Extract AppBannerDataFetcher into an InstallableManager.

chrome/browser/installable/installable_checker.cc

+// 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.
+
+#include "chrome/browser/installable/installable_checker.h"
+
+#include "base/bind.h"
+#include "base/strings/string_util.h"
+#include "chrome/browser/manifest/manifest_icon_downloader.h"
+#include "chrome/browser/manifest/manifest_icon_selector.h"
+#include "chrome/browser/profiles/profile.h"
+#include "content/public/browser/browser_context.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/navigation_handle.h"
+#include "content/public/browser/service_worker_context.h"
+#include "content/public/browser/storage_partition.h"
+#include "third_party/WebKit/public/platform/WebDisplayMode.h"
+
+namespace {
+
+const int kIconSizeUnset = -1;
+
+const char kPngExtension[] = ".png";
+
+// This constant is the icon size on Android (48dp) multiplied by the scale
+// factor of a Nexus 5 device (3). For mobile and desktop platforms, a 144px
+// icon is an approximate, appropriate lower bound.
+// TODO(dominickn): consolidate this constant with minimum_icon_size_in_dp
+// across platforms.
+const int kIconMinimumSizeInPx = 144;
+
+// Returns true if |manifest| specifies a PNG icon that is at least 144x144px
+// (or has size "any").
+bool DoesManifestContainRequiredIcon(const content::Manifest& manifest) {
+  for (const auto& icon : manifest.icons) {
+    // The type field is optional. If it isn't present, fall back on checking
+    // the src extension, and allow the icon if the extension ends with png.
+    if (!base::EqualsASCII(icon.type.string(), "image/png") &&
+        !(icon.type.is_null() &&
+          base::EndsWith(icon.src.ExtractFileName(), kPngExtension,
+                         base::CompareCase::INSENSITIVE_ASCII)))
+      continue;
+
+    for (const auto& size : icon.sizes) {
+      if (size.IsEmpty())  // "any"
+        return true;
+      if (size.width() >= kIconMinimumSizeInPx &&
+          size.height() >= kIconMinimumSizeInPx) {
+        return true;
+      }
+    }
+  }
+
+  return false;
+}
+
+}  // anonymous namespace
+
+DEFINE_WEB_CONTENTS_USER_DATA_KEY(installable::InstallableChecker);
+
+namespace installable {
+
+InstallableParams::InstallableParams()
+    : ideal_icon_size_in_dp(kIconSizeUnset),
+      minimum_icon_size_in_dp(kIconSizeUnset),
+      check_valid_webapp_manifest(false),
+      check_service_worker(false),
+      check_valid_icon(false) { }
+
+InstallableChecker::InstallableChecker(content::WebContents* web_contents)
+    : content::WebContentsObserver(web_contents),
+      status_(DORMANT),
+      processing_error_(NO_ERROR),
+      manifest_error_(NO_ERROR),
+      valid_webapp_manifest_error_(NO_ERROR),
+      service_worker_error_(NO_ERROR),
+      icon_error_(NO_ERROR),
+      ideal_icon_size_in_dp_(kIconSizeUnset),
+      minimum_icon_size_in_dp_(kIconSizeUnset),
+      has_valid_webapp_manifest_(false),
+      has_service_worker_(false),
+      weak_factory_(this) {}
+
+InstallableChecker::~InstallableChecker() { }
+
+bool InstallableChecker::IsManifestValidForWebApp(
+    const content::Manifest& manifest) {
+  if (manifest.IsEmpty()) {
+    valid_webapp_manifest_error_ = MANIFEST_EMPTY;
+    return false;
+  }
+
+  if (!manifest.start_url.is_valid()) {
+    valid_webapp_manifest_error_ = START_URL_NOT_VALID;
+    return false;
+  }
+
+  if ((manifest.name.is_null() || manifest.name.string().empty()) &&
+      (manifest.short_name.is_null() || manifest.short_name.string().empty())) {
+    valid_webapp_manifest_error_ = MANIFEST_MISSING_NAME_OR_SHORT_NAME;
+    return false;
+  }
+
+  // TODO(dominickn,mlamouri): when Chrome supports "minimal-ui", it should be
+  // accepted. If we accept it today, it would fallback to "browser" and make
+  // this check moot. See https://crbug.com/604390.
