Golang util.DecodeHandleFromRowKey函數代碼示例

// Next implements plan.Plan Next interface.
func (r *TableDefaultPlan) Next(ctx context.Context) (row *plan.Row, err error) {
	if r.iter == nil {
		var txn kv.Transaction
		txn, err = ctx.GetTxn(false)
		if err != nil {
			return nil, errors.Trace(err)
		}
		r.iter, err = txn.Seek([]byte(r.T.FirstKey()))
		if err != nil {
			return nil, errors.Trace(err)
		}
	}
	if !r.iter.Valid() || !strings.HasPrefix(r.iter.Key(), r.T.KeyPrefix()) {
		return
	}
	// TODO: check if lock valid
	// the record layout in storage (key -> value):
	// r1 -> lock-version
	// r1_col1 -> r1 col1 value
	// r1_col2 -> r1 col2 value
	// r2 -> lock-version
	// r2_col1 -> r2 col1 value
	// r2_col2 -> r2 col2 value
	// ...
	rowKey := r.iter.Key()
	handle, err := util.DecodeHandleFromRowKey(rowKey)
	if err != nil {
		return nil, errors.Trace(err)
	}

	txn, err := ctx.GetTxn(false)
	if err != nil {
		return nil, errors.Trace(err)
	}
	// It is very likely that we will fetch rows after current row later, enable the RangePrefetchOnCacheMiss
	// option may help reducing RPC calls.
	// TODO: choose a wiser option value.
	txn.SetOption(kv.RangePrefetchOnCacheMiss, nil)
	defer txn.DelOption(kv.RangePrefetchOnCacheMiss)

	// TODO: we could just fetch mentioned columns' values
	row = &plan.Row{}
	row.Data, err = r.T.Row(ctx, handle)
	if err != nil {
		return nil, errors.Trace(err)
	}
	// Put rowKey to the tail of record row
	rke := &plan.RowKeyEntry{
		Tbl: r.T,
		Key: rowKey,
	}
	row.RowKeys = append(row.RowKeys, rke)

	rk := r.T.RecordKey(handle, nil)
	err = kv.NextUntil(r.iter, util.RowKeyPrefixFilter(rk))
	if err != nil {
		return nil, errors.Trace(err)
	}
	return
}

// Next implements plan.Plan Next interface.
func (r *TableNilPlan) Next(ctx context.Context) (row *plan.Row, err error) {
	if r.iter == nil {
		var txn kv.Transaction
		txn, err = ctx.GetTxn(false)
		if err != nil {
			return nil, errors.Trace(err)
		}
		r.iter, err = txn.Seek([]byte(r.T.FirstKey()), nil)
		if err != nil {
			return nil, errors.Trace(err)
		}
	}
	if !r.iter.Valid() || !strings.HasPrefix(r.iter.Key(), r.T.KeyPrefix()) {
		return
	}
	id, err := util.DecodeHandleFromRowKey(r.iter.Key())
	if err != nil {
		return nil, errors.Trace(err)
	}
	rk := r.T.RecordKey(id, nil)
	// Even though the data is nil, we should return not nil row,
	// or the iteration will stop.
	row = &plan.Row{}
	r.iter, err = kv.NextUntil(r.iter, util.RowKeyPrefixFilter(rk))
	return
}

// Do implements the plan.Plan interface, iterates rows but does nothing.
func (r *TableNilPlan) Do(ctx context.Context, f plan.RowIterFunc) error {
	h := r.T.FirstKey()
	prefix := r.T.KeyPrefix()
	txn, err := ctx.GetTxn(false)
	if err != nil {
		return err
	}
	it, err := txn.Seek([]byte(h), nil)
	if err != nil {
		return err
	}
	defer it.Close()
	for it.Valid() && strings.HasPrefix(it.Key(), prefix) {
		var err error
		id, err := util.DecodeHandleFromRowKey(it.Key())
		if err != nil {
			return err
		}

