Implementing EvictedDomainCookieCounter to keep user metrics on cookie eviction and reinstatement.

chrome/browser/net/evicted_domain_cookie_counter_unittest.cc

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <string>
+#include <vector>
+
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/time.h"
+#include "chrome/browser/net/evicted_domain_cookie_counter.h"
+#include "googleurl/src/gurl.h"
+#include "net/cookies/canonical_cookie.h"
+#include "net/cookies/cookie_monster.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace chrome_browser_net {
+
+using base::Time;
+using base::TimeDelta;
+
+namespace {
+
+const char* google_url1 = "http://www.google.com";
+const char* google_url2 = "http://mail.google.com";
+const char* other_url1 = "http://www.example.com";
+const char* other_url2 = "http://www.example.co.uk";
+
+class EvictedDomainCookieCounterTest : public testing::Test {
+ protected:
+  class MockDelegate : public EvictedDomainCookieCounter::Delegate {
+   public:
+    explicit MockDelegate(EvictedDomainCookieCounterTest* tester);
+
+    // EvictedDomainCookieCounter::Delegate implementation.
+    virtual void Report(
+        const EvictedDomainCookieCounter::EvictedCookie& evicted_cookie,
+        const Time& reinstatement_time) OVERRIDE;
+    virtual Time CurrentTime() const OVERRIDE;
+
+   private:
+    EvictedDomainCookieCounterTest* tester_;
+  };
+
+  EvictedDomainCookieCounterTest();
+  virtual ~EvictedDomainCookieCounterTest();
+
+  // testing::Test implementation.
+  virtual void SetUp() OVERRIDE;
+  virtual void TearDown() OVERRIDE;
+
+  // Initialization that allows parameters to be specified.
+  void InitCounter(size_t max_size, size_t purge_count);
+
+  // Wrapper to allocate new cookie and store it in |cookies_|.
+  // If |max_age| == 0, then the cookie does not expire.
+  void CreateNewCookie(
+      const char* url, const std::string& cookie_line, int64 max_age);
+
+  // Clears |cookies_| and creates common cookies for multiple tests.
+  void InitStockCookies();
+
+  // Sets simulation time to |rel_time|.
+  void GotoTime(int64 rel_time);
+
+  // Simulates time-passage by |delta_second|.
+  void StepTime(int64 delta_second);
+
+  // Simulates cookie addition or update.
+  void Add(net::CanonicalCookie* cookie);
+
+  // Simulates cookie removal.
+  void Remove(net::CanonicalCookie* cookie);
+
+  // Simulates cookie eviction.
+  void Evict(net::CanonicalCookie* cookie);
+
+  // For semi-realism, time considered are relative to |mock_time_base_|.
+  Time mock_time_base_;
+  Time mock_time_;
+
+  // To store allocated cookies for reuse.
+  ScopedVector<net::CanonicalCookie> cookies_;
+
+  scoped_refptr<EvictedDomainCookieCounter> cookie_counter_;
+
+  // Statistics as comma-separated string of duration (in seconds) between
+  // eviction and reinstatement for each cookie, in the order of eviction.
+  std::string google_stat_;
+  std::string other_stat_;
+};
+
+EvictedDomainCookieCounterTest::MockDelegate::MockDelegate(
+    EvictedDomainCookieCounterTest* tester)
+    : tester_(tester) {}
+
+void EvictedDomainCookieCounterTest::MockDelegate::Report(
+    const EvictedDomainCookieCounter::EvictedCookie& evicted_cookie,
+    const Time& reinstatement_time) {
+  std::string& dest = evicted_cookie.is_google ?
