From d8b6b06e70718e4fd9bde65d6c5951860e7affae Mon Sep 17 00:00:00 2001
From: Evan Shrubsole <eshr@webrtc.org>
Date: Thu, 12 Jan 2023 12:28:10 +0000
Subject: [PATCH] [Unwrap] Delete rtc::TimestampWrapAroundHandler

Bug: webrtc:13982
Change-Id: Ia2999e952a55d97dbd69ff19cf12c8f712b1a62f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/290882
Commit-Queue: Evan Shrubsole <eshr@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#39087}
---
 rtc_base/time_utils.cc          | 22 --------------
 rtc_base/time_utils.h           | 11 -------
 rtc_base/time_utils_unittest.cc | 53 ---------------------------------
 3 files changed, 86 deletions(-)

diff --git a/rtc_base/time_utils.cc b/rtc_base/time_utils.cc
index 96282f06cf..78434536e1 100644
--- a/rtc_base/time_utils.cc
+++ b/rtc_base/time_utils.cc
@@ -175,28 +175,6 @@ int64_t TimeDiff(int64_t later, int64_t earlier) {
   return later - earlier;
 }
 
-TimestampWrapAroundHandler::TimestampWrapAroundHandler()
-    : last_ts_(0), num_wrap_(-1) {}
-
-int64_t TimestampWrapAroundHandler::Unwrap(uint32_t ts) {
-  if (num_wrap_ == -1) {
-    last_ts_ = ts;
-    num_wrap_ = 0;
-    return ts;
-  }
-
-  if (ts < last_ts_) {
-    if (last_ts_ >= 0xf0000000 && ts < 0x0fffffff)
-      ++num_wrap_;
-  } else if ((ts - last_ts_) > 0xf0000000) {
-    // Backwards wrap. Unwrap with last wrap count and don't update last_ts_.
-    return ts + (num_wrap_ - 1) * (int64_t{1} << 32);
-  }
-
-  last_ts_ = ts;
-  return ts + (num_wrap_ << 32);
-}
-
 int64_t TmToSeconds(const tm& tm) {
   static short int mdays[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
   static short int cumul_mdays[12] = {0,   31,  59,  90,  120, 151,
diff --git a/rtc_base/time_utils.h b/rtc_base/time_utils.h
index 6a3cfda3d1..271c1d6e93 100644
--- a/rtc_base/time_utils.h
+++ b/rtc_base/time_utils.h
@@ -114,17 +114,6 @@ inline int64_t TimeUntil(int64_t later) {
   return later - TimeMillis();
 }
 
-class TimestampWrapAroundHandler {
- public:
-  TimestampWrapAroundHandler();
-
-  int64_t Unwrap(uint32_t ts);
-
- private:
-  uint32_t last_ts_;
-  int64_t num_wrap_;
-};
-
 // Convert from tm, which is relative to 1900-01-01 00:00 to number of
 // seconds from 1970-01-01 00:00 ("epoch"). Don't return time_t since that
 // is still 32 bits on many systems.
diff --git a/rtc_base/time_utils_unittest.cc b/rtc_base/time_utils_unittest.cc
index abd44660b2..09fb816636 100644
--- a/rtc_base/time_utils_unittest.cc
+++ b/rtc_base/time_utils_unittest.cc
@@ -63,59 +63,6 @@ TEST(TimeTest, TestTimeDiff64) {
   EXPECT_EQ(-ts_diff, rtc::TimeDiff(ts_earlier, ts_later));
 }
 
-class TimestampWrapAroundHandlerTest : public ::testing::Test {
- public:
-  TimestampWrapAroundHandlerTest() {}
-
- protected:
-  TimestampWrapAroundHandler wraparound_handler_;
-};
-
-TEST_F(TimestampWrapAroundHandlerTest, Unwrap) {
-  // Start value.
-  int64_t ts = 2;
-  EXPECT_EQ(ts,
-            wraparound_handler_.Unwrap(static_cast<uint32_t>(ts & 0xffffffff)));
-
-  // Wrap backwards.
-  ts = -2;
-  EXPECT_EQ(ts,
-            wraparound_handler_.Unwrap(static_cast<uint32_t>(ts & 0xffffffff)));
-
-  // Forward to 2 again.
-  ts = 2;
-  EXPECT_EQ(ts,
-            wraparound_handler_.Unwrap(static_cast<uint32_t>(ts & 0xffffffff)));
-
-  // Max positive skip ahead, until max value (0xffffffff).
-  for (uint32_t i = 0; i <= 0xf; ++i) {
-    ts = (i << 28) + 0x0fffffff;
-    EXPECT_EQ(
-        ts, wraparound_handler_.Unwrap(static_cast<uint32_t>(ts & 0xffffffff)));
-  }
-
-  // Wrap around.
-  ts += 2;
-  EXPECT_EQ(ts,
-            wraparound_handler_.Unwrap(static_cast<uint32_t>(ts & 0xffffffff)));
-
-  // Max wrap backward...
-  ts -= 0x0fffffff;
-  EXPECT_EQ(ts,
-            wraparound_handler_.Unwrap(static_cast<uint32_t>(ts & 0xffffffff)));
-
-  // ...and back again.
-  ts += 0x0fffffff;
-  EXPECT_EQ(ts,
-            wraparound_handler_.Unwrap(static_cast<uint32_t>(ts & 0xffffffff)));
-}
-
-TEST_F(TimestampWrapAroundHandlerTest, NoNegativeStart) {
-  int64_t ts = 0xfffffff0;
-  EXPECT_EQ(ts,
-            wraparound_handler_.Unwrap(static_cast<uint32_t>(ts & 0xffffffff)));
-}
-
 class TmToSeconds : public ::testing::Test {
  public:
   TmToSeconds() {