Draft: proposal: generator(all): Introduce the model struct diff mechanism , the `ormDiffTag` , and the generator

[scbizu]

背景

在一些特定的业务场景(审计日志)下，往往会需要在 model 层 (不管是 M¹ -> M 还是 P² ->(C³) -> M ) 记录一些 changelog(auditlog) 变化

Proposal

The Generator (diff模板生成)

在 (YAML)model struct 上生成 diff 方法，diff 方法接受另一个 M (提供 option , 可以带入一个 P -> C -> M 的转换过程)。

// 方法摘要
func (m *Model) Diff(m1 *Model) (bool,Differ,error)

The Differ

Differ 用来描述一次具体的DIFF结果，DIFF 结果可以按照不同业务场景组装:

• Extras: 提供额外信息展示
• OnKey: 用来描述oplog是否需要在 Key 的层级聚合

type Differ struct{
   // not export field , export behavior as method
   before *M
  // not export field , export behavior as method
  after *M
}

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Footnotes

1. M: Model Struct ↩

2. P: (API)Protocol(ProtoBuffer/Thrift/Json-To-Go) Struct ↩

3. C: The Converter between P <-> M ↩