Line data Source code
1 : // Copyright 2021 The LevelDB-Go and Pebble Authors. All rights reserved. Use
2 : // of this source code is governed by a BSD-style license that can be found in
3 : // the LICENSE file.
4 :
5 : package pebble
6 :
7 : import (
8 : "fmt"
9 : "strconv"
10 :
11 : "github.com/cockroachdb/errors"
12 : "github.com/cockroachdb/pebble/internal/manifest"
13 : "github.com/cockroachdb/pebble/sstable"
14 : "github.com/cockroachdb/pebble/vfs"
15 : "github.com/cockroachdb/pebble/vfs/atomicfs"
16 : )
17 :
18 : // FormatMajorVersion is a constant controlling the format of persisted
19 : // data. Backwards incompatible changes to durable formats are gated
20 : // behind new format major versions.
21 : //
22 : // At any point, a database's format major version may be bumped.
23 : // However, once a database's format major version is increased,
24 : // previous versions of Pebble will refuse to open the database.
25 : //
26 : // The zero value format is the FormatDefault constant. The exact
27 : // FormatVersion that the default corresponds to may change with time.
28 : type FormatMajorVersion uint64
29 :
30 : // SafeValue implements redact.SafeValue.
31 0 : func (v FormatMajorVersion) SafeValue() {}
32 :
33 : // String implements fmt.Stringer.
34 1 : func (v FormatMajorVersion) String() string {
35 1 : // NB: This must not change. It's used as the value for the on-disk
36 1 : // version marker file.
37 1 : //
38 1 : // Specifically, this value must always parse as a base 10 integer
39 1 : // that fits in a uint64. We format it as zero-padded, 3-digit
40 1 : // number today, but the padding may change.
41 1 : return fmt.Sprintf("%03d", v)
42 1 : }
43 :
44 : const (
45 : // FormatDefault leaves the format version unspecified. When used to create a
46 : // new store, Pebble will choose the earliest format version it supports.
47 : FormatDefault FormatMajorVersion = iota
48 :
49 : // 21.2 versions.
50 :
51 : // FormatMostCompatible maintains the most backwards compatibility,
52 : // maintaining bi-directional compatibility with RocksDB 6.2.1 in
53 : // the particular configuration described in the Pebble README.
54 : // Deprecated.
55 : _ // FormatMostCompatible
56 :
57 : // formatVersionedManifestMarker is the first
58 : // backwards-incompatible change made to Pebble, introducing the
59 : // format-version marker file for handling backwards-incompatible
60 : // changes more broadly, and replacing the `CURRENT` file with a
61 : // marker file.
62 : //
63 : // This format version is intended as an intermediary version state.
64 : // It is deliberately unexported to discourage direct use of this
65 : // format major version. Clients should use FormatVersioned which
66 : // also ensures earlier versions of Pebble fail to open a database
67 : // written in a future format major version.
68 : // Deprecated.
69 : _ // formatVersionedManifestMarker
70 :
71 : // FormatVersioned is a new format major version that replaces the
72 : // old `CURRENT` file with a new 'marker' file scheme. Previous
73 : // Pebble versions will be unable to open the database unless
74 : // they're aware of format versions.
75 : // Deprecated.
76 : _ // FormatVersioned
77 :
78 : // FormatSetWithDelete is a format major version that introduces a new key
79 : // kind, base.InternalKeyKindSetWithDelete. Previous Pebble versions will be
80 : // unable to open this database.
81 : // Deprecated.
82 : _ // FormatSetWithDelete
83 :
84 : // 22.1 versions.
85 :
86 : // FormatBlockPropertyCollector is a format major version that introduces
87 : // BlockPropertyCollectors.
88 : // Deprecated.
89 : _ // FormatBlockPropertyCollector
90 :
91 : // FormatSplitUserKeysMarked is a format major version that guarantees that
92 : // all files that share user keys with neighbors are marked for compaction
93 : // in the manifest. Ratcheting to FormatSplitUserKeysMarked will block
94 : // (without holding mutexes) until the scan of the LSM is complete and the
95 : // manifest has been rotated.
