terraform/helper/hashcode/hashcode.go

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package hashcode
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import (
"bytes"
"fmt"
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"hash/crc32"
)
// String hashes a string to a unique hashcode.
//
// crc32 returns a uint32, but for our use we need
// and non negative integer. Here we cast to an integer
// and invert it if the result is negative.
func String(s string) int {
v := int(crc32.ChecksumIEEE([]byte(s)))
if v >= 0 {
return v
}
if -v >= 0 {
return -v
}
// v == MinInt
return 0
}
// Strings hashes a list of strings to a unique hashcode.
func Strings(strings []string) string {
var buf bytes.Buffer
for _, s := range strings {
buf.WriteString(fmt.Sprintf("%s-", s))
}
return fmt.Sprintf("%d", String(buf.String()))
}