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util/chainedio/chainedio_reader.go

@@ -0,0 +1,34 @@
+package chainedio
+
+import "io"
+
+type ChainedReader struct {
+	Readers   []io.Reader
+	curReader int
+}
+
+func NewChainedReader(reader ...io.Reader) *ChainedReader {
+	return &ChainedReader{
+		Readers:   reader,
+		curReader: 0,
+	}
+}
+
+func (c *ChainedReader) Read(buf []byte) (n int, err error) {
+
+	n = 0
+
+	for c.curReader < len(c.Readers) {
+		n, err = c.Readers[c.curReader].Read(buf)
+		if err == io.EOF {
+			c.curReader++
+			continue
+		}
+		break
+	}
+	if c.curReader == len(c.Readers) {
+		err = io.EOF // actually, there was no gap
+	}
+
+	return
+}