96 : // Deprecated.
97 : _ // FormatSplitUserKeysMarked
98 :
99 : // 22.2 versions.
100 :
101 : // FormatSplitUserKeysMarkedCompacted is a format major version that
102 : // guarantees that all files explicitly marked for compaction in the manifest
103 : // have been compacted. Combined with the FormatSplitUserKeysMarked format
104 : // major version, this version guarantees that there are no user keys split
105 : // across multiple files within a level L1+. Ratcheting to this format version
106 : // will block (without holding mutexes) until all necessary compactions for
107 : // files marked for compaction are complete.
108 : // Deprecated.
109 : _ // FormatSplitUserKeysMarkedCompacted
110 :
111 : // FormatRangeKeys is a format major version that introduces range keys.
112 : // Deprecated.
113 : _ // FormatRangeKeys
114 :
115 : // FormatMinTableFormatPebblev1 is a format major version that guarantees that
116 : // tables created by or ingested into the DB at or above this format major
117 : // version will have a table format version of at least Pebblev1 (Block
118 : // Properties).
119 : // Deprecated.
120 : _ // FormatMinTableFormatPebblev1
121 :
122 : // FormatPrePebblev1Marked is a format major version that guarantees that all
123 : // sstables with a table format version pre-Pebblev1 (i.e. those that are
124 : // guaranteed to not contain block properties) are marked for compaction in
125 : // the manifest. Ratcheting to FormatPrePebblev1Marked will block (without
126 : // holding mutexes) until the scan of the LSM is complete and the manifest has
127 : // been rotated.
128 : // Deprecated.
129 : _ // FormatPrePebblev1Marked
130 :
131 : // 23.1 versions.
132 :
133 : // formatUnusedPrePebblev1MarkedCompacted is an unused format major version.
134 : // This format major version was originally intended to ship in the 23.1
135 : // release. It was later decided that this should be deferred until a
136 : // subsequent release. The original ordering is preserved so as not to
137 : // introduce breaking changes in Cockroach.
138 : _ // formatUnusedPrePebblev1MarkedCompacted
139 :
140 : // FormatSSTableValueBlocks is a format major version that adds support for
141 : // storing values in value blocks in the sstable. Value block support is not
142 : // necessarily enabled when writing sstables, when running with this format
143 : // major version.
144 : _ // FormatSSTableValueBlocks
145 :
146 : // FormatFlushableIngest is a format major version that enables lazy
147 : // addition of ingested sstables into the LSM structure. When an ingest
148 : // overlaps with a memtable, a record of the ingest is written to the WAL
149 : // without waiting for a flush. Subsequent reads treat the ingested files as
150 : // a level above the overlapping memtable. Once the memtable is flushed, the
151 : // ingested files are moved into the lowest possible levels.
152 : //
153 : // This feature is behind a format major version because it required
154 : // breaking changes to the WAL format.
155 : FormatFlushableIngest
156 :
157 : // 23.2 versions.
158 :
159 : // FormatPrePebblev1MarkedCompacted is a format major version that guarantees
160 : // that all sstables explicitly marked for compaction in the manifest (see
161 : // FormatPrePebblev1Marked) have been compacted. Ratcheting to this format
162 : // version will block (without holding mutexes) until all necessary
163 : // compactions for files marked for compaction are complete.
164 : FormatPrePebblev1MarkedCompacted
165 :
166 : // FormatDeleteSizedAndObsolete is a format major version that adds support
167 : // for deletion tombstones that encode the size of the value they're
168 : // expected to delete. This format major version is required before the
169 : // associated key kind may be committed through batch applications or
170 : // ingests. It also adds support for keys that are marked obsolete (see
171 : // sstable/format.go for details).
172 : FormatDeleteSizedAndObsolete
173 :
174 : // FormatVirtualSSTables is a format major version that adds support for
175 : // virtual sstables that can reference a sub-range of keys in an underlying
176 : // physical sstable. This information is persisted through new,
177 : // backward-incompatible fields in the Manifest, and therefore requires
178 : // a format major version.
