Add support for persistent file access in apps.

This replaces chrome.fileSystem.getEntry(By)Id with retainEntry,
restoreEntry and isRestorable, which enable restoring file access after
an app is closed for apps with the fileSystem.retainFiles permission.
Retained files are evicted by LRU, with a maximum of 500 retained files.

BUG=224684

Review URL: https://chromiumcodereview.appspot.com/14607023

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@202276 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 239 insertions, 0 deletions

diff --git a/apps/saved_files_service_unittest.cc b/apps/saved_files_service_unittest.cc
new file mode 100644
index 0000000..4d31485
--- /dev/null
+++ b/apps/saved_files_service_unittest.cc
@@ -0,0 +1,239 @@
+// 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 CheckEntrySequenceNumber(int id, int sequence_number) {
+    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 CheckRangeEnqueuedInOrder(int start, int end) {
+    SavedFileEntry entry;
+    for (int i = start; i < end; i++) {
+      CheckEntrySequenceNumber(i, i + 1);
+    }
+  }
+
+  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(CheckEntrySequenceNumber(1, 0));
+  TRACE_CALL(CheckEntrySequenceNumber(2, 0));
+  TRACE_CALL(CheckEntrySequenceNumber(3, 0));
+
+  // Test that only entry #1 has a sequence number.
+  service_->EnqueueFileEntry(extension_->id(), GenerateId(1));
+  TRACE_CALL(CheckEntrySequenceNumber(1, 1));
+  TRACE_CALL(CheckEntrySequenceNumber(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(CheckEntrySequenceNumber(1, 1));
+  TRACE_CALL(CheckEntrySequenceNumber(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(CheckEntrySequenceNumber(1, 1));
+  TRACE_CALL(CheckEntrySequenceNumber(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(CheckEntrySequenceNumber(1, 1));
+  TRACE_CALL(CheckEntrySequenceNumber(2, 2));
+
+  // Test that entry #1 has been assigned the next sequence number.
+  service_->EnqueueFileEntry(extension_->id(), GenerateId(1));
+  TRACE_CALL(CheckEntrySequenceNumber(1, 3));
+  TRACE_CALL(CheckEntrySequenceNumber(2, 2));
+  TRACE_CALL(CheckEntrySequenceNumber(3, 0));
+
+  EXPECT_FALSE(service_->IsRegistered(extension_->id(), "another id"));
+  SavedFileEntry entry;
+  EXPECT_FALSE(service_->GetFileEntry(extension_->id(), "another id"));
+
+  // ClearQueueIfNoRetainPermission should be a no-op because the app has the
+  // fileSystem.retainFiles permission.
+  service_->ClearQueueIfNoRetainPermission(extension_);
+  TRACE_CALL(CheckEntrySequenceNumber(1, 3));
+  TRACE_CALL(CheckEntrySequenceNumber(2, 2));
+  TRACE_CALL(CheckEntrySequenceNumber(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(CheckEntrySequenceNumber(1, 3));
+  TRACE_CALL(CheckEntrySequenceNumber(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(CheckEntrySequenceNumber(1, 0));
+  SavedFileEntry entry;
+  service_->EnqueueFileEntry(extension_->id(), GenerateId(1));
+  TRACE_CALL(CheckEntrySequenceNumber(1, 1));
+  EXPECT_FALSE(service_->IsRegistered(extension_->id(), "another id"));
+  EXPECT_FALSE(service_->GetFileEntry(extension_->id(), "another id"));
+
+  // ClearQueueIfNoRetainPermission should clear the queue, since the app does
+  // not have the "retainFiles" permission.
+  service_->ClearQueueIfNoRetainPermission(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(CheckRangeEnqueuedInOrder(0, 10));
+  TRACE_CALL(CheckEntrySequenceNumber(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(CheckEntrySequenceNumber(0, 0));
+  TRACE_CALL(CheckRangeEnqueuedInOrder(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(CheckRangeEnqueuedInOrder(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(CheckEntrySequenceNumber(2, 12));
+  TRACE_CALL(CheckRangeEnqueuedInOrder(1, 1));
+  TRACE_CALL(CheckRangeEnqueuedInOrder(3, 11));
+
+  // Check that retained entries are unchanged after a clear.
+  service_->Clear(extension_->id());
+  TRACE_CALL(CheckEntrySequenceNumber(2, 12));
+  TRACE_CALL(CheckRangeEnqueuedInOrder(1, 1));
+  TRACE_CALL(CheckRangeEnqueuedInOrder(3, 11));
+}
+
+TEST_F(SavedFilesServiceUnitTest, SequenceNumberCompactionTest) {
+  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(CheckEntrySequenceNumber(0, 1));
+  TRACE_CALL(CheckEntrySequenceNumber(1, 2));
+  TRACE_CALL(CheckEntrySequenceNumber(2, 7));
+  TRACE_CALL(CheckEntrySequenceNumber(3, 6));
+  service_->Clear(extension_->id());
+  TRACE_CALL(CheckEntrySequenceNumber(0, 1));
+  TRACE_CALL(CheckEntrySequenceNumber(1, 2));
+  TRACE_CALL(CheckEntrySequenceNumber(2, 7));
+  TRACE_CALL(CheckEntrySequenceNumber(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(CheckRangeEnqueuedInOrder(0, 4));
+  service_->Clear(extension_->id());
+  TRACE_CALL(CheckRangeEnqueuedInOrder(0, 4));
+}
+#endif