Skip to content

Commit

Permalink
Change Usd_Clip to hold a shared pointer to the array of time mappings.
Browse files Browse the repository at this point in the history 
Set up this array in Usd_ClipSet where all the Usd_Clip objects are
allocated. Prevents N^2 memory usage on the number of time mappings in
a clip set.
  • Loading branch information
@marktucker
marktucker committed Feb 19, 2022
1 parent 77fa6ca commit f96b8f3
Show file tree
Hide file tree
Showing 3 changed files with 80 additions and 76 deletions.
100 changes: 30 additions & 70 deletions pxr/usd/usd/clip.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -69,23 +69,6 @@ UsdGetClipRelatedFields()
};
}

struct Usd_SortByExternalTime
{
bool
operator()(const Usd_Clip::TimeMapping& x,
const Usd_Clip::ExternalTime y) const
{
return x.externalTime < y;
}

bool
operator()(const Usd_Clip::TimeMapping& x,
const Usd_Clip::TimeMapping& y) const
{
return x.externalTime < y.externalTime;
}
};

std::ostream&
operator<<(std::ostream& out, const Usd_ClipRefPtr& clip)
{
Expand Down Expand Up @@ -118,7 +101,7 @@ Usd_Clip::Usd_Clip(
ExternalTime clipAuthoredStartTime,
ExternalTime clipStartTime,
ExternalTime clipEndTime,
const TimeMappings& timeMapping)
const std::shared_ptr<TimeMappings> &timeMapping)
: sourceLayerStack(clipSourceLayerStack)
, sourcePrimPath(clipSourcePrimPath)
, sourceLayerIndex(clipSourceLayerIndex)
Expand All @@ -129,29 +112,6 @@ Usd_Clip::Usd_Clip(
, endTime(clipEndTime)
, times(timeMapping)
{
if (!times.empty()) {
// Maintain the relative order of entries with the same stage time for
// jump discontinuities in case the authored times array was unsorted.
std::stable_sort(times.begin(), times.end(), Usd_SortByExternalTime());

// Jump discontinuities are represented by consecutive entries in the
// times array with the same stage time, e.g. (10, 10), (10, 0).
// We represent this internally as (10 - SafeStep(), 10), (10, 0)
// because a lot of the desired behavior just falls out from this
// representation.
for (size_t i = 0; i < times.size() - 1; ++i) {
if (times[i].externalTime == times[i + 1].externalTime) {
times[i].externalTime =
times[i].externalTime - UsdTimeCode::SafeStep();
times[i].isJumpDiscontinuity = true;
}
}

// Add sentinel values to the beginning and end for convenience.
times.insert(times.begin(), times.front());
times.insert(times.end(), times.back());
}

// For performance reasons, we want to defer the loading of the layer
// for this clip until absolutely needed. However, if the layer happens
// to already be opened, we can take advantage of that here.
Expand Down Expand Up @@ -195,8 +155,8 @@ _GetBracketingTimeSegment(
}
else {
*m2 = std::distance(times.begin(),
std::lower_bound(times.begin(), times.end(),
time, Usd_SortByExternalTime()));
std::lower_bound(times.begin(), times.end(),
time, Usd_Clip::Usd_SortByExternalTime()));
*m1 = *m2 - 1;
}

Expand Down Expand Up @@ -336,7 +296,7 @@ Usd_Clip::_GetBracketingTimeSamplesForPathFromClipLayer(
// s2, since s2 is in the range of (m2, m3), we use those mappings to map
// s2 to e2. So, our final answer is (e1, e2).
size_t m1, m2;
if (!_GetBracketingTimeSegment(times, time, &m1, &m2)) {
if (!_GetBracketingTimeSegment(*times, time, &m1, &m2)) {
*tLower = lowerInClip;
*tUpper = upperInClip;
return true;
Expand Down Expand Up @@ -389,11 +349,11 @@ Usd_Clip::_GetBracketingTimeSamplesForPathFromClipLayer(
};

for (int i1 = m1, i2 = m2; i1 >= 0 && i2 >= 0; --i1, --i2) {
if (_CanTranslate(times, i1, i2, /*lower=*/true)) { break; }
if (_CanTranslate(*times, i1, i2, /*lower=*/true)) { break; }
}

for (size_t i1 = m1, i2 = m2, sz = times.size(); i1 < sz && i2 < sz; ++i1, ++i2) {
if (_CanTranslate(times, i1, i2, /*lower=*/false)) { break; }
for (size_t i1 = m1, i2 = m2, sz = times->size(); i1 < sz && i2 < sz; ++i1, ++i2) {
if (_CanTranslate(*times, i1, i2, /*lower=*/false)) { break; }
}