		// do nothing
		if m, err := f(id, nil); !m || err != nil {
			return err
		}

		rk := r.T.RecordKey(id, nil)
		if it, err = kv.NextUntil(it, util.RowKeyPrefixFilter(rk)); err != nil {
			return err
		}
	}
	return nil
}

func updateOldRows(ctx context.Context, t *tables.Table, col *column.Col) error {
	txn, err := ctx.GetTxn(false)
	if err != nil {
		return errors.Trace(err)
	}
	it, err := txn.Seek([]byte(t.FirstKey()))
	if err != nil {
		return errors.Trace(err)
	}
	defer it.Close()

	prefix := t.KeyPrefix()
	for it.Valid() && strings.HasPrefix(it.Key(), prefix) {
		handle, err0 := util.DecodeHandleFromRowKey(it.Key())
		if err0 != nil {
			return errors.Trace(err0)
		}
		k := t.RecordKey(handle, col)

		// TODO: check and get timestamp/datetime default value.
		// refer to getDefaultValue in stmt/stmts/stmt_helper.go.
		if err0 = t.SetColValue(txn, k, col.DefaultValue); err0 != nil {
			return errors.Trace(err0)
		}

		rk := t.RecordKey(handle, nil)
		if it, err0 = kv.NextUntil(it, util.RowKeyPrefixFilter(rk)); err0 != nil {
			return errors.Trace(err0)
		}
	}

	return nil
}

// Do scans over rows' kv pair in the table, and constructs them into row data.
func (r *TableDefaultPlan) Do(ctx context.Context, f plan.RowIterFunc) error {
	t := r.T
	txn, err := ctx.GetTxn(false)
	if err != nil {
		return err
	}
	head := t.FirstKey()
	prefix := t.KeyPrefix()

	it, err := txn.Seek([]byte(head), nil)
	if err != nil {
		return err
	}
	defer it.Close()
	for it.Valid() && strings.HasPrefix(it.Key(), prefix) {
		// TODO: check if lock valid
		// the record layout in storage (key -> value):
		// r1 -> lock-version
		// r1_col1 -> r1 col1 value
		// r1_col2 -> r1 col2 value
		// r2 -> lock-version
		// r2_col1 -> r2 col1 value
		// r2_col2 -> r2 col2 value
		// ...
		var err error
		rowKey := it.Key()
		h, err := util.DecodeHandleFromRowKey(rowKey)
		if err != nil {
			return err
		}

		// TODO: we could just fetch mentioned columns' values
		rec, err := t.Row(ctx, h)
		if err != nil {
			return err
		}
		// Put rowKey to the tail of record row
		rks := &RowKeyList{}
		rke := &RowKeyEntry{
			Tbl: t,
			Key: rowKey,
		}
		rks.appendKeys(rke)
		rec = append(rec, rks)
		m, err := f(int64(0), rec)
		if !m || err != nil {
			return err
		}

		rk := t.RecordKey(h, nil)
		it, err = kv.NextUntil(it, util.RowKeyPrefixFilter(rk))
		if err != nil {
			return err
		}
	}
	return nil
}

func (d *ddl) buildIndex(ctx context.Context, t table.Table, idxInfo *model.IndexInfo, unique bool) error {
	firstKey := t.FirstKey()
	prefix := t.KeyPrefix()

	txn, err := ctx.GetTxn(false)
	if err != nil {
		return errors.Trace(err)
	}
	it, err := txn.Seek([]byte(firstKey))
	if err != nil {
		return errors.Trace(err)
	}
	defer it.Close()
	for it.Valid() && strings.HasPrefix(it.Key(), prefix) {
		var err error
		handle, err := util.DecodeHandleFromRowKey(it.Key())
		log.Info("building index...", handle)
		if err != nil {
			return errors.Trace(err)
		}
		// TODO: v is timestamp ?
		// fetch datas
		cols := t.Cols()
		var vals []interface{}
		for _, v := range idxInfo.Columns {
			var (
				data []byte
				val  interface{}
			)
			col := cols[v.Offset]
			k := t.RecordKey(handle, col)
			data, err = txn.Get([]byte(k))
			if err != nil {
				return errors.Trace(err)
			}
			val, err = t.DecodeValue(data, col)
			if err != nil {
				return errors.Trace(err)
			}
			vals = append(vals, val)
		}
		// build index
		kvX := kv.NewKVIndex(t.IndexPrefix(), idxInfo.Name.L, unique)
		err = kvX.Create(txn, vals, handle)
		if err != nil {
			return errors.Trace(err)
		}

