[Paint Preview] File Manager

This CL introduces a FileManager class for managing the top level
paint_preview/ directory and the immediate per-url subdirectories.
All creation/deletion of these directories should occur through this
class. However, files within the per-url subdirectories can be modified
by any component of paint_preview (primarily the capture and
compositing code).

This class will be an integral component of a higher level manager
class. The manager will call into this class when it needs to perform
a capture or do deletion.

Bug: 1010042
Change-Id: I7b45a8f730837fcc1d0262ab0dcf3c89698974f8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1833289
Commit-Queue: Calder Kitagawa <ckitagawa@chromium.org>
Reviewed-by: Ian Vollick <vollick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#701702}

components/BUILD.gn

@@ -241,6 +241,7 @@ test("components_unittests") {
       "//components/page_image_annotation/core:unit_tests",
       "//components/page_load_metrics/browser:unit_tests",
       "//components/page_load_metrics/renderer:unit_tests",
+      "//components/paint_preview/browser:unit_tests",
       "//components/paint_preview/common:unit_tests",
       "//components/password_manager/content/browser:unit_tests",
       "//components/payments/content:unit_tests",

components/paint_preview/browser/BUILD.gn

+# Copyright 2019 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.
+
+import("//testing/test.gni")
+
+if (!is_ios) {
+  static_library("browser") {
+    sources = [
+      "file_manager.cc",
+      "file_manager.h",
+    ]
+
+    deps = [
+      "//base",
+      "//url",
+    ]
+  }
+
+  source_set("unit_tests") {
+    testonly = true
+
+    sources = [
+      "file_manager_unittest.cc",
+    ]
+
+    deps = [
+      ":browser",
+      "//base",
+      "//base/test:test_support",
+      "//testing/gmock",
+      "//testing/gtest",
+      "//url",
+    ]
+  }
+
+  test("paint_preview_browser_unit_tests") {
+    deps = [
+      ":unit_tests",
+      "//base",
+      "//base/test:test_support",
+      "//components/test:run_all_unittests",
+    ]
+  }
+}

components/paint_preview/browser/file_manager.cc

+// Copyright 2019 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 "components/paint_preview/browser/file_manager.h"
+
+#include "base/files/file_enumerator.h"
+#include "base/files/file_util.h"
+#include "base/hash/hash.h"
+#include "base/strings/strcat.h"
+#include "base/strings/string_number_conversions.h"
+
+namespace paint_preview {
+
+namespace {
+
+constexpr char kPaintPreviewDirname[] = "paint_preview";
+
+std::string HashToHex(const GURL& url) {
+  uint32_t hash = base::PersistentHash(url.spec());
+  return base::HexEncode(&hash, sizeof(uint32_t));
+}
+
+}  // namespace
+
+FileManager::FileManager(const base::FilePath& root_directory)
+    : root_directory_(root_directory.AppendASCII(kPaintPreviewDirname)) {}
+FileManager::~FileManager() = default;
+
+size_t FileManager::GetSizeOfArtifactsFor(const GURL& url) {
+  return base::ComputeDirectorySize(
+      root_directory_.AppendASCII(HashToHex(url)));
+}
+
+bool FileManager::GetCreatedTime(const GURL& url, base::Time* created_time) {
+  base::File::Info info;
+  if (!base::GetFileInfo(root_directory_.AppendASCII(HashToHex(url)), &info))
+    return false;
+  *created_time = info.creation_time;
+  return true;
+}
+
+bool FileManager::GetLastAccessedTime(const GURL& url,
+                                      base::Time* last_accessed_time) {
+  return LastAccessedTimeInternal(root_directory_.AppendASCII(HashToHex(url)),
+                                  last_accessed_time);
+}
+
+bool FileManager::CreateOrGetDirectoryFor(const GURL& url,
+                                          base::FilePath* directory) {
+  base::FilePath path = root_directory_.AppendASCII(HashToHex(url));
+  base::File::Error error = base::File::FILE_OK;
+  if (base::CreateDirectoryAndGetError(path, &error)) {
+    *directory = path;
+    return true;
+  }
+  DLOG(ERROR) << "Error failed to create directory: " << path
+              << " with error code " << error;
+  return false;
+}
+
+void FileManager::DeleteArtifactsFor(const std::vector<GURL>& urls) {
+  for (const auto& url : urls)
+    base::DeleteFile(root_directory_.AppendASCII(HashToHex(url)), true);
+}
+
+void FileManager::DeleteAll() {
+  base::DeleteFile(root_directory_, true);
+}
+
+void FileManager::DeleteAllOlderThan(base::Time deletion_time) {
+  std::vector<base::FilePath> dirs_to_delete;
+  base::FileEnumerator enumerator(root_directory_, false,
+                                  base::FileEnumerator::DIRECTORIES);
+  base::Time last_accessed_time;
+  for (base::FilePath dir = enumerator.Next(); !dir.empty();
+       dir = enumerator.Next()) {
+    if (!LastAccessedTimeInternal(dir, &last_accessed_time))
+      continue;
+    if (last_accessed_time < deletion_time)
+      dirs_to_delete.push_back(dir);
+  }
+  for (const auto& dir : dirs_to_delete)
+    base::DeleteFile(dir, true);
+}
+
+bool FileManager::LastAccessedTimeInternal(const base::FilePath& path,
+                                           base::Time* last_accessed_time) {
+  base::File::Info info;
+  if (!base::GetFileInfo(path, &info))
+    return false;
+  *last_accessed_time = info.last_accessed;
+  return true;
+}
+
+}  // namespace paint_preview

