about summary refs log tree commit diff
path: root/tvix/store/src/store_io.rs
blob: 615d1f50f4a3bbcc6bb1d17d89d90df15d211f44 (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
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
//! This module provides an implementation of EvalIO.
//!
//! It can be used by the tvix evalutator to talk to a tvix store.

use data_encoding::BASE64;
use nix_compat::{
    nixhash::{HashAlgo, NixHash, NixHashWithMode},
    store_path::{build_regular_ca_path, StorePath},
};
use std::{io, path::Path, path::PathBuf, sync::Arc};
use tracing::{error, instrument, warn};
use tvix_eval::{EvalIO, FileType, StdIO};

use crate::{
    blobservice::BlobService,
    directoryservice::{self, DirectoryService},
    import,
    nar::calculate_size_and_sha256,
    pathinfoservice::PathInfoService,
    proto::NamedNode,
    B3Digest,
};

/// Implements [EvalIO], asking given [PathInfoService], [DirectoryService]
/// and [BlobService].
///
/// In case the given path does not exist in these stores, we ask StdIO.
/// This is to both cover cases of syntactically valid store paths, that exist
/// on the filesystem (still managed by Nix), as well as being able to read
/// files outside store paths.
pub struct TvixStoreIO {
    blob_service: Arc<dyn BlobService>,
    directory_service: Arc<dyn DirectoryService>,
    path_info_service: Arc<dyn PathInfoService>,
    std_io: StdIO,
}

impl TvixStoreIO {
    pub fn new(
        blob_service: Arc<dyn BlobService>,
        directory_service: Arc<dyn DirectoryService>,
        path_info_service: Arc<dyn PathInfoService>,
    ) -> Self {
        Self {
            blob_service,
            directory_service,
            path_info_service,
            std_io: StdIO {},
        }
    }

    /// for a given [StorePath] and additional [Path] inside the store path,
    /// look up the [PathInfo], and if it exists, traverse the directory structure to
    /// return the [crate::proto::node::Node] specified by `sub_path`.
    #[instrument(skip(self), ret, err)]
    fn store_path_to_root_node(
        &self,
        store_path: &StorePath,
        sub_path: &Path,
    ) -> Result<Option<crate::proto::node::Node>, crate::Error> {
        let path_info = {
            match self.path_info_service.get(store_path.digest)? {
                // If there's no PathInfo found, early exit
                None => return Ok(None),
                Some(path_info) => path_info,
            }
        };

        let root_node = {
            match path_info.node {
                None => {
                    warn!(
                        "returned PathInfo {:?} node is None, this shouldn't happen.",
                        &path_info
                    );
                    return Ok(None);
                }
                Some(root_node) => match root_node.node {
                    None => {
                        warn!("node for {:?} is None, this shouldn't happen.", &root_node);
                        return Ok(None);
                    }
                    Some(root_node) => root_node,
                },
            }
        };

        directoryservice::traverse_to(self.directory_service.clone(), root_node, sub_path)
    }

    /// Imports a given path on the filesystem into the store, and returns the
    /// [crate::proto::PathInfo] describing the path, that was sent to
    /// [PathInfoService].
    /// While not part of the [EvalIO], it's still useful for clients who
    /// care about the [PathInfo].
    #[instrument(skip(self), ret, err)]
    pub fn import_path_with_pathinfo(
        &self,
        path: &std::path::Path,
    ) -> Result<crate::proto::PathInfo, io::Error> {
        // Call [import::ingest_path], which will walk over the given path and return a root_node.
        let root_node = import::ingest_path(
            self.blob_service.clone(),
            self.directory_service.clone(),
            path,
        )
        .expect("error during import_path");

        // Render the NAR
        let (nar_size, nar_sha256) = calculate_size_and_sha256(
            &root_node,
            self.blob_service.clone(),
            self.directory_service.clone(),
        )
        .expect("error during nar calculation"); // TODO: handle error

        // We populate the struct directly, as we know the sha256 digest has the
        // right size.
        let nar_hash_with_mode = NixHashWithMode::Recursive(NixHash {
            algo: HashAlgo::Sha256,
            digest: nar_sha256.to_vec(),
        });

        let name = path
            .file_name()
            .expect("path must not be ..")
            .to_str()
            .expect("path must be valid unicode");

        let output_path =
            build_regular_ca_path(name, &nar_hash_with_mode, Vec::<String>::new(), false).unwrap();

