
) -> BoxStream<'a, Result<IngestionEntry<'a>, Error>>
where
    BS: BlobService + Clone + 'a,
{
    let iter = WalkDir::new(path)
        .follow_links(false)
        .follow_root_links(false)
        .contents_first(true)
        .into_iter();

    dir_entry_iter_to_ingestion_stream(blob_service, iter, path)
}

/// Converts an iterator of [walkdir::DirEntry]s into a stream of ingestion entries.
/// This can then be fed into [ingest_entries] to ingest all the entries into the castore.
///
/// The root is the [Path] in the filesystem that is being ingested into the castore.
pub fn dir_entry_iter_to_ingestion_stream<'a, BS, I>(
    blob_service: BS,
    iter: I,
    root: &'a Path,
) -> BoxStream<'a, Result<IngestionEntry<'a>, Error>>
where
    BS: BlobService + Clone + 'a,
    I: Iterator<Item = Result<DirEntry, walkdir::Error>> + Send + 'a,
{
    let prefix = root.parent().unwrap_or_else(|| Path::new(""));

    let iter = iter.map(move |entry| match entry {
        Ok(entry) => dir_entry_to_ingestion_entry(blob_service.clone(), &entry, prefix),
        Err(error) => Err(Error::UnableToStat(
            root.to_path_buf(),
            error.into_io_error().expect("walkdir err must be some"),
        )),
    });

    Box::pin(futures::stream::iter(iter))
}

/// Converts a [walkdir::DirEntry] into an [IngestionEntry], uploading blobs to the
/// provided [BlobService].
///
/// The prefix path is stripped from the path of each entry. This is usually the parent path
/// of the path being ingested so that the last element of the stream only has one component.
fn dir_entry_to_ingestion_entry<'a, BS>(
    blob_service: BS,
    entry: &DirEntry,
    prefix: &Path,
) -> Result<IngestionEntry<'a>, Error>
where
    BS: BlobService + 'a,
{
    let file_type = entry.file_type();

    let path = entry
        .path()
        .strip_prefix(prefix)
        .expect("Tvix bug: failed to strip root path prefix")
        .to_path_buf();

    if file_type.is_dir() {
        Ok(IngestionEntry::Dir { path })
    } else if file_type.is_symlink() {
        let target = std::fs::read_link(entry.path())
            .map_err(|e| Error::UnableToStat(entry.path().to_path_buf(), e))?;

        Ok(IngestionEntry::Symlink { path, target })
    } else if file_type.is_file() {
        let metadata = entry
            .metadata()
            .map_err(|e| Error::UnableToStat(entry.path().to_path_buf(), e.into()))?;

        // TODO: In the future, for small files, hash right away and upload async.
        let digest = Box::pin(upload_blob_at_path(
            blob_service,
            entry.path().to_path_buf(),
        ));

        Ok(IngestionEntry::Regular {
            path,
            size: metadata.size(),
            // If it's executable by the user, it'll become executable.
            // This matches nix's dump() function behaviour.
            executable: metadata.permissions().mode() & 64 != 0,
            digest,
        })
    } else {
        Ok(IngestionEntry::Unknown { path, file_type })
    }
}