components/paint_preview/browser/file_manager.h

+// Copyright 2019 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.
+
+#ifndef COMPONENTS_PAINT_PREVIEW_BROWSER_FILE_MANAGER_H_
+#define COMPONENTS_PAINT_PREVIEW_BROWSER_FILE_MANAGER_H_
+
+#include "base/files/file_path.h"
+#include "base/macros.h"
+#include "base/time/time.h"
+#include "url/gurl.h"
+
+namespace paint_preview {
+
+// Manages paint preview files associated with a root directory (typically a
+// user profile).
+class FileManager {
+ public:
+  // Create a file manager for |root_directory|/paint_previews
+  explicit FileManager(const base::FilePath& root_directory);
+  ~FileManager();
+
+  // Get statistics about the time of creation and size of artifacts.
+  size_t GetSizeOfArtifactsFor(const GURL& url);
+  bool GetCreatedTime(const GURL& url, base::Time* created_time);
+  bool GetLastAccessedTime(const GURL& url, base::Time* last_accessed_time);
+
+  // Creates or gets a subdirectory under |root_directory|/paint_previews/
+  // for |url| and assigns it to |directory|. Returns true and modifies
+  // |directory| on success.
+  bool CreateOrGetDirectoryFor(const GURL& url, base::FilePath* directory);
+
+  // Deletes artifacts associated with |urls|.
+  void DeleteArtifactsFor(const std::vector<GURL>& urls);
+
+  // Deletes all stored paint previews stored in the |profile_directory_|.
+  void DeleteAll();
+
+  // Deletes all captures with access times older than |deletion_time|. Slow and
+  // blocking as it relies on base::FileEnumerator.
+  void DeleteAllOlderThan(base::Time deletion_time);
+
+ private:
+  bool LastAccessedTimeInternal(const base::FilePath& path,
+                                base::Time* last_accessed_time);
+
+  base::FilePath root_directory_;
+
+  DISALLOW_COPY_AND_ASSIGN(FileManager);
+};
+
+}  // namespace paint_preview
+
+#endif  // COMPONENTS_PAINT_PREVIEW_BROWSER_FILE_MANAGER_H_

