1 // Copyright (c) 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "base/basictypes.h" 6 #include "net/quic/congestion_control/cube_root.h" 7 #include "testing/gtest/include/gtest/gtest.h" 8 9 namespace net { 10 namespace test { 11 12 class CubeRootTest : public ::testing::Test { 13 protected: 14 CubeRootTest() { 15 } 16 }; 17 18 TEST_F(CubeRootTest, LowRoot) { 19 for (uint32 i = 1; i < 256; ++i) { 20 uint64 cube = i * i * i; 21 uint8 cube_root = CubeRoot::Root(cube); 22 EXPECT_EQ(i, cube_root); 23 } 24 } 25 26 TEST_F(CubeRootTest, HighRoot) { 27 // Test the range we will opperate in, 1300 to 130 000. 28 // We expect some loss in accuracy, accepting +-0.2%. 29 for (uint64 i = 1300; i < 20000; i += 100) { 30 uint64 cube = i * i * i; 31 uint32 cube_root = CubeRoot::Root(cube); 32 uint32 margin = cube_root >> 9; // Calculate 0.2% roughly by 33 // dividing by 512. 34 EXPECT_LE(i - margin, cube_root); 35 EXPECT_GE(i + margin, cube_root); 36 } 37 for (uint64 i = 20000; i < 130000; i *= 2) { 38 uint64 cube = i * i * i; 39 uint32 cube_root = CubeRoot::Root(cube); 40 uint32 margin = cube_root >> 9; 41 EXPECT_LE(i - margin, cube_root); 42 EXPECT_GE(i + margin, cube_root); 43 } 44 } 45 46 } // namespace test 47 } // namespace net 48