+  if (manifest.display != blink::WebDisplayModeStandalone &&
+      manifest.display != blink::WebDisplayModeFullscreen) {
+    valid_webapp_manifest_error_ = MANIFEST_DISPLAY_NOT_SUPPORTED;
+    return false;
+  }
+
+  if (!DoesManifestContainRequiredIcon(manifest)) {
+    valid_webapp_manifest_error_ = MANIFEST_MISSING_SUITABLE_ICON;
+    return false;
+  }
+
+  return true;
+}
+
+void InstallableChecker::Start(const InstallableParams& params,
+                               const InstallableCallback& callback) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  // Always reset processing_error_, as it records events like navigation which
+  // are outside of fetching/validating resources.
+  processing_error_ = NO_ERROR;
+
+  // If we've already working on a task, or running callbacks, add the new task
+  // to the pending list and return. It will be dealt with once the current work
+  // completes. We keep the pending list separate in case this call was
+  // initiated during an InstallableCallback invocation, which modifies the
+  // tasks_ list.
+  if (IsActive() || HasFlag(RUNNING_CALLBACKS)) {
+    pending_tasks_.push_back({params, callback});
+    return;
+  }
+
+  tasks_.push_back({params, callback});
+  SetFlag(STARTED);
+  StartTask();
+}
+
+void InstallableChecker::Cancel() {
+  // Clear the STARTED flag to signal that we should stop work immediately.
+  // Callers of this method should immediately call back to FetchResource() or
+  // Start(), which will terminate the current task and run callbacks.
+  ClearFlag(STARTED);
+}
+
+bool InstallableChecker::DoesIconSizeMatch(
+    const InstallableParams& params) const {
+  return (ideal_icon_size_in_dp_ == params.ideal_icon_size_in_dp) &&
+         (minimum_icon_size_in_dp_ == params.minimum_icon_size_in_dp);
+}
+
+ErrorCode InstallableChecker::GetErrorCode(const InstallableParams& params) {
+  if (processing_error_ != NO_ERROR)
+    return processing_error_;
+  if (manifest_error_ != NO_ERROR)
+    return manifest_error_;
+  if (params.check_valid_webapp_manifest &&
+      valid_webapp_manifest_error_ != NO_ERROR) {
+    return valid_webapp_manifest_error_;
+  }
+  if (params.check_service_worker && service_worker_error_ != NO_ERROR)
+    return service_worker_error_;
+  if (params.check_valid_icon && icon_error_ != NO_ERROR)
+    return icon_error_;
+
+  return NO_ERROR;
+}
+
+content::WebContents* InstallableChecker::GetWebContents() {
+  content::WebContents* contents = web_contents();
+  if (!contents || contents->IsBeingDestroyed())
+    return nullptr;
+  return contents;
+}
+
+bool InstallableChecker::IsComplete(const InstallableParams& params) const {
+  // Returns true if for all resources:
+  //  a. the params did not request it, OR
+  //  b. the resource has been retrieved.
+  return (HasFlag(MANIFEST_FETCHED)) &&
+         (!params.check_valid_webapp_manifest || HasFlag(MANIFEST_VALIDATED)) &&
+         (!params.check_service_worker || HasFlag(SERVICE_WORKER_CHECKED)) &&
+         (!params.check_valid_icon ||
+          (HasFlag(ICON_FETCHED) && DoesIconSizeMatch(params)));
+}
+
+bool InstallableChecker::IsRunning(content::WebContents* web_contents) {
+  if (!web_contents) {
+    processing_error_ = RENDERER_EXITING;
+    return false;
+  }
+
+  if (!IsActive()) {
+    processing_error_ = USER_NAVIGATED;
+    return false;
+  }
+
+  return true;
+}
+
+void InstallableChecker::Reset() {
+  status_ = DORMANT;
+  processing_error_ = NO_ERROR;
+  manifest_error_ = NO_ERROR;
+  valid_webapp_manifest_error_ = NO_ERROR;
+  service_worker_error_ = NO_ERROR;
+  icon_error_ = NO_ERROR;
+
+  ideal_icon_size_in_dp_ = kIconSizeUnset;
+  minimum_icon_size_in_dp_ = kIconSizeUnset;
+
+  tasks_.clear();
+  pending_tasks_.clear();
+
+  manifest_url_ = GURL();
+  manifest_ = content::Manifest();
+  icon_url_ = GURL();
+  icon_.reset(nullptr);
+  has_valid_webapp_manifest_ = false;
+  has_service_worker_ = false;
+}
+
+void InstallableChecker::RunCallbacks() {
+  // Post a callback and delete it from the list of tasks if:
+  //  - the STARTED status bit is missing. This means that we've either finished
+  //    all possible checks, or we have canceled the pipeline
+  //  - the params that the callback was started with have been satisfied.