179 : FormatVirtualSSTables
180 :
181 : // FormatSyntheticPrefixSuffix is a format major version that adds support for
182 : // sstables to have their content exposed in a different prefix or suffix of
183 : // keyspace than the actual prefix/suffix persisted in the keys in such
184 : // sstables. The prefix and suffix replacement information is stored in new
185 : // fields in the Manifest and thus requires a format major version.
186 : FormatSyntheticPrefixSuffix
187 :
188 : // FormatFlushableIngestExcises is a format major version that adds support for
189 : // having excises unconditionally being written as flushable ingestions. This
190 : // is implemented through adding a new key kind that can go in the same batches
191 : // as flushable ingested sstables.
192 : FormatFlushableIngestExcises
193 :
194 : // FormatColumnarBlocks is a format major version enabling use of the
195 : // TableFormatPebblev5 table format, that encodes sstable data blocks, index
196 : // blocks and keyspan blocks by organizing the KVs into columns within the
197 : // block.
198 : FormatColumnarBlocks
199 :
200 : // TODO(msbutler): add major version for synthetic suffixes
201 :
202 : // -- Add new versions here --
203 :
204 : // FormatNewest is the most recent format major version.
205 : FormatNewest FormatMajorVersion = iota - 1
206 :
207 : // Experimental versions, which are excluded by FormatNewest (but can be used
208 : // in tests) can be defined here.
209 :
210 : // -- Add experimental versions here --
211 :
212 : // internalFormatNewest is the most recent, possibly experimental format major
213 : // version.
214 : internalFormatNewest FormatMajorVersion = iota - 2
215 : )
216 :
217 : // FormatMinSupported is the minimum format version that is supported by this
218 : // Pebble version.
219 : const FormatMinSupported = FormatFlushableIngest
220 :
221 : // FormatMinForSharedObjects it the minimum format version that supports shared
222 : // objects (see CreateOnShared option).
223 : const FormatMinForSharedObjects = FormatVirtualSSTables
224 :
225 : // IsSupported returns true if the version is supported by the current Pebble
226 : // version.
227 0 : func (v FormatMajorVersion) IsSupported() bool {
228 0 : return v == FormatDefault && v >= FormatMinSupported && v <= internalFormatNewest
229 0 : }
230 :
231 : // MaxTableFormat returns the maximum sstable.TableFormat that can be used at
232 : // this FormatMajorVersion.
233 1 : func (v FormatMajorVersion) MaxTableFormat() sstable.TableFormat {
234 1 : switch v {
235 1 : case FormatDefault, FormatFlushableIngest, FormatPrePebblev1MarkedCompacted:
236 1 : return sstable.TableFormatPebblev3
237 : case FormatDeleteSizedAndObsolete, FormatVirtualSSTables, FormatSyntheticPrefixSuffix,
238 1 : FormatFlushableIngestExcises:
239 1 : return sstable.TableFormatPebblev4
240 1 : case FormatColumnarBlocks:
241 1 : return sstable.TableFormatPebblev5
242 0 : default:
243 0 : panic(fmt.Sprintf("pebble: unsupported format major version: %s", v))
244 : }
245 : }
246 :
247 : // MinTableFormat returns the minimum sstable.TableFormat that can be used at
248 : // this FormatMajorVersion.
249 1 : func (v FormatMajorVersion) MinTableFormat() sstable.TableFormat {
250 1 : switch v {
251 : case FormatDefault, FormatFlushableIngest, FormatPrePebblev1MarkedCompacted,
252 : FormatDeleteSizedAndObsolete, FormatVirtualSSTables, FormatSyntheticPrefixSuffix,
253 1 : FormatFlushableIngestExcises, FormatColumnarBlocks:
254 1 : return sstable.TableFormatPebblev1
255 0 : default:
256 0 : panic(fmt.Sprintf("pebble: unsupported format major version: %s", v))
257 : }
258 : }
259 :
260 : // formatMajorVersionMigrations defines the migrations from one format
261 : // major version to the next. Each migration is defined as a closure
262 : // which will be invoked on the database before the new format major
263 : // version is committed. Migrations must be idempotent. Migrations are
264 : // invoked with d.mu locked.
