about summary refs log tree commit diff
path: root/tvix/castore/src/import/fs.rs
blob: 9d3ecfe6ab7a3258548dc5408d589c43e9cfe8da (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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
//! Import from a real filesystem.

use futures::stream::BoxStream;
use futures::StreamExt;
use std::fs::FileType;
use std::os::unix::ffi::OsStringExt;
use std::os::unix::fs::MetadataExt;
use std::os::unix::fs::PermissionsExt;
use tracing::instrument;
use walkdir::DirEntry;
use walkdir::WalkDir;

use crate::blobservice::BlobService;
use crate::directoryservice::DirectoryService;
use crate::proto::node::Node;
use crate::B3Digest;

use super::ingest_entries;
use super::IngestionEntry;
use super::IngestionError;

/// 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.
///
/// This function will walk the filesystem using `walkdir` and will consume
/// `O(#number of entries)` space.
#[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, IngestionError<Error>>
where
    P: AsRef<std::path::Path> + std::fmt::Debug,
    BS: BlobService + Clone,
    DS: DirectoryService,
{
    let iter = WalkDir::new(path.as_ref())
        .follow_links(false)
        .follow_root_links(false)
        .contents_first(true)
        .into_iter();

    let entries = dir_entries_to_ingestion_stream(blob_service, iter, path.as_ref());
    ingest_entries(directory_service, entries).await
}

/// 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 produced stream is buffered, so uploads can happen concurrently.
///
/// The root is the [Path] in the filesystem that is being ingested into the castore.
pub fn dir_entries_to_ingestion_stream<'a, BS, I>(
    blob_service: BS,
    iter: I,
    root: &'a std::path::Path,
) -> BoxStream<'a, Result<IngestionEntry, Error>>
where
    BS: BlobService + Clone + 'a,
    I: Iterator<Item = Result<DirEntry, walkdir::Error>> + Send + 'a,
{
    let prefix = root.parent().unwrap_or_else(|| std::path::Path::new(""));

    Box::pin(
        futures::stream::iter(iter)
            .map(move |x| {
                let blob_service = blob_service.clone();
                async move {
                    match x {
                        Ok(dir_entry) => {
                            dir_entry_to_ingestion_entry(blob_service, &dir_entry, prefix).await
                        }
                        Err(e) => Err(Error::Stat(
                            prefix.to_path_buf(),
                            e.into_io_error().expect("walkdir err must be some"),
                        )),
                    }
                }
            })
            .buffered(50),
    )
}

/// 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.
pub async fn dir_entry_to_ingestion_entry<BS>(
    blob_service: BS,
    entry: &DirEntry,
    prefix: &std::path::Path,
) -> Result<IngestionEntry, Error>
where
    BS: BlobService,
{
    let file_type = entry.file_type();

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

    // convert to castore PathBuf
    let path = crate::path::PathBuf::from_host_path(fs_path, false)
        .unwrap_or_else(|e| panic!("Tvix bug: walkdir direntry cannot be parsed: {}", e));

    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::Stat(entry.path().to_path_buf(), e))?
            .into_os_string()
            .into_vec();

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

        let digest = upload_blob(blob_service, entry.path().to_path_buf()).await?;

        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 {
        return Err(Error::FileType(fs_path.to_path_buf(), file_type));
    }
}

/// Uploads the file at the provided [Path] the the [BlobService].
#[instrument(skip(blob_service), fields(path), err)]
async fn upload_blob<BS>(
    blob_service: BS,
    path: impl AsRef<std::path::Path>,
) -> Result<B3Digest, Error>
where
    BS: BlobService,
{
    let mut file = match tokio::fs::File::open(path.as_ref()).await {
        Ok(file) => file,
        Err(e) => return Err(Error::BlobRead(path.as_ref().to_path_buf(), e)),
    };

    let mut writer = blob_service.open_write().await;

    if let Err(e) = tokio::io::copy(&mut file, &mut writer).await {
        return Err(Error::BlobRead(path.as_ref().to_path_buf(), e));
    };

    let digest = writer
        .close()
        .await
        .map_err(|e| Error::BlobFinalize(path.as_ref().to_path_buf(), e))?;

    Ok(digest)
}

#[derive(Debug, thiserror::Error)]
pub enum Error {
    #[error("unsupported file type at {0}: {1:?}")]
    FileType(std::path::PathBuf, FileType),

    #[error("unable to stat {0}: {1}")]
    Stat(std::path::PathBuf, std::io::Error),

    #[error("unable to open {0}: {1}")]
    Open(std::path::PathBuf, std::io::Error),

    #[error("unable to read {0}: {1}")]
    BlobRead(std::path::PathBuf, std::io::Error),

    // TODO: proper error for blob finalize
    #[error("unable to finalize blob {0}: {1}")]
    BlobFinalize(std::path::PathBuf, std::io::Error),
}