553 feature request graphical timetable streckengrafik performance optimisation

[aiAdrian]

Description

Graphical Timetable Performance Optimization

The calculation time for the extractSectionTracks method has been significantly reduced:

• Google Chrome: Improved by a factor of 3 (from ~75ms to ~25ms)
• Microsoft Edge: Improved by a factor of 5 (from ~620ms to ~115ms)

These optimizations enhance responsiveness and reduce latency across browsers, especially for Edge users.

Performance Improvement: extractSectionTracks Method

Goal: Improve rendering performance of the graphical timetable by introducing caching and more efficient data structures.

Extended Functionality

Caching introduced: Added getTrainrunSectionFromCacheDuringRendering() method using a Map<number, TrainrunSection> to avoid redundant service calls.

Cache integration: The cache is now used across multiple methods:

• render()
• extractStreckenGleis()
• extractSectionTracks()
• calculateMinimumHeadwayTimeAtNode()
• computeTrackAlignments()
• setMaxTrackMap()

 Performance Improvements

• Optimized data structure: Replaced number[][] with Uint8Array for dataMatrix to reduce memory usage and improve access speed.

• Frequency unrolling refactored: New method extractSectionTracksUnrollFreq() handles train frequency loops more efficiently.

• Occupation band optimization: extractSectionTracksFillOccupationBand() fills occupancy data with bounds checking and performance tuning.

 Logic Enhancements

• headwayTime calculation now uses the cache.

• Precomputations like travelTimeIdxPart and baseTimeCellIdx improve loop performance

Issues

#553

Checklist

• This PR contains a description of the changes I'm making
• I've read the Contribution Guidelines
• I've added tests for changes or features I've introduced
• I documented any high-level concepts I'm introducing in documentation/
• CI is currently green and this is ready for review

[shenriotpro]

I can't say I understand the logic, but I love the result :)

[aiAdrian]

There to many changes in sg6 - made every very bugy while rebasing. Thus i will make a new branch and merge the changes manually into. The reported bug is related to the bug we fixed

[aiAdrian]

After extended testing with the latest version of Netzgrafik-Editor, I came to the conclusion that the additional complexity introduced is not justified. The expected performance gain could no longer be demonstrated in a significant way. Therefore, I propose not to merge this. Many thanks to all reviewers and contributors. I believe it is always worthwhile to weigh increased complexity against actual benefit. At this moment, I don’t think there is sufficient gain.