+  // We run through the entire tasks_ vector here since we may have completed
+  // other tasks while working on the current one. For example, we may have
+  // initiated a full check on page load for app banners. Whilst that runs,
+  // multiple other requests may come in and be queued. When the app banner task
+  // completes, the queued requests will be moved to the tasks_ vector, and as
+  // we have already fetched all resources, we can dispatch their callbacks
+  // immediately.
+  SetFlag(RUNNING_CALLBACKS);
+  for (auto it = tasks_.begin(); it != tasks_.end();) {
+    const InstallableParams& params = it->first;
+    if (!IsActive() || IsComplete(params)) {
+      InstallableResult result = {
+          GetErrorCode(params), manifest_url_, manifest_,
+          params.check_valid_icon ? icon_url_ : GURL::EmptyGURL(),
+          params.check_valid_icon ? icon_.get() : nullptr,
+          params.check_valid_webapp_manifest ? has_valid_webapp_manifest_
+                                             : false,
+          params.check_service_worker ? has_service_worker_ : false};
+      // We must run this directly to guarantee the callback gets consistent
+      // results. If we PostTask, a second Task may begin that invalidates the
+      // icon object before the callback gets a chance to use it.
+      it->second.Run(result);
+      it = tasks_.erase(it);
+    } else {
+      ++it;
+    }
+  }
+  ClearFlag(RUNNING_CALLBACKS);
+}
+
+void InstallableChecker::StartTask() {
+  RunCallbacks();
+
+  if (!pending_tasks_.empty()) {
+    // Shift any pending tasks to the end of tasks_.
+    tasks_.insert(tasks_.end(), pending_tasks_.begin(), pending_tasks_.end());
+    pending_tasks_.clear();
+  }
+
+  // If there's nothing to do, exit. Resources remain cached so any future calls
+  // won't re-fetch anything that has already been retrieved.
+  if (tasks_.empty()) {
+    ClearFlag(STARTED);
+    return;
+  }
+
+  // If we are requesting an icon, and the requested size differs from any
+  // previously fetched (or if we haven't yet fetched an icon), reset the icon
+  // state. This has no impact on the other resources, so don't reset them.
+  const InstallableParams& params = tasks_[0].first;
+  if (params.check_valid_icon && !DoesIconSizeMatch(params)) {
+    ideal_icon_size_in_dp_ = params.ideal_icon_size_in_dp;
+    minimum_icon_size_in_dp_ = params.minimum_icon_size_in_dp;
+    icon_url_ = GURL();
+    icon_.reset(nullptr);
+    icon_error_ = NO_ERROR;
+    ClearFlag(ICON_FETCHED);
+  }
+
+  FetchResource();
+}
+
+void InstallableChecker::FetchResource() {
+  DCHECK(!tasks_.empty());
+  const InstallableParams& params = tasks_[0].first;
+
+  // Cancel if there is an error code for any resource requested by params.
+  if (GetErrorCode(params) != NO_ERROR)
+    Cancel();
+
+  // If not active, then Cancel() has been called. Go straight back to
+  // StartTask, which will clear the current task. Otherwise, if we fall through
+  // to the else case, we've fetched everything necessary for this task, so
+  // call StartTask to run its callback and start the next task.
+  if (!IsActive())
+    StartTask();
+  else if (!HasFlag(MANIFEST_FETCHED))
+    FetchManifest();
+  else if (params.check_valid_webapp_manifest && !HasFlag(MANIFEST_VALIDATED))
+    CheckValidWebappManifest();
+  else if (params.check_service_worker && !HasFlag(SERVICE_WORKER_CHECKED))
+    CheckServiceWorker();
+  else if (params.check_valid_icon && !HasFlag(ICON_FETCHED))
+    ExtractAndFetchBestIcon();
+  else
+    StartTask();
+}
+
+void InstallableChecker::FetchManifest() {
+  DCHECK(!HasFlag(MANIFEST_FETCHED));
+  DCHECK(manifest_.IsEmpty());
+  DCHECK(manifest_url_.is_empty());
+
+  content::WebContents* web_contents = GetWebContents();
+  DCHECK(web_contents);
+
+  web_contents->GetManifest(base::Bind(&InstallableChecker::OnDidGetManifest,
+                                       weak_factory_.GetWeakPtr()));
+}
+
+void InstallableChecker::OnDidGetManifest(const GURL& manifest_url,
+                                          const content::Manifest& manifest) {
+  if (!IsRunning(GetWebContents()))
+    Cancel();
+  else if (manifest_url.is_empty())
+    manifest_error_ = NO_MANIFEST;
+  else if (manifest.IsEmpty())
+    manifest_error_ = MANIFEST_EMPTY;
+
+  manifest_url_ = manifest_url;
+  manifest_ = manifest;
+
+  SetFlag(MANIFEST_FETCHED);
+  FetchResource();
+}
+
+void InstallableChecker::CheckValidWebappManifest() {
+  DCHECK(!HasFlag(MANIFEST_VALIDATED));
+  DCHECK(!manifest_.IsEmpty());
+
+  has_valid_webapp_manifest_ = IsManifestValidForWebApp(manifest_);
+  if (!has_valid_webapp_manifest_)
+    Cancel();
+
+  SetFlag(MANIFEST_VALIDATED);
+  FetchResource();
+}
+
+void InstallableChecker::CheckServiceWorker() {
+  DCHECK(!HasFlag(SERVICE_WORKER_CHECKED));
+  DCHECK(!manifest_.IsEmpty());
+
+  content::WebContents* web_contents = GetWebContents();
+
+  // Check to see if there is a single service worker controlling this page
+  // and the manifest's start url.
