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Type:
Improvement
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Resolution: Unresolved
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Priority:
Major - P3
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None
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Affects Version/s: None
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Component/s: None
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Labels:
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Service Arch
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v8.0
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Service Arch 2024-04-01, Service Arch 2024-04-15, Service Arch 2024-04-29, Service Arch 2024-05-13
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41
The code generated for OplogEntryBase takes an OpTime and calls toBSON(), which constructs its own BSONOBjBuilder and allocates its own memory, rather than re-using the Builder in the calling function.
void OplogEntryBase::serialize(BSONObjBuilder* builder) const {
_hasMembers.required();
/// snipped
if (_donorOpTime) {
const BSONObj localObject = (*_donorOpTime).toBSON(); // why not reuse the builder?
builder->append(kDonorOpTimeFieldName, localObject);
}
This is very wasteful and appears to be happening in all of our IDL-generated files that have OpTime members.
This is true for non-optional OpTimes also:
void ElectionParticipantMetrics::serialize(BSONObjBuilder* builder) const {
_hasMembers.required();
// snipped
{
const BSONObj localObject = _lastWrittenOpTimeAtElection.toBSON();
builder->append(kLastWrittenOpTimeAtElectionFieldName, localObject);
}