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content / browser / preloading / prerender / prerender_no_vary_search_hint_commit_deferring_condition.cc [blame]
// Copyright 2024 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "content/browser/preloading/prerender/prerender_no_vary_search_hint_commit_deferring_condition.h"
#include <memory>
#include <optional>
#include "base/check.h"
#include "base/feature_list.h"
#include "base/functional/callback_forward.h"
#include "base/memory/ptr_util.h"
#include "base/no_destructor.h"
#include "base/task/single_thread_task_runner.h"
#include "base/time/time.h"
#include "content/browser/preloading/prerender/prerender_host.h"
#include "content/browser/renderer_host/frame_tree_node.h"
#include "content/browser/renderer_host/navigation_request.h"
#include "content/public/browser/commit_deferring_condition.h"
namespace content {
namespace {
// Returns the root prerender frame tree node associated with navigation_request
// of ongoing prerender activation.
FrameTreeNode* GetRootPrerenderFrameTreeNode(
FrameTreeNodeId prerender_frame_tree_node_id) {
FrameTreeNode* root =
FrameTreeNode::GloballyFindByID(prerender_frame_tree_node_id);
if (root) {
CHECK(root->IsOutermostMainFrame());
}
return root;
}
} // namespace
// static
std::unique_ptr<CommitDeferringCondition>
PrerenderNoVarySearchHintCommitDeferringCondition::MaybeCreate(
NavigationRequest& navigation_request,
NavigationType navigation_type,
std::optional<FrameTreeNodeId> candidate_prerender_frame_tree_node_id) {
// Don't create if No-Vary-Search support for prerender is not enabled.
if (!base::FeatureList::IsEnabled(blink::features::kPrerender2NoVarySearch)) {
return nullptr;
}
// Don't create if this navigation is not for prerender page activation.
if (navigation_type != NavigationType::kPrerenderedPageActivation) {
return nullptr;
}
// For `navigation_type` == `NavigationType::kPrerenderedPageActivation`
// `candidate_prerender_frame_tree_node_id` has always a value as we are
// trying to activate a prerender.
CHECK(candidate_prerender_frame_tree_node_id.has_value());
// Don't create if associated PrerenderHost has already received headers.
FrameTreeNode* prerender_frame_tree_node = GetRootPrerenderFrameTreeNode(
candidate_prerender_frame_tree_node_id.value());
// If there is no prerender frame tree node stop here.
if (!prerender_frame_tree_node) {
return nullptr;
}
PrerenderHost& prerender_host =
PrerenderHost::GetFromFrameTreeNode(*prerender_frame_tree_node);
if (prerender_host.were_headers_received()) {
return nullptr;
}
// Don't wait for the No-Vary-Search header if this navigation can match
// without the header
if (prerender_host.IsUrlMatch(navigation_request.GetURL())) {
return nullptr;
}
// Reach here only when the No-Vary-Search hint is specified.
CHECK(prerender_host.no_vary_search_expected().has_value());
return base::WrapUnique(new PrerenderNoVarySearchHintCommitDeferringCondition(
navigation_request, candidate_prerender_frame_tree_node_id.value()));
}
PrerenderNoVarySearchHintCommitDeferringCondition::
~PrerenderNoVarySearchHintCommitDeferringCondition() {
block_until_head_timer_.reset();
// Stop observing the associated PrerenderHost to avoid use-after-free.
FrameTreeNode* prerender_frame_tree_node =
GetRootPrerenderFrameTreeNode(candidate_prerender_frame_tree_node_id_);
if (!prerender_frame_tree_node) {
// In this case the commit deferring condition was removed as an
// observer by the PrerenderHost destructor.
return;
}
PrerenderHost& prerender_host =
PrerenderHost::GetFromFrameTreeNode(*prerender_frame_tree_node);
prerender_host.RemoveObserver(this);
if (waiting_on_headers_) {
waiting_on_headers_ = false;
prerender_host.OnWaitingForHeadersFinished(
GetNavigationHandle(), PrerenderHost::WaitingForHeadersFinishedReason::
kMaybeNavigationCancelled);
}
}
PrerenderNoVarySearchHintCommitDeferringCondition::
PrerenderNoVarySearchHintCommitDeferringCondition(
NavigationRequest& navigation_request,
FrameTreeNodeId candidate_prerender_frame_tree_node_id)
: CommitDeferringCondition(navigation_request),
candidate_prerender_frame_tree_node_id_(
candidate_prerender_frame_tree_node_id) {
CHECK(base::FeatureList::IsEnabled(blink::features::kPrerender2NoVarySearch));
CHECK(candidate_prerender_frame_tree_node_id_);
FrameTreeNode* prerender_frame_tree_node =
GetRootPrerenderFrameTreeNode(candidate_prerender_frame_tree_node_id_);
// The prerender frame tree node is alive. This condition was also checked in
// `MaybeCreate` static method.