+      tester_->google_stat_ : tester_->other_stat_;
+  if (!dest.empty())
+    dest.append(",");
+  TimeDelta delta(reinstatement_time - evicted_cookie.eviction_time);
+  dest.append(base::Int64ToString(delta.InSeconds()));
+}
+
+Time EvictedDomainCookieCounterTest::MockDelegate::CurrentTime() const {
+  return tester_->mock_time_;
+}
+
+EvictedDomainCookieCounterTest::EvictedDomainCookieCounterTest() {}
+
+EvictedDomainCookieCounterTest::~EvictedDomainCookieCounterTest() {}
+
+void EvictedDomainCookieCounterTest::SetUp() {
+  mock_time_base_ = Time::Now() - TimeDelta::FromHours(1);
+  mock_time_ = mock_time_base_;
+}
+
+void EvictedDomainCookieCounterTest::TearDown() {
+}
+
+void EvictedDomainCookieCounterTest::InitCounter(size_t max_size,
+                                                 size_t purge_count) {
+  scoped_ptr<MockDelegate> cookie_counter_delegate(new MockDelegate(this));
+  cookie_counter_ = new EvictedDomainCookieCounter(
+      NULL,
+      cookie_counter_delegate.PassAs<EvictedDomainCookieCounter::Delegate>(),
+      max_size,
+      purge_count);
+}
+
+void EvictedDomainCookieCounterTest::CreateNewCookie(
+    const char* url, const std::string& cookie_line, int64 max_age) {
+  std::string line(cookie_line);
+  if (max_age)
+    line.append(";max-age=" + base::Int64ToString(max_age));
+  net::CanonicalCookie* cookie = net::CanonicalCookie::Create(
+      GURL(url), line, mock_time_, net::CookieOptions());
+  DCHECK(cookie);
+  cookies_.push_back(cookie);
+}
+
+void EvictedDomainCookieCounterTest::InitStockCookies() {
+  cookies_.clear();
+  CreateNewCookie(google_url1, "a1=1", 3000);           // cookies_[0].
+  CreateNewCookie(google_url2, "a2=1", 2000);           // cookies_[1].
+  CreateNewCookie(other_url1, "a1=1", 1000);            // cookies_[2].
+  CreateNewCookie(other_url1, "a2=1", 1001);            // cookies_[3].
+  CreateNewCookie(google_url1, "a1=1;Path=/sub", 999);  // cookies_[4].
+  CreateNewCookie(other_url2, "a2=1", 0);               // cookies_[5].
+}
+
+void EvictedDomainCookieCounterTest::GotoTime(int64 rel_time) {
+  mock_time_ = mock_time_base_ + TimeDelta::FromSeconds(rel_time);
+}
+
+void EvictedDomainCookieCounterTest::StepTime(int64 delta_second) {
+  mock_time_ += TimeDelta::FromSeconds(delta_second);
+}
+
+void EvictedDomainCookieCounterTest::Add(net::CanonicalCookie* cookie) {
+  cookie_counter_->OnCookieChanged(
+      *cookie, false, net::CookieMonster::Delegate::CHANGE_COOKIE_EXPLICIT);
+}
+
+void EvictedDomainCookieCounterTest::Remove(net::CanonicalCookie* cookie) {
+  cookie_counter_->OnCookieChanged(
+      *cookie, true, net::CookieMonster::Delegate::CHANGE_COOKIE_EXPLICIT);
+}
+
+void EvictedDomainCookieCounterTest::Evict(net::CanonicalCookie* cookie) {
+  cookie_counter_->OnCookieChanged(
+      *cookie, true, net::CookieMonster::Delegate::CHANGE_COOKIE_EVICTED);
+}
+
+// EvictedDomainCookieCounter takes (and owns) a CookieMonster::Delegate for
+// chaining. To ensure that the chaining indeed occurs, we implement a
+// dummy CookieMonster::Delegate to increment an integer.
+TEST_F(EvictedDomainCookieCounterTest, TestChain) {
+  int result = 0;
+
+  class ChangedDelegateDummy : public net::CookieMonster::Delegate {
+   public:
+    explicit ChangedDelegateDummy(int* result) : result_(result) {}
+
+    virtual void OnCookieChanged(const net::CanonicalCookie& cookie,
+                                 bool removed,
+                                 ChangeCause cause) OVERRIDE {
+      ++(*result_);
+    }
+
+   private:
+    virtual ~ChangedDelegateDummy() {}
+
+    int* result_;
+  };
+
+  scoped_ptr<MockDelegate> cookie_counter_delegate(new MockDelegate(this));
+  cookie_counter_ = new EvictedDomainCookieCounter(
+      new ChangedDelegateDummy(&result),
+      cookie_counter_delegate.PassAs<EvictedDomainCookieCounter::Delegate>(),
+      10,
+      5);
+  InitStockCookies();
+  // Perform 6 cookie transactions.
+  for (int i = 0; i < 6; ++i) {
+    Add(cookies_[i]);
+    StepTime(1);
+    Evict(cookies_[i]);
+    StepTime(1);
+    Remove(cookies_[i]);
+  }
+  EXPECT_EQ(18, result);  // 6 cookies x 3 operations each.
