Details
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Bug
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Resolution: Out of scope
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P2: Important
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None
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5.4.0 Beta
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None
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Linux 64bits
Description
Rendering very large text documents can easily increase the memory usage of applications very high.
Attached is a Text item in which the QString documentation is loaded.
Here is an excerpt of ms_print of the massif peak snapshot of the attached trace:
69 30,628,915,902 500,959,864 499,513,679 1,446,185 0 99.71% (499,513,679B) (heap allocation functions) malloc/new/new[], --alloc-fns, etc. ->86.84% (435,023,672B) 0x69A3A84: QArrayData::allocate(unsigned long, unsigned long, unsigned long, QFlags<QArrayData::AllocationOption>) (qarraydata.cpp:93) | ->51.02% (255,613,536B) 0x4FF6B39: QTypedArrayData<QSGGeometry::TexturedPoint2D>::allocate(unsigned long, QFlags<QArrayData::AllocationOption>) (qarraydata.h:216) | | ->51.02% (255,613,536B) 0x4FF5890: QVector<QSGGeometry::TexturedPoint2D>::reallocData(int, int, QFlags<QArrayData::AllocationOption>) (qvector.h:499) | | ->51.02% (255,613,536B) 0x4FF4D28: QVector<QSGGeometry::TexturedPoint2D>::reserve(int) (qvector.h:359) | | ->51.02% (255,613,536B) 0x4FF37BF: QSGDistanceFieldGlyphNode::updateGeometry() (qsgdistancefieldglyphnode.cpp:204) ...
The plain text document including all markup is 389996 bytes, at 435,023,672B just for distance field nodes, this means that each character takes around 1115 bytes or memory.
Various tests revealed that the per-character cost is between 500 and 1000 bytes of memory.
As reference, the render process in Chromium takes 50MB to load the formated QString documentation, including images.
Attachments
Issue Links
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