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content / browser / renderer_host / navigation_transitions / navigation_entry_screenshot_manager.cc [blame]
// Copyright 2023 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/renderer_host/navigation_transitions/navigation_entry_screenshot_manager.h"
#include "base/functional/bind.h"
#include "base/memory/ptr_util.h"
#include "base/metrics/histogram_functions.h"
#include "base/system/sys_info.h"
#include "base/task/thread_pool.h"
#include "base/time/default_tick_clock.h"
#include "content/browser/renderer_host/navigation_transitions/navigation_entry_screenshot.h"
#include "content/browser/renderer_host/navigation_transitions/navigation_entry_screenshot_cache.h"
#include "content/browser/renderer_host/navigation_transitions/navigation_transition_config.h"
#include "content/browser/renderer_host/navigation_transitions/navigation_transition_utils.h"
#include "services/resource_coordinator/public/cpp/memory_instrumentation/browser_metrics.h"
#include "ui/display/screen.h"
namespace content {
NavigationEntryScreenshotManager::NavigationEntryScreenshotManager()
: // `NO_AUTO_EVICT` since we want to manually limit the global cache size
// by the number of bytes of the thumbnails, rather than the number of
// entries in the cache.
managed_caches_(base::LRUCacheSet<int>::NO_AUTO_EVICT),
tick_clock_(base::DefaultTickClock::GetInstance()),
cleanup_delay_(
NavigationTransitionConfig::GetCleanupDelayForInvisibleCaches()) {
CHECK(NavigationTransitionConfig::AreBackForwardTransitionsEnabled());
DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
max_cache_size_in_bytes_ =
NavigationTransitionConfig::ComputeCacheSizeInBytes();
listener_ = std::make_unique<base::MemoryPressureListener>(
FROM_HERE,
base::BindRepeating(&NavigationEntryScreenshotManager::OnMemoryPressure,
base::Unretained(this)));
// Start recording memory usage.
RecordScreenshotCacheSizeAfterDelay();
}
NavigationEntryScreenshotManager::~NavigationEntryScreenshotManager() = default;
void NavigationEntryScreenshotManager::OnScreenshotCached(
NavigationEntryScreenshotCacheEvictor* cache,
size_t size) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (managed_caches_.Get(cache) == managed_caches_.end()) {
Register(cache);
}
// We shouldn't be able to capture anything greater than the budget.
CHECK_LE(size, max_cache_size_in_bytes_);
current_cache_size_in_bytes_ += size;
EvictIfOutOfMemoryBudget();
}
void NavigationEntryScreenshotManager::OnScreenshotRemoved(
NavigationEntryScreenshotCacheEvictor* cache,
size_t size) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
CHECK(!IsEmpty());
auto it = managed_caches_.Get(cache);
CHECK(it != managed_caches_.end());
CHECK_GE(current_cache_size_in_bytes_, size);
current_cache_size_in_bytes_ -= size;
if (cache->IsEmpty()) {
Unregister(cache);
}
}
void NavigationEntryScreenshotManager::OnScreenshotCompressed(
NavigationEntryScreenshotCacheEvictor* cache,
size_t old_size,
size_t new_size) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
CHECK(!IsEmpty());
CHECK(managed_caches_.Peek(cache) != managed_caches_.end());
CHECK_GE(current_cache_size_in_bytes_, old_size);
current_cache_size_in_bytes_ -= old_size;
current_cache_size_in_bytes_ += new_size;
}
void NavigationEntryScreenshotManager::OnVisibilityChanged(
NavigationEntryScreenshotCacheEvictor* cache) {
if (cache->IsEmpty()) {
CHECK(managed_caches_.Peek(cache) == managed_caches_.end());
return;
}
auto last_visible_time = cache->GetLastVisibleTime();
if (last_visible_time && !cleanup_task_.IsRunning()) {
ScheduleCleanup(*last_visible_time);
}
}
bool NavigationEntryScreenshotManager::IsEmpty() const {
CHECK(managed_caches_.empty() == (current_cache_size_in_bytes_ == 0U));
return managed_caches_.empty();
}
void NavigationEntryScreenshotManager::Register(
NavigationEntryScreenshotCacheEvictor* cache) {
