summaryrefslogtreecommitdiff
path: root/vendor/codeberg.org/gruf/go-mangler/v2/pointer.go
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/codeberg.org/gruf/go-mangler/v2/pointer.go')
-rw-r--r--vendor/codeberg.org/gruf/go-mangler/v2/pointer.go81
1 files changed, 81 insertions, 0 deletions
diff --git a/vendor/codeberg.org/gruf/go-mangler/v2/pointer.go b/vendor/codeberg.org/gruf/go-mangler/v2/pointer.go
new file mode 100644
index 000000000..d732b2f67
--- /dev/null
+++ b/vendor/codeberg.org/gruf/go-mangler/v2/pointer.go
@@ -0,0 +1,81 @@
+package mangler
+
+import (
+ "reflect"
+ "unsafe"
+
+ "codeberg.org/gruf/go-xunsafe"
+)
+
+// derefPointerType returns a Mangler capable of dereferencing
+// and formatting the given pointer type currently in TypeIter{}.
+// note this will fetch a sub-Mangler for resulting value type.
+func derefPointerType(t xunsafe.TypeIter) Mangler {
+ var derefs int
+ var indirects int64
+ rtype := t.Type
+ flags := t.Flag
+
+ // Iteratively dereference pointer types.
+ for rtype.Kind() == reflect.Pointer {
+
+ // Only if this is actual indirect memory do we
+ // perform a derefence, otherwise we just skip over
+ // and increase the dereference indicator, i.e. '1'.
+ if flags&xunsafe.Reflect_flagIndir != 0 {
+ indirects |= 1 << derefs
+ }
+ derefs++
+
+ // Get next elem type.
+ rtype = rtype.Elem()
+
+ // Get next set of dereferenced element type flags.
+ flags = xunsafe.ReflectPointerElemFlags(flags, rtype)
+ }
+
+ // Ensure this is a reasonable number of derefs.
+ if derefs > 4*int(unsafe.Sizeof(indirects)) {
+ return nil
+ }
+
+ // Wrap value as TypeIter.
+ vt := t.Child(rtype, flags)
+
+ // Get value mangler.
+ fn := loadOrGet(vt)
+ if fn == nil {
+ return nil
+ }
+
+ return func(buf []byte, ptr unsafe.Pointer) []byte {
+ for i := 0; i < derefs; i++ {
+ switch {
+ case indirects&1<<i == 0:
+ // No dereference needed.
+ buf = append(buf, '1')
+
+ case ptr == nil:
+ // Nil value, return here.
+ buf = append(buf, '0')
+ return buf
+
+ default:
+ // Further deref ptr.
+ buf = append(buf, '1')
+ ptr = *(*unsafe.Pointer)(ptr)
+ }
+ }
+
+ if ptr == nil {
+ // Final nil val check.
+ buf = append(buf, '0')
+ return buf
+ }
+
+ // Mangle fully deref'd.
+ buf = append(buf, '1')
+ buf = fn(buf, ptr)
+ return buf
+ }
+}