1 files changed, 23 insertions, 0 deletions
diff --git a/internal/bufpool/class.go b/internal/bufpool/class.go
new file mode 100644
index 00000000..60842d5e
--- /dev/null
+++ b/internal/bufpool/class.go
@@ -0,0 +1,23 @@
+package bufpool
+
+var sizeClasses = [...]int{
+	DefaultBufferCap,
+	64 << 10,
+	128 << 10,
+	256 << 10,
+	512 << 10,
+	1 << 20,
+	2 << 20,
+	4 << 20,
+	maxPooledBuffer,
+}
+
+func classFor(size int) (idx, classCap int, ok bool) {
+	for i, class := range sizeClasses {
+		if size <= class {
+			return i, class, true
+		}
+	}
+
+	return -1, size, false
+}