		rk := []byte(t.RecordKey(handle, nil))
		it, err = kv.NextUntil(it, util.RowKeyPrefixFilter(rk))
		if err != nil {
			return errors.Trace(err)
		}
	}
	return nil
}

func (d *ddl) getSnapshotRows(t table.Table, version uint64, seekHandle int64) ([]int64, error) {
	ver := kv.Version{Ver: version}

	snap, err := d.store.GetSnapshot(ver)
	if err != nil {
		return nil, errors.Trace(err)
	}

	defer snap.MvccRelease()

	firstKey := t.RecordKey(seekHandle, nil)
	prefix := []byte(t.KeyPrefix())

	it := snap.NewMvccIterator([]byte(firstKey), ver)
	defer it.Close()

	handles := make([]int64, 0, maxBatchSize)

	for it.Valid() {
		key := []byte(it.Key())
		if !bytes.HasPrefix(key, prefix) {
			break
		}

		var handle int64
		handle, err = util.DecodeHandleFromRowKey(string(key))
		if err != nil {
			return nil, errors.Trace(err)
		}

		rk := t.RecordKey(handle, nil)

		handles = append(handles, handle)
		if len(handles) == maxBatchSize {
			seekHandle = handle + 1
			break
		}

		err = kv.NextUntil(it, util.RowKeyPrefixFilter(rk))
		if terror.ErrorEqual(err, kv.ErrNotExist) {
			break
		} else if err != nil {
			return nil, errors.Trace(err)
		}
	}

	return handles, nil
}

// IterRecords implements table.Table IterRecords interface.
func (t *Table) IterRecords(ctx context.Context, startKey string, cols []*column.Col, fn table.RecordIterFunc) error {
	txn, err := ctx.GetTxn(false)
	if err != nil {
		return errors.Trace(err)
	}

	it, err := txn.Seek([]byte(startKey))
	if err != nil {
		return errors.Trace(err)
	}
	defer it.Close()

	if !it.Valid() {
		return nil
	}

	log.Debugf("startKey %q, key:%q,value:%q", startKey, it.Key(), it.Value())

	prefix := t.KeyPrefix()
	for it.Valid() && strings.HasPrefix(it.Key(), prefix) {
		// first kv pair is row lock information.
		// TODO: check valid lock
		// get row handle
		var err error
		handle, err := util.DecodeHandleFromRowKey(it.Key())
		if err != nil {
			return errors.Trace(err)
		}

		data, err := t.RowWithCols(ctx, handle, cols)
		if err != nil {
			return errors.Trace(err)
		}
		more, err := fn(handle, data, cols)
		if !more || err != nil {
			return errors.Trace(err)
		}

		rk := t.RecordKey(handle, nil)
		err = kv.NextUntil(it, util.RowKeyPrefixFilter(rk))
		if err != nil {
			return errors.Trace(err)
		}
	}
	return nil
}

func (s *DeleteStmt) tryDeleteUsingIndex(ctx context.Context, t table.Table) (bool, error) {
	log.Info("try delete with index", ctx)
	p, err := s.indexPlan(ctx)
	if p == nil || err != nil {
		return false, errors.Trace(err)
	}
	var rowKeys []*plan.RowKeyEntry
	for {
		row, err1 := p.Next(ctx)
		if err1 != nil {
			return false, errors.Trace(err1)
		}
		if row == nil {
			break
		}
		rowKeys = append(rowKeys, row.RowKeys...)
	}
	var cnt uint64
	for _, rowKey := range rowKeys {
		if s.Limit != nil && cnt >= s.Limit.Count {
			break
		}
		handle, err := util.DecodeHandleFromRowKey(rowKey.Key)
		if err != nil {
			return false, errors.Trace(err)
		}
		data, err := t.Row(ctx, handle)
		if err != nil {
			return false, err
		}
		log.Infof("try delete with index id:%d, ctx:%s", handle, ctx)
		ok, err := s.hitWhere(ctx, t, data)
		if err != nil {
			return false, errors.Trace(err)
		}
		if !ok {
			return true, nil
		}
		err = s.removeRow(ctx, t, handle, data)
		if err != nil {
			return false, err
		}
		cnt++
	}
	return true, nil
}

