initial

src/server/web/helpers/Buffer.go

@@ -0,0 +1,42 @@
+package helpers
+
+import "bytes"
+
+type SeekingBuffer struct {
+	str    string
+	buffer *bytes.Buffer
+	offset int64
+	size   int64
+}
+
+func NewSeekingBuffer(str string) *SeekingBuffer {
+	return &SeekingBuffer{
+		str:    str,
+		buffer: bytes.NewBufferString(str),
+		offset: 0,
+	}
+}
+
+func (fb *SeekingBuffer) Read(p []byte) (n int, err error) {
+	n, err = fb.buffer.Read(p)
+	fb.offset += int64(n)
+	return n, err
+}
+
+func (fb *SeekingBuffer) Seek(offset int64, whence int) (ret int64, err error) {
+	var newoffset int64
+	switch whence {
+	case 0:
+		newoffset = offset
+	case 1:
+		newoffset = fb.offset + offset
+	case 2:
+		newoffset = int64(len(fb.str)) - offset
+	}
+	if newoffset == fb.offset {
+		return newoffset, nil
+	}
+	fb.buffer = bytes.NewBufferString(fb.str[newoffset:])
+	fb.offset = newoffset
+	return fb.offset, nil
+}