components/paint_preview/browser/file_manager_unittest.cc

+// Copyright 2019 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 "components/paint_preview/browser/file_manager.h"
+
+#include "base/files/file.h"
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "base/files/scoped_temp_dir.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace paint_preview {
+
+TEST(FileManagerTest, TestStats) {
+  base::Time now = base::Time::Now();
+  base::ScopedTempDir temp_dir;
+  ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
+  FileManager manager(temp_dir.GetPath());
+  GURL url("https://www.chromium.org");
+  base::FilePath directory;
+  EXPECT_TRUE(manager.CreateOrGetDirectoryFor(url, &directory));
+  EXPECT_FALSE(directory.empty());
+
+  base::Time created_time;
+  EXPECT_TRUE(manager.GetCreatedTime(url, &created_time));
+
+  base::TouchFile(directory, now - base::TimeDelta::FromSeconds(1),
+                  now - base::TimeDelta::FromSeconds(1));
+  base::Time accessed_time;
+  EXPECT_TRUE(manager.GetLastAccessedTime(url, &accessed_time));
+  base::FilePath proto_path = directory.AppendASCII("paint_preview.pb");
+  base::File file(proto_path,
+                  base::File::FLAG_CREATE_ALWAYS | base::File::FLAG_WRITE);
+  const size_t kSize = 50;
+  std::string zeros(kSize, '0');
+  file.Write(0, zeros.data(), zeros.size());
+  file.Close();
+  base::TouchFile(directory, now + base::TimeDelta::FromSeconds(1),
+                  now + base::TimeDelta::FromSeconds(1));
+  base::Time later_accessed_time;
+  EXPECT_TRUE(manager.GetLastAccessedTime(url, &later_accessed_time));
+  EXPECT_GT(later_accessed_time, accessed_time);
+
+  EXPECT_GE(manager.GetSizeOfArtifactsFor(url), kSize);
+}
+
+TEST(FileManagerTest, TestCreateOrGetDirectory) {
+  base::ScopedTempDir temp_dir;
+  ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
+  FileManager manager(temp_dir.GetPath());
+  GURL url("https://www.chromium.org");
+  base::FilePath new_directory;
+  EXPECT_TRUE(manager.CreateOrGetDirectoryFor(url, &new_directory));
+  EXPECT_FALSE(new_directory.empty());
+  EXPECT_TRUE(base::PathExists(new_directory));
+  base::FilePath old_directory;
+  EXPECT_TRUE(manager.CreateOrGetDirectoryFor(url, &old_directory));
+  EXPECT_FALSE(old_directory.empty());
+  EXPECT_EQ(old_directory, new_directory);
+  EXPECT_TRUE(base::PathExists(old_directory));
+}
+
+TEST(FileManagerTest, TestDeleteArtifactsFor) {
+  base::ScopedTempDir temp_dir;
+  ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
+  FileManager manager(temp_dir.GetPath());
+  GURL cr_url("https://www.chromium.org");
+  base::FilePath cr_directory;
+  EXPECT_TRUE(manager.CreateOrGetDirectoryFor(cr_url, &cr_directory));
+  EXPECT_FALSE(cr_directory.empty());
+  EXPECT_TRUE(base::PathExists(cr_directory));
+  GURL w3_url("https://www.w3.org");
+  base::FilePath w3_directory;
+  EXPECT_TRUE(manager.CreateOrGetDirectoryFor(w3_url, &w3_directory));
+  EXPECT_FALSE(w3_directory.empty());
+  EXPECT_TRUE(base::PathExists(w3_directory));
+  manager.DeleteArtifactsFor(std::vector<GURL>({cr_url}));
+  EXPECT_FALSE(base::PathExists(cr_directory));
+  EXPECT_TRUE(base::PathExists(w3_directory));
+  base::FilePath new_cr_directory;
+  EXPECT_TRUE(manager.CreateOrGetDirectoryFor(cr_url, &new_cr_directory));
+  EXPECT_FALSE(new_cr_directory.empty());
+  EXPECT_TRUE(base::PathExists(new_cr_directory));
+  EXPECT_EQ(cr_directory, new_cr_directory);
+  manager.DeleteArtifactsFor(std::vector<GURL>({cr_url, w3_url}));
+  EXPECT_FALSE(base::PathExists(new_cr_directory));
+  EXPECT_FALSE(base::PathExists(w3_directory));
+}
+
+TEST(FileManagerTest, TestDeleteAll) {
+  base::ScopedTempDir temp_dir;
+  ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
+  FileManager manager(temp_dir.GetPath());
+  GURL cr_url("https://www.chromium.org");
+  base::FilePath cr_directory;
+  EXPECT_TRUE(manager.CreateOrGetDirectoryFor(cr_url, &cr_directory));
+  EXPECT_FALSE(cr_directory.empty());
+  EXPECT_TRUE(base::PathExists(cr_directory));
+  GURL w3_url("https://www.w3.org");
+  base::FilePath w3_directory;
+  EXPECT_TRUE(manager.CreateOrGetDirectoryFor(w3_url, &w3_directory));
+  EXPECT_FALSE(w3_directory.empty());
+  EXPECT_TRUE(base::PathExists(w3_directory));
+  manager.DeleteAll();
+  EXPECT_FALSE(base::PathExists(cr_directory));
+  EXPECT_FALSE(base::PathExists(w3_directory));
+}
+
+TEST(FileManagerTest, TestDeleteAllOlderThan) {
+  base::Time now = base::Time::Now();
+  base::ScopedTempDir temp_dir;
+  ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
+  FileManager manager(temp_dir.GetPath());
+  GURL cr_url("https://www.chromium.org");
+  base::FilePath cr_directory;
+  EXPECT_TRUE(manager.CreateOrGetDirectoryFor(cr_url, &cr_directory));
+  EXPECT_FALSE(cr_directory.empty());
+  EXPECT_TRUE(base::PathExists(cr_directory));
+  base::TouchFile(cr_directory, now - base::TimeDelta::FromSeconds(1),
+                  now - base::TimeDelta::FromSeconds(1));
+
+  GURL w3_url("https://www.w3.org");
+  base::FilePath w3_directory;
+  EXPECT_TRUE(manager.CreateOrGetDirectoryFor(w3_url, &w3_directory));
+  EXPECT_FALSE(w3_directory.empty());
+  EXPECT_TRUE(base::PathExists(w3_directory));
+  base::TouchFile(w3_directory, now + base::TimeDelta::FromSeconds(1),
+                  now + base::TimeDelta::FromSeconds(1));
+  manager.DeleteAllOlderThan(now);
+  EXPECT_FALSE(base::PathExists(cr_directory));
+  EXPECT_TRUE(base::PathExists(w3_directory));
+}
+
+}  // namespace paint_preview