265 : //
266 : // Each migration is responsible for invoking finalizeFormatVersUpgrade
267 : // to set the new format major version. RatchetFormatMajorVersion will
268 : // panic if a migration returns a nil error but fails to finalize the
269 : // new format major version.
270 : var formatMajorVersionMigrations = map[FormatMajorVersion]func(*DB) error{
271 0 : FormatFlushableIngest: func(d *DB) error { return nil },
272 1 : FormatPrePebblev1MarkedCompacted: func(d *DB) error {
273 1 : // Before finalizing the format major version, rewrite any sstables
274 1 : // still marked for compaction. Note all format major versions
275 1 : // migrations are invoked with DB.mu locked.
276 1 : if err := d.compactMarkedFilesLocked(); err != nil {
277 0 : return err
278 0 : }
279 1 : return d.finalizeFormatVersUpgrade(FormatPrePebblev1MarkedCompacted)
280 : },
281 1 : FormatDeleteSizedAndObsolete: func(d *DB) error {
282 1 : return d.finalizeFormatVersUpgrade(FormatDeleteSizedAndObsolete)
283 1 : },
284 1 : FormatVirtualSSTables: func(d *DB) error {
285 1 : return d.finalizeFormatVersUpgrade(FormatVirtualSSTables)
286 1 : },
287 1 : FormatSyntheticPrefixSuffix: func(d *DB) error {
288 1 : return d.finalizeFormatVersUpgrade(FormatSyntheticPrefixSuffix)
289 1 : },
290 1 : FormatFlushableIngestExcises: func(d *DB) error {
291 1 : return d.finalizeFormatVersUpgrade(FormatFlushableIngestExcises)
292 1 : },
293 1 : FormatColumnarBlocks: func(d *DB) error {
294 1 : return d.finalizeFormatVersUpgrade(FormatColumnarBlocks)
295 1 : },
296 : }
297 :
298 : const formatVersionMarkerName = `format-version`
299 :
300 : // lookupFormatMajorVersion retrieves the format version from the format version
301 : // marker file.
302 : //
303 : // If such a file does not exist, returns FormatDefault. Note that this case is
304 : // only acceptable if we are creating a new store (we no longer support
305 : // FormatMostCompatible which is the only one with no version marker file).
306 : func lookupFormatMajorVersion(
307 : fs vfs.FS, dirname string, ls []string,
308 1 : ) (FormatMajorVersion, *atomicfs.Marker, error) {
309 1 : m, versString, err := atomicfs.LocateMarkerInListing(fs, dirname, formatVersionMarkerName, ls)
310 1 : if err != nil {
311 0 : return 0, nil, err
312 0 : }
313 1 : if versString == "" {
314 1 : return FormatDefault, m, nil
315 1 : }
316 1 : v, err := strconv.ParseUint(versString, 10, 64)
317 1 : if err != nil {
318 0 : return 0, nil, errors.Wrap(err, "parsing format major version")
319 0 : }
320 1 : vers := FormatMajorVersion(v)
321 1 : if vers == FormatDefault {
322 0 : return 0, nil, errors.Newf("pebble: default format major version should not persisted", vers)
323 0 : }
324 1 : if vers > internalFormatNewest {
325 0 : return 0, nil, errors.Newf("pebble: database %q written in unknown format major version %d", dirname, vers)
326 0 : }
327 1 : if vers < FormatMinSupported {
328 0 : return 0, nil, errors.Newf("pebble: database %q written in format major version %d which is no longer supported", dirname, vers)
329 0 : }
330 1 : return vers, m, nil
331 : }
332 :
333 : // FormatMajorVersion returns the database's active format major
334 : // version. The format major version may be higher than the one
335 : // provided in Options when the database was opened if the existing
336 : // database was written with a higher format version.