        // assemble a new root_node with a name that is derived from the nar hash.
        let renamed_root_node = {
            let name = output_path.to_string().into_bytes().into();

            match root_node {
                crate::proto::node::Node::Directory(n) => {
                    crate::proto::node::Node::Directory(crate::proto::DirectoryNode { name, ..n })
                }
                crate::proto::node::Node::File(n) => {
                    crate::proto::node::Node::File(crate::proto::FileNode { name, ..n })
                }
                crate::proto::node::Node::Symlink(n) => {
                    crate::proto::node::Node::Symlink(crate::proto::SymlinkNode { name, ..n })
                }
            }
        };

        // assemble the [crate::proto::PathInfo] object.
        let path_info = crate::proto::PathInfo {
            node: Some(crate::proto::Node {
                node: Some(renamed_root_node),
            }),
            // There's no reference scanning on path contents ingested like this.
            references: vec![],
            narinfo: Some(crate::proto::NarInfo {
                nar_size,
                nar_sha256: nar_sha256.to_vec().into(),
                signatures: vec![],
                reference_names: vec![],
                // TODO: narinfo for talosctl.src contains `CA: fixed:r:sha256:1x13j5hy75221bf6kz7cpgld9vgic6bqx07w5xjs4pxnksj6lxb6`
                // do we need this anywhere?
            }),
        };

        // put into [PathInfoService], and return the PathInfo that we get back
        // from there (it might contain additional signatures).
        let path_info = self.path_info_service.put(path_info)?;

        Ok(path_info)
    }
}

/// For given NAR sha256 digest and name, return the new [StorePath] this would have.
#[instrument(skip(nar_sha256_digest), ret, fields(nar_sha256_digest=BASE64.encode(nar_sha256_digest)))]
fn calculate_nar_based_store_path(nar_sha256_digest: &[u8; 32], name: &str) -> StorePath {
    // We populate the struct directly, as we know the sha256 digest has the
    // right size.
    let nar_hash_with_mode = NixHashWithMode::Recursive(NixHash {
        algo: HashAlgo::Sha256,
        digest: nar_sha256_digest.to_vec(),
    });

    build_regular_ca_path(name, &nar_hash_with_mode, Vec::<String>::new(), false).unwrap()
}

impl EvalIO for TvixStoreIO {
    #[instrument(skip(self), ret, err)]
    fn path_exists(&self, path: &Path) -> Result<bool, io::Error> {
        if let Ok((store_path, sub_path)) =
            StorePath::from_absolute_path_full(&path.to_string_lossy())
        {
            if self
                .store_path_to_root_node(&store_path, &sub_path)?
                .is_some()
            {
                Ok(true)
            } else {
                // As tvix-store doesn't manage /nix/store on the filesystem,
                // we still need to also ask self.std_io here.
                self.std_io.path_exists(path)
            }
        } else {
            // The store path is no store path, so do regular StdIO.
            self.std_io.path_exists(path)
        }
    }

    #[instrument(skip(self), ret, err)]
    fn read_to_string(&self, path: &Path) -> Result<String, io::Error> {
        if let Ok((store_path, sub_path)) =
            StorePath::from_absolute_path_full(&path.to_string_lossy())
        {
            if let Some(node) = self.store_path_to_root_node(&store_path, &sub_path)? {
                // depending on the node type, treat read_to_string differently
                match node {
                    crate::proto::node::Node::Directory(_) => {
                        // This would normally be a io::ErrorKind::IsADirectory (still unstable)
                        Err(io::Error::new(
                            io::ErrorKind::Unsupported,
                            "tried to read directory at {path} to string",
                        ))
                    }
                    crate::proto::node::Node::File(file_node) => {
                        let digest: B3Digest =
                            file_node.digest.clone().try_into().map_err(|_e| {
                                error!(
                                    file_node = ?file_node,
                                    "invalid digest"
                                );
                                io::Error::new(
                                    io::ErrorKind::InvalidData,
                                    format!("invalid digest length in file node: {:?}", file_node),
                                )
                            })?;

