golang implements paging algorithm instance code

preface

This article mainly introduces the golang paging algorithm related content, share for your reference and learning, the following words do not say much, let's have a look at the detailed introduction

The sample code is as follows:

// The paging method returns the contents of the paging based on the number of pages passed, per page, total  7 A number of pages   before  1 . 2 . 3 . 4 . 5  after   Format return , Less than 5 A page returns a specific number of pages 
func Paginator(page, prepage int, nums int64) map[string]interface{} {

 var firstpage int // before 1 Page address 
 var lastpage int // after 1 Page address 
 // According to the nums The total number, and prepage Number each page   Generating total pages 
 totalpages := int(math.Ceil(float64(nums) / float64(prepage))) //page The total number of 
 if page > totalpages {
  page = totalpages
 }
 if page <= 0 {
  page = 1
 }
 var pages []int
 switch {
 case page >= totalpages-5 && totalpages > 5: // The last 5 page 
  start := totalpages - 5 + 1
  firstpage = page - 1
  lastpage = int(math.Min(float64(totalpages), float64(page+1)))
  pages = make([]int, 5)
  for i, _ := range pages {
   pages[i] = start + i
  }
 case page >= 3 && totalpages > 5:
  start := page - 3 + 1
  pages = make([]int, 5)
  firstpage = page - 3
  for i, _ := range pages {
   pages[i] = start + i
  }
  firstpage = page - 1
  lastpage = page + 1
 default:
  pages = make([]int, int(math.Min(5, float64(totalpages))))
  for i, _ := range pages {
   pages[i] = i + 1
  }
  firstpage = int(math.Max(float64(1), float64(page-1)))
  lastpage = page + 1
  //fmt.Println(pages)
 }
 paginatorMap := make(map[string]interface{})
 paginatorMap["pages"] = pages
 paginatorMap["totalpages"] = totalpages
 paginatorMap["firstpage"] = firstpage
 paginatorMap["lastpage"] = lastpage
 paginatorMap["currpage"] = page
 return paginatorMap
}

The test results are as follows

func main(){
 pageSize := 3 
 var rsCount int64 = 100
 currentPage := 8
 res := Paginator(currentPage,pageSize,rsCount)
 fmt.Println(res) 
}

The results are as follows

map[pages:[6 7 8 9 10] totalpages:34 firstpage:7 lastpage:9 currpage:8]

conclusion