Memory Leak Fixed in STL Generation

Symptoms

• Memory usage could grow during long-running sessions, especially with many cancelled conversions.
• Some users observed slower UI responsiveness after many conversions (GC pressure).
• Abort-heavy traffic could leave queued stream chunks longer than expected.

Root cause

• An abort path kept references to large ArrayBuffers (image rasters + intermediate mesh buffers) longer than needed.
• Some streaming responses weren’t releasing back-pressure queues promptly when the client disconnected.

Fix

• Explicit cleanup on abort: intermediate buffers are nulled and GC-friendly within the same tick.
• Stream finalization hardening: we close/tear down streams on disconnect to prevent queued chunks from piling up.
• More aggressive timeouts for hung conversions (without impacting successful long-running jobs).

123- If you batch-convert many PNGs to STL, keep the tab open until downloads finish.
- If you cancel conversions frequently, this update prevents memory from creeping over time.
- We also improved abort handling to return faster and free resources sooner.

Verification

• Stress tests with repeated convert/abort cycles to ensure buffers are released quickly.
• Disconnect simulations to verify stream teardown and queue cleanup.
• Monitoring memory plateaus instead of unbounded growth during long sessions.

Who was affected

This only became noticeable during heavy, long-lived sessions — for example, converting dozens of PNGs to STL back-to-back without reloading the tab, or repeatedly starting and cancelling conversions. A typical one-off conversion was never affected, and no output files were ever corrupted; the issue was purely about memory that should have been released staying around longer than intended.

How to tell if you were hitting it

• The tab felt progressively slower the longer you kept it open and kept converting.
• Browser task manager showed the tab's memory climbing and not coming back down between jobs.
• Symptoms cleared after a refresh — a classic sign of retained memory rather than a logic bug.

After this fix, memory now plateaus during long sessions instead of growing without bound, so you can keep the tab open across many conversions without a gradual slowdown.