Add support for persistent file access in apps.

apps/saved_files_service_unittest.cc

Index: apps/saved_files_service_unittest.cc
diff --git a/apps/saved_files_service_unittest.cc b/apps/saved_files_service_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c7239721dedc402962657360128a7723b10ad03f
--- /dev/null
+++ b/apps/saved_files_service_unittest.cc
@@ -0,0 +1,238 @@
+// 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 <algorithm>
+
+#include "apps/saved_files_service.h"
+#include "base/files/file_path.h"
+#include "base/string_number_conversions.h"
+#include "base/test/values_test_util.h"
+#include "base/values.h"
+#include "chrome/browser/extensions/extension_prefs.h"
+#include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/extension_system.h"
+#include "chrome/browser/extensions/test_extension_environment.h"
+#include "chrome/common/extensions/extension.h"
+#include "chrome/test/base/testing_profile.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+#if !defined(OS_ANDROID)
+
+#define TRACE_CALL(expression) \
+  do {                         \
+    SCOPED_TRACE(#expression); \
+    expression;                \
+  } while (0)
+
+using apps::SavedFileEntry;
+using apps::SavedFilesService;
+
+namespace {
+
+std::string GenerateId(int i) {
+  return base::IntToString(i) + ":filename.ext";
+}
+
+}  // namespace
+
+class SavedFilesServiceUnitTest : public testing::Test {
+ protected:
+  virtual void SetUp() OVERRIDE {
+    testing::Test::SetUp();
+    extension_ = env_.MakeExtension(*base::test::ParseJson(
+        "{"
+        "  \"app\": {"
+        "    \"background\": {"
+        "      \"scripts\": [\"background.js\"]"
+        "    }"
+        "  },"
+        "  \"permissions\": ["
+        "    {\"fileSystem\": [\"retainFiles\"]}"
+        "  ]"
+        "}"));
+    service_ = SavedFilesService::Get(env_.profile());
+    path_ = base::FilePath(FILE_PATH_LITERAL("filename.ext"));
+  }
+
+  virtual void TearDown() OVERRIDE {
+    SavedFilesService::ClearMaxSequenceNumberForTest();
+    SavedFilesService::ClearLruSizeForTest();
+    testing::Test::TearDown();
+  }
+
+  // Check that a registered file entry has the correct value.
+  void CheckSavedFileEntry(int id, int sequence_number) {

[koz (OOO until 15th September), 2013/05/23 07:32:22]

I think this would be better named CheckEntrySequenceNumber(). It does a lot of
other checks but most are just opportunistic consistency checks.

[Sam McNally, 2013/05/24 00:46:03]

Done.

+    std::string id_string = GenerateId(id);
+    SCOPED_TRACE(id_string);
+    EXPECT_TRUE(service_->IsRegistered(extension_->id(), id_string));
+    const SavedFileEntry* entry =
+        service_->GetFileEntry(extension_->id(), id_string);
+    ASSERT_TRUE(entry);
+    EXPECT_EQ(id_string, entry->id);
+    EXPECT_EQ(path_, entry->path);
+    EXPECT_TRUE(entry->writable);
+    EXPECT_EQ(sequence_number, entry->sequence_number);
+  }
+
+  // Check that a range of registered file entries have the correct values.
+  void CheckSavedFileEntries(int start, int end) {

[koz (OOO until 15th September), 2013/05/23 07:32:22]

CheckRangeEnqueuedInOrder()?

[Sam McNally, 2013/05/24 00:46:03]

Done.

+    SavedFileEntry entry;
+    for (int i = start; i < end; i++) {
+      CheckSavedFileEntry(i, i + 1);
+    }
+  }

[koz (OOO until 15th September), 2013/05/23 07:32:22]

nit: newline

[Sam McNally, 2013/05/24 00:46:03]

Done.

