media/cast/net/frame_id_wrap_helper_test.cc

   1 // Copyright 2014 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 <gtest/gtest.h>
   6 #include "media/cast/cast_defines.h"
   7 #include "media/cast/net/cast_transport_defines.h"
   8
   9 namespace media {
  10 namespace cast {
  11
  12 class FrameIdWrapHelperTest : public ::testing::Test {
  13  protected:
  14   FrameIdWrapHelperTest() {}
  15   ~FrameIdWrapHelperTest() override {}
  16
  17   void RunOneTest(uint32 starting_point, int iterations) {
  18     const int window_size = 127;
  19     uint32 window_base = starting_point;
  20     frame_id_wrap_helper_.largest_frame_id_seen_ = starting_point;
  21     for (int i = 0; i < iterations; i++) {
  22       uint32 largest_frame_id_seen =
  23           frame_id_wrap_helper_.largest_frame_id_seen_;
  24       int offset = rand() % window_size;
  25       uint32 frame_id = window_base + offset;
  26       uint32 mapped_frame_id =
  27           frame_id_wrap_helper_.MapTo32bitsFrameId(frame_id & 0xff);
  28       EXPECT_EQ(frame_id, mapped_frame_id)
  29           << " Largest ID seen: " << largest_frame_id_seen
  30           << " Window base: " << window_base
  31           << " Offset: " << offset;
  32       window_base = frame_id;
  33     }
  34   }
  35
  36   FrameIdWrapHelper frame_id_wrap_helper_;
  37
  38   DISALLOW_COPY_AND_ASSIGN(FrameIdWrapHelperTest);
  39 };
  40
  41 TEST_F(FrameIdWrapHelperTest, FirstFrame) {
  42   EXPECT_EQ(kStartFrameId, frame_id_wrap_helper_.MapTo32bitsFrameId(255u));
  43 }
  44
  45 TEST_F(FrameIdWrapHelperTest, Rollover) {
  46   uint32 new_frame_id = 0u;
  47   for (int i = 0; i <= 256; ++i) {
  48     new_frame_id =
  49         frame_id_wrap_helper_.MapTo32bitsFrameId(static_cast<uint8>(i));
  50   }
  51   EXPECT_EQ(256u, new_frame_id);
  52 }
  53
  54 TEST_F(FrameIdWrapHelperTest, OutOfOrder) {
  55   uint32 new_frame_id = 0u;
  56   for (int i = 0; i < 255; ++i) {
  57     new_frame_id =
  58         frame_id_wrap_helper_.MapTo32bitsFrameId(static_cast<uint8>(i));
  59   }
  60   EXPECT_EQ(254u, new_frame_id);
  61   new_frame_id = frame_id_wrap_helper_.MapTo32bitsFrameId(0u);
  62   EXPECT_EQ(256u, new_frame_id);
  63   new_frame_id = frame_id_wrap_helper_.MapTo32bitsFrameId(255u);
  64   EXPECT_EQ(255u, new_frame_id);
  65   new_frame_id = frame_id_wrap_helper_.MapTo32bitsFrameId(1u);
  66   EXPECT_EQ(257u, new_frame_id);
  67 }
  68
  69 TEST_F(FrameIdWrapHelperTest, Windowed) {
  70   srand(0);
  71   for (int i = 0; i < 50000 && !HasFailure(); i++) {
  72     RunOneTest(i * 4711, 20);
  73     // Test wrap-around scenarios.
  74     RunOneTest(0x7fffff00ul, 20);
  75     RunOneTest(0xffffff00ul, 20);
  76   }
  77 }
  78
  79 }  // namespace cast
  80 }  // namespace media