+  Profile* profile =
+      Profile::FromBrowserContext(web_contents->GetBrowserContext());
+  content::StoragePartition* storage_partition =
+      content::BrowserContext::GetStoragePartition(
+          profile, web_contents->GetSiteInstance());
+  DCHECK(storage_partition);
+
+  storage_partition->GetServiceWorkerContext()->CheckHasServiceWorker(
+      web_contents->GetLastCommittedURL(), manifest_.start_url,
+      base::Bind(&InstallableChecker::OnDidCheckHasServiceWorker,
+                 weak_factory_.GetWeakPtr()));
+}
+
+void InstallableChecker::OnDidCheckHasServiceWorker(bool has_service_worker) {
+  if (!IsRunning(GetWebContents()))
+    Cancel();
+
+  has_service_worker_ = has_service_worker;
+  if (!has_service_worker)
+    service_worker_error_ = NO_MATCHING_SERVICE_WORKER;
+
+  SetFlag(SERVICE_WORKER_CHECKED);
+  FetchResource();
+}
+
+void InstallableChecker::ExtractAndFetchBestIcon() {
+  // icon_url_ and icon_ should have both been reset if this method is called.
+  DCHECK(!HasFlag(ICON_FETCHED));
+  DCHECK(!manifest_.IsEmpty());
+  DCHECK(icon_url_.is_empty());
+  DCHECK(icon_.get() == nullptr);
+  DCHECK_GT(ideal_icon_size_in_dp_, 0);
+  DCHECK_GT(minimum_icon_size_in_dp_, 0);
+
+  GURL icon_url = ManifestIconSelector::FindBestMatchingIcon(
+      manifest_.icons, ideal_icon_size_in_dp_, minimum_icon_size_in_dp_);
+
+  // First, check the icon URL. If it exists, see if the ManifestIconDownloader
+  // is able to download it. If it can, it will call OnAppIconFetched. Any
+  // conditional failures will set the ICON_FETCHED bit and fall through back to
+  // FetchResource.
+  if (icon_url.is_empty()) {
+    icon_error_ = NO_ACCEPTABLE_ICON;
+  } else {
+    bool can_download_icon = ManifestIconDownloader::Download(
+        GetWebContents(), icon_url, ideal_icon_size_in_dp_,
+        minimum_icon_size_in_dp_,
+        base::Bind(&InstallableChecker::OnAppIconFetched,
+                   weak_factory_.GetWeakPtr(), icon_url));
+    if (can_download_icon)
+      return;
+    icon_error_ = CANNOT_DOWNLOAD_ICON;
+  }
+
+  SetFlag(ICON_FETCHED);
+  FetchResource();
+}
+
+void InstallableChecker::OnAppIconFetched(const GURL icon_url,
+                                          const SkBitmap& bitmap) {
+  if (!IsRunning(GetWebContents())) {
+    Cancel();
+  } else if (bitmap.drawsNothing()) {
+    icon_error_ = NO_ICON_AVAILABLE;
+  } else {
+    icon_url_ = icon_url;
+    icon_.reset(new SkBitmap(bitmap));
+  }
+
+  SetFlag(ICON_FETCHED);
+  FetchResource();
+}
+
+void InstallableChecker::DidFinishNavigation(
+    content::NavigationHandle* handle) {
+  if (handle->IsInMainFrame() && handle->HasCommitted() &&
+      !handle->IsErrorPage() && !handle->IsSamePage()) {
+    Reset();
+  }
+}
+
+void InstallableChecker::WebContentsDestroyed() {
+  Reset();
+  Observe(nullptr);
+}
+
+// static
+int InstallableChecker::GetMinimumIconSizeInPx() {
+  return kIconMinimumSizeInPx;
+}
+
+}  // namespace installable