337 1 : func (d *DB) FormatMajorVersion() FormatMajorVersion {
338 1 : return FormatMajorVersion(d.mu.formatVers.vers.Load())
339 1 : }
340 :
341 : // TableFormat returns the TableFormat that the database is currently using when
342 : // writing sstables. The table format is determined by the database's format
343 : // major version, as well as experimental settings like EnableValueBlocks and
344 : // EnableColumnarBlocks.
345 1 : func (d *DB) TableFormat() sstable.TableFormat {
346 1 : // The table is typically written at the maximum allowable format implied by
347 1 : // the current format major version of the DB.
348 1 : f := d.FormatMajorVersion().MaxTableFormat()
349 1 : switch f {
350 1 : case sstable.TableFormatPebblev3:
351 1 : // In format major versions with maximum table formats of Pebblev3,
352 1 : // value blocks were conditional on an experimental setting. In format
353 1 : // major versions with maximum table formats of Pebblev4 and higher,
354 1 : // value blocks are always enabled.
355 1 : if d.opts.Experimental.EnableValueBlocks == nil || !d.opts.Experimental.EnableValueBlocks() {
356 1 : f = sstable.TableFormatPebblev2
357 1 : }
358 1 : case sstable.TableFormatPebblev5:
359 1 : if d.opts.Experimental.EnableColumnarBlocks == nil || !d.opts.Experimental.EnableColumnarBlocks() {
360 0 : f = sstable.TableFormatPebblev4
361 0 : }
362 : }
363 1 : return f
364 : }
365 :
366 : // RatchetFormatMajorVersion ratchets the opened database's format major
367 : // version to the provided version. It errors if the provided format
368 : // major version is below the database's current version. Once a
369 : // database's format major version is upgraded, previous Pebble versions
370 : // that do not know of the format version will be unable to open the
371 : // database.
372 1 : func (d *DB) RatchetFormatMajorVersion(fmv FormatMajorVersion) error {
373 1 : if err := d.closed.Load(); err != nil {
374 0 : panic(err)
375 : }
376 :
377 1 : d.mu.Lock()
378 1 : defer d.mu.Unlock()
379 1 : return d.ratchetFormatMajorVersionLocked(fmv)
380 : }
381 :
382 1 : func (d *DB) ratchetFormatMajorVersionLocked(formatVers FormatMajorVersion) error {
383 1 : if d.opts.ReadOnly {
384 0 : return ErrReadOnly
385 0 : }
386 1 : if formatVers > internalFormatNewest {
387 0 : // Guard against accidentally forgetting to update internalFormatNewest.
388 0 : return errors.Errorf("pebble: unknown format version %d", formatVers)
389 0 : }
390 1 : if currentVers := d.FormatMajorVersion(); currentVers > formatVers {
391 0 : return errors.Newf("pebble: database already at format major version %d; cannot reduce to %d",
392 0 : currentVers, formatVers)
393 0 : }
394 1 : if d.mu.formatVers.ratcheting {
395 0 : return errors.Newf("pebble: database format major version upgrade is in-progress")
396 0 : }
397 1 : d.mu.formatVers.ratcheting = true
398 1 : defer func() { d.mu.formatVers.ratcheting = false }()
399 :
400 1 : for nextVers := d.FormatMajorVersion() + 1; nextVers <= formatVers; nextVers++ {
401 1 : if err := formatMajorVersionMigrations[nextVers](d); err != nil {
402 0 : return errors.Wrapf(err, "migrating to version %d", nextVers)
403 0 : }
404 :
405 : // NB: The migration is responsible for calling
406 : // finalizeFormatVersUpgrade to finalize the upgrade. This
407 : // structure is necessary because some migrations may need to
408 : // update in-memory state (without ever dropping locks) after
409 : // the upgrade is finalized. Here we assert that the upgrade
410 : // did occur.