+}
+
+// Basic flow: add cookies, evict, then reinstate.
+TEST_F(EvictedDomainCookieCounterTest, TestBasicFlow) {
+  InitCounter(10, 4);
+  InitStockCookies();
+  // Add all cookies at (relative time) t = 0.
+  for (int i = 0; i < 6; ++i)
+    Add(cookies_[i]);
+  EXPECT_EQ(0u, cookie_counter_->GetStorageSize());  // No activities on add.
+  EXPECT_EQ(";", google_stat_ + ";" + other_stat_);
+  // Evict cookies at t = [1,3,6,10,15,21].
+  for (int i = 0; i < 6; ++i) {
+    StepTime(i + 1);
+    Evict(cookies_[i]);
+  }
+  EXPECT_EQ(6u, cookie_counter_->GetStorageSize());  // Storing all evictions.
+  EXPECT_EQ(";", google_stat_ + ";" + other_stat_);
+  // Reinstate cookies at t = [22,23,24,25,26,27].
+  for (int i = 0; i < 6; ++i) {
+    StepTime(1);
+    Add(cookies_[i]);
+  }
+  EXPECT_EQ(0u, cookie_counter_->GetStorageSize());  // Everything is removed.
+  // Expected reinstatement delays: [21,20,18,15,11,6].
+  EXPECT_EQ("21,20,11;18,15,6", google_stat_ + ";" + other_stat_);
+}
+
+// Removed cookies are ignored by EvictedDomainCookieCounter.
+TEST_F(EvictedDomainCookieCounterTest, TestRemove) {
+  InitCounter(10, 4);
+  InitStockCookies();
+  // Add all cookies at (relative time) t = 0.
+  for (int i = 0; i < 6; ++i)
+    Add(cookies_[i]);
+  // Remove cookies at t = [1,3,6,10,15,21].
+  for (int i = 0; i < 6; ++i) {
+    StepTime(i + 1);
+    Remove(cookies_[i]);
+  }
+  EXPECT_EQ(0u, cookie_counter_->GetStorageSize());
+  // Add cookies again at t = [22,23,24,25,26,27].
+  for (int i = 0; i < 5; ++i) {
+    StepTime(1);
+    Add(cookies_[i]);
+  }
+  EXPECT_EQ(0u, cookie_counter_->GetStorageSize());
+  // No cookies were evicted, so no reinstatement take place.
+  EXPECT_EQ(";", google_stat_ + ";" + other_stat_);
+}
+
+// Expired cookies should not be counted by EvictedDomainCookieCounter.
+TEST_F(EvictedDomainCookieCounterTest, TestExpired) {
+  InitCounter(10, 4);
+  InitStockCookies();
+  // Add all cookies at (relative time) t = 0.
+  for (int i = 0; i < 6; ++i)
+    Add(cookies_[i]);
+  // Evict cookies at t = [1,3,6,10,15,21].
+  for (int i = 0; i < 6; ++i) {
+    StepTime(i + 1);
+    Evict(cookies_[i]);
+  }
+  EXPECT_EQ(6u, cookie_counter_->GetStorageSize());
+  GotoTime(1000);  // t = 1000, so cookies_[2,4] expire.
+
+  // Reinstate cookies at t = [1000,1000,(1000),1000,(1000),1000].
+  InitStockCookies();  // Refresh cookies, so new cookies expire in the future.
+  for (int i = 0; i < 6; ++i)
+    Add(cookies_[i]);
+  EXPECT_EQ(0u, cookie_counter_->GetStorageSize());
+  // Reinstatement delays: [999,997,(994),990,(985),979].
+  EXPECT_EQ("999,997;990,979", google_stat_ + ";" + other_stat_);
+}
+
+// Garbage collection should remove the oldest evicted cookies.
+TEST_F(EvictedDomainCookieCounterTest, TestGarbageCollection) {
+  InitCounter(4, 2);  // Reduced capacity.
+  InitStockCookies();
+  // Add all cookies at (relative time) t = 0.
+  for (int i = 0; i < 6; ++i)
+    Add(cookies_[i]);
+  // Evict cookies at t = [1,3,6,10].
+  for (int i = 0; i < 4; ++i) {
+    StepTime(i + 1);
+    Evict(cookies_[i]);
+  }
+  EXPECT_EQ(4u, cookie_counter_->GetStorageSize());  // Reached capacity.