if (translatedLower && !translatedUpper) {
Expand All @@ -414,18 +374,18 @@ Usd_Clip::_GetBracketingTimeSamplesForPathFromClipLayer(
//
// The 'timingOutsideClip' test case in testUsdModelClips exercises
// this behavior.
if (lowerInClip < times.front().internalTime) {
translatedLower.reset(times.front().externalTime);
if (lowerInClip < times->front().internalTime) {
translatedLower.reset(times->front().externalTime);
}
else if (lowerInClip > times.back().internalTime) {
translatedLower.reset(times.back().externalTime);
else if (lowerInClip > times->back().internalTime) {
translatedLower.reset(times->back().externalTime);
}

if (upperInClip < times.front().internalTime) {
translatedUpper.reset(times.front().externalTime);
if (upperInClip < times->front().internalTime) {
translatedUpper.reset(times->front().externalTime);
}
else if (upperInClip > times.back().internalTime) {
translatedUpper.reset(times.back().externalTime);
else if (upperInClip > times->back().internalTime) {
translatedUpper.reset(times->back().externalTime);
}
}

Expand All @@ -452,7 +412,7 @@ Usd_Clip::GetBracketingTimeSamplesForPath(
// Each external time in the clip times array is considered a time
// sample.
if (_GetBracketingTimeSamples(
times.cbegin(), times.cend(), time,
times->cbegin(), times->cend(), time,
&bracketingTimes[numTimes], &bracketingTimes[numTimes + 1])) {
numTimes += 2;
}
Expand Down Expand Up @@ -505,7 +465,7 @@ Usd_Clip::_ListTimeSamplesForPathFromClipLayer(
{
std::set<InternalTime> timeSamplesInClip =
_GetLayerForClip()->ListTimeSamplesForPath(_TranslatePathToClip(path));
if (times.empty()) {
if (times->empty()) {
*timeSamples = std::move(timeSamplesInClip);

// Filter out all samples that are outside the clip's active range
Expand All @@ -528,9 +488,9 @@ Usd_Clip::_ListTimeSamplesForPathFromClipLayer(
// To deal with this, every internal time sample has to be checked
// against the entire mapping function.
for (InternalTime t: timeSamplesInClip) {
for (size_t i = 0; i < times.size() - 1; ++i) {
const TimeMapping& m1 = times[i];
const TimeMapping& m2 = times[i+1];
for (size_t i = 0; i < times->size() - 1; ++i) {
const TimeMapping& m1 = (*times)[i];
const TimeMapping& m2 = (*times)[i+1];

// Ignore time mappings whose external time domain does not
// intersect the times at which this clip is active.
Expand Down Expand Up @@ -576,7 +536,7 @@ Usd_Clip::ListTimeSamplesForPath(const SdfPath& path) const

// Each entry in the clip's time mapping is considered a time sample,
// so add them in here.
for (const TimeMapping& t : times) {
for (const TimeMapping& t : *times) {
if (startTime <= t.externalTime && t.externalTime < endTime) {
timeSamples.insert(t.externalTime);
}
Expand Down Expand Up @@ -651,12 +611,12 @@ Usd_Clip::InternalTime
Usd_Clip::_TranslateTimeToInternal(ExternalTime extTime) const
{
size_t i1, i2;
if (!_GetBracketingTimeSegment(times, extTime, &i1, &i2)) {
if (!_GetBracketingTimeSegment(*times, extTime, &i1, &i2)) {
return extTime;
}

const TimeMapping& m1 = times[i1];
const TimeMapping& m2 = times[i2];
const TimeMapping& m1 = (*times)[i1];
const TimeMapping& m2 = (*times)[i2];

// If the time segment ends on the left side of a jump discontinuity
// we use the authored external time for the translation.
Expand All @@ -681,8 +641,8 @@ Usd_Clip::_TranslateTimeToInternal(ExternalTime extTime) const
// This avoids all of the issues above and more closely matches the intent
// expressed in the authored times metadata.
if (m2.isJumpDiscontinuity) {
TF_VERIFY(i2 + 1 < times.size());
const TimeMapping& m3 = times[i2 + 1];
TF_VERIFY(i2 + 1 < times->size());
const TimeMapping& m3 = (*times)[i2 + 1];
return _TranslateTimeToInternalHelper(
extTime, m1, TimeMapping(m3.externalTime, m2.internalTime));
}
Expand Down Expand Up @@ -718,8 +678,8 @@ Usd_Clip::ExternalTime
Usd_Clip::_TranslateTimeToExternal(
InternalTime intTime, size_t i1, size_t i2) const
{
const TimeMapping& m1 = times[i1];
const TimeMapping& m2 = times[i2];
const TimeMapping& m1 = (*times)[i1];
const TimeMapping& m2 = (*times)[i2];