411 1 : if d.FormatMajorVersion() != nextVers {
412 0 : d.opts.Logger.Fatalf("pebble: successful migration to format version %d never finalized the upgrade", nextVers)
413 0 : }
414 : }
415 1 : return nil
416 : }
417 :
418 : // finalizeFormatVersUpgrade is typically only be called from within a
419 : // format major version migration.
420 : //
421 : // See formatMajorVersionMigrations.
422 1 : func (d *DB) finalizeFormatVersUpgrade(formatVers FormatMajorVersion) error {
423 1 : if err := d.writeFormatVersionMarker(formatVers); err != nil {
424 0 : return err
425 0 : }
426 1 : d.mu.formatVers.vers.Store(uint64(formatVers))
427 1 : d.opts.EventListener.FormatUpgrade(formatVers)
428 1 : return nil
429 : }
430 :
431 1 : func (d *DB) writeFormatVersionMarker(formatVers FormatMajorVersion) error {
432 1 : // We use the marker to encode the active format version in the
433 1 : // marker filename. Unlike other uses of the atomic marker, there is
434 1 : // no file with the filename `formatVers.String()` on the
435 1 : // filesystem.
436 1 : return d.mu.formatVers.marker.Move(formatVers.String())
437 1 : }
438 :
439 : // compactMarkedFilesLocked performs a migration that schedules rewrite
440 : // compactions to compact away any sstables marked for compaction.
441 : // compactMarkedFilesLocked is run while ratcheting the database's format major
442 : // version to FormatSplitUserKeysMarkedCompacted.
443 : //
444 : // Note that while this method is called with the DB.mu held, and will not
445 : // return until all marked files have been compacted, the mutex is dropped while
446 : // waiting for compactions to complete (or for slots to free up).
447 1 : func (d *DB) compactMarkedFilesLocked() error {
448 1 : curr := d.mu.versions.currentVersion()
449 1 : for curr.Stats.MarkedForCompaction > 0 {
450 0 : // Attempt to schedule a compaction to rewrite a file marked for
451 0 : // compaction.
452 0 : d.maybeScheduleCompactionPicker(func(picker compactionPicker, env compactionEnv) *pickedCompaction {
453 0 : return picker.pickRewriteCompaction(env)
454 0 : })
455 :
456 : // The above attempt might succeed and schedule a rewrite compaction. Or
457 : // there might not be available compaction concurrency to schedule the
458 : // compaction. Or compaction of the file might have already been in
459 : // progress. In any scenario, wait until there's some change in the
460 : // state of active compactions.
461 :
462 : // Before waiting, check that the database hasn't been closed. Trying to
463 : // schedule the compaction may have dropped d.mu while waiting for a
464 : // manifest write to complete. In that dropped interim, the database may
465 : // have been closed.
466 0 : if err := d.closed.Load(); err != nil {
467 0 : return err.(error)
468 0 : }
469 :
470 : // Some flush or compaction may have scheduled or completed while we waited
471 : // for the manifest lock in maybeScheduleCompactionPicker. Get the latest
472 : // Version before waiting on a compaction.
473 0 : curr = d.mu.versions.currentVersion()
474 0 :
475 0 : // Only wait on compactions if there are files still marked for compaction.
476 0 : // NB: Waiting on this condition variable drops d.mu while blocked.
477 0 : if curr.Stats.MarkedForCompaction > 0 {
478 0 : if d.mu.compact.compactingCount == 0 {
479 0 : panic("expected a compaction of marked files in progress")
480 : }
481 0 : d.mu.compact.cond.Wait()
482 0 : // Refresh the current version again.
483 0 : curr = d.mu.versions.currentVersion()
484 : }
485 : }
486 1 : return nil
487 : }
488 :
489 : // findFilesFunc scans the LSM for files, returning true if at least one
490 : // file was found. The returned array contains the matched files, if any, per
491 : // level.
492 : type findFilesFunc func(v *version) (found bool, files [numLevels][]*fileMetadata, _ error)
493 :
494 : // This method is not used currently, but it will be useful the next time we need
495 : // to mark files for compaction.
