Saving a pcap takes minutes

[claui]

On Packetry 0.2.0, saving captured packets to a pcap file usually takes minutes, while loading is instant.

Steps to reproduce

1. Open Packetry.
2. Load any pcap file from your local file system. Observe that the file loads instantly, i.e. within tenths of seconds for a ~100MB pcap file.
3. Press the Save button on the toolbar. A file chooser comes up.
4. In the file chooser, pick a file name and hit Save.
5. Watch the progress bar near the bottom of the window:

Expected behavior

Saving a ~100MB pcap file, originally recorded and saved using Packetry, takes about three minutes on a fast SSD.

Actual behavior

Saving a ~100MB pcap file, originally recorded and saved using Packetry, takes less than 30 seconds on a fast SSD.

Affected builds

This has occurred as long as I can remember. I only learned today via Discord that it’s not supposed to be that slow.

Builds with which I can reproduce the symptom:

• GSG’s own v0.2.0 AppImage build

• the current 0.2.0-1 package on the AUR, built from tagged upstream sources using --release

• the older 0.1.0-1 AUR package, built from tagged upstream sources using --release

• most (if not all) of the post-v0.1.0 tip-of-the-tree builds I’ve tried, built using the VCS package packetry-git on the AUR via --release

Notes

The above steps use a previously-saved pcap file for convenience. However, the same symptoms occur when saving a fresh Cynthion-recorded file.

Packetry says that the pcap file I’ve used has ~2.7M transactions and ~5.5M packets.

[depili]

I can confirm this on macos with cargo run --release and 71827e2fcdcf227b3bbdab93b67cf4893f169e54

Saving a full speed 56 second capture of a ftdi-ft serial traffic with 4.13MiB reported size in packetry took around 5 minutes to save the 4,3M captured packets. This resulted in 75MB .pcap file.

[martinling]

I've been unable to reproduce this here. I have a 300MB file I use regularly for benchmarking, with 1.5M transactions and 3.5M packets, and it saves in about 5 seconds on a release build. On a debug build it takes a couple of minutes.

[martinling]

Turned out my file was a poor test because it used old dummy timestamp data. With a fresh capture I could reproduce the problem. Fixed in #170.

[claui]

Thank you for the fix @martinling!