new: parsing BLE flags and company identifiers from advertisements

vendor/github.com/chzyer/test/disk.go

@@ -0,0 +1,106 @@
+package test
+
+import (
+	"encoding/hex"
+	"io"
+)
+
+type MemDisk struct {
+	data       [][]byte
+	size       int64
+	woff, roff int
+}
+
+func NewMemDisk() *MemDisk {
+	return &MemDisk{}
+}
+
+func (w *MemDisk) Write(b []byte) (int, error) {
+	n, err := w.WriteAt(b, int64(w.woff))
+	w.woff += n
+	return n, err
+}
+
+func (w *MemDisk) getData(off int64) []byte {
+	idx := int(off >> 20)
+	if idx >= cap(w.data) {
+		newdata := make([][]byte, idx+1)
+		copy(newdata, w.data)
+		w.data = newdata
+	}
+	if len(w.data[idx]) == 0 {
+		w.data[idx] = make([]byte, 1<<20)
+	}
+
+	return w.data[idx][off&((1<<20)-1):]
+}
+
+func (w *MemDisk) WriteAt(b []byte, off int64) (int, error) {
+	n := len(b)
+	for len(b) > 0 {
+		buf := w.getData(off)
+		m := copy(buf, b)
+		if off+int64(m) > w.size {
+			w.size = off + int64(m)
+		}
+		b = b[m:]
+		off += int64(m)
+	}
+	return n, nil
+}
+
+func (w *MemDisk) ReadAt(b []byte, off int64) (int, error) {
+	byteRead := 0
+	for byteRead < len(b) {
+		if off >= w.size {
+			return 0, io.EOF
+		}
+		buf := w.getData(off)
+		if int64(len(buf))+off > w.size {
+			buf = buf[:w.size-off]
+		}
+		if len(buf) == 0 {
+			return byteRead, io.EOF
+		}
+		n := copy(b[byteRead:], buf)
+		off += int64(n)
+		byteRead += n
+	}
+	return byteRead, nil
+}
+
+func (w *MemDisk) Dump() string {
+	return hex.Dump(w.getData(0))
+}
+
+func (w *MemDisk) SeekRead(offset int64, whence int) (ret int64) {
+	switch whence {
+	case 0:
+		w.roff += int(offset)
+	case 1:
+		w.roff = int(offset)
+	default:
+	}
+	return int64(w.roff)
+}
+
+func (w *MemDisk) SeekWrite(offset int64, whence int) (ret int64) {
+	switch whence {
+	case 0:
+		w.woff += int(offset)
+	case 1:
+		w.woff = int(offset)
+	default:
+	}
+	return int64(w.woff)
+}
+
+func (w *MemDisk) Read(b []byte) (int, error) {
+	n, err := w.ReadAt(b, int64(w.roff))
+	w.roff += n
+	return n, err
+}
+
+func (w *MemDisk) Close() error {
+	return nil
+}