Add a cache counter for iOS.

ios/chrome/browser/browsing_data/cache_counter_unittest.cc

Index: ios/chrome/browser/browsing_data/cache_counter_unittest.cc
diff --git a/ios/chrome/browser/browsing_data/cache_counter_unittest.cc b/ios/chrome/browser/browsing_data/cache_counter_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..da62052aa81bd84d2b709f6a62a19f9cc968e816
--- /dev/null
+++ b/ios/chrome/browser/browsing_data/cache_counter_unittest.cc
@@ -0,0 +1,326 @@
+// Copyright 2016 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.
+//
+// Note that this file only tests the basic behavior of the cache counter, as in
+// when it counts and when not, when result is nonzero and when not. It does not
+// test whether the result of the counting is correct. This is the
+// responsibility of a lower layer, and is tested in
+// DiskCacheBackendTest.CalculateSizeOfAllEntries in net_unittests.
+
+#include "ios/chrome/browser/browsing_data/cache_counter.h"
+
+#include "base/bind.h"
+#include "base/run_loop.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "base/time/time.h"
+#include "components/browsing_data/core/browsing_data_utils.h"
+#include "components/browsing_data/core/pref_names.h"
+#include "components/prefs/pref_registry_simple.h"
+#include "components/prefs/testing_pref_service.h"
+#include "ios/web/public/test/test_browser_state.h"
+#include "ios/web/public/test/test_web_thread_bundle.h"
+#include "ios/web/public/web_thread.h"
+#include "net/disk_cache/disk_cache.h"
+#include "net/http/http_cache.h"
+#include "net/http/http_transaction_factory.h"
+#include "net/url_request/url_request_context.h"
+#include "net/url_request/url_request_context_getter.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+class CacheCounterTest : public testing::Test {
+ public:
+  CacheCounterTest() {
+    prefs_.registry()->RegisterIntegerPref(
+        browsing_data::prefs::kDeleteTimePeriod,
+        static_cast<int>(browsing_data::ALL_TIME));
+    prefs_.registry()->RegisterBooleanPref(browsing_data::prefs::kDeleteCache,
+                                           true);
+
+    context_getter_ = browser_state_.GetRequestContext();
+  }
+
+  ~CacheCounterTest() override {}
+
+  web::TestBrowserState* browser_state() { return &browser_state_; }
+
+  PrefService* prefs() { return &prefs_; }
+
+  void SetCacheDeletionPref(bool value) {
+    prefs()->SetBoolean(browsing_data::prefs::kDeleteCache, value);
+  }
+
+  void SetDeletionPeriodPref(browsing_data::TimePeriod period) {
+    prefs()->SetInteger(browsing_data::prefs::kDeleteTimePeriod,
+                        static_cast<int>(period));
+  }
+
+  // Create a cache entry on the IO thread.
+  void CreateCacheEntry() {
+    current_operation_ = OPERATION_ADD_ENTRY;
+    next_step_ = STEP_GET_BACKEND;
+
+    web::WebThread::PostTask(web::WebThread::IO, FROM_HERE,
+                             base::Bind(&CacheCounterTest::CacheOperationStep,
+                                        base::Unretained(this), net::OK));
+    WaitForIOThread();
+  }
+
+  // Clear the cache on the IO thread.
+  void ClearCache() {
+    current_operation_ = OPERATION_CLEAR_CACHE;
+    next_step_ = STEP_GET_BACKEND;
+
+    web::WebThread::PostTask(web::WebThread::IO, FROM_HERE,
+                             base::Bind(&CacheCounterTest::CacheOperationStep,
+                                        base::Unretained(this), net::OK));
+    WaitForIOThread();
+  }
+
+  // Wait for IO thread operations, such as cache creation, counting, writing,
+  // deletion etc.
+  void WaitForIOThread() {
+    DCHECK_CURRENTLY_ON(web::WebThread::UI);
+    run_loop_.reset(new base::RunLoop());
+    run_loop_->Run();
+  }
+
+  // A callback method to be used by counters to report the result.
