gotosocial/vendor/codeberg.org/gruf/go-bitutil/abs.go

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[feature] update proof-of-work to allow setting required rounds (#4186) # Description This updates our proof-of-work middleware, NoLLaMas, to work on a more easily configurable algorithm (thank you f0x for bringing this to my attention!). Instead of requiring that a solution with pre-determined number of '0' chars be found, it now pre-computes a result with a pre-determined nonce value that it expects the client to iterate up-to. (though with some level of jitter applied, to prevent it being too-easily gamed). This allows the user to configure roughly how many hash-encode rounds they want their clients to have to complete. ## Checklist - [x] I/we have read the [GoToSocial contribution guidelines](https://codeberg.org/superseriousbusiness/gotosocial/src/branch/main/CONTRIBUTING.md). - [x] I/we have discussed the proposed changes already, either in an issue on the repository, or in the Matrix chat. - [x] I/we have not leveraged AI to create the proposed changes. - [x] I/we have performed a self-review of added code. - [x] I/we have written code that is legible and maintainable by others. - [x] I/we have commented the added code, particularly in hard-to-understand areas. - [x] I/we have made any necessary changes to documentation. - [ ] I/we have added tests that cover new code. - [x] I/we have run tests and they pass locally with the changes. - [x] I/we have run `go fmt ./...` and `golangci-lint run`. Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4186 Co-authored-by: kim <grufwub@gmail.com> Co-committed-by: kim <grufwub@gmail.com>
2025-05-26 11:57:50 +02:00
package bitutil
// Abs8 returns the absolute value of i (calculated without branching).
func Abs8(i int8) int8 {
const bits = 8
u := uint64(i >> (bits - 1))
return (i ^ int8(u)) + int8(u&1)
}
// Abs16 returns the absolute value of i (calculated without branching).
func Abs16(i int16) int16 {
const bits = 16
u := uint64(i >> (bits - 1))
return (i ^ int16(u)) + int16(u&1)
}
// Abs32 returns the absolute value of i (calculated without branching).
func Abs32(i int32) int32 {
const bits = 32
u := uint64(i >> (bits - 1))
return (i ^ int32(u)) + int32(u&1)
}
// Abs64 returns the absolute value of i (calculated without branching).
func Abs64(i int64) int64 {
const bits = 64
u := uint64(i >> (bits - 1))
return (i ^ int64(u)) + int64(u&1)
}