From 0c594e3c81632323f71a51d7f3a1411a9ecb0020 Mon Sep 17 00:00:00 2001
From: "qiheng.zhou" <qiheng.zhou@bytedance.com>
Date: Fri, 23 Feb 2024 18:22:27 +0800
Subject: [PATCH] feat: allow GetBytes to get all bytes

---
 nocopy_linkbuffer.go      |  9 +++++++++
 nocopy_linkbuffer_test.go | 25 +++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/nocopy_linkbuffer.go b/nocopy_linkbuffer.go
index 555ba5ce..c888c3c8 100644
--- a/nocopy_linkbuffer.go
+++ b/nocopy_linkbuffer.go
@@ -557,8 +557,17 @@ func (b *LinkBuffer) Bytes() []byte {
 }
 
 // GetBytes will read and fill the slice p as much as possible.
+// If p is not passed, return all readable bytes.
 func (b *LinkBuffer) GetBytes(p [][]byte) (vs [][]byte) {
 	node, flush := b.read, b.flush
+	if len(p) == 0 {
+		n := 0
+		for ; node != flush; node = node.next {
+			n++
+		}
+		node = b.read
+		p = make([][]byte, n)
+	}
 	var i int
 	for i = 0; node != flush && i < len(p); node = node.next {
 		if node.Len() > 0 {
diff --git a/nocopy_linkbuffer_test.go b/nocopy_linkbuffer_test.go
index c3f9b9d8..a376b7bf 100644
--- a/nocopy_linkbuffer_test.go
+++ b/nocopy_linkbuffer_test.go
@@ -84,6 +84,31 @@ func TestLinkBuffer(t *testing.T) {
 	Equal(t, buf.Len(), 100)
 }
 
+func TestGetBytes(t *testing.T) {
+	buf := NewLinkBuffer()
+	var (
+		num         = 10
+		b           = 1
+		expectedLen = 0
+	)
+	for i := 0; i < num; i++ {
+		expectedLen += b
+		n, err := buf.WriteBinary(make([]byte, b))
+		MustNil(t, err)
+		Equal(t, n, b)
+		b *= 10
+	}
+	buf.Flush()
+	Equal(t, int(buf.length), expectedLen)
+	bs := buf.GetBytes(nil)
+	actualLen := 0
+	for i := 0; i < len(bs); i++ {
+		actualLen += len(bs[i])
+	}
+	Equal(t, actualLen, expectedLen)
+
+}
+
 // TestLinkBufferWithZero test more case with n is invalid.
 func TestLinkBufferWithInvalid(t *testing.T) {
 	// clean & new