+  void CountingCallback(
+      std::unique_ptr<browsing_data::BrowsingDataCounter::Result> result) {
+    DCHECK_CURRENTLY_ON(web::WebThread::UI);
+    finished_ = result->Finished();
+
+    if (finished_) {
+      result_ =
+          static_cast<browsing_data::BrowsingDataCounter::FinishedResult*>(
+              result.get())
+              ->Value();
+    }
+
+    if (run_loop_ && finished_)
+      run_loop_->Quit();
+  }
+
+  // Get the last reported counter result.
+  browsing_data::BrowsingDataCounter::ResultInt GetResult() {
+    DCHECK(finished_);
+    return result_;
+  }
+
+ private:
+  enum CacheOperation {
+    OPERATION_ADD_ENTRY,
+    OPERATION_CLEAR_CACHE,
+  };
+
+  enum CacheEntryCreationStep {
+    STEP_GET_BACKEND,
+    STEP_CLEAR_CACHE,
+    STEP_CREATE_ENTRY,
+    STEP_WRITE_DATA,
+    STEP_CALLBACK,
+    STEP_DONE
+  };
+
+  // One step in the process of creating a cache entry or clearing the cache.
+  // Every step must be executed on IO thread after the previous one has
+  // finished.
+  void CacheOperationStep(int rv) {
+    while (rv != net::ERR_IO_PENDING && next_step_ != STEP_DONE) {
+      // The testing browser state uses a memory cache which should not cause
+      // any errors.
+      DCHECK_GE(rv, 0);
+
+      switch (next_step_) {
+        case STEP_GET_BACKEND: {
+          next_step_ = current_operation_ == OPERATION_ADD_ENTRY
+                           ? STEP_CREATE_ENTRY
+                           : STEP_CLEAR_CACHE;
+
+          net::HttpCache* http_cache = context_getter_->GetURLRequestContext()
+                                           ->http_transaction_factory()
+                                           ->GetCache();
+
+          rv = http_cache->GetBackend(
+              &backend_, base::Bind(&CacheCounterTest::CacheOperationStep,
+                                    base::Unretained(this)));
+
+          break;
+        }
+
+        case STEP_CLEAR_CACHE: {
+          next_step_ = STEP_CALLBACK;
+
+          DCHECK(backend_);
+          rv = backend_->DoomAllEntries(base::Bind(
+              &CacheCounterTest::CacheOperationStep, base::Unretained(this)));
+
+          break;
+        }
+
+        case STEP_CREATE_ENTRY: {
+          next_step_ = STEP_WRITE_DATA;
+
+          DCHECK(backend_);
+          rv = backend_->CreateEntry(
+              "entry_key", &entry_,
+              base::Bind(&CacheCounterTest::CacheOperationStep,
+                         base::Unretained(this)));
+
+          break;
+        }
+
+        case STEP_WRITE_DATA: {
+          next_step_ = STEP_CALLBACK;
+
+          std::string data = "entry data";
+          scoped_refptr<net::StringIOBuffer> buffer =
+              new net::StringIOBuffer(data);
+
+          rv = entry_->WriteData(
+              0, 0, buffer.get(), data.size(),
+              base::Bind(&CacheCounterTest::CacheOperationStep,
+                         base::Unretained(this)),
+              true);
+
+          break;
+        }
+
+        case STEP_CALLBACK: {
+          next_step_ = STEP_DONE;
+
+          if (current_operation_ == OPERATION_ADD_ENTRY)
+            entry_->Close();
+
+          web::WebThread::PostTask(
+              web::WebThread::UI, FROM_HERE,
+              base::Bind(&CacheCounterTest::Callback, base::Unretained(this)));
+
+          break;
+        }
+
+        case STEP_DONE: {
+          NOTREACHED();
+        }
+      }
+    }
+  }
+
+  // General completion callback.