// Exec implements the stmt.Statement Exec interface.
func (s *DeleteStmt) Exec(ctx context.Context) (_ rset.Recordset, err error) {
	if s.MultiTable && len(s.TableIdents) == 0 {
		return nil, nil
	}
	p, err := s.plan(ctx)
	if err != nil {
		return nil, errors.Trace(err)
	}
	if p == nil {
		return nil, nil
	}
	defer p.Close()
	tblIDMap := make(map[int64]bool, len(s.TableIdents))
	// Get table alias map.
	tblNames := make(map[string]string)
	if s.MultiTable {
		// Delete from multiple tables should consider table ident list.
		fs := p.GetFields()
		for _, f := range fs {
			if f.TableName != f.OrgTableName {
				tblNames[f.TableName] = f.OrgTableName
			} else {
				tblNames[f.TableName] = f.TableName
			}
		}
		for _, t := range s.TableIdents {
			// Consider DBName.
			oname, ok := tblNames[t.Name.O]
			if !ok {
				return nil, errors.Errorf("Unknown table '%s' in MULTI DELETE", t.Name.O)
			}

			t.Name.O = oname
			t.Name.L = strings.ToLower(oname)

			var tbl table.Table
			tbl, err = getTable(ctx, t)
			if err != nil {
				return nil, errors.Trace(err)
			}
			tblIDMap[tbl.TableID()] = true
		}
	}
	rowKeyMap := make(map[string]table.Table)
	for {
		row, err1 := p.Next(ctx)
		if err1 != nil {
			return nil, errors.Trace(err1)
		}
		if row == nil {
			break
		}

		for _, entry := range row.RowKeys {
			if s.MultiTable {
				tid := entry.Tbl.TableID()
				if _, ok := tblIDMap[tid]; !ok {
					continue
				}
			}
			rowKeyMap[entry.Key] = entry.Tbl
		}
	}

	for k, t := range rowKeyMap {
		handle, err := util.DecodeHandleFromRowKey(k)
		if err != nil {
			return nil, errors.Trace(err)
		}
		data, err := t.Row(ctx, handle)
		if err != nil {
			return nil, errors.Trace(err)
		}
		err = s.removeRow(ctx, t, handle, data)
		if err != nil {
			return nil, errors.Trace(err)
		}
	}
	return nil, nil
}

func (s *DeleteStmt) execMultiTable(ctx context.Context) (_ rset.Recordset, err error) {
	log.Info("Delete from multi-table")
	if len(s.TableIdents) == 0 {
		return nil, nil
	}
	p, err := s.indexPlan(ctx)
	if err != nil {
		return nil, errors.Trace(err)
	}
	if p == nil {
		return nil, nil
	}
	tblIDMap := make(map[int64]bool, len(s.TableIdents))
	// Get table alias map.
	fs := p.GetFields()
	tblAliasMap := make(map[string]string)
	for _, f := range fs {
		if f.TableName != f.OrgTableName {
			tblAliasMap[f.TableName] = f.OrgTableName
		}
	}

	for _, t := range s.TableIdents {
		// Consider DBName.
		oname, ok := tblAliasMap[t.Name.O]
		if ok {
			t.Name.O = oname
			t.Name.L = strings.ToLower(oname)
		}

		var tbl table.Table
		tbl, err = getTable(ctx, t)
		if err != nil {
			return nil, errors.Trace(err)
		}
		tblIDMap[tbl.TableID()] = true
	}
	rowKeyMap := make(map[string]table.Table)
	err = p.Do(ctx, func(_ interface{}, in []interface{}) (bool, error) {
		// Generate ids for coming deletion.
		var rowKeys *plans.RowKeyList
		if in != nil && len(in) > 0 {
			t := in[len(in)-1]
			switch vt := t.(type) {
			case *plans.RowKeyList:
				rowKeys = vt
			}
		}
		if rowKeys != nil {
			for _, entry := range rowKeys.Keys {
				tid := entry.Tbl.TableID()
				if _, ok := tblIDMap[tid]; !ok {
					continue
				}
				rowKeyMap[entry.Key] = entry.Tbl
			}
		}
		return true, nil
	})

	if err != nil {
		return nil, errors.Trace(err)
	}
	for k, t := range rowKeyMap {
		id, err := util.DecodeHandleFromRowKey(k)
		if err != nil {
			return nil, errors.Trace(err)
		}
		data, err := t.Row(ctx, id)
		if err != nil {
			return nil, errors.Trace(err)
		}
		err = s.removeRow(ctx, t, id, data)
		if err != nil {
			return nil, errors.Trace(err)
		}
	}
	return nil, nil
}

