frostfs-node/pkg/local_object_storage/writecache/iterate.go
Evgenii Stratonikov c0f6c988f0 [#1085] shard: dump data from write-cache
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
2022-01-26 15:28:13 +03:00

73 lines
1.8 KiB
Go

package writecache
import (
"errors"
"fmt"
"github.com/nspcc-dev/neofs-sdk-go/object"
"go.etcd.io/bbolt"
)
// ErrNoDefaultBucket is returned by IterateDB when default bucket for objects is missing.
var ErrNoDefaultBucket = errors.New("no default bucket")
// Iterate iterates over all objects present in write cache.
// This is very difficult to do correctly unless write-cache is put in read-only mode.
// Thus we silently fail if shard is not in read-only mode to avoid reporting misleading results.
func (c *cache) Iterate(f func([]byte) error) error {
c.modeMtx.RLock()
defer c.modeMtx.RUnlock()
if c.mode != ModeReadOnly {
return nil
}
err := c.db.View(func(tx *bbolt.Tx) error {
b := tx.Bucket(defaultBucket)
return b.ForEach(func(k, data []byte) error {
if _, ok := c.flushed.Peek(string(k)); ok {
return nil
}
return f(data)
})
})
if err != nil {
return err
}
return c.fsTree.Iterate(func(addr *object.Address, data []byte) error {
if _, ok := c.flushed.Peek(addr.String()); ok {
return nil
}
return f(data)
})
}
// IterateDB iterates over all objects stored in bbolt.DB instance and passes them to f until error return.
// It is assumed that db is an underlying database of some WriteCache instance.
//
// Returns ErrNoDefaultBucket if there is no default bucket in db.
//
// DB must not be nil and should be opened.
func IterateDB(db *bbolt.DB, f func(*object.Address) error) error {
return db.View(func(tx *bbolt.Tx) error {
b := tx.Bucket(defaultBucket)
if b == nil {
return ErrNoDefaultBucket
}
var addr *object.Address
return b.ForEach(func(k, v []byte) error {
if addr == nil {
addr = object.NewAddress()
}
err := addr.Parse(string(k))
if err != nil {
return fmt.Errorf("could not parse object address: %w", err)
}
return f(addr)
})
})
}