github.com/pingcap/tiflow@v0.0.0-20240520035814-5bf52d54e205/cdc/processor/tablepb/table.go (about)

     1  // Copyright 2020 PingCAP, Inc.
     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  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package tablepb
    15  
    16  import (
    17  	"bytes"
    18  	"encoding"
    19  	"encoding/hex"
    20  	"encoding/json"
    21  	"fmt"
    22  	"strconv"
    23  	"strings"
    24  	"sync/atomic"
    25  )
    26  
    27  // Load TableState with THREAD-SAFE
    28  func (s *TableState) Load() TableState {
    29  	return TableState(atomic.LoadInt32((*int32)(s)))
    30  }
    31  
    32  // Store TableState with THREAD-SAFE
    33  func (s *TableState) Store(new TableState) {
    34  	atomic.StoreInt32((*int32)(s), int32(new))
    35  }
    36  
    37  // CompareAndSwap is just like sync/atomic.Atomic*.CompareAndSwap.
    38  func (s *TableState) CompareAndSwap(old, new TableState) bool {
    39  	oldx := int32(old)
    40  	newx := int32(new)
    41  	return atomic.CompareAndSwapInt32((*int32)(s), oldx, newx)
    42  }
    43  
    44  // TableID is the ID of the table
    45  type TableID = int64
    46  
    47  // Ts is the timestamp with a logical count
    48  type Ts = uint64
    49  
    50  // Key is a custom type for bytes encoded in memcomparable format.
    51  // Key is read-only, must not be mutated.
    52  type Key []byte
    53  
    54  var (
    55  	_ fmt.Stringer = Key{}
    56  	_ fmt.Stringer = (*Key)(nil)
    57  )
    58  
    59  func (k Key) String() string {
    60  	return hex.EncodeToString(k)
    61  }
    62  
    63  var (
    64  	_ json.Marshaler = Key{}
    65  	_ json.Marshaler = (*Key)(nil)
    66  )
    67  
    68  // MarshalJSON implements json.Marshaler.
    69  // It is helpful to format span in log.
    70  func (k Key) MarshalJSON() ([]byte, error) {
    71  	return json.Marshal(k.String())
    72  }
    73  
    74  var (
    75  	_ encoding.TextMarshaler = Span{}
    76  	_ encoding.TextMarshaler = (*Span)(nil)
    77  )
    78  
    79  // MarshalText implements encoding.TextMarshaler (used in proto.CompactTextString).
    80  // It is helpful to format span in log.
    81  func (s Span) MarshalText() ([]byte, error) {
    82  	return []byte(s.String()), nil
    83  }
    84  
    85  func (s *Span) String() string {
    86  	length := len("{table_id:,start_key:,end_key:}")
    87  	length += 8 // for TableID
    88  	length += len(s.StartKey) + len(s.EndKey)
    89  	b := strings.Builder{}
    90  	b.Grow(length)
    91  	b.Write([]byte("{table_id:"))
    92  	b.Write([]byte(strconv.Itoa(int(s.TableID))))
    93  	if len(s.StartKey) > 0 {
    94  		b.Write([]byte(",start_key:"))
    95  		b.Write([]byte(s.StartKey.String()))
    96  	}
    97  	if len(s.EndKey) > 0 {
    98  		b.Write([]byte(",end_key:"))
    99  		b.Write([]byte(s.EndKey.String()))
   100  	}
   101  	b.Write([]byte("}"))
   102  	return b.String()
   103  }
   104  
   105  // Less compares two Spans, defines the order between spans.
   106  func (s *Span) Less(b *Span) bool {
   107  	if s.TableID < b.TableID {
   108  		return true
   109  	}
   110  	if bytes.Compare(s.StartKey, b.StartKey) < 0 {
   111  		return true
   112  	}
   113  	return false
   114  }
   115  
   116  // Eq compares two Spans, defines the equality between spans.
   117  func (s *Span) Eq(b *Span) bool {
   118  	return s.TableID == b.TableID &&
   119  		bytes.Equal(s.StartKey, b.StartKey) &&
   120  		bytes.Equal(s.EndKey, b.EndKey)
   121  }