Loop over a dynamic nested struct in golang

huangapple
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英文:

Loop over a dynamic nested struct in golang

问题

我已经创建了一个动态结构体来解析JSON。结构体如下：

  1. type Partition struct {
  2.     DiskName      string      `json:"disk_name"`
  3.     Mountpoint    interface{} `json:"mountpoint,omitempty"`
  4.     Size          string      `json:"size"`
  5.     Fstype        string      `json:"fstype,omitempty"`
  6.     SubPartitions bool        `json:"sub_partitions"`
  7.     Partitions    []Partition `json:"partitions,omitempty"`
  8. }
  10. type NasInfo struct {
  11.     Blockdevices []struct {
  12.         DiskName   string      `json:"disk_name"`
  13.         Mountpoint interface{} `json:"mountpoint,omitempty"`
  14.         Size       string      `json:"size"`
  15.         Fstype     string      `json:"fstype,omitempty"`
  16.         Partitions []Partition `json:"partitions,omitempty"`
  17.     } `json:"blockdevices"`
  18. }

现在，一个块设备中可以有多个分区，而一个分区中又可以有更多的子分区。我想手动为分区结构体中的字段赋值。我该如何做到这一点？我该如何迭代每个分区和子分区，并为其赋值？有没有办法可以做到这一点？

目前我使用的代码只能处理一个分区和一个子分区。有没有办法可以迭代每个分区并为其赋值？

英文:

I have created a dynamic struct to unmarshal a JSON.
Struct looks like :

  1. type Partition struct {
  2. 	DiskName      string      `json:"disk_name"`
  3. 	Mountpoint    interface{} `json:"mountpoint,omitempty"`
  4. 	Size          string      `json:"size"`
  5. 	Fstype        string      `json:"fstype,omitempty"`
  6. 	SubPartitions bool        `json:"sub_partitions"`
  7. 	Partitions    []Partition `json:"partitions,omitempty"`
  8. }
  10. type NasInfo struct {
  11. 	Blockdevices []struct {
  12. 		DiskName   string      `json:"disk_name"`
  13. 		Mountpoint interface{} `json:"mountpoint,omitempty"`
  14. 		Size       string      `json:"size"`
  15. 		Fstype     string      `json:"fstype,omitempty"`
  16. 		Partitions []Partition `json:"partitions,omitempty"`
  17. 	} `json:"blockdevices"`
  18. }

Now there can be many partitions inside block devices, and a partition can have more sub partitions in it. I want to manually assign value to a field in partition struct. How can i do that.
How can i iterate over each partition and sub partitions and assign a manual value to it.
Is there any way to do this ?

Currently using this :

  1. 	totalPartitions := len(diskInfo.Blockdevices[0].Partitions)
  2. 	if totalPartitions > 0 {
  3. 		for i := 0; i < totalPartitions; i++ {
  4. 			if diskInfo.Blockdevices[0].Partitions[i].Partitions != nil {
  5. 				diskInfo.Blockdevices[0].Partitions[i].SubPartitions = true
  6. 			} else {
  7. 				diskInfo.Blockdevices[0].Partitions[i].SubPartitions = false
  8. 			}
  9. 		}
  10. 	}

But it can only handle 1 partition with one sub partition. Is there any way i can iterate over each and assign value to it?

答案1

得分: 1

由于SubPartitions标志与Partitions相关联，一种选择是删除SubPartitions字段，并添加一个计算该值的方法：

  1. func (p *Partition) HasSubPartitions() bool {
  2.     // 注意：要检查切片是否为空，建议查看`len(slice)`而不是`nil`（可能存在非nil指针指向长度为0的切片）
  3.     return len(p.Partitions) > 0
  4. }
英文:

Since that SubPartitions flag is coupled with Partitions, one option is to remove the SubPartitions field, and add a method that computes this value :

  1. func (p *Partition) HasSubPartitions() bool {
  2.     // note : to check if a slice is empty or not, it is advised to look at
  3.     // 'len(slice)' rather than nil (it is possible to have a non-nil pointer
  4.     // to a 0 length slice)
  5.     return len(p.Partitions) > 0  
  6. }

答案2

得分: 1

写一个函数

  1. func markSubPartition(p *Partition) {
  2.     if len(p.Partitions) > 0 {
  3.         p.SubPartitions = true
  4.         for _, part := range p.Partitions {
  5.             markSubPartition(part)
  6.         }
  7.     } else {
  8.         p.SubPartitions = false
  9.     }
  10. }

并按照以下方式循环遍历块设备：

  1. for _, part := range diskInfo.Blockdevices[0].Partitions {
  2.     markSubPartition(part)
  3. }

还需要修改你的结构体，将partition字段更改为：

  1. Partitions []*Partition `json:"partitions,omitempty"`

希望对你有所帮助，谢谢！

英文:

Write a function

  1. func markSubPartition(p *Partition) {
  2. if len(p.Partitions) > 0 {
  3. 	p.SubPartitions = true
  4. 	for _, part := range p.Partitions {
  5. 		markSubPartition(part)
  6. 	}
  7. } else {
  8. 	p.SubPartitions = false
  9. }}

And loop over blockdevices like this

  1. for _, part := range diskInfo.Blockdevices[0].Partitions {
  2. 				markSubPartition(part)}

Also need to alter your struct change partition field to :
Partitions []*Partition json:"partitions,omitempty"
Hope it helps, Thanks!

huangapple
  • 本文由 发表于 2021年5月19日 05:18:06
  • 转载请务必保留本文链接：https://go.coder-hub.com/67594087.html
  • dynamic
  • go
  • loops
  • struct
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