+  StepTime(5);
+  Evict(cookies_[4]);  // Evict at t = 15, garbage collection takes place.
+  EXPECT_EQ(2u, cookie_counter_->GetStorageSize());
+  StepTime(6);
+  Evict(cookies_[5]);  // Evict at t = 21.
+  EXPECT_EQ(3u, cookie_counter_->GetStorageSize());
+  EXPECT_EQ(";", google_stat_ + ";" + other_stat_);
+  // Reinstate cookies at t = [(100),(100),(100),100,100,100].
+  GotoTime(100);
+  for (int i = 0; i < 6; ++i)
+    Add(cookies_[i]);
+  // Expected reinstatement delays: [(99),(97),(94),90,85,79]
+  EXPECT_EQ("85;90,79", google_stat_ + ";" + other_stat_);
+}
+
+// Garbage collection should remove the specified number of evicted cookies
+// even when there are ties amongst oldest evicted cookies.
+TEST_F(EvictedDomainCookieCounterTest, TestGarbageCollectionTie) {
+  InitCounter(9, 3);
+  // Add 10 cookies at time [0,1,3,6,...,45]
+  for (int i = 0; i < 10; ++i) {
+    StepTime(i);
+    CreateNewCookie(google_url1, "a" + base::IntToString(i) + "=1", 3000);
+    Add(cookies_[i]);
+  }
+  // Evict 6 cookies at t = [100,...,100].
+  GotoTime(100);
+  for (int i = 0; i < 6; ++i)
+    Evict(cookies_[i]);
+  EXPECT_EQ(6u, cookie_counter_->GetStorageSize());
+  // Evict 3 cookies at t = [210,220,230].
+  GotoTime(200);
+  for (int i = 6; i < 9; ++i) {
+    StepTime(10);
+    Evict(cookies_[i]);
+  }
+  EXPECT_EQ(9u, cookie_counter_->GetStorageSize());  // Reached capacity.
+  // Evict 1 cookie at t = 300, and garbage collection takes place.
+  GotoTime(300);
+  Evict(cookies_[9]);
+  // Some arbitrary 4 out of 6 cookies evicted at t = 100 are gone from storage.
+  EXPECT_EQ(6u, cookie_counter_->GetStorageSize());  // 10 - 4.
+  // Reinstate cookies at t = [400,...,400].
+  GotoTime(400);
+  for (int i = 0; i < 10; ++i)
+    Add(cookies_[i]);
+  EXPECT_EQ(0u, cookie_counter_->GetStorageSize());
+  // Expected reinstatement delays:
+  // [300,300,300,300,300,300 <= keeping 2 only,190,180,170,100].
+  EXPECT_EQ("300,300,190,180,170,100;", google_stat_ + ";" + other_stat_);
+}
+
+// Garbage collection prioritize removal of expired cookies.
+TEST_F(EvictedDomainCookieCounterTest, TestGarbageCollectionWithExpiry) {
+  InitCounter(5, 1);
+  InitStockCookies();
+  // Add all cookies at (relative time) t = 0.
+  for (int i = 0; i < 6; ++i)
+    Add(cookies_[i]);
+  // Evict cookies at t = [1,3,6,10,15].
+  for (int i = 0; i < 5; ++i) {
+    StepTime(i + 1);
+    Evict(cookies_[i]);
+  }
+  EXPECT_EQ(5u, cookie_counter_->GetStorageSize());  // Reached capacity.
+  GotoTime(1200);  // t = 1200, so cookies_[2,3,4] expire.
+  // Evict cookies_[5] (not expired) at t = 1200.
+  Evict(cookies_[5]);
+  // Garbage collection would have taken place, removing 3 expired cookies,
+  // so that there's no need to remove more.
+  EXPECT_EQ(3u, cookie_counter_->GetStorageSize());
+  // Reinstate cookies at t = [1500,1500,(1500),(1500),(1500),1500].
+  GotoTime(1500);
+  InitStockCookies();  // Refresh cookies, so new cookies expire in the future.
+  for (int i = 0; i < 6; ++i)
+    Add(cookies_[i]);
+  EXPECT_EQ(0u, cookie_counter_->GetStorageSize());
+  // Reinstatement delays: [1499,1497,(1494),(1490),(1485),300].
+  EXPECT_EQ("1499,1497;300", google_stat_ + ";" + other_stat_);
+}
+
+}  // namespace
+
+}  // namespace chrome_browser_net