Apply default wallpaper from customization manifest.

chrome/browser/chromeos/customization_wallpaper_downloader.cc

+// Copyright 2014 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 "chrome/browser/chromeos/customization_wallpaper_downloader.h"
+
+#include "base/file_util.h"
+#include "content/public/browser/browser_thread.h"
+#include "net/base/load_flags.h"
+#include "net/url_request/url_request_context_getter.h"
+#include "url/gurl.h"
+
+namespace {
+// This is temporary file suffix (for downloading or resizing).
+const char kTemporarySuffix[] = ".temp";
+
+// Sleep between wallpaper retries (used multiplied by retry number).
+const unsigned kRetrySleepSeconds = 10;
+
+// Do not retry beyond this number of attempts.
+const unsigned kMaxRetries = 200;

[Daniel Erat, 2014/04/14 15:26:15]

where did these numbers come from? why is it meaningful to give up after 200
retries, especially if we're sleeping ~2000 seconds between retries at that
point?

[Alexander Alekseev, 2014/04/15 01:57:16]

The original idea was to "never give up". 200 retries means 2 days.
I don't have better ideas though.

+}
+
+namespace chromeos {
+
+CustomizationWallpaperDownloader::CustomizationWallpaperDownloader(
+    net::URLRequestContextGetter* url_context_getter,
+    const GURL& wallpaper_url,
+    const base::FilePath& wallpaper_dir,
+    const base::FilePath& wallpaper_downloaded_file,
+    base::Callback<void(const GURL&)> on_url_fetched)
+    : url_context_getter_(url_context_getter),
+      wallpaper_url_(wallpaper_url),
+      wallpaper_dir_(wallpaper_dir),
+      wallpaper_downloaded_file_(wallpaper_downloaded_file),
+      wallpaper_temporary_file_(wallpaper_downloaded_file.value() +
+                                kTemporarySuffix),
+      retries_(0),
+      on_url_fetched_(on_url_fetched),
+      weak_factory_(this) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+}
+
+CustomizationWallpaperDownloader::~CustomizationWallpaperDownloader() {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+}
+
+void CustomizationWallpaperDownloader::StartRequest() {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+  DCHECK(wallpaper_url_.is_valid());
+  ++retries_;

[Daniel Erat, 2014/04/14 15:26:15]

should |retries_| actually be named |attempts_|? "retry" means that the previous
try failed.

[Alexander Alekseev, 2014/04/15 01:57:16]

Done.

+
+  url_fetcher_.reset(
+      net::URLFetcher::Create(wallpaper_url_, net::URLFetcher::GET, this));
+  url_fetcher_->SetRequestContext(url_context_getter_);
+  url_fetcher_->SetLoadFlags(net::LOAD_BYPASS_CACHE | net::LOAD_DISABLE_CACHE |
+                             net::LOAD_DO_NOT_SAVE_COOKIES |
+                             net::LOAD_DO_NOT_SEND_COOKIES |
+                             net::LOAD_DO_NOT_SEND_AUTH_DATA);
+  base::SequencedWorkerPool* blocking_pool =
+      content::BrowserThread::GetBlockingPool();
+  url_fetcher_->SaveResponseToFileAtPath(
+      wallpaper_temporary_file_,
+      blocking_pool->GetSequencedTaskRunner(blocking_pool->GetSequenceToken()));
+  url_fetcher_->Start();
+}
+
+void CustomizationWallpaperDownloader::Retry() {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+  if (retries_ > kMaxRetries) {
+    LOG(WARNING)
+        << "Failed to fetch customized wallpaper. Retry limit reached.";
+    // Destroy self.
+    ServicesCustomizationDocument::GetInstance()->DestroyWallpaperDownloader();

[Daniel Erat, 2014/04/14 15:26:15]

having CustomizationWallpaperDownloader call into ServicesCustomizationDocument
like this creates a circular dependency between the two classes. why not instead
have SCD observe CWD and get notified when the download completes successfully
or fails, and then keep all of the logic about what to do with the CWD inside of
SCD?

[Dmitry Polukhin, 2014/04/14 20:26:37]

Good suggestion how to eliminate DestroyWallpaperDownloader.

[Alexander Alekseev, 2014/04/15 01:57:16]

Done.

