about summary refs log tree commit diff
path: root/tvix/store/src/pathinfoservice/bigtable.rs
blob: d608cbdb817f0abea73e8720551243af7610223a (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
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
use super::PathInfoService;
use crate::proto;
use crate::proto::PathInfo;
use async_stream::try_stream;
use bigtable_rs::{bigtable, google::bigtable::v2 as bigtable_v2};
use bytes::Bytes;
use data_encoding::HEXLOWER;
use futures::stream::BoxStream;
use prost::Message;
use serde::{Deserialize, Serialize};
use serde_with::{serde_as, DurationSeconds};
use tonic::async_trait;
use tracing::trace;
use tvix_castore::Error;

/// There should not be more than 10 MiB in a single cell.
/// https://cloud.google.com/bigtable/docs/schema-design#cells
const CELL_SIZE_LIMIT: u64 = 10 * 1024 * 1024;

/// Provides a [DirectoryService] implementation using
/// [Bigtable](https://cloud.google.com/bigtable/docs/)
/// as an underlying K/V store.
///
/// # Data format
/// We use Bigtable as a plain K/V store.
/// The row key is the digest of the store path, in hexlower.
/// Inside the row, we currently have a single column/cell, again using the
/// hexlower store path digest.
/// Its value is the PathInfo message, serialized in canonical protobuf.
/// We currently only populate this column.
///
/// Listing is ranging over all rows, and calculate_nar is returning a
/// "unimplemented" error.
#[derive(Clone)]
pub struct BigtablePathInfoService {
    client: bigtable::BigTable,
    params: BigtableParameters,

    #[cfg(test)]
    #[allow(dead_code)]
    /// Holds the temporary directory containing the unix socket, and the
    /// spawned emulator process.
    emulator: std::sync::Arc<(tempfile::TempDir, async_process::Child)>,
}

/// Represents configuration of [BigtablePathInfoService].
/// This currently conflates both connect parameters and data model/client
/// behaviour parameters.
#[serde_as]
#[derive(Clone, Debug, PartialEq, Deserialize, Serialize)]
pub struct BigtableParameters {
    project_id: String,
    instance_name: String,
    #[serde(default)]
    is_read_only: bool,
    #[serde(default = "default_channel_size")]
    channel_size: usize,

    #[serde_as(as = "Option<DurationSeconds<String>>")]
    #[serde(default = "default_timeout")]
    timeout: Option<std::time::Duration>,
    table_name: String,
    family_name: String,

    #[serde(default = "default_app_profile_id")]
    app_profile_id: String,
}

fn default_app_profile_id() -> String {
    "default".to_owned()
}

fn default_channel_size() -> usize {
    4
}

fn default_timeout() -> Option<std::time::Duration> {
    Some(std::time::Duration::from_secs(4))
}

impl BigtablePathInfoService {
    #[cfg(not(test))]
    pub async fn connect(params: BigtableParameters) -> Result<Self, bigtable::Error> {
        let connection = bigtable::BigTableConnection::new(
            &params.project_id,
            &params.instance_name,
            params.is_read_only,
            params.channel_size,
            params.timeout,
        )
        .await?;

        Ok(Self {
            client: connection.client(),
            params,
        })
    }

    #[cfg(test)]
    pub async fn connect(params: BigtableParameters) -> Result<Self, bigtable::Error> {
        use std::time::Duration;

        use async_process::{Command, Stdio};
        use tempfile::TempDir;
        use tokio_retry::{strategy::ExponentialBackoff, Retry};

        let tmpdir = TempDir::new().unwrap();

        let socket_path = tmpdir.path().join("cbtemulator.sock");

        let emulator_process = Command::new("cbtemulator")
            .arg("-address")
            .arg(socket_path.clone())
            .stderr(Stdio::piped())
            .stdout(Stdio::piped())
            .kill_on_drop(true)
            .spawn()
            .expect("failed to spawn emulator");

        Retry::spawn(
            ExponentialBackoff::from_millis(20)
                .max_delay(Duration::from_secs(1))
                .take(3),
            || async {
                if socket_path.exists() {
                    Ok(())
                } else {
                    Err(())
                }
            },
        )
        .await
        .expect("failed to wait for socket");

