about summary refs log tree commit diff
path: root/tvix/castore/src/import/mod.rs
blob: ff27c0fcfd2bba331bf663e54c72a6a464e71f51 (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
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
//! Deals with ingesting contents into castore.
//! The main library function here is [ingest_entries], receiving a stream of
//! [IngestionEntry].
//!
//! Specific implementations, such as ingesting from the filesystem, live in
//! child modules.

use crate::blobservice::BlobService;
use crate::directoryservice::DirectoryPutter;
use crate::directoryservice::DirectoryService;
use crate::proto::node::Node;
use crate::proto::Directory;
use crate::proto::DirectoryNode;
use crate::proto::FileNode;
use crate::proto::SymlinkNode;
use crate::B3Digest;
use futures::Future;
use futures::{Stream, StreamExt};
use std::fs::FileType;
use std::pin::Pin;
use tracing::Level;

#[cfg(target_family = "unix")]
use std::os::unix::ffi::OsStrExt;

use std::{
    collections::HashMap,
    path::{Path, PathBuf},
};
use tracing::instrument;

mod error;
pub use error::Error;

pub mod fs;

/// Ingests [IngestionEntry] from the given stream into a the passed [DirectoryService].
/// On success, returns the root [Node].
///
/// The stream must have the following invariants:
/// - All children entries must come before their parents.
/// - The last entry must be the root node which must have a single path component.
/// - Every entry should have a unique path, and only consist of normal components.
///   This means, no windows path prefixes, absolute paths, `.` or `..`.
///
/// Internally we maintain a [HashMap] of [PathBuf] to partially populated [Directory] at that
/// path. Once we receive an [IngestionEntry] for the directory itself, we remove it from the
/// map and upload it to the [DirectoryService] through a lazily created [DirectoryPutter].
///
/// On success, returns the root node.
#[instrument(skip_all, ret(level = Level::TRACE), err)]
pub async fn ingest_entries<'a, DS, S>(directory_service: DS, mut entries: S) -> Result<Node, Error>
where
    DS: AsRef<dyn DirectoryService>,
    S: Stream<Item = Result<IngestionEntry<'a>, Error>> + Send + std::marker::Unpin,
{
    // For a given path, this holds the [Directory] structs as they are populated.
    let mut directories: HashMap<PathBuf, Directory> = HashMap::default();
    let mut maybe_directory_putter: Option<Box<dyn DirectoryPutter>> = None;

    let root_node = loop {
        let mut entry = entries
            .next()
            .await
            // The last entry of the stream must have 1 path component, after which
            // we break the loop manually.
            .expect("Tvix bug: unexpected end of stream")?;

        debug_assert!(
            entry
                .path()
                .components()
                .all(|x| matches!(x, std::path::Component::Normal(_))),
            "path may only contain normal components"
        );

        let name = entry
            .path()
            .file_name()
            // If this is the root node, it will have an empty name.
            .unwrap_or_default()
            .as_bytes()
            .to_owned()
            .into();

        let node = match &mut entry {
            IngestionEntry::Dir { .. } => {
                // If the entry is a directory, we traversed all its children (and
                // populated it in `directories`).
                // If we don't have it in there, it's an empty directory.
                let directory = directories
                    .remove(entry.path())
                    // In that case, it contained no children
                    .unwrap_or_default();

                let directory_size = directory.size();
                let directory_digest = directory.digest();

                // Use the directory_putter to upload the directory.
                // If we don't have one yet (as that's the first one to upload),
                // initialize the putter.
                maybe_directory_putter
                    .get_or_insert_with(|| directory_service.as_ref().put_multiple_start())
                    .put(directory)
                    .await?;

                Node::Directory(DirectoryNode {
                    name,
                    digest: directory_digest.into(),
                    size: directory_size,
                })
            }
            IngestionEntry::Symlink { ref target, .. } => Node::Symlink(SymlinkNode {
                name,
                target: target.as_os_str().as_bytes().to_owned().into(),
            }),
            IngestionEntry::Regular {
                size,
                executable,
                digest,
                ..
            } => Node::File(FileNode {
                name,
                digest: digest.await?.into(),
                size: *size,
                executable: *executable,
            }),
            IngestionEntry::Unknown { path, file_type } => {
                return Err(Error::UnsupportedFileType(path.clone(), *file_type));
            }
        };

        if entry.path().components().count() == 1 {
            break node;
        }

        // record node in parent directory, creating a new [Directory] if not there yet.
        directories
            .entry(entry.path().parent().unwrap().to_path_buf())
            .or_default()
            .add(node);
    };

    // if there were directories uploaded, make sure we flush the putter, so
    // they're all persisted to the backend.
    if let Some(mut directory_putter) = maybe_directory_putter {
        let root_directory_digest = directory_putter.close().await?;

        #[cfg(debug_assertions)]
        {
            if let Node::Directory(directory_node) = &root_node {
                debug_assert_eq!(
                    root_directory_digest,
                    directory_node
                        .digest
                        .to_vec()
                        .try_into()
                        .expect("invalid digest len")
                )
            } else {
                unreachable!("Tvix bug: directory putter initialized but no root directory node");
            }
        }
    };

    Ok(root_node)
}

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

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

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

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

    Ok(digest)
}

type BlobFut<'a> = Pin<Box<dyn Future<Output = Result<B3Digest, Error>> + Send + 'a>>;

pub enum IngestionEntry<'a> {
    Regular {
        path: PathBuf,
        size: u64,
        executable: bool,
        digest: BlobFut<'a>,
    },
    Symlink {
        path: PathBuf,
        target: PathBuf,
    },
    Dir {
        path: PathBuf,
    },
    Unknown {
        path: PathBuf,
        file_type: FileType,
    },
}

impl<'a> IngestionEntry<'a> {
    fn path(&self) -> &Path {
        match self {
            IngestionEntry::Regular { path, .. } => path,
            IngestionEntry::Symlink { path, .. } => path,
            IngestionEntry::Dir { path } => path,
            IngestionEntry::Unknown { path, .. } => path,
        }
    }
}