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RasterCache adds a new mechanism for particularly complex pictures or…
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… display lists
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@ColdPaleLight
ColdPaleLight committed Mar 9, 2022
1 parent 1875f0a commit d2aea6a
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Showing 3 changed files with 181 additions and 15 deletions.
47 changes: 36 additions & 11 deletions flow/raster_cache.cc
View file
Original file line number Diff line number Diff line change
Expand Up @@ -62,7 +62,8 @@ static bool CanRasterizeRect(const SkRect& cull_rect) {

static bool IsPictureWorthRasterizing(SkPicture* picture,
bool will_change,
bool is_complex) {
bool is_complex,
bool is_high_priority) {
if (will_change) {
// If the picture is going to change in the future, there is no point in
// doing to extra work to rasterize.
Expand All @@ -75,7 +76,7 @@ static bool IsPictureWorthRasterizing(SkPicture* picture,
return false;
}

if (is_complex) {
if (is_complex || is_high_priority) {
// The caller seems to have extra information about the picture and thinks
// the picture is always worth rasterizing.
return true;
Expand All @@ -90,6 +91,7 @@ static bool IsDisplayListWorthRasterizing(
DisplayList* display_list,
bool will_change,
bool is_complex,
bool is_high_priority,
DisplayListComplexityCalculator* complexity_calculator) {
if (will_change) {
// If the display list is going to change in the future, there is no point
Expand All @@ -103,7 +105,7 @@ static bool IsDisplayListWorthRasterizing(
return false;
}

if (is_complex) {
if (is_complex || is_high_priority) {
// The caller seems to have extra information about the display list and
// thinks the display list is always worth rasterizing.
return true;
Expand Down Expand Up @@ -180,6 +182,7 @@ void RasterCache::Prepare(PrerollContext* context,
Entry& entry = cache_[cache_key];
entry.access_count++;
entry.used_this_frame = true;
entry.unused_count = 0;
if (!entry.image) {
entry.image = RasterizeLayer(context, layer, ctm, checkerboard_images_);
}
Expand Down Expand Up @@ -222,12 +225,13 @@ bool RasterCache::Prepare(PrerollContext* context,
bool is_complex,
bool will_change,
const SkMatrix& untranslated_matrix,
const SkPoint& offset) {
const SkPoint& offset,
bool is_high_priority) {
if (!GenerateNewCacheInThisFrame()) {
return false;
}

if (!IsPictureWorthRasterizing(picture, will_change, is_complex)) {
if (!IsPictureWorthRasterizing(picture, will_change, is_complex, is_high_priority)) {
// We only deal with pictures that are worthy of rasterization.
return false;
}
Expand All @@ -245,7 +249,8 @@ bool RasterCache::Prepare(PrerollContext* context,

// Creates an entry, if not present prior.
Entry& entry = cache_[cache_key];
if (entry.access_count < access_threshold_) {
entry.is_high_priority = is_high_priority;
if (!is_high_priority && entry.access_count < access_threshold_) {
// Frame threshold has not yet been reached.
return false;
}
Expand All @@ -270,7 +275,8 @@ bool RasterCache::Prepare(PrerollContext* context,
bool is_complex,
bool will_change,
const SkMatrix& untranslated_matrix,
const SkPoint& offset) {
const SkPoint& offset,
bool is_high_priority) {
if (!GenerateNewCacheInThisFrame()) {
return false;
}
Expand All @@ -280,7 +286,7 @@ bool RasterCache::Prepare(PrerollContext* context,
context->gr_context->backend())
: DisplayListComplexityCalculator::GetForSoftware();

if (!IsDisplayListWorthRasterizing(display_list, will_change, is_complex,
if (!IsDisplayListWorthRasterizing(display_list, will_change, is_complex, is_high_priority,
complexity_calculator)) {
// We only deal with display lists that are worthy of rasterization.
return false;
Expand All @@ -300,7 +306,8 @@ bool RasterCache::Prepare(PrerollContext* context,

// Creates an entry, if not present prior.
Entry& entry = cache_[cache_key];
if (entry.access_count < access_threshold_) {
entry.is_high_priority = is_high_priority;
if (!is_high_priority && entry.access_count < access_threshold_) {
// Frame threshold has not yet been reached.
return false;
}
Expand Down Expand Up @@ -345,6 +352,7 @@ void RasterCache::Touch(const RasterCacheKey& cache_key) {
if (it != cache_.end()) {
it->second.used_this_frame = true;
it->second.access_count++;
it->second.unused_count = 0;
}
}