// Exec implements the stmt.Statement Exec interface.
func (s *UpdateStmt) Exec(ctx context.Context) (_ rset.Recordset, err error) {
	p, err := s.plan(ctx)
	if err != nil {
		return nil, errors.Trace(err)
	}
	defer p.Close()
	updatedRowKeys := make(map[string]bool)

	// Get table alias map.
	fs := p.GetFields()

	columns, err0 := getUpdateColumns(s.List, fs)
	if err0 != nil {
		return nil, errors.Trace(err0)
	}

	m := map[interface{}]interface{}{}
	var records []*plan.Row
	for {
		row, err1 := p.Next(ctx)
		if err1 != nil {
			return nil, errors.Trace(err1)
		}
		if row == nil {
			break
		}
		if len(row.RowKeys) == 0 {
			// Nothing to update
			continue
		}
		records = append(records, row)
	}

	for _, row := range records {
		rowData := row.Data

		// Set EvalIdentFunc
		m[expression.ExprEvalIdentFunc] = func(name string) (interface{}, error) {
			return plans.GetIdentValue(name, p.GetFields(), rowData, field.DefaultFieldFlag)
		}

		// Update rows
		offset := 0
		for _, entry := range row.RowKeys {
			tbl := entry.Tbl
			k := entry.Key
			lastOffset := offset
			offset += len(tbl.Cols())
			data := rowData[lastOffset:offset]

			_, ok := updatedRowKeys[k]
			if ok {
				// Each matching row is updated once, even if it matches the conditions multiple times.
				continue
			}
			// Update row
			handle, err2 := util.DecodeHandleFromRowKey(k)
			if err2 != nil {
				return nil, errors.Trace(err2)
			}

			err2 = updateRecord(ctx, handle, data, tbl, columns, m, lastOffset, false)
			if err2 != nil {
				return nil, errors.Trace(err2)
			}

			updatedRowKeys[k] = true
		}
	}
	return nil, nil
}

// Exec implements the stmt.Statement Exec interface.
func (s *UpdateStmt) Exec(ctx context.Context) (_ rset.Recordset, err error) {
	p, err := s.plan(ctx)
	if err != nil {
		return nil, errors.Trace(err)
	}
	defer p.Close()
	updatedRowKeys := make(map[string]bool)
	for {
		row, err1 := p.Next(ctx)
		if err1 != nil {
			return nil, errors.Trace(err1)
		}
		if row == nil {
			break
		}
		rowData := row.Data
		if len(row.RowKeys) == 0 {
			// Nothing to update
			return nil, nil
		}
		// Set EvalIdentFunc
		m := make(map[interface{}]interface{})
		m[expressions.ExprEvalIdentFunc] = func(name string) (interface{}, error) {
			return plans.GetIdentValue(name, p.GetFields(), rowData, field.DefaultFieldFlag)
		}
		// Update rows
		start := 0
		for _, entry := range row.RowKeys {
			tbl := entry.Tbl
			k := entry.Key
			_, ok := updatedRowKeys[k]
			if ok {
				// Each matching row is updated once, even if it matches the conditions multiple times.
				continue
			}
			// Update row
			handle, err2 := util.DecodeHandleFromRowKey(k)
			if err2 != nil {
				return nil, errors.Trace(err2)
			}
			end := start + len(tbl.Cols())
			data := rowData[start:end]
			start = end
			tcols, err2 := getUpdateColumns(tbl, s.List, s.MultipleTable)
			if err2 != nil {
				return nil, errors.Trace(err2)
			}
			if len(tcols) == 0 {
				// Nothing to update for this table.
				continue
			}
			// Get data in the table
			err2 = updateRecord(ctx, handle, data, tbl, tcols, s.List, nil, m)
			if err2 != nil {
				return nil, errors.Trace(err2)
			}
			updatedRowKeys[k] = true
		}
	}
	return nil, nil
}