        // populate the emulator
        for cmd in &[
            vec!["createtable", &params.table_name],
            vec!["createfamily", &params.table_name, &params.family_name],
        ] {
            Command::new("cbt")
                .args({
                    let mut args = vec![
                        "-instance",
                        &params.instance_name,
                        "-project",
                        &params.project_id,
                    ];
                    args.extend_from_slice(cmd);
                    args
                })
                .env(
                    "BIGTABLE_EMULATOR_HOST",
                    format!("unix://{}", socket_path.to_string_lossy()),
                )
                .output()
                .await
                .expect("failed to run cbt setup command");
        }

        let connection = bigtable_rs::bigtable::BigTableConnection::new_with_emulator(
            &format!("unix://{}", socket_path.to_string_lossy()),
            &params.project_id,
            &params.instance_name,
            false,
            None,
        )?;

        Ok(Self {
            client: connection.client(),
            params,
            emulator: (tmpdir, emulator_process).into(),
        })
    }
}

/// Derives the row/column key for a given output path.
/// We use hexlower encoding, also because it can't be misinterpreted as RE2.
fn derive_pathinfo_key(digest: &[u8; 20]) -> String {
    HEXLOWER.encode(digest)
}

#[async_trait]
impl PathInfoService for BigtablePathInfoService {
    async fn get(&self, digest: [u8; 20]) -> Result<Option<PathInfo>, Error> {
        let mut client = self.client.clone();
        let path_info_key = derive_pathinfo_key(&digest);

        let request = bigtable_v2::ReadRowsRequest {
            app_profile_id: self.params.app_profile_id.to_string(),
            table_name: client.get_full_table_name(&self.params.table_name),
            rows_limit: 1,
            rows: Some(bigtable_v2::RowSet {
                row_keys: vec![path_info_key.clone().into()],
                row_ranges: vec![],
            }),
            // Filter selected family name, and column qualifier matching the digest.
            // The latter is to ensure we don't fail once we start adding more metadata.
            filter: Some(bigtable_v2::RowFilter {
                filter: Some(bigtable_v2::row_filter::Filter::Chain(
                    bigtable_v2::row_filter::Chain {
                        filters: vec![
                            bigtable_v2::RowFilter {
                                filter: Some(
                                    bigtable_v2::row_filter::Filter::FamilyNameRegexFilter(
                                        self.params.family_name.to_string(),
                                    ),
                                ),
                            },
                            bigtable_v2::RowFilter {
                                filter: Some(
                                    bigtable_v2::row_filter::Filter::ColumnQualifierRegexFilter(
                                        path_info_key.clone().into(),
                                    ),
                                ),
                            },
                        ],
                    },
                )),
            }),
            ..Default::default()
        };

        let mut response = client
            .read_rows(request)
            .await
            .map_err(|e| Error::StorageError(format!("unable to read rows: {}", e)))?;

        if response.len() != 1 {
            if response.len() > 1 {
                // This shouldn't happen, we limit number of rows to 1
                return Err(Error::StorageError(
                    "got more than one row from bigtable".into(),
                ));
            }
            // else, this is simply a "not found".
            return Ok(None);
        }

        let (row_key, mut cells) = response.pop().unwrap();
        if row_key != path_info_key.as_bytes() {
            // This shouldn't happen, we requested this row key.
            return Err(Error::StorageError(
                "got wrong row key from bigtable".into(),
            ));
        }

        let cell = cells
            .pop()
            .ok_or_else(|| Error::StorageError("found no cells".into()))?;

        // Ensure there's only one cell (so no more left after the pop())
        // This shouldn't happen, We filter out other cells in our query.
        if !cells.is_empty() {
            return Err(Error::StorageError(
                "more than one cell returned from bigtable".into(),
            ));
        }

        // We also require the qualifier to be correct in the filter above,
        // so this shouldn't happen.
        if path_info_key.as_bytes() != cell.qualifier {
            return Err(Error::StorageError("unexpected cell qualifier".into()));
        }