Expand Down Expand Up @@ -384,6 +392,7 @@ bool RasterCache::Draw(const RasterCacheKey& cache_key,
Entry& entry = it->second;
entry.access_count++;
entry.used_this_frame = true;
entry.unused_count = 0;

if (entry.image) {
entry.image->draw(canvas, paint);
Expand All @@ -405,9 +414,25 @@ void RasterCache::SweepOneCacheAfterFrame(RasterCacheKey::Map<Entry>& cache,

for (auto it = cache.begin(); it != cache.end(); ++it) {
Entry& entry = it->second;

if (!entry.used_this_frame) {
dead.push_back(it);
entry.unused_count++;
if (entry.unused_count < entry.unused_threshold()) {
if (entry.image) {
RasterCacheKeyKind kind = it->first.kind();
switch (kind) {
case RasterCacheKeyKind::kPictureMetrics:
picture_metrics.unused_count++;
picture_metrics.unused_bytes += entry.image->image_bytes();
break;
case RasterCacheKeyKind::kLayerMetrics:
layer_metrics.unused_count++;
layer_metrics.unused_bytes += entry.image->image_bytes();
break;
}
}
} else {
dead.push_back(it);
}
} else if (entry.image) {
RasterCacheKeyKind kind = it->first.kind();
switch (kind) {
Expand Down
28 changes: 24 additions & 4 deletions flow/raster_cache.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -67,19 +67,32 @@ struct RasterCacheMetrics {
*/
size_t in_use_bytes = 0;

/**
* The number of cache entries with images unused but keeped in this frame.
*/
size_t unused_count = 0;

/**
* The size of all of the images unused but keeped in this frame.
*/
size_t unused_bytes = 0;
/**
* The total cache entries that had images during this frame whether
* they were used in the frame or held memory during the frame and then
* were evicted after it ended.
*/
size_t total_count() const { return in_use_count + eviction_count; }
size_t total_count() const {
return in_use_count + unused_count + eviction_count;
}

/**
* The size of all of the cached images during this frame whether
* they were used in the frame or held memory during the frame and then
* were evicted after it ended.
*/
size_t total_bytes() const { return in_use_bytes + eviction_bytes; }
size_t total_bytes() const {
return in_use_bytes + unused_bytes + eviction_bytes;
}
};

class RasterCache {
Expand Down Expand Up @@ -186,13 +199,15 @@ class RasterCache {
bool is_complex,
bool will_change,
const SkMatrix& untranslated_matrix,
const SkPoint& offset = SkPoint());
const SkPoint& offset = SkPoint(),
bool is_high_priority = false);
bool Prepare(PrerollContext* context,
DisplayList* display_list,
bool is_complex,
bool will_change,
const SkMatrix& untranslated_matrix,
const SkPoint& offset = SkPoint());
const SkPoint& offset = SkPoint(),
bool is_high_priority = false);

// If there is cache entry for this picture, display list or layer, mark it as
// used for this frame in order to not get evicted. This is needed during
Expand Down Expand Up @@ -286,9 +301,14 @@ class RasterCache {

private:
struct Entry {
// If the entry is high priority, it will always cache on first usage and
// survive 3 frames without usage.
bool is_high_priority = false;
bool used_this_frame = false;
size_t access_count = 0;
size_t unused_count = 0;
std::unique_ptr<RasterCacheResult> image;
size_t unused_threshold() const { return is_high_priority ? 3 : 1; }
};

void Touch(const RasterCacheKey& cache_key);
Expand Down
121 changes: 121 additions & 0 deletions flow/raster_cache_unittests.cc
View file
Original file line number Diff line number Diff line change
Expand Up @@ -58,6 +58,26 @@ TEST(RasterCache, ThresholdIsRespectedForSkPicture) {
ASSERT_TRUE(cache.Draw(*picture, dummy_canvas));
}

TEST(RasterCache, HighPriorityIsRespectedForSkPicture) {
flutter::RasterCache cache;

SkMatrix matrix = SkMatrix::I();

auto picture = GetSamplePicture();

SkCanvas dummy_canvas;

PrerollContextHolder preroll_context_holder = GetSamplePrerollContextHolder();

cache.PrepareNewFrame();

// Prepare should cache it when 1st access.
ASSERT_TRUE(cache.Prepare(&preroll_context_holder.preroll_context,
picture.get(), true, false, matrix, SkPoint(),
/**is_high_priority=*/true));
ASSERT_TRUE(cache.Draw(*picture, dummy_canvas));
}

