diff options
Diffstat (limited to 'tx.go')
| -rw-r--r-- | tx.go | 92 |
1 files changed, 92 insertions, 0 deletions
@@ -2,6 +2,7 @@ package bolt import ( "errors" + "fmt" "sort" "time" "unsafe" @@ -175,6 +176,14 @@ func (tx *Tx) Commit() error { return err } + // If strict mode is enabled then perform a consistency check. + if tx.db.StrictMode { + if err := tx.Check(); err != nil { + err := err.(ErrorList) + panic("check fail: " + err.Error() + ": " + err.join("; ")) + } + } + // Write meta to disk. if err := tx.writeMeta(); err != nil { tx.close() @@ -218,6 +227,89 @@ func (tx *Tx) close() { tx.db = nil } +// Check performs several consistency checks on the database for this transaction. +// An error is returned if any inconsistency is found or if executed on a read-only transaction. +func (tx *Tx) Check() error { + if !tx.writable { + return ErrTxNotWritable + } + + var errors ErrorList + + // Check if any pages are double freed. + freed := make(map[pgid]bool) + for _, id := range tx.db.freelist.all() { + if freed[id] { + errors = append(errors, fmt.Errorf("page %d: already freed", id)) + } + freed[id] = true + } + + // Track every reachable page. + reachable := make(map[pgid]*page) + reachable[0] = tx.page(0) // meta0 + reachable[1] = tx.page(1) // meta1 + for i := uint32(0); i <= tx.page(tx.meta.freelist).overflow; i++ { + reachable[tx.meta.freelist+pgid(i)] = tx.page(tx.meta.freelist) + } + + // Recursively check buckets. + tx.checkBucket(&tx.root, reachable, &errors) + + // Ensure all pages below high water mark are either reachable or freed. + for i := pgid(0); i < tx.meta.pgid; i++ { + _, isReachable := reachable[i] + if !isReachable && !freed[i] { + errors = append(errors, fmt.Errorf("page %d: unreachable unfreed", int(i))) + } else if isReachable && freed[i] { + errors = append(errors, fmt.Errorf("page %d: reachable freed", int(i))) + } + } + + if len(errors) > 0 { + return errors + } + + return nil +} + +func (tx *Tx) checkBucket(b *Bucket, reachable map[pgid]*page, errors *ErrorList) { + // Ignore inline buckets. + if b.root == 0 { + return + } + + // Check every page used by this bucket. + b.tx.forEachPage(b.root, 0, func(p *page, _ int) { + // Ensure each page is only referenced once. + for i := pgid(0); i <= pgid(p.overflow); i++ { + var id = p.id + i + if _, ok := reachable[id]; ok { + *errors = append(*errors, fmt.Errorf("page %d: multiple references", int(id))) + } + reachable[id] = p + } + + // Retrieve page info. + info, err := b.tx.Page(int(p.id)) + if err != nil { + *errors = append(*errors, err) + } else if info == nil { + *errors = append(*errors, fmt.Errorf("page %d: out of bounds: %d", int(p.id), int(b.tx.meta.pgid))) + } else if info.Type != "branch" && info.Type != "leaf" { + *errors = append(*errors, fmt.Errorf("page %d: invalid type: %s", int(p.id), info.Type)) + } + }) + + // Check each bucket within this bucket. + _ = b.ForEach(func(k, v []byte) error { + if child := b.Bucket(k); child != nil { + tx.checkBucket(child, reachable, errors) + } + return nil + }) +} + // allocate returns a contiguous block of memory starting at a given page. func (tx *Tx) allocate(count int) (*page, error) { p, err := tx.db.allocate(count) |