496 : var _ = (*DB)(nil).markFilesLocked
497 :
498 : // markFilesLocked durably marks the files that match the given findFilesFunc for
499 : // compaction.
500 0 : func (d *DB) markFilesLocked(findFn findFilesFunc) error {
501 0 : jobID := d.newJobIDLocked()
502 0 :
503 0 : // Acquire a read state to have a view of the LSM and a guarantee that none
504 0 : // of the referenced files will be deleted until we've unreferenced the read
505 0 : // state. Some findFilesFuncs may read the files, requiring they not be
506 0 : // deleted.
507 0 : rs := d.loadReadState()
508 0 : var (
509 0 : found bool
510 0 : files [numLevels][]*fileMetadata
511 0 : err error
512 0 : )
513 0 : func() {
514 0 : defer rs.unrefLocked()
515 0 : // Note the unusual locking: unlock, defer Lock(). The scan of the files in
516 0 : // the version does not need to block other operations that require the
517 0 : // DB.mu. Drop it for the scan, before re-acquiring it.
518 0 : d.mu.Unlock()
519 0 : defer d.mu.Lock()
520 0 : found, files, err = findFn(rs.current)
521 0 : }()
522 0 : if err != nil {
523 0 : return err
524 0 : }
525 :
526 : // The database lock has been acquired again by the defer within the above
527 : // anonymous function.
528 0 : if !found {
529 0 : // Nothing to do.
530 0 : return nil
531 0 : }
532 :
533 : // After scanning, if we found files to mark, we fetch the current state of
534 : // the LSM (which may have changed) and set MarkedForCompaction on the files,
535 : // and update the version's Stats.MarkedForCompaction count, which are both
536 : // protected by d.mu.
537 :
538 : // Lock the manifest for a coherent view of the LSM. The database lock has
539 : // been re-acquired by the defer within the above anonymous function.
540 0 : d.mu.versions.logLock()
541 0 : vers := d.mu.versions.currentVersion()
542 0 : for l, filesToMark := range files {
543 0 : if len(filesToMark) == 0 {
544 0 : continue
545 : }
546 0 : for _, f := range filesToMark {
547 0 : // Ignore files to be marked that have already been compacted or marked.
548 0 : if f.CompactionState == manifest.CompactionStateCompacted ||
549 0 : f.MarkedForCompaction {
550 0 : continue
551 : }
552 : // Else, mark the file for compaction in this version.
553 0 : vers.Stats.MarkedForCompaction++
554 0 : f.MarkedForCompaction = true
555 : }
556 : // The compaction picker uses the markedForCompactionAnnotator to
557 : // quickly find files marked for compaction, or to quickly determine
558 : // that there are no such files marked for compaction within a level.
559 : // A b-tree node may be annotated with an annotation recording that
560 : // there are no files marked for compaction within the node's subtree,
561 : // based on the assumption that it's static.
562 : //
563 : // Since we're marking files for compaction, these b-tree nodes'
564 : // annotations will be out of date. Clear the compaction-picking
565 : // annotation, so that it's recomputed the next time the compaction
566 : // picker looks for a file marked for compaction.
567 0 : markedForCompactionAnnotator.InvalidateLevelAnnotation(vers.Levels[l])
568 : }
569 :
570 : // The 'marked-for-compaction' bit is persisted in the MANIFEST file
571 : // metadata. We've already modified the in-memory file metadata, but the
572 : // manifest hasn't been updated. Force rotation to a new MANIFEST file,
573 : // which will write every file metadata to the new manifest file and ensure
574 : // that the now marked-for-compaction file metadata are persisted as marked.
575 : // NB: This call to logAndApply will unlockthe MANIFEST, which we locked up
576 : // above before obtaining `vers`.
577 0 : return d.mu.versions.logAndApply(
578 0 : jobID,
579 0 : &manifest.VersionEdit{},
580 0 : map[int]*LevelMetrics{},
581 0 : true, /* forceRotation */
582 0 : func() []compactionInfo { return d.getInProgressCompactionInfoLocked(nil) })
583 : }
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