src/components/policy/core/common/cloud/rate_limiter_unittest.cc

   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 "components/policy/core/common/cloud/rate_limiter.h"
   6
   7 #include "base/bind.h"
   8 #include "base/bind_helpers.h"
   9 #include "base/test/simple_test_tick_clock.h"
  10 #include "base/test/test_simple_task_runner.h"
  11 #include "base/time/tick_clock.h"
  12 #include "testing/gtest/include/gtest/gtest.h"
  13
  14 namespace policy {
  15
  16 class RateLimiterTest : public testing::Test {
  17  public:
  18   RateLimiterTest()
  19       : task_runner_(new base::TestSimpleTaskRunner()),
  20         clock_(new base::SimpleTestTickClock()),
  21         callbacks_(0),
  22         max_requests_(5),
  23         duration_(base::TimeDelta::FromHours(1)),
  24         small_delta_(base::TimeDelta::FromMinutes(1)),
  25         limiter_(max_requests_,
  26                  duration_,
  27                  base::Bind(&RateLimiterTest::Callback, base::Unretained(this)),
  28                  task_runner_,
  29                  scoped_ptr<base::TickClock>(clock_).Pass()) {}
  30   virtual ~RateLimiterTest() {}
  31
  32  protected:
  33   void Callback() {
  34     callbacks_++;
  35   }
  36
  37   scoped_refptr<base::TestSimpleTaskRunner> task_runner_;
  38   base::SimpleTestTickClock* clock_;
  39   size_t callbacks_;
  40   const size_t max_requests_;
  41   const base::TimeDelta duration_;
  42   const base::TimeDelta small_delta_;
  43   RateLimiter limiter_;
  44 };
  45
  46 TEST_F(RateLimiterTest, LimitRequests) {
  47   size_t count = 0;
  48   for (size_t i = 0; i < max_requests_; ++i) {
  49     EXPECT_EQ(count, callbacks_);
  50     limiter_.PostRequest();
  51     ++count;
  52     EXPECT_EQ(count, callbacks_);
  53     EXPECT_TRUE(task_runner_->GetPendingTasks().empty());
  54     clock_->Advance(small_delta_);
  55   }
  56
  57   for (size_t i = 0; i < 10; ++i) {
  58     limiter_.PostRequest();
  59     EXPECT_EQ(max_requests_, callbacks_);
  60     clock_->Advance(small_delta_);
  61     EXPECT_FALSE(task_runner_->GetPendingTasks().empty());
  62   }
  63
  64   // Now advance the clock beyond the duration. The callback is invoked once.
  65   callbacks_ = 0;
  66   clock_->Advance(duration_);
  67   task_runner_->RunPendingTasks();
  68   EXPECT_EQ(1u, callbacks_);
  69   EXPECT_TRUE(task_runner_->GetPendingTasks().empty());
  70 }
  71
  72 TEST_F(RateLimiterTest, Steady) {
  73   const base::TimeDelta delta = duration_ / 2;
  74   size_t count = 0;
  75   for (int i = 0; i < 100; ++i) {
  76     EXPECT_EQ(count, callbacks_);
  77     limiter_.PostRequest();
  78     ++count;
  79     EXPECT_EQ(count, callbacks_);
  80     EXPECT_TRUE(task_runner_->GetPendingTasks().empty());
  81     clock_->Advance(delta);
  82   }
  83 }
  84
  85 TEST_F(RateLimiterTest, RetryAfterDelay) {
  86   size_t count = 0;
  87   base::TimeDelta total_delta;
  88   // Fill the queue.
  89   for (size_t i = 0; i < max_requests_; ++i) {
  90     EXPECT_EQ(count, callbacks_);
  91     limiter_.PostRequest();
  92     ++count;
  93     EXPECT_EQ(count, callbacks_);
  94     EXPECT_TRUE(task_runner_->GetPendingTasks().empty());
  95     clock_->Advance(small_delta_);
  96     total_delta += small_delta_;
  97   }
  98
  99   // Now post a request that will be delayed.
 100   EXPECT_EQ(max_requests_, callbacks_);
 101   limiter_.PostRequest();
 102   EXPECT_EQ(max_requests_, callbacks_);
 103   EXPECT_FALSE(task_runner_->GetPendingTasks().empty());
 104
 105   while (total_delta < duration_) {
 106     task_runner_->RunPendingTasks();
 107     // The queue is still full, so another task is immediately posted.
 108     EXPECT_FALSE(task_runner_->GetPendingTasks().empty());
 109     clock_->Advance(small_delta_);
 110     total_delta += small_delta_;
 111   }
 112
 113   // Now advance time beyond the initial duration. It will immediately execute
 114   // the callback.
 115   EXPECT_EQ(max_requests_, callbacks_);
 116   task_runner_->RunPendingTasks();
 117   EXPECT_TRUE(task_runner_->GetPendingTasks().empty());
 118   EXPECT_EQ(max_requests_ + 1, callbacks_);
 119 }
 120
 121 }  // namespace policy