fdeea1dfac
Includes: 1. mode change read lock operation in every exported method that r/w the underlying database; 2. returning `ErrDegradedMode` logical error if any exported method is called in degraded (without a metabase) mode. Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
50 lines
974 B
Go
50 lines
974 B
Go
package meta
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import (
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"github.com/nspcc-dev/neo-go/pkg/util/slice"
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"go.etcd.io/bbolt"
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)
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var (
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shardInfoBucket = []byte{shardInfoPrefix}
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shardIDKey = []byte("id")
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)
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// ReadShardID reads shard id from db.
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// If id is missing, returns nil, nil.
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func (db *DB) ReadShardID() ([]byte, error) {
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db.modeMtx.RLock()
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defer db.modeMtx.RUnlock()
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if db.mode.NoMetabase() {
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return nil, ErrDegradedMode
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}
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var id []byte
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err := db.boltDB.View(func(tx *bbolt.Tx) error {
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b := tx.Bucket(shardInfoBucket)
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if b != nil {
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id = slice.Copy(b.Get(shardIDKey))
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}
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return nil
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})
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return id, err
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}
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// WriteShardID writes shard it to db.
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func (db *DB) WriteShardID(id []byte) error {
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db.modeMtx.RLock()
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defer db.modeMtx.RUnlock()
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if db.mode.NoMetabase() {
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return ErrDegradedMode
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}
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return db.boltDB.Update(func(tx *bbolt.Tx) error {
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b, err := tx.CreateBucketIfNotExists(shardInfoBucket)
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if err != nil {
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return err
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}
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return b.Put(shardIDKey, id)
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})
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}
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