github.com/ecodeclub/eorm@v0.0.2-0.20231001112437-dae71da914d0/internal/sharding/types.go (about)

     1  // Copyright 2021 ecodeclub
     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 sharding
    16  
    17  import (
    18  	"context"
    19  
    20  	operator "github.com/ecodeclub/eorm/internal/operator"
    21  	"github.com/ecodeclub/eorm/internal/query"
    22  )
    23  
    24  var EmptyResp = Response{}
    25  var EmptyQuery = Query{}
    26  
    27  type Algorithm interface {
    28  	// Sharding 返回分库分表之后目标库和目标表信息
    29  	Sharding(ctx context.Context, req Request) (Response, error)
    30  	// Broadcast 返回所有的目标库、目标表
    31  	Broadcast(ctx context.Context) []Dst
    32  	// ShardingKeys 返回所有的 sharding key
    33  	// 这部分不包含任何放在 context.Context 中的部分，例如 shadow 标记位等
    34  	// 或者说，它只是指数据库中用于分库分表的列
    35  	ShardingKeys() []string
    36  }
    37  
    38  // Executor sql 语句执行器
    39  type Executor interface {
    40  	Exec(ctx context.Context) Result
    41  }
    42  
    43  // QueryBuilder  sharding sql 构造抽象
    44  type QueryBuilder interface {
    45  	Build(ctx context.Context) ([]Query, error)
    46  }
    47  
    48  type Query = query.Query
    49  
    50  type Dst struct {
    51  	// Name 数据源的逻辑名字
    52  	Name  string
    53  	DB    string
    54  	Table string
    55  }
    56  
    57  func (r Dst) Equals(l Dst) bool {
    58  	return r.Name == l.Name && r.DB == l.DB && r.Table == l.Table
    59  }
    60  
    61  func (r Dst) NotEquals(l Dst) bool {
    62  	return r.Name != l.Name || r.DB != l.DB || r.Table != l.Table
    63  }
    64  
    65  type Request struct {
    66  	Op       operator.Op
    67  	SkValues map[string]any
    68  }
    69  
    70  type Response struct {
    71  	Dsts []Dst
    72  }