Method check

tx_check.go:38–89

(cfg checkConfig, ch chan error)

}

func (tx *Tx) check(cfg checkConfig, ch chan error) {
	defer func() {
		if r := recover(); r != nil {
			ch <- panicked{r}
		}
	}()
	// Force loading free list if opened in ReadOnly mode.
	tx.db.loadFreelist()

	// Check if any pages are double freed.
	freed := make(map[common.Pgid]bool)
	all := make([]common.Pgid, tx.db.freelist.Count())
	tx.db.freelist.Copyall(all)
	for _, id := range all {
		if freed[id] {
			ch <- fmt.Errorf("page %d: already freed", id)
		}
		freed[id] = true
	}

	// Track every reachable page.
	reachable := make(map[common.Pgid]*common.Page)
	reachable[0] = tx.page(0) // meta0
	reachable[1] = tx.page(1) // meta1
	if tx.meta.Freelist() != common.PgidNoFreelist {
		for i := uint32(0); i <= tx.page(tx.meta.Freelist()).Overflow(); i++ {
			reachable[tx.meta.Freelist()+common.Pgid(i)] = tx.page(tx.meta.Freelist())
		}
	}

	if cfg.pageId == 0 {
		// Check the whole db file, starting from the root bucket and
		// recursively check all child buckets.
		tx.recursivelyCheckBucket(&tx.root, reachable, freed, cfg.kvStringer, ch)

		// Ensure all pages below high water mark are either reachable or freed.
		for i := common.Pgid(0); i < tx.meta.Pgid(); i++ {
			_, isReachable := reachable[i]
			if !isReachable && !freed[i] {
				ch <- fmt.Errorf("page %d: unreachable unfreed", int(i))
			}
		}
	} else {
		// Check the db file starting from a specified pageId.
		if cfg.pageId < 2 || cfg.pageId >= uint64(tx.meta.Pgid()) {
			ch <- fmt.Errorf("page ID (%d) out of range [%d, %d)", cfg.pageId, 2, tx.meta.Pgid())
			return
		}

		tx.recursivelyCheckPage(common.Pgid(cfg.pageId), reachable, freed, cfg.kvStringer, ch)
	}
}

func (tx *Tx) recursivelyCheckPage(pageId common.Pgid, reachable map[common.Pgid]*common.Page, freed map[common.Pgid]bool,
	kvStringer KVStringer, ch chan error) {