archiver: add buffer test

internal/archiver/buffer_test.go

@@ -0,0 +1,41 @@
+package archiver
+
+import (
+	"testing"
+)
+
+func TestBufferPoolReuse(t *testing.T) {
+	// Test that buffers are actually reused from the pool
+	pool := newBufferPool(1024)
+
+	// Get a buffer and modify it
+	buf1 := pool.Get()
+	buf1.Data[0] = 0xFF
+	originalAddr := &buf1.Data[0]
+	buf1.Release()
+
+	// Get another buffer and check if it's the same underlying slice
+	buf2 := pool.Get()
+	if &buf2.Data[0] != originalAddr {
+		t.Error("buffer was not reused from pool")
+	}
+	buf2.Release()
+}
+
+func TestBufferPoolLargeBuffers(t *testing.T) {
+	// Test that buffers larger than defaultSize are not returned to pool
+	pool := newBufferPool(1024)
+	buf := pool.Get()
+
+	// Grow the buffer beyond default size
+	buf.Data = append(buf.Data, make([]byte, 2048)...)
+	originalCap := cap(buf.Data)
+
+	buf.Release()
+
+	// Get a new buffer - should not be the same slice
+	newBuf := pool.Get()
+	if cap(newBuf.Data) == originalCap {
+		t.Error("large buffer was incorrectly returned to pool")
+	}
+}