xnyhps
Joined 14 years ago
Joined 14 years ago
Streaming parsers give you a stream of events like "open tag 'message'", "attribute 'from'", "open tag 'body'", "close tag 'body'" and you need to gather those and translate them back into the top-level elements of the stream. This is pretty tedious, and if you do it wrong you may end up leaking memory (if you keep the entire tree around in memory) or even introduce vulnerabilities (similar to https://bugs.chromium.org/p/project-zero/issues/detail?id=22... ).
Also, I don’t expect it to be 100% correct everywhere, sometimes the GPS data is just not good enough or I might have traveled in a way that the map wouldn’t allow, but there were some instances I found where I thought it should’ve been able to find a match and it didn’t.
Some examples: the GPS error is often more than the distance between a road and a cycling path next to the road, so it often confuses them.
The default cycling profile of OSRM actually takes into account the possibility of dismounting and walking with the bike. This is very useful when that is what you did, but it also creates a lot of extra possibilities. For example, a one way cycling path can then be used in the opposite direction by walking.
There’s also a limit to how many points it can process at once (and it becomes quite slow if you increase that). Should I slice up the trip in multiple segments and then somehow connect them, or is it better to drop some of the points? Still haven’t found out what the best option is.
It also helped me spot some subtle errors or missing data on OSM, but that's easy enough to fix.
Anything not on those locations is not protected, so there's no Data Vault for Chrome's cookie file, for example.