Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

plugins/inputs/sflow/binaryio/minreader.go

@@ -0,0 +1,37 @@
+package binaryio
+
+import "io"
+
+// MinimumReader is the implementation for MinReader.
+type MinimumReader struct {
+	reader                 io.Reader
+	minNumberOfBytesToRead int64 // Min number of bytes we need to read from the reader
+}
+
+// MinReader reads from the reader but ensures there is at least N bytes read from the reader.
+// The reader should call Close() when they are done reading.
+// Closing the MinReader will read and discard any unread bytes up to minNumberOfBytesToRead.
+// CLosing the MinReader does NOT close the underlying reader.
+// The underlying implementation is a MinimumReader, which implements ReaderCloser.
+func MinReader(r io.Reader, minNumberOfBytesToRead int64) *MinimumReader {
+	return &MinimumReader{
+		reader:                 r,
+		minNumberOfBytesToRead: minNumberOfBytesToRead,
+	}
+}
+
+func (r *MinimumReader) Read(p []byte) (n int, err error) {
+	n, err = r.reader.Read(p)
+	r.minNumberOfBytesToRead -= int64(n)
+	return n, err
+}
+
+// Close does not close the underlying reader, only the MinimumReader
+func (r *MinimumReader) Close() error {
+	if r.minNumberOfBytesToRead > 0 {
+		b := make([]byte, r.minNumberOfBytesToRead)
+		_, err := r.reader.Read(b)
+		return err
+	}
+	return nil
+}

plugins/inputs/sflow/binaryio/minreader_test.go

@@ -0,0 +1,39 @@
+package binaryio
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestMinReader(t *testing.T) {
+	b := []byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
+	r := bytes.NewBuffer(b)
+
+	mr := MinReader(r, 10)
+
+	toRead := make([]byte, 5)
+	n, err := mr.Read(toRead)
+	if err != nil {
+		t.Error(err)
+	}
+	if n != 5 {
+		t.Error("Expected n to be 5, but was ", n)
+	}
+	if !bytes.Equal(toRead, []byte{1, 2, 3, 4, 5}) {
+		t.Error("expected 5 specific bytes to be read")
+	}
+	err = mr.Close()
+	if err != nil {
+		t.Error(err)
+	}
+	n, err = r.Read(toRead) // read from the outer stream
+	if err != nil {
+		t.Error(err)
+	}
+	if n != 5 {
+		t.Error("Expected n to be 5, but was ", n)
+	}
+	if !bytes.Equal(toRead, []byte{11, 12, 13, 14, 15}) {
+		t.Error("expected the last 5 bytes to be read")
+	}
+}