TEST(RasterCache, MetricsOmitUnpopulatedEntries) {
size_t threshold = 2;
flutter::RasterCache cache(threshold);
Expand Down Expand Up @@ -141,6 +161,26 @@ TEST(RasterCache, ThresholdIsRespectedForDisplayList) {
ASSERT_TRUE(cache.Draw(*display_list, dummy_canvas));
}

TEST(RasterCache, HighPriorityIsRespectedForDisplayList) {
flutter::RasterCache cache;

SkMatrix matrix = SkMatrix::I();

auto display_list = GetSampleDisplayList();

SkCanvas dummy_canvas;

PrerollContextHolder preroll_context_holder = GetSamplePrerollContextHolder();

cache.PrepareNewFrame();

// Prepare should cache it when 1st access.
ASSERT_TRUE(cache.Prepare(&preroll_context_holder.preroll_context,
display_list.get(), true, false, matrix, SkPoint(),
/**is_high_priority=*/true));
ASSERT_TRUE(cache.Draw(*display_list, dummy_canvas));
}

TEST(RasterCache, AccessThresholdOfZeroDisablesCachingForSkPicture) {
size_t threshold = 0;
flutter::RasterCache cache(threshold);
Expand Down Expand Up @@ -291,6 +331,87 @@ TEST(RasterCache, SweepsRemoveUnusedDisplayLists) {
ASSERT_FALSE(cache.Draw(*display_list, dummy_canvas));
}

void PrepareAndCleanupEmptyFrame(flutter::RasterCache& cache, size_t times) {
for (size_t i = 0; i < times; i++) {
cache.PrepareNewFrame();
cache.CleanupAfterFrame(); // Extra frame without a Get image access.
}
}

TEST(RasterCache, KeepUnusedSkPicturesIfIsHighPriority) {
size_t threshold = 1;
flutter::RasterCache cache(threshold);

SkMatrix matrix = SkMatrix::I();

auto picture = GetSamplePicture();

SkCanvas dummy_canvas;

PrerollContextHolder preroll_context_holder = GetSamplePrerollContextHolder();

cache.PrepareNewFrame();

ASSERT_TRUE(cache.Prepare(&preroll_context_holder.preroll_context,
picture.get(), true, false, matrix, SkPoint(),
/**is_high_priority=*/true));
ASSERT_TRUE(cache.Draw(*picture, dummy_canvas));

cache.CleanupAfterFrame();

PrepareAndCleanupEmptyFrame(cache, 1);
cache.PrepareNewFrame();
ASSERT_TRUE(cache.Draw(*picture, dummy_canvas));
cache.CleanupAfterFrame();

PrepareAndCleanupEmptyFrame(cache, 2);
cache.PrepareNewFrame();
ASSERT_TRUE(cache.Draw(*picture, dummy_canvas));
cache.CleanupAfterFrame();

PrepareAndCleanupEmptyFrame(cache, 3);
cache.PrepareNewFrame();
ASSERT_FALSE(cache.Draw(*picture, dummy_canvas));
cache.CleanupAfterFrame();
}

TEST(RasterCache, KeepUnusedDisplayListsIfIsHighPriority) {
size_t threshold = 1;
flutter::RasterCache cache(threshold);

SkMatrix matrix = SkMatrix::I();

auto display_list = GetSampleDisplayList();

SkCanvas dummy_canvas;

PrerollContextHolder preroll_context_holder = GetSamplePrerollContextHolder();

cache.PrepareNewFrame();

ASSERT_TRUE(cache.Prepare(&preroll_context_holder.preroll_context,
display_list.get(), true, false, matrix, SkPoint(),
/**is_high_priority=*/true));
ASSERT_TRUE(cache.Draw(*display_list, dummy_canvas));

cache.CleanupAfterFrame();

PrepareAndCleanupEmptyFrame(cache, 1);
cache.PrepareNewFrame();
ASSERT_TRUE(cache.Draw(*display_list, dummy_canvas));
cache.CleanupAfterFrame();

PrepareAndCleanupEmptyFrame(cache, 2);
cache.PrepareNewFrame();
ASSERT_TRUE(cache.Draw(*display_list, dummy_canvas));
cache.CleanupAfterFrame();

PrepareAndCleanupEmptyFrame(cache, 3);
cache.PrepareNewFrame();
ASSERT_FALSE(cache.Draw(*display_list, dummy_canvas));
cache.CleanupAfterFrame();
}

// Construct a cache result whose device target rectangle rounds out to be one
// pixel wider than the cached image. Verify that it can be drawn without
// triggering any assertions.
Expand Down

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