CHECK(prerender_frame_tree_node);
PrerenderHost& prerender_host =
PrerenderHost::GetFromFrameTreeNode(*prerender_frame_tree_node);
// We only create `this` instance if headers were not received by the
// associated prerender. This condition was also checked in `MaybeCreate`
// static method.
CHECK(!prerender_host.were_headers_received());
// Add this commit deferring condition as an observer of the associated
// PrerenderHost.
prerender_host.AddObserver(this);
}
CommitDeferringCondition::Result
PrerenderNoVarySearchHintCommitDeferringCondition::WillCommitNavigation(
base::OnceClosure resume) {
FrameTreeNode* prerender_frame_tree_node =
GetRootPrerenderFrameTreeNode(candidate_prerender_frame_tree_node_id_);
// If the prerender FrameTreeNode is gone, the prerender activation is allowed
// to continue here but will fail soon.
if (!prerender_frame_tree_node) {
return Result::kProceed;
}
// If headers were already received, proceed.
PrerenderHost& prerender_host =
PrerenderHost::GetFromFrameTreeNode(*prerender_frame_tree_node);
if (prerender_host.were_headers_received()) {
return Result::kProceed;
}
// `resume` callback is always set by
// `CommitDeferringConditionRunner::ProcessConditions`.
CHECK(resume);
// We now need to wait for headers.
resume_ = std::move(resume);
base::TimeDelta block_until_head_timeout =
prerender_host.WaitUntilHeadTimeout();
PrerenderHost::WaitingForHeadersStartedReason reason =
PrerenderHost::WaitingForHeadersStartedReason::kWithoutTimeout;
if (block_until_head_timeout.is_positive()) {
CHECK(!block_until_head_timer_);
block_until_head_timer_ = std::make_unique<base::OneShotTimer>();
block_until_head_timer_->SetTaskRunner(GetTimerTaskRunner());
block_until_head_timer_->Start(
FROM_HERE, block_until_head_timeout,
base::BindOnce(&PrerenderNoVarySearchHintCommitDeferringCondition::
OnBlockUntilHeadTimerElapsed,
Unretained(this)));
reason = PrerenderHost::WaitingForHeadersStartedReason::kWithTimeout;
}
// Let the `prerender_host` know that this navigation is waiting on the
// associated prerender's headers.
waiting_on_headers_ = true;
prerender_host.OnWaitingForHeadersStarted(GetNavigationHandle(), reason);
return Result::kDefer;
}
const char*
PrerenderNoVarySearchHintCommitDeferringCondition::TraceEventName() const {
return "PrerenderNoVarySearchHintCommitDeferringCondition";
}
void PrerenderNoVarySearchHintCommitDeferringCondition::OnHeadersReceived() {
// Verify all conditions are met:
// * headers should have been received and
// * the prerender_frame_tree_node is still alive.
FrameTreeNode* prerender_frame_tree_node =
GetRootPrerenderFrameTreeNode(candidate_prerender_frame_tree_node_id_);
// `OnHeadersReceived` is called by `PrerenderHost::ReadyToCommitNavigation`.
// Prerender frame tree node is alive, see:
// `PrerenderHostRegistry::ReadyToCommitNavigation`.
CHECK(prerender_frame_tree_node);
PrerenderHost& prerender_host =
PrerenderHost::GetFromFrameTreeNode(*prerender_frame_tree_node);
CHECK(prerender_host.were_headers_received());
// Remove the observer from the prerender host.
prerender_host.RemoveObserver(this);
// Let the `prerender_host` know that this navigation is done waiting on the
// associated prerender's headers.
if (waiting_on_headers_) {
waiting_on_headers_ = false;
// Determine the finished reason.
using FinishedReason = PrerenderHost::WaitingForHeadersFinishedReason;
std::optional<FinishedReason> reason;
if (prerender_host.no_vary_search_parse_error().has_value()) {
using ParseError = network::mojom::NoVarySearchParseError;
switch (prerender_host.no_vary_search_parse_error().value()) {
case ParseError::kOk:
// kOk indicates there is no header. See the definition of this enum.
reason = FinishedReason::kNoVarySearchHeaderNotReceived;
break;
case ParseError::kDefaultValue:
// kDefaultValue indicates parsing is correct but led to default
// value.