        // Try to parse the value into a PathInfo message
        let path_info = proto::PathInfo::decode(Bytes::from(cell.value))
            .map_err(|e| Error::StorageError(format!("unable to decode pathinfo proto: {}", e)))?;

        let store_path = path_info
            .validate()
            .map_err(|e| Error::StorageError(format!("invalid PathInfo: {}", e)))?;

        if store_path.digest() != &digest {
            return Err(Error::StorageError("PathInfo has unexpected digest".into()));
        }

        Ok(Some(path_info))
    }

    async fn put(&self, path_info: PathInfo) -> Result<PathInfo, Error> {
        let store_path = path_info
            .validate()
            .map_err(|e| Error::InvalidRequest(format!("pathinfo failed validation: {}", e)))?;

        let mut client = self.client.clone();
        let path_info_key = derive_pathinfo_key(store_path.digest());

        let data = path_info.encode_to_vec();
        if data.len() as u64 > CELL_SIZE_LIMIT {
            return Err(Error::StorageError(
                "PathInfo exceeds cell limit on Bigtable".into(),
            ));
        }

        let resp = client
            .check_and_mutate_row(bigtable_v2::CheckAndMutateRowRequest {
                table_name: client.get_full_table_name(&self.params.table_name),
                app_profile_id: self.params.app_profile_id.to_string(),
                row_key: path_info_key.clone().into(),
                predicate_filter: Some(bigtable_v2::RowFilter {
                    filter: Some(bigtable_v2::row_filter::Filter::ColumnQualifierRegexFilter(
                        path_info_key.clone().into(),
                    )),
                }),
                // If the column was already found, do nothing.
                true_mutations: vec![],
                // Else, do the insert.
                false_mutations: vec![
                    // https://cloud.google.com/bigtable/docs/writes
                    bigtable_v2::Mutation {
                        mutation: Some(bigtable_v2::mutation::Mutation::SetCell(
                            bigtable_v2::mutation::SetCell {
                                family_name: self.params.family_name.to_string(),
                                column_qualifier: path_info_key.clone().into(),
                                timestamp_micros: -1, // use server time to fill timestamp
                                value: data,
                            },
                        )),
                    },
                ],
            })
            .await
            .map_err(|e| Error::StorageError(format!("unable to mutate rows: {}", e)))?;

        if resp.predicate_matched {
            trace!("already existed")
        }

        Ok(path_info)
    }

    fn list(&self) -> BoxStream<'static, Result<PathInfo, Error>> {
        let mut client = self.client.clone();

        let request = bigtable_v2::ReadRowsRequest {
            app_profile_id: self.params.app_profile_id.to_string(),
            table_name: client.get_full_table_name(&self.params.table_name),
            filter: Some(bigtable_v2::RowFilter {
                filter: Some(bigtable_v2::row_filter::Filter::FamilyNameRegexFilter(
                    self.params.family_name.to_string(),
                )),
            }),
            ..Default::default()
        };

        let stream = try_stream! {
            // TODO: add pagination, we don't want to hold all of this in memory.
            let response = client
                .read_rows(request)
                .await
                .map_err(|e| Error::StorageError(format!("unable to read rows: {}", e)))?;

            for (row_key, mut cells) in response {
                let cell = cells
                    .pop()
                    .ok_or_else(|| Error::StorageError("found no cells".into()))?;

                // The cell must have the same qualifier as the row key
                if row_key != cell.qualifier {
                    Err(Error::StorageError("unexpected cell qualifier".into()))?;
                }

                // Ensure there's only one cell (so no more left after the pop())
                // This shouldn't happen, We filter out other cells in our query.
                if !cells.is_empty() {

                    Err(Error::StorageError(
                        "more than one cell returned from bigtable".into(),
                    ))?
                }

                // Try to parse the value into a PathInfo message.
                let path_info = proto::PathInfo::decode(Bytes::from(cell.value))
                    .map_err(|e| Error::StorageError(format!("unable to decode pathinfo proto: {}", e)))?;

                // Validate the containing PathInfo, ensure its StorePath digest
                // matches row key.
                let store_path = path_info
                    .validate()
                    .map_err(|e| Error::StorageError(format!("invalid PathInfo: {}", e)))?;

                if store_path.digest().as_slice() != row_key.as_slice() {
                    Err(Error::StorageError("PathInfo has unexpected digest".into()))?
                }


                yield path_info
            }
        };

        Box::pin(stream)
    }
}