1 files changed, 104 insertions, 0 deletions
diff --git a/vendor/github.com/goccy/go-json/codec.go b/vendor/github.com/goccy/go-json/codec.go
new file mode 100644
index 000000000..e109d9921
--- /dev/null
+++ b/vendor/github.com/goccy/go-json/codec.go
@@ -0,0 +1,104 @@
+package json
+
+import (
+	"fmt"
+	"reflect"
+	"sync/atomic"
+	"unsafe"
+)
+
+const (
+	maxAcceptableTypeAddrRange = 1024 * 1024 * 2 // 2 Mib
+)
+
+var (
+	cachedDecoder    []decoder
+	cachedDecoderMap unsafe.Pointer // map[uintptr]decoder
+	baseTypeAddr     uintptr
+	maxTypeAddr      uintptr
+	typeAddrShift    uintptr
+)
+
+//go:linkname typelinks reflect.typelinks
+func typelinks() ([]unsafe.Pointer, [][]int32)
+
+//go:linkname rtypeOff reflect.rtypeOff
+func rtypeOff(unsafe.Pointer, int32) unsafe.Pointer
+
+func setupCodec() error {
+	sections, offsets := typelinks()
+	if len(sections) != 1 {
+		return fmt.Errorf("failed to get sections")
+	}
+	if len(offsets) != 1 {
+		return fmt.Errorf("failed to get offsets")
+	}
+	section := sections[0]
+	offset := offsets[0]
+	var (
+		min         uintptr = uintptr(^uint(0))
+		max         uintptr = 0
+		isAligned64         = true
+		isAligned32         = true
+	)
+	for i := 0; i < len(offset); i++ {
+		typ := (*rtype)(rtypeOff(section, offset[i]))
+		addr := uintptr(unsafe.Pointer(typ))
+		if min > addr {
+			min = addr
+		}
+		if max < addr {
+			max = addr
+		}
+		if typ.Kind() == reflect.Ptr {
+			addr = uintptr(unsafe.Pointer(typ.Elem()))
+			if min > addr {
+				min = addr
+			}
+			if max < addr {
+				max = addr
+			}
+		}
+
+		// check every address is aligned from the base address
+		isAligned64 = isAligned64 && (addr-min)&63 == 0
+		isAligned32 = isAligned32 && (addr-min)&31 == 0
+	}
+	addrRange := max - min
+	if addrRange == 0 {
+		return fmt.Errorf("failed to get address range of types")
+	}
+	if isAligned64 {
+		typeAddrShift = 6
+	} else if isAligned32 {
+		typeAddrShift = 5
+	}
+	cacheSize := addrRange >> typeAddrShift
+	if cacheSize > maxAcceptableTypeAddrRange {
+		return fmt.Errorf("too big address range %d", addrRange)
+	}
+	cachedDecoder = make([]decoder, cacheSize)
+	baseTypeAddr = min
+	maxTypeAddr = max
+	return nil
+}
+
+func init() {
+	_ = setupCodec()
+}
+
+func loadDecoderMap() map[uintptr]decoder {
+	p := atomic.LoadPointer(&cachedDecoderMap)
+	return *(*map[uintptr]decoder)(unsafe.Pointer(&p))
+}
+
+func storeDecoder(typ uintptr, dec decoder, m map[uintptr]decoder) {
+	newDecoderMap := make(map[uintptr]decoder, len(m)+1)
+	newDecoderMap[typ] = dec
+
+	for k, v := range m {
+		newDecoderMap[k] = v
+	}
+
+	atomic.StorePointer(&cachedDecoderMap, *(*unsafe.Pointer)(unsafe.Pointer(&newDecoderMap)))
+}