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Golang Txn.Run方法代码示例

本文整理汇总了Golang中github.com/cockroachdb/cockroach/pkg/internal/client.Txn.Run方法的典型用法代码示例。如果您正苦于以下问题:Golang Txn.Run方法的具体用法?Golang Txn.Run怎么用?Golang Txn.Run使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在github.com/cockroachdb/cockroach/pkg/internal/client.Txn的用法示例。


在下文中一共展示了Txn.Run方法的2个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的Golang代码示例。

示例1: restoreTableDesc

func restoreTableDesc(
	ctx context.Context,
	txn *client.Txn,
	database sqlbase.DatabaseDescriptor,
	table sqlbase.TableDescriptor,
) error {
	// Run getDescriptorID again to make sure the database hasn't been dropped
	// while we were importing.
	var err error
	if table.ParentID, err = getDescriptorID(txn, tableKey{name: database.Name}); err != nil {
		return err
	}
	tableIDKey := tableKey{parentID: table.ParentID, name: table.Name}.Key()
	tableDescKey := sqlbase.MakeDescMetadataKey(table.ID)

	// Check for an existing table.
	var existingDesc sqlbase.Descriptor
	existingIDKV, err := txn.Get(tableIDKey)
	if err != nil {
		return err
	}
	if existingIDKV.Value != nil {
		existingID, err := existingIDKV.Value.GetInt()
		if err != nil {
			return err
		}
		existingDescKV, err := txn.Get(sqlbase.MakeDescMetadataKey(sqlbase.ID(existingID)))
		if err != nil {
			return err
		}
		if err := existingDescKV.Value.GetProto(&existingDesc); err != nil {
			return err
		}
	}

	// Write the new descriptors. First the ID -> TableDescriptor for the new
	// table, then flip (or initialize) the name -> ID entry so any new queries
	// will use the new one. If there was an existing table, it can now be
	// cleaned up.
	b := txn.NewBatch()
	b.CPut(tableDescKey, sqlbase.WrapDescriptor(&table), nil)
	if existingTable := existingDesc.GetTable(); existingTable == nil {
		b.CPut(tableIDKey, table.ID, nil)
	} else {
		existingIDKV.Value.ClearChecksum()
		b.CPut(tableIDKey, table.ID, existingIDKV.Value)
		// TODO(dan): This doesn't work for interleaved tables. Fix it when we
		// fix the empty range interleaved table TODO below.
		existingDataPrefix := roachpb.Key(keys.MakeTablePrefix(uint32(existingTable.ID)))
		b.DelRange(existingDataPrefix, existingDataPrefix.PrefixEnd(), false)
		zoneKey, _, descKey := GetKeysForTableDescriptor(existingTable)
		// Delete the desc and zone entries. Leave the name because the new
		// table is using it.
		b.Del(descKey)
		b.Del(zoneKey)
	}
	return txn.Run(b)
}
开发者ID:BramGruneir,项目名称:cockroach,代码行数:58,代码来源:backup.go

示例2: Ingest

// Ingest loads some data in an sstable into an empty range. Only the keys
// between startKey and endKey are loaded. If newTableID is non-zero, every
// row's key is rewritten to be for that table.
func Ingest(
	ctx context.Context,
	txn *client.Txn,
	path string,
	checksum uint32,
	startKey, endKey roachpb.Key,
	newTableID sqlbase.ID,
) error {
	// TODO(mjibson): An appropriate value for this should be determined. The
	// current value was guessed at but appears to work well.
	const batchSize = 10000

	// TODO(dan): Check if the range being ingested into is empty. If newTableID
	// is non-zero, it'll have to be derived from startKey and endKey.

	f, err := os.Open(path)
	if err != nil {
		return err
	}
	defer f.Close()
	crc := crc32.New(crc32.MakeTable(crc32.Castagnoli))
	if _, err := io.Copy(crc, f); err != nil {
		return nil
	}
	if c := crc.Sum32(); c != checksum {
		return errors.Errorf("%s: checksum mismatch got %d expected %d", path, c, checksum)
	}

	sst, err := engine.MakeRocksDBSstFileReader()
	if err != nil {
		return err
	}
	defer sst.Close()
	if err := sst.AddFile(path); err != nil {
		return err
	}

	b := txn.NewBatch()
	var v roachpb.Value
	count := 0
	ingestFunc := func(kv engine.MVCCKeyValue) (bool, error) {
		v = roachpb.Value{RawBytes: kv.Value}
		v.ClearChecksum()
		if log.V(3) {
			log.Infof(ctx, "Put %s %s\n", kv.Key.Key, v.PrettyPrint())
		}
		b.Put(kv.Key.Key, &v)
		count++
		if count > batchSize {
			if err := txn.Run(b); err != nil {
				return true, err
			}
			b = txn.NewBatch()
			count = 0
		}
		return false, nil
	}
	if newTableID != 0 {
		// MakeRekeyMVCCKeyValFunc modifies the keys, but this is safe because
		// the one we get back from rocksDBIterator.Key is a copy (not a
		// reference to the mmaped file.)
		ingestFunc = MakeRekeyMVCCKeyValFunc(newTableID, ingestFunc)
	}
	startKeyMVCC, endKeyMVCC := engine.MVCCKey{Key: startKey}, engine.MVCCKey{Key: endKey}
	if err := sst.Iterate(startKeyMVCC, endKeyMVCC, ingestFunc); err != nil {
		return err
	}
	return txn.Run(b)
}
开发者ID:BramGruneir,项目名称:cockroach,代码行数:72,代码来源:backup.go


注:本文中的github.com/cockroachdb/cockroach/pkg/internal/client.Txn.Run方法示例由纯净天空整理自Github/MSDocs等开源代码及文档管理平台,相关代码片段筛选自各路编程大神贡献的开源项目,源码版权归原作者所有,传播和使用请参考对应项目的License;未经允许,请勿转载。