reason = FinishedReason::kNoVarySearchHeaderReceivedButDefaultValue;
break;
case ParseError::kNotDictionary:
case ParseError::kUnknownDictionaryKey:
case ParseError::kNonBooleanKeyOrder:
case ParseError::kParamsNotStringList:
case ParseError::kExceptNotStringList:
case ParseError::kExceptWithoutTrueParams:
reason = FinishedReason::kNoVarySearchHeaderParseFailed;
break;
}
} else if (prerender_host.no_vary_search().has_value()) {
std::optional<UrlMatchType> match_type =
prerender_host.IsUrlMatch(GetNavigationHandle().GetURL());
if (match_type.has_value()) {
CHECK_EQ(match_type.value(), UrlMatchType::kNoVarySearch)
<< "PrerenderNoVarySearchHintCommitDeferringCondition should be "
<< "created only for UrlMatchType::kNoVarySearch.";
reason = FinishedReason::kNoVarySearchHeaderReceivedAndMatched;
} else {
reason = FinishedReason::kNoVarySearchHeaderReceivedButNotMatched;
}
}
CHECK(reason.has_value());
prerender_host.OnWaitingForHeadersFinished(GetNavigationHandle(), *reason);
}
// We don't need the timer anymore.
block_until_head_timer_.reset();
// Resume the navigation once the prerender main page has received the
// headers.
CHECK(resume_);
std::move(resume_).Run();
// Don't add any more code as "this" is destroyed by calling the
// resume_ callback.
}
void PrerenderNoVarySearchHintCommitDeferringCondition::OnHostDestroyed(
PrerenderFinalStatus status) {
FrameTreeNode* prerender_frame_tree_node =
GetRootPrerenderFrameTreeNode(candidate_prerender_frame_tree_node_id_);
if (prerender_frame_tree_node) {
PrerenderHost& prerender_host =
PrerenderHost::GetFromFrameTreeNode(*prerender_frame_tree_node);
// Remove the observer from the prerender host.
prerender_host.RemoveObserver(this);
// We might need to hold more state to know.
if (waiting_on_headers_) {
// Let the `prerender_host` know that this navigation is done waiting on
// the associated prerender's headers.
waiting_on_headers_ = false;
prerender_host.OnWaitingForHeadersFinished(
GetNavigationHandle(),
PrerenderHost::WaitingForHeadersFinishedReason::kHostDestroyed);
}
} else {
waiting_on_headers_ = false;
}
// We don't need the timer anymore.
block_until_head_timer_.reset();
// If we have not resumed the navigation, do it now. This could happen if the
// prerender is cancelled before receiving headers.
if (resume_) {
std::move(resume_).Run();
}
// Don't add any more code as "this" is destroyed by calling the
// resume_ callback.
}
void PrerenderNoVarySearchHintCommitDeferringCondition::
OnBlockUntilHeadTimerElapsed() {
// We should never fire the timer if we are not waiting on headers.
CHECK(waiting_on_headers_);
waiting_on_headers_ = false;
FrameTreeNode* prerender_frame_tree_node =
GetRootPrerenderFrameTreeNode(candidate_prerender_frame_tree_node_id_);
if (prerender_frame_tree_node) {
PrerenderHost& prerender_host =
PrerenderHost::GetFromFrameTreeNode(*prerender_frame_tree_node);
// Let the `prerender_host` know that this navigation is done waiting on the
// associated prerender's headers.
prerender_host.OnWaitingForHeadersFinished(
GetNavigationHandle(),
PrerenderHost::WaitingForHeadersFinishedReason::kTimeoutElapsed);
}
if (resume_) {
std::move(resume_).Run();
}
// Don't add any more code as "this" is destroyed by calling the
// resume_ callback.
}
scoped_refptr<base::SingleThreadTaskRunner>
PrerenderNoVarySearchHintCommitDeferringCondition::GetTimerTaskRunner() {
return GetTimerTaskRunnerForTesting() // IN-TEST
? GetTimerTaskRunnerForTesting() // IN-TEST
: base::SingleThreadTaskRunner::GetCurrentDefault();
}
// static
scoped_refptr<base::SingleThreadTaskRunner>&
PrerenderNoVarySearchHintCommitDeferringCondition::
GetTimerTaskRunnerForTesting() {
static base::NoDestructor<scoped_refptr<base::SingleThreadTaskRunner>>
timer_task_runner_for_testing;
return *timer_task_runner_for_testing;
}
// static
void PrerenderNoVarySearchHintCommitDeferringCondition::
SetTimerTaskRunnerForTesting(
scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
GetTimerTaskRunnerForTesting() = std::move(task_runner); // IN-TEST
}
} // namespace content