bench: Three ways to process a byte buffer.

tests/bench/bytebuf-1-inplace.py

+# Doing some operation on bytearray
+# Inplace - the most memory efficient way
+import bench
+
+def test(num):
+    for i in iter(range(num//10000)):
+        ba = bytearray(b"\0" * 1000)
+        for i in range(len(ba)):
+            ba[i] += 1
+
+bench.run(test)

tests/bench/bytebuf-2-join_map_bytes.py

+# Doing some operation on bytearray
+# Pretty weird way - map bytearray thru function, but make sure that
+# function return bytes of size 1, then join them together. Surely,
+# this is slowest way to do it.
+import bench
+
+def test(num):
+    for i in iter(range(num//10000)):
+        ba = bytearray(b"\0" * 1000)
+        ba2 = b''.join(map(lambda x:bytes([x + 1]), ba))
+
+bench.run(test)

tests/bench/bytebuf-3-bytarray_map.py

+# Doing some operation on bytearray
+# No joins, but still map().
+import bench
+
+def test(num):
+    for i in iter(range(num//10000)):
+        ba = bytearray(b"\0" * 1000)
+        ba2 = bytearray(map(lambda x: x + 1, ba))
+
+bench.run(test)