vendor/github.com/hashicorp/terraform/helper/hashcode/hashcode.go

   1 package hashcode
   2
   3 import (
   4         "bytes"
   5         "fmt"
   6         "hash/crc32"
   7 )
   8
   9 // String hashes a string to a unique hashcode.
  10 //
  11 // crc32 returns a uint32, but for our use we need
  12 // and non negative integer. Here we cast to an integer
  13 // and invert it if the result is negative.
  14 func String(s string) int {
  15         v := int(crc32.ChecksumIEEE([]byte(s)))
  16         if v >= 0 {
  17                 return v
  18         }
  19         if -v >= 0 {
  20                 return -v
  21         }
  22         // v == MinInt
  23         return 0
  24 }
  25
  26 // Strings hashes a list of strings to a unique hashcode.
  27 func Strings(strings []string) string {
  28         var buf bytes.Buffer
  29
  30         for _, s := range strings {
  31                 buf.WriteString(fmt.Sprintf("%s-", s))
  32         }
  33
  34         return fmt.Sprintf("%d", String(buf.String()))
  35 }