                        let reader = {
                            let resp = self.blob_service.open_read(&digest)?;
                            match resp {
                                Some(blob_reader) => blob_reader,
                                None => {
                                    error!(
                                        blob.digest = %digest,
                                        "blob not found",
                                    );
                                    Err(io::Error::new(
                                        io::ErrorKind::NotFound,
                                        format!("blob {} not found", &digest),
                                    ))?
                                }
                            }
                        };

                        io::read_to_string(reader)
                    }
                    crate::proto::node::Node::Symlink(_symlink_node) => Err(io::Error::new(
                        io::ErrorKind::Unsupported,
                        "read_to_string for symlinks is unsupported",
                    ))?,
                }
            } else {
                // As tvix-store doesn't manage /nix/store on the filesystem,
                // we still need to also ask self.std_io here.
                self.std_io.read_to_string(path)
            }
        } else {
            // The store path is no store path, so do regular StdIO.
            self.std_io.read_to_string(path)
        }
    }

    #[instrument(skip(self), ret, err)]
    fn read_dir(&self, path: &Path) -> Result<Vec<(bytes::Bytes, FileType)>, io::Error> {
        if let Ok((store_path, sub_path)) =
            StorePath::from_absolute_path_full(&path.to_string_lossy())
        {
            if let Some(node) = self.store_path_to_root_node(&store_path, &sub_path)? {
                match node {
                    crate::proto::node::Node::Directory(directory_node) => {
                        // fetch the Directory itself.
                        let digest = directory_node.digest.clone().try_into().map_err(|_e| {
                            io::Error::new(
                                io::ErrorKind::InvalidData,
                                format!(
                                    "invalid digest length in directory node: {:?}",
                                    directory_node
                                ),
                            )
                        })?;

                        if let Some(directory) = self.directory_service.get(&digest)? {
                            let mut children: Vec<(bytes::Bytes, FileType)> = Vec::new();
                            for node in directory.nodes() {
                                children.push(match node {
                                    crate::proto::node::Node::Directory(e) => {
                                        (e.name, FileType::Directory)
                                    }
                                    crate::proto::node::Node::File(e) => {
                                        (e.name, FileType::Regular)
                                    }
                                    crate::proto::node::Node::Symlink(e) => {
                                        (e.name, FileType::Symlink)
                                    }
                                })
                            }
                            Ok(children)
                        } else {
                            // If we didn't get the directory node that's linked, that's a store inconsistency!
                            error!(
                                directory.digest = %digest,
                                path = ?path,
                                "directory not found",
                            );
                            Err(io::Error::new(
                                io::ErrorKind::NotFound,
                                format!("directory {digest} does not exist"),
                            ))?
                        }
                    }
                    crate::proto::node::Node::File(_file_node) => {
                        // This would normally be a io::ErrorKind::NotADirectory (still unstable)
                        Err(io::Error::new(
                            io::ErrorKind::Unsupported,
                            "tried to readdir path {:?}, which is a file",
                        ))?
                    }
                    crate::proto::node::Node::Symlink(_symlink_node) => Err(io::Error::new(
                        io::ErrorKind::Unsupported,
                        "read_dir for symlinks is unsupported",
                    ))?,
                }
            } else {
                self.std_io.read_dir(path)
            }
        } else {
            self.std_io.read_dir(path)
        }
    }

    #[instrument(skip(self), ret, err)]
    fn import_path(&self, path: &std::path::Path) -> Result<PathBuf, std::io::Error> {
        let path_info = self.import_path_with_pathinfo(path)?;

        // from the [PathInfo], extract the store path (as string).
        Ok({
            let mut path = PathBuf::from(nix_compat::store_path::STORE_DIR_WITH_SLASH);

            let root_node_name = path_info.node.unwrap().node.unwrap().get_name().to_vec();

            // This must be a string, otherwise it would have failed validation.
            let root_node_name = String::from_utf8(root_node_name).unwrap();

            // append to the PathBuf
            path.push(root_node_name);

            // and return it
            path
        })
    }

    #[instrument(skip(self), ret)]
    fn store_dir(&self) -> Option<String> {
        Some("/nix/store".to_string())
    }
}