+  void Callback() {
+    DCHECK_CURRENTLY_ON(web::WebThread::UI);
+    if (run_loop_)
+      run_loop_->Quit();
+  }
+
+  web::TestWebThreadBundle bundle_;
+  std::unique_ptr<base::RunLoop> run_loop_;
+
+  CacheOperation current_operation_;
+  CacheEntryCreationStep next_step_;
+
+  scoped_refptr<net::URLRequestContextGetter> context_getter_;
+  disk_cache::Backend* backend_;
+  disk_cache::Entry* entry_;
+
+  bool finished_;
+  browsing_data::BrowsingDataCounter::ResultInt result_;
+
+  web::TestBrowserState browser_state_;
+  TestingPrefServiceSimple prefs_;
+};
+
+// Tests that for the empty cache, the result is zero.
+TEST_F(CacheCounterTest, Empty) {
+  CacheCounter counter(browser_state());
+  counter.Init(prefs(), base::Bind(&CacheCounterTest::CountingCallback,
+                                   base::Unretained(this)));
+  counter.Restart();
+
+  WaitForIOThread();
+  EXPECT_EQ(0u, GetResult());
+}
+
+// Tests that for a non-empty cache, the result is nonzero, and after deleting
+// its contents, it's zero again. Note that the exact value of the result
+// is tested in DiskCacheBackendTest.CalculateSizeOfAllEntries.
+TEST_F(CacheCounterTest, BeforeAndAfterClearing) {
+  CreateCacheEntry();
+
+  CacheCounter counter(browser_state());
+  counter.Init(prefs(), base::Bind(&CacheCounterTest::CountingCallback,
+                                   base::Unretained(this)));
+  counter.Restart();
+
+  WaitForIOThread();
+  EXPECT_NE(0u, GetResult());
+
+  ClearCache();
+  counter.Restart();
+
+  WaitForIOThread();
+  EXPECT_EQ(0u, GetResult());
+}
+
+// Tests that the counter starts counting automatically when the deletion
+// pref changes to true.
+TEST_F(CacheCounterTest, PrefChanged) {
+  SetCacheDeletionPref(false);
+
+  CacheCounter counter(browser_state());
+  counter.Init(prefs(), base::Bind(&CacheCounterTest::CountingCallback,
+                                   base::Unretained(this)));
+  SetCacheDeletionPref(true);
+
+  WaitForIOThread();
+  EXPECT_EQ(0u, GetResult());
+}
+
+// Tests that the counter does not count if the deletion preference is false.
+TEST_F(CacheCounterTest, PrefIsFalse) {
+  SetCacheDeletionPref(false);
+
+  CacheCounter counter(browser_state());
+  counter.Init(prefs(), base::Bind(&CacheCounterTest::CountingCallback,
+                                   base::Unretained(this)));
+  counter.Restart();
+
+  EXPECT_FALSE(counter.pending());
+}
+
+// Tests that the counting is restarted when the time period changes. Currently,
+// the results should be the same for every period. This is because the counter
+// always counts the size of the entire cache, and it is up to the UI
+// to interpret it as exact value or upper bound.
+TEST_F(CacheCounterTest, PeriodChanged) {
+  CreateCacheEntry();
+
+  CacheCounter counter(browser_state());
+  counter.Init(prefs(), base::Bind(&CacheCounterTest::CountingCallback,
+                                   base::Unretained(this)));
+
+  SetDeletionPeriodPref(browsing_data::LAST_HOUR);
+  WaitForIOThread();
+  browsing_data::BrowsingDataCounter::ResultInt result = GetResult();
+
+  SetDeletionPeriodPref(browsing_data::LAST_DAY);
+  WaitForIOThread();
+  EXPECT_EQ(result, GetResult());
+
+  SetDeletionPeriodPref(browsing_data::LAST_WEEK);
+  WaitForIOThread();
+  EXPECT_EQ(result, GetResult());
+
+  SetDeletionPeriodPref(browsing_data::FOUR_WEEKS);
+  WaitForIOThread();
+  EXPECT_EQ(result, GetResult());
+
+  SetDeletionPeriodPref(browsing_data::ALL_TIME);
+  WaitForIOThread();
+  EXPECT_EQ(result, GetResult());
+}
+
+}  // namespace