github.com/TeaOSLab/EdgeNode@v1.3.8/internal/utils/ranges/range.go (about)

     1  // Copyright 2022 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
     2  
     3  package rangeutils
     4  
     5  import "strconv"
     6  
     7  type Range [2]int64
     8  
     9  func NewRange(start int64, end int64) Range {
    10  	return [2]int64{start, end}
    11  }
    12  
    13  func (this Range) Start() int64 {
    14  	return this[0]
    15  }
    16  
    17  func (this Range) End() int64 {
    18  	return this[1]
    19  }
    20  
    21  func (this Range) Length() int64 {
    22  	return this[1] - this[0] + 1
    23  }
    24  
    25  func (this Range) Convert(total int64) (newRange Range, ok bool) {
    26  	if total <= 0 {
    27  		return this, false
    28  	}
    29  	if this[0] < 0 {
    30  		this[0] += total
    31  		if this[0] < 0 {
    32  			return this, false
    33  		}
    34  		this[1] = total - 1
    35  	}
    36  	if this[1] < 0 {
    37  		this[1] = total - 1
    38  	}
    39  	if this[1] > total-1 {
    40  		this[1] = total - 1
    41  	}
    42  	if this[0] > this[1] {
    43  		return this, false
    44  	}
    45  
    46  	return this, true
    47  }
    48  
    49  // ComposeContentRangeHeader 组合Content-Range Header
    50  // totalSize 可能是一个数字，也可能是一个星号（*）
    51  func (this Range) ComposeContentRangeHeader(totalSize string) string {
    52  	return "bytes " + strconv.FormatInt(this[0], 10) + "-" + strconv.FormatInt(this[1], 10) + "/" + totalSize
    53  }