1 files changed, 78 insertions, 0 deletions
diff --git a/vendor/github.com/pion/transport/replaydetector/fixedbig.go b/vendor/github.com/pion/transport/replaydetector/fixedbig.go
new file mode 100644
index 0000000..a571a1a
--- /dev/null
+++ b/vendor/github.com/pion/transport/replaydetector/fixedbig.go
@@ -0,0 +1,78 @@
+package replaydetector
+
+import (
+	"fmt"
+)
+
+// fixedBigInt is the fix-sized multi-word integer.
+type fixedBigInt struct {
+	bits    []uint64
+	n       uint
+	msbMask uint64
+}
+
+// newFixedBigInt creates a new fix-sized multi-word int.
+func newFixedBigInt(n uint) *fixedBigInt {
+	chunkSize := (n + 63) / 64
+	if chunkSize == 0 {
+		chunkSize = 1
+	}
+	return &fixedBigInt{
+		bits:    make([]uint64, chunkSize),
+		n:       n,
+		msbMask: (1 << (64 - n%64)) - 1,
+	}
+}
+
+// Lsh is the left shift operation.
+func (s *fixedBigInt) Lsh(n uint) {
+	if n == 0 {
+		return
+	}
+	nChunk := int(n / 64)
+	nN := n % 64
+
+	for i := len(s.bits) - 1; i >= 0; i-- {
+		var carry uint64
+		if i-nChunk >= 0 {
+			carry = s.bits[i-nChunk] << nN
+			if i-nChunk-1 >= 0 {
+				carry |= s.bits[i-nChunk-1] >> (64 - nN)
+			}
+		}
+		s.bits[i] = (s.bits[i] << n) | carry
+	}
+	s.bits[len(s.bits)-1] &= s.msbMask
+}
+
+// Bit returns i-th bit of the fixedBigInt.
+func (s *fixedBigInt) Bit(i uint) uint {
+	if i >= s.n {
+		return 0
+	}
+	chunk := i / 64
+	pos := i % 64
+	if s.bits[chunk]&(1<<pos) != 0 {
+		return 1
+	}
+	return 0
+}
+
+// SetBit sets i-th bit to 1.
+func (s *fixedBigInt) SetBit(i uint) {
+	if i >= s.n {
+		return
+	}
+	chunk := i / 64
+	pos := i % 64
+	s.bits[chunk] |= 1 << pos
+}
+
+// String returns string representation of fixedBigInt.
+func (s *fixedBigInt) String() string {
+	var out string
+	for i := len(s.bits) - 1; i >= 0; i-- {
+		out += fmt.Sprintf("%016X", s.bits[i])
+	}
+	return out
+}