github.com/matrixorigin/matrixone@v1.2.0/pkg/txn/storage/tae/read.go (about)

     1  // Copyright 2021 - 2022 Matrix Origin
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package taestorage
    16  
    17  import (
    18  	"context"
    19  	"encoding"
    20  	"io"
    21  
    22  	"github.com/matrixorigin/matrixone/pkg/common/moerr"
    23  	apipb "github.com/matrixorigin/matrixone/pkg/pb/api"
    24  	"github.com/matrixorigin/matrixone/pkg/pb/txn"
    25  	"github.com/matrixorigin/matrixone/pkg/txn/storage"
    26  )
    27  
    28  // Read implements storage.TxnTAEStorage
    29  func (s *taeStorage) Read(
    30  	ctx context.Context,
    31  	txnMeta txn.TxnMeta,
    32  	op uint32,
    33  	payload []byte) (res storage.ReadResult, err error) {
    34  	switch op {
    35  	case uint32(apipb.OpCode_OpGetLogTail):
    36  		return handleRead(ctx, txnMeta, payload, s.taeHandler.HandleGetLogTail)
    37  	default:
    38  		return nil, moerr.NewNotSupported(ctx, "known read op: %v", op)
    39  	}
    40  }
    41  
    42  type unmashaler[T any] interface {
    43  	*T
    44  	encoding.BinaryUnmarshaler
    45  }
    46  
    47  type mashaler[T any] interface {
    48  	*T
    49  	encoding.BinaryMarshaler
    50  }
    51  
    52  func handleRead[PReq unmashaler[Req], PResp mashaler[Resp], Req, Resp any](
    53  	ctx context.Context,
    54  	txnMeta txn.TxnMeta,
    55  	payload []byte,
    56  	fn func(context.Context, txn.TxnMeta, PReq, PResp) (func(), error),
    57  ) (res storage.ReadResult, err error) {
    58  
    59  	var preq PReq = new(Req)
    60  	if len(payload) != 0 {
    61  		if err := preq.UnmarshalBinary(payload); err != nil {
    62  			return nil, err
    63  		}
    64  	}
    65  
    66  	var presp PResp = new(Resp)
    67  	defer logReq("read", preq, txnMeta, presp, &err)()
    68  	defer func() {
    69  		if closer, ok := (any)(presp).(io.Closer); ok {
    70  			_ = closer.Close()
    71  		}
    72  	}()
    73  
    74  	cb, err := fn(ctx, txnMeta, preq, presp)
    75  	if cb != nil {
    76  		defer cb()
    77  	}
    78  	if err != nil {
    79  		return nil, err
    80  	}
    81  
    82  	data, err := presp.MarshalBinary()
    83  	if err != nil {
    84  		return nil, err
    85  	}
    86  	res = &readResult{
    87  		payload: data,
    88  	}
    89  
    90  	return res, nil
    91  }