// Clients should never be trying to map an internal time through a jump
// discontinuity.
Expand Down Expand Up @@ -747,8 +707,8 @@ Usd_Clip::_TranslateTimeToExternal(
// This avoids all of the issues above and more closely matches the intent
// expressed in the authored times metadata.
if (m2.isJumpDiscontinuity) {
TF_VERIFY(i2 + 1 < times.size());
const TimeMapping& m3 = times[i2 + 1];
TF_VERIFY(i2 + 1 < times->size());
const TimeMapping& m3 = (*times)[i2 + 1];
return _TranslateTimeToExternalHelper(
intTime, m1, TimeMapping(m3.externalTime, m2.internalTime));
}
Expand Down
23 changes: 21 additions & 2 deletions pxr/usd/usd/clip.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -105,6 +105,25 @@ struct Usd_Clip

typedef std::vector<TimeMapping> TimeMappings;

/// Structure used to sort TimeMapping objects. Used by both Usd_Clip and
/// Usd_ClipSet.
struct Usd_SortByExternalTime
{
bool
operator()(const Usd_Clip::TimeMapping& x,
const Usd_Clip::ExternalTime y) const
{
return x.externalTime < y;
}

bool
operator()(const Usd_Clip::TimeMapping& x,
const Usd_Clip::TimeMapping& y) const
{
return x.externalTime < y.externalTime;
}
};

Usd_Clip();
Usd_Clip(
const PcpLayerStackPtr& clipSourceLayerStack,
Expand All @@ -115,7 +134,7 @@ struct Usd_Clip
ExternalTime clipAuthoredStartTime,
ExternalTime clipStartTime,
ExternalTime clipEndTime,
const TimeMappings& timeMapping);
const std::shared_ptr<TimeMappings> &timeMapping);

bool HasField(const SdfPath& path, const TfToken& field) const;

Expand Down Expand Up @@ -201,7 +220,7 @@ struct Usd_Clip
ExternalTime endTime;

/// Mapping of external to internal times.
TimeMappings times;
std::shared_ptr<const TimeMappings> times;

private:
friend class UsdStage;
Expand Down
33 changes: 29 additions & 4 deletions pxr/usd/usd/clipSet.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -351,15 +351,40 @@ Usd_ClipSet::Usd_ClipSet(
}

// Generate the clip time mapping that applies to all clips.
Usd_Clip::TimeMappings timeMapping;
std::shared_ptr<Usd_Clip::TimeMappings> times(new Usd_Clip::TimeMappings());
if (clipDef.clipTimes) {
for (const auto& clipTime : *clipDef.clipTimes) {
const Usd_Clip::ExternalTime extTime = clipTime[0];
const Usd_Clip::InternalTime intTime = clipTime[1];
timeMapping.push_back(Usd_Clip::TimeMapping(extTime, intTime));
times->push_back(Usd_Clip::TimeMapping(extTime, intTime));
}
}

if (!times->empty()) {
// Maintain the relative order of entries with the same stage time for
// jump discontinuities in case the authored times array was unsorted.
std::stable_sort(times->begin(), times->end(),
Usd_Clip::Usd_SortByExternalTime());

// Jump discontinuities are represented by consecutive entries in the
// times array with the same stage time, e.g. (10, 10), (10, 0).
// We represent this internally as (10 - SafeStep(), 10), (10, 0)
// because a lot of the desired behavior just falls out from this
// representation.
for (size_t i = 0; i < times->size() - 1; ++i) {
if ((*times)[i].externalTime == (*times)[i + 1].externalTime) {
(*times)[i].externalTime =
(*times)[i].externalTime - UsdTimeCode::SafeStep();
(*times)[i].isJumpDiscontinuity = true;
}
}

// Add sentinel values to the beginning and end for convenience.
times->insert(times->begin(), times->front());
times->insert(times->end(), times->back());
}


// Build up the final vector of clips.
const _TimeToClipMap::const_iterator itBegin = startTimeToClip.begin();
const _TimeToClipMap::const_iterator itEnd = startTimeToClip.end();
Expand All @@ -384,7 +409,7 @@ Usd_ClipSet::Usd_ClipSet(
/* clipAuthoredStartTime = */ clipEntry.startTime,
/* clipStartTime = */ clipStartTime,
/* clipEndTime = */ clipEndTime,
/* clipTimes = */ timeMapping));
/* clipTimes = */ times));

valueClips.push_back(clip);
}
Expand Down Expand Up @@ -416,7 +441,7 @@ Usd_ClipSet::Usd_ClipSet(
/* clipAuthoredStartTime= */ Usd_ClipTimesEarliest,
/* clipStartTime = */ Usd_ClipTimesEarliest,
/* clipEndTime = */ Usd_ClipTimesLatest,
/* clipTimes = */ Usd_Clip::TimeMappings()));
/* clipTimes = */ std::make_shared<Usd_Clip::TimeMappings>()));

if (generatedManifest) {
// If we generated a manifest layer pull on the clip so that it takes
Expand Down

0 comments on commit f96b8f3

Please sign in to comment.