+  }
+
+  const base::TimeDelta delay =
+      base::TimeDelta::FromSeconds(kRetrySleepSeconds) * retries_;
+  VLOG(1) << "Schedule Customized Wallpaper download in " << delay.InSecondsF()
+          << " seconds.";
+  request_scheduled_.Start(
+      FROM_HERE, delay, this, &CustomizationWallpaperDownloader::StartRequest);
+}
+
+void CustomizationWallpaperDownloader::Start() {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+  scoped_ptr<bool> success(new bool(false));
+
+  base::Closure mkdir_closure =
+      base::Bind(&CustomizationWallpaperDownloader::CreateWallpaperDirectory,
+                 wallpaper_dir_,
+                 base::Unretained(success.get()));
+  base::Closure on_created_closure =
+      base::Bind(&CustomizationWallpaperDownloader::OnWallpaperDirectoryCreated,
+                 weak_factory_.GetWeakPtr(),
+                 base::Passed(success.Pass()));
+  if (!content::BrowserThread::PostBlockingPoolTaskAndReply(
+          FROM_HERE, mkdir_closure, on_created_closure)) {
+    LOG(WARNING) << "Failed to start Customized Wallpaper download.";
+  }
+}
+
+// static
+void CustomizationWallpaperDownloader::CreateWallpaperDirectory(

[Daniel Erat, 2014/04/14 15:26:15]

private static method -> should probably be function in anonymous namespace
instead

[Alexander Alekseev, 2014/04/15 01:57:16]

Done.

+    const base::FilePath& wallpaper_dir,
+    bool* success) {
+  DCHECK(content::BrowserThread::GetBlockingPool()->RunsTasksOnCurrentThread());
+  DCHECK(success);
+
+  *success = CreateDirectoryAndGetError(wallpaper_dir, NULL);
+}
+
+void CustomizationWallpaperDownloader::OnWallpaperDirectoryCreated(
+    scoped_ptr<bool> success) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+  if (*success)
+    StartRequest();
+}
+
+void CustomizationWallpaperDownloader::OnURLFetchComplete(
+    const net::URLFetcher* source) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+  DCHECK_EQ(url_fetcher_.get(), source);
+
+  const net::URLRequestStatus status = source->GetStatus();
+  const int response_code = source->GetResponseCode();
+
+  const bool server_error =
+      !status.is_success() || (response_code >= 500 && response_code < 600);

[Daniel Erat, 2014/04/14 15:26:15]

are there constants anywhere for HTTP response codes that you can use instead?

[Alexander Alekseev, 2014/04/15 01:57:16]

I've replaced this with constants, but I don't know if it actually became more
readable. 

Done.

+
+  VLOG(1) << "CustomizationWallpaperDownloader::OnURLFetchComplete(): status="
+          << status.status();
+
+  if (server_error) {
+    url_fetcher_.reset();
+    Retry();
+    return;
+  }
+
+  base::FilePath response_path;
+  url_fetcher_->GetResponseAsFilePath(true, &response_path);
+  url_fetcher_.reset();
+
+  scoped_ptr<bool> success(new bool(false));
+
+  base::Closure rename_closure =
+      base::Bind(&CustomizationWallpaperDownloader::RenameTemporaryFile,
+                 response_path,
+                 wallpaper_downloaded_file_,
+                 base::Unretained(success.get()));
+  base::Closure on_rename_closure =
+      base::Bind(&CustomizationWallpaperDownloader::OnTemporaryFileRenamed,
+                 weak_factory_.GetWeakPtr(),
+                 base::Passed(success.Pass()));
+  if (!content::BrowserThread::PostBlockingPoolTaskAndReply(
+          FROM_HERE, rename_closure, on_rename_closure)) {
+    LOG(WARNING)
+        << "Failed to start Customized Wallpaper Rename DownloadedFile.";
+    // Destroy self.
+    ServicesCustomizationDocument::GetInstance()->DestroyWallpaperDownloader();
+  }
+}
+
+void CustomizationWallpaperDownloader::OnTemporaryFileRenamed(
+    scoped_ptr<bool> success) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+  if (!success) {
+    // Destroy self.
+    ServicesCustomizationDocument::GetInstance()->DestroyWallpaperDownloader();
+    return;
+  }
+  on_url_fetched_.Run(wallpaper_url_);
+}
+
+// static
+void CustomizationWallpaperDownloader::RenameTemporaryFile(

[Daniel Erat, 2014/04/14 15:26:15]

private static method -> should probably be function in anonymous namespace
instead

[Alexander Alekseev, 2014/04/15 01:57:16]

Done.

+    const base::FilePath& from,
+    const base::FilePath& to,
+    bool* success) {
+  DCHECK(content::BrowserThread::GetBlockingPool()->RunsTasksOnCurrentThread());
+  DCHECK(success);
+
+  base::File::Error error;
+  if (ReplaceFile(from, to, &error)) {
+    *success = true;
+  } else {
+    LOG(WARNING)
+        << "Failed to rename temporary file of Customized Wallpaper. error="
+        << error;
+    *success = false;
+  }
+}
+
+}  //   namespace chromeos