CHECK(managed_caches_.Peek(cache) == managed_caches_.end());
managed_caches_.Put(std::move(cache));
OnVisibilityChanged(cache);
}
void NavigationEntryScreenshotManager::Unregister(
NavigationEntryScreenshotCacheEvictor* cache) {
auto it = managed_caches_.Peek(cache);
CHECK(it != managed_caches_.end());
managed_caches_.Erase(it);
}
base::TimeTicks NavigationEntryScreenshotManager::Now() const {
return tick_clock_->NowTicks();
}
void NavigationEntryScreenshotManager::ScheduleCleanup(
base::TimeTicks last_visible_time) {
const auto delay = cleanup_delay_ - (Now() - last_visible_time);
auto callback = base::BindOnce(&NavigationEntryScreenshotManager::RunCleanup,
weak_factory_.GetWeakPtr());
cleanup_task_.Start(FROM_HERE, delay, std::move(callback));
}
void NavigationEntryScreenshotManager::RunCleanup() {
std::optional<base::TimeTicks> earliest_last_visible_time;
const base::TimeTicks now = Now();
auto it = managed_caches_.begin();
while (it != managed_caches_.end()) {
auto* cache = *it;
it++;
const auto last_visible_time = cache->GetLastVisibleTime();
if (!last_visible_time) {
continue;
}
CHECK_LE(*last_visible_time, now);
if (now - *last_visible_time >= cleanup_delay_) {
cache->Purge(
NavigationEntryScreenshotCacheEvictor::PurgeReason::kInvisible);
CHECK(cache->IsEmpty());
CHECK(managed_caches_.Peek(cache) == managed_caches_.end());
} else if (!earliest_last_visible_time) {
earliest_last_visible_time = *last_visible_time;
} else {
earliest_last_visible_time =
std::min(*earliest_last_visible_time, *last_visible_time);
}
}
if (earliest_last_visible_time) {
ScheduleCleanup(*earliest_last_visible_time);
}
}
// The current implementation iterates through the tabs in the LRU order and
// evict screenshots from each tab, until either the global size satisfies the
// budget, or the cache of the current tab is empty.
//
// One alternative is to always evict the navigation entries in LRU order,
// regardless of which tab the entry is from. The pro of this alternative is to
// have all the eviction logic inside the global manager.
void NavigationEntryScreenshotManager::EvictIfOutOfMemoryBudget() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
CHECK(!IsEmpty());
// Start with the least recently used.
// TODO(khushalsagar): Evict from invisible caches first?
auto it = managed_caches_.rbegin();
while (current_cache_size_in_bytes_ > max_cache_size_in_bytes_) {
CHECK(it != managed_caches_.rend());
auto* cache = *it;
cache->EvictScreenshotsUntilUnderBudgetOrEmpty();
CHECK(cache->IsEmpty() ||
current_cache_size_in_bytes_ <= max_cache_size_in_bytes_);
if (cache->IsEmpty()) {
// No need to unregister this cache -
// `EvictScreenshotsUntilUnderBudgetOrEmpty` takes care of that.
CHECK(managed_caches_.Peek(cache) == managed_caches_.end());
it = managed_caches_.rbegin();
}
}
}
void NavigationEntryScreenshotManager::OnMemoryPressure(
base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (memory_pressure_level !=
base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL) {
return;
}
// Using a while loop because `Purge` erases the iterator.
auto it = managed_caches_.begin();
while (it != managed_caches_.end()) {
auto* cache = *it;
cache->Purge(
NavigationEntryScreenshotCacheEvictor::PurgeReason::kMemoryPressure);
CHECK(cache->IsEmpty());
it = managed_caches_.begin();
}
CHECK(IsEmpty());
}
void NavigationEntryScreenshotManager::RecordScreenshotCacheSizeAfterDelay() {
GetUIThreadTaskRunner({})->PostDelayedTask(
FROM_HERE,
base::BindOnce(
&NavigationEntryScreenshotManager::RecordScreenshotCacheSize,
weak_factory_.GetWeakPtr()),
memory_instrumentation::GetDelayForNextMemoryLog());
}
void NavigationEntryScreenshotManager::RecordScreenshotCacheSize() {
MEMORY_METRICS_HISTOGRAM_MB(
"Navigation.GestureTransition.ScreenshotCacheSize",
current_cache_size_in_bytes_ / (1024 * 1024));
RecordScreenshotCacheSizeAfterDelay();
}
} // namespace content