+  extensions::TestExtensionEnvironment env_;
+  const extensions::Extension* extension_;
+  SavedFilesService* service_;
+  base::FilePath path_;
+};
+
+TEST_F(SavedFilesServiceUnitTest, RetainTwoFilesTest) {
+  service_->RegisterFileEntry(extension_->id(), GenerateId(1), path_, true);
+  service_->RegisterFileEntry(extension_->id(), GenerateId(2), path_, true);
+  service_->RegisterFileEntry(extension_->id(), GenerateId(3), path_, true);
+
+  // Test that no entry has a sequence number.
+  TRACE_CALL(CheckSavedFileEntry(1, 0));
+  TRACE_CALL(CheckSavedFileEntry(2, 0));
+  TRACE_CALL(CheckSavedFileEntry(3, 0));
+
+  // Test that only entry #1 has a sequence number.
+  service_->EnqueueFileEntry(extension_->id(), GenerateId(1));
+  TRACE_CALL(CheckSavedFileEntry(1, 1));
+  TRACE_CALL(CheckSavedFileEntry(2, 0));
+
+  // Test that entry #1 has not changed sequence number because it is the most
+  // recently enqueued entry.
+  service_->EnqueueFileEntry(extension_->id(), GenerateId(1));
+  TRACE_CALL(CheckSavedFileEntry(1, 1));
+  TRACE_CALL(CheckSavedFileEntry(2, 0));
+
+  // Test that entry #1 is unchanged and entry #2 has been assigned the next
+  // sequence number.
+  service_->EnqueueFileEntry(extension_->id(), GenerateId(2));
+  TRACE_CALL(CheckSavedFileEntry(1, 1));
+  TRACE_CALL(CheckSavedFileEntry(2, 2));
+
+  // Test that both entries #1 and #2 are unchanged because #2 is the most
+  // recently enqueued entry.
+  service_->EnqueueFileEntry(extension_->id(), GenerateId(2));
+  TRACE_CALL(CheckSavedFileEntry(1, 1));
+  TRACE_CALL(CheckSavedFileEntry(2, 2));
+
+  // Test that entry #1 has been assigned the next sequence number.
+  service_->EnqueueFileEntry(extension_->id(), GenerateId(1));
+  TRACE_CALL(CheckSavedFileEntry(1, 3));
+  TRACE_CALL(CheckSavedFileEntry(2, 2));
+  TRACE_CALL(CheckSavedFileEntry(3, 0));
+
+  EXPECT_FALSE(service_->IsRegistered(extension_->id(), "another id"));
+  SavedFileEntry entry;
+  EXPECT_FALSE(service_->GetFileEntry(extension_->id(), "another id"));
+
+  // MaybeClearQueue should be a no-op because the app has the
+  // fileSystem.retainFiles permission.
+  service_->MaybeClearQueue(extension_);
+  TRACE_CALL(CheckSavedFileEntry(1, 3));
+  TRACE_CALL(CheckSavedFileEntry(2, 2));
+  TRACE_CALL(CheckSavedFileEntry(3, 0));
+
+  // Test that after a clear, retained file entries are unchanged, but file
+  // entries that have been registered but not retained are no longer
+  // registered.
+  service_->Clear(extension_->id());
+  TRACE_CALL(CheckSavedFileEntry(1, 3));
+  TRACE_CALL(CheckSavedFileEntry(2, 2));
+  EXPECT_FALSE(service_->IsRegistered(extension_->id(), GenerateId(3)));
+}
+
+TEST_F(SavedFilesServiceUnitTest, NoRetainFilesPermissionTest) {
+  extension_ = env_.MakeExtension(*base::test::ParseJson(
+      "{\"app\": {\"background\": {\"scripts\": [\"background.js\"]}},"
+      "\"permissions\": [\"fileSystem\"]}"));
+  service_->RegisterFileEntry(extension_->id(), GenerateId(1), path_, true);
+  TRACE_CALL(CheckSavedFileEntry(1, 0));
+  SavedFileEntry entry;
+  service_->EnqueueFileEntry(extension_->id(), GenerateId(1));
+  TRACE_CALL(CheckSavedFileEntry(1, 1));
+  EXPECT_FALSE(service_->IsRegistered(extension_->id(), "another id"));
+  EXPECT_FALSE(service_->GetFileEntry(extension_->id(), "another id"));
+
+  // MaybeClearQueue should clear the queue, since the app does not have the
+  // "retainFiles" permission.
+  service_->MaybeClearQueue(extension_);
+  std::vector<SavedFileEntry> entries =
+      service_->GetAllFileEntries(extension_->id());
+  EXPECT_TRUE(entries.empty());
+}
+
+TEST_F(SavedFilesServiceUnitTest, EvictionTest) {
+  SavedFilesService::SetLruSizeForTest(10);
+  for (int i = 0; i < 10; i++) {
+    service_->RegisterFileEntry(extension_->id(), GenerateId(i), path_, true);
+    service_->EnqueueFileEntry(extension_->id(), GenerateId(i));
+  }
+  service_->RegisterFileEntry(extension_->id(), GenerateId(10), path_, true);
+
+  // Expect that entries 0 to 9 are in the queue, but 10 is not.
+  TRACE_CALL(CheckSavedFileEntries(0, 10));
+  TRACE_CALL(CheckSavedFileEntry(10, 0));
+  service_->EnqueueFileEntry(extension_->id(), GenerateId(10));
+
+  // Expect that entries 1 to 10 are in the queue, but entry 0 is not.
+  TRACE_CALL(CheckSavedFileEntry(0, 0));
+  TRACE_CALL(CheckSavedFileEntries(1, 11));
+
+  // Check that retained entries are unchanged after a clear.
+  service_->Clear(extension_->id());
+  SavedFileEntry entry;
+  EXPECT_FALSE(service_->GetFileEntry(extension_->id(), GenerateId(0)));
+  TRACE_CALL(CheckSavedFileEntries(1, 11));
+
+  // Expect that entry 2 is now at the back of the queue, and no further entries
+  // have been evicted.
+  service_->EnqueueFileEntry(extension_->id(), GenerateId(2));
+  TRACE_CALL(CheckSavedFileEntry(2, 12));
+  TRACE_CALL(CheckSavedFileEntries(1, 1));
+  TRACE_CALL(CheckSavedFileEntries(3, 11));
+
+  // Check that retained entries are unchanged after a clear.
+  service_->Clear(extension_->id());
+  TRACE_CALL(CheckSavedFileEntry(2, 12));
+  TRACE_CALL(CheckSavedFileEntries(1, 1));
+  TRACE_CALL(CheckSavedFileEntries(3, 11));
+}
+
+TEST_F(SavedFilesServiceUnitTest, SequenceNumberCompactionTest) {

