A Qt/OpenGL-based implementation of a heap history visualisation UI in along the lines of Gerardo Richarte's HeapDraw (for more details, check http://actes.sstic.org/SSTIC07/Rump_sessions/SSTIC07-rump-Richarte-Heap_Massaging.pdf)
The tool had been reimplemented by various people in various places a few times, usually in a hackish / nonscalable manner. zynamics used to hand source code for a JOGL-based UI out with some of our trainings, but that tool is not easily portable to modern OpenGL or 64-bit address spaces.
Other common mistakes include:
- Not using OpenGL to render lots of rectangles.
- Using floats or other low-precision coordinates to represent rectangle corners and hence suffering from rounding errors.
- Not using a language that can deal with a couple million rectangles.
The codebase in this repository has the following goals:
- Fast and scalable to 20m+ allocations. Haven't tried, but should work.
- As precise as possible. Use precise integer arithmetic as much as possible to avoid rounding errors shifting rectangles around.
- Useable. This will take some time.
Instructions for the moment:
- Build using stock QtCreator.
- You will need: libgflags-dev mesa-common-dev libqt4-opengl-dev
- The current trunk will simply try to load /tmp/heap.json - use the enclosed json file as an example.
A million tasks are still left to do. Useful things that should be added:
- Code to display tooltips when the mouse hovers over a block.
- Code to highlight a block when it is clicked / selected.
- Code to add horizontal red lines, too.
- Code to select all blocks that are modified between two events.
Contributions very welcome.
- CTRL + wheel: Zoom in / out
- Click + drag: Pan diagram
- CTRL + shift + wheel: Squash / stretch horizontally
- shift + wheel: Squash / stretch vertically
Cheers, Halvar Flake / Thomas Dullien