pgRouting on (very) large graphs

Posted on March 23, 2023 in Dev • 4 min read

I recently performed routing and graph analysis on a very large graph built on top of some OpenData file. The underlying graph had about 40M edges, which is about the size of the road network mapped by OpenStreetMap in North America. Not that much, but still a bit tricky to handle.

Continue reading

Parallel GPG decryption

Posted on January 14, 2023 in Dev • 3 min read

I recently had to decrypt about 500k asymetrically GPG-encrypted strings and found out that it can take quite a lot of time while not being as straightforward as one might think to process in a concurrent manner to accelerate the computation time. Here is a quick work around for GPG parallel decryption.

Continue reading

Bicycle routing avoiding road works

Posted on July 16, 2019 in Dev • 2 min read

Many cities (and administrative areas) in France are providing OpenData feeds concerning ongoing road works. All are not as detailed or as precise, but they all provide the information about potential traffic disruption in this area.

When you ride a bicycle, most road work may actually affect your route, either directly (bicycle lane closed without any deviation) or indirectly (road works usually means a lot of traffic jam, and it may be tricky even with a bicycle). Can we have a router avoiding road works?

Continue reading

Cycl’Assist/Cygnal 0.4 is out!

Posted on January 22, 2019 in Dev • 2 min read

Cycl’Assist aims to be a webapp to ease tracking and reporting issues with bike infrastructures while riding your bike (any danger on the way such as holes in the ground, cars parked like sh*t, road work, etc). You can think of it as Waze for bikes :) Version 0 …

Continue reading

Manage expiration of cached assets with Service Worker caching

Posted on January 05, 2019 in Dev • 4 min read

My Cygnal app uses OSM map tiles to render the map on which the reports are shown. It is meant to be used in realtime, on your mobile phone, mounted on your bike and there can often be some network issues in this setup.

I was looking for a way …

Continue reading