diff options
Diffstat (limited to 'vendor/codeberg.org/gruf/go-atomics/bytes.go')
-rw-r--r-- | vendor/codeberg.org/gruf/go-atomics/bytes.go | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/vendor/codeberg.org/gruf/go-atomics/bytes.go b/vendor/codeberg.org/gruf/go-atomics/bytes.go new file mode 100644 index 000000000..3e40d186c --- /dev/null +++ b/vendor/codeberg.org/gruf/go-atomics/bytes.go @@ -0,0 +1,57 @@ +package atomics + +import ( + "sync/atomic" + "unsafe" +) + +// Bytes provides user-friendly means of performing atomic operations on []byte types. +type Bytes struct{ ptr unsafe.Pointer } + +// NewBytes will return a new Bytes instance initialized with zero value. +func NewBytes() *Bytes { + var v []byte + return &Bytes{ + ptr: unsafe.Pointer(&v), + } +} + +// Store will atomically store []byte value in address contained within v. +func (v *Bytes) Store(val []byte) { + atomic.StorePointer(&v.ptr, unsafe.Pointer(&val)) +} + +// Load will atomically load []byte value at address contained within v. +func (v *Bytes) Load() []byte { + return *(*[]byte)(atomic.LoadPointer(&v.ptr)) +} + +// CAS performs a compare-and-swap for a(n) []byte value at address contained within v. +func (v *Bytes) CAS(cmp, swp []byte) bool { + for { + // Load current value at address + ptr := atomic.LoadPointer(&v.ptr) + cur := *(*[]byte)(ptr) + + // Perform comparison against current + if !(string(cur) == string(cmp)) { + return false + } + + // Attempt to replace pointer + if atomic.CompareAndSwapPointer( + &v.ptr, + ptr, + unsafe.Pointer(&swp), + ) { + return true + } + } +} + +// Swap atomically stores new []byte value into address contained within v, and returns previous value. +func (v *Bytes) Swap(swp []byte) []byte { + ptr := unsafe.Pointer(&swp) + ptr = atomic.SwapPointer(&v.ptr, ptr) + return *(*[]byte)(ptr) +} |