func (s *DeleteStmt) execMultiTable(ctx context.Context) (_ rset.Recordset, err error) {
	log.Info("Delete from multi-table")
	if len(s.TableIdents) == 0 {
		return nil, nil
	}
	p, err := s.indexPlan(ctx)
	if err != nil {
		return nil, errors.Trace(err)
	}
	if p == nil {
		return nil, nil
	}
	defer p.Close()
	tblIDMap := make(map[int64]bool, len(s.TableIdents))
	// Get table alias map.
	fs := p.GetFields()
	tblAliasMap := make(map[string]string)
	for _, f := range fs {
		if f.TableName != f.OrgTableName {
			tblAliasMap[f.TableName] = f.OrgTableName
		}
	}

	for _, t := range s.TableIdents {
		// Consider DBName.
		oname, ok := tblAliasMap[t.Name.O]
		if ok {
			t.Name.O = oname
			t.Name.L = strings.ToLower(oname)
		}

		var tbl table.Table
		tbl, err = getTable(ctx, t)
		if err != nil {
			return nil, errors.Trace(err)
		}
		tblIDMap[tbl.TableID()] = true
	}
	rowKeyMap := make(map[string]table.Table)
	for {
		row, err1 := p.Next(ctx)
		if err1 != nil {
			return nil, errors.Trace(err1)
		}
		if row == nil {
			break
		}
		for _, entry := range row.RowKeys {
			tid := entry.Tbl.TableID()
			if _, ok := tblIDMap[tid]; !ok {
				continue
			}
			rowKeyMap[entry.Key] = entry.Tbl
		}
	}
	for k, t := range rowKeyMap {
		id, err := util.DecodeHandleFromRowKey(k)
		if err != nil {
			return nil, errors.Trace(err)
		}
		data, err := t.Row(ctx, id)
		if err != nil {
			return nil, errors.Trace(err)
		}
		err = s.removeRow(ctx, t, id, data)
		if err != nil {
			return nil, errors.Trace(err)
		}
	}
	return nil, nil
}

// Exec implements the stmt.Statement Exec interface.
func (s *UpdateStmt) Exec(ctx context.Context) (_ rset.Recordset, err error) {
	p, err := s.plan(ctx)
	if err != nil {
		return nil, errors.Trace(err)
	}
	defer p.Close()

	fs := p.GetFields()
	columns, err := getUpdateColumns(s.List, fs)
	if err != nil {
		return nil, errors.Trace(err)
	}

	var records []*plan.Row
	for {
		row, err1 := p.Next(ctx)
		if err1 != nil {
			return nil, errors.Trace(err1)
		}
		if row == nil {
			break
		}
		if len(row.RowKeys) == 0 {
			// Nothing to update
			continue
		}
		records = append(records, row)
	}

	evalMap := map[interface{}]interface{}{}
	updatedRowKeys := make(map[string]bool)
	for _, row := range records {
		rowData := row.Data

		// Set ExprEvalIdentReferFunc.
		evalMap[expression.ExprEvalIdentReferFunc] = func(name string, scope int, index int) (interface{}, error) {
			return rowData[index], nil
		}

		// Update rows.
		offset := 0
		for _, entry := range row.RowKeys {
			tbl := entry.Tbl
			k := entry.Key
			lastOffset := offset
			offset += len(tbl.Cols())
			data := rowData[lastOffset:offset]

			_, ok := updatedRowKeys[k]
			if ok {
				// Each matching row is updated once, even if it matches the conditions multiple times.
				continue
			}

			// Update row
			handle, err1 := util.DecodeHandleFromRowKey(k)
			if err1 != nil {
				return nil, errors.Trace(err1)
			}

			err1 = updateRecord(ctx, handle, data, tbl, columns, evalMap, lastOffset, false)
			if err1 != nil {
				return nil, errors.Trace(err1)
			}

			updatedRowKeys[k] = true
		}
	}
	return nil, nil
}