[koz (OOO until 15th September), 2013/05/23 07:32:22]

Just wanted to say, these tests are awesome!

+  SavedFilesService::SetMaxSequenceNumberForTest(8);
+  SavedFilesService::SetLruSizeForTest(8);
+  for (int i = 0; i < 4; i++) {
+    service_->RegisterFileEntry(extension_->id(), GenerateId(i), path_, true);
+    service_->EnqueueFileEntry(extension_->id(), GenerateId(i));
+  }
+  service_->EnqueueFileEntry(extension_->id(), GenerateId(2));
+  service_->EnqueueFileEntry(extension_->id(), GenerateId(3));
+  service_->EnqueueFileEntry(extension_->id(), GenerateId(2));
+
+  // The sequence numbers should be sparse, as they have not gone over the
+  // limit.
+  TRACE_CALL(CheckSavedFileEntry(0, 1));
+  TRACE_CALL(CheckSavedFileEntry(1, 2));
+  TRACE_CALL(CheckSavedFileEntry(2, 7));
+  TRACE_CALL(CheckSavedFileEntry(3, 6));
+  service_->Clear(extension_->id());
+  TRACE_CALL(CheckSavedFileEntry(0, 1));
+  TRACE_CALL(CheckSavedFileEntry(1, 2));
+  TRACE_CALL(CheckSavedFileEntry(2, 7));
+  TRACE_CALL(CheckSavedFileEntry(3, 6));
+
+  // This should push the sequence number to the limit of 8, and trigger a
+  // sequence number compaction. Expect that the sequence numbers are
+  // contiguous from 1 to 4.
+  service_->EnqueueFileEntry(extension_->id(), GenerateId(3));
+  TRACE_CALL(CheckSavedFileEntries(0, 4));
+  service_->Clear(extension_->id());
+  TRACE_CALL(CheckSavedFileEntries(0, 4));
+}
+#endif