EVeventhelix·Aug 23, 2024Submission
Nanolog supports logging with 7 ns median latency
123 points · Open discussionPlatformLab
NanoLog
C++2019–2024
PlatformLab / NanoLog
NanoLog
Nanolog is an extremely performant nanosecond scale logging system for C++ that exposes a simple printf-like API.
4Distinct people
4Mentions
0Explicit recommenders
3.4KGitHub stars
What to know before exploring
What it is
Nanolog is an extremely performant nanosecond scale logging system for C++ that exposes a simple printf-like API.
GitHub
Where it is used
No documented product use has been verified yet.
What people are saying
No recommendation phrase was found in the indexed comments.
No classified warning is attached to this page. Read the discussions before treating silence as approval.
Also in these discussions
No other repository is repeatedly linked in the same discussions.
This week on Hacker News
Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 3:56:07 PM UTC.
No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.
Mentions over time
HN mentions by year4 dated mentions
Observed mentions: 2019-01-18 16:16:38 UTC to 2024-08-23 12:32:15 UTC.
Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.
View mention counts and date ranges
| Period | Start (UTC) | End (exclusive, UTC) | Mentions | Submissions | Comments |
|---|---|---|---|---|---|
| 2019 | 2019-01-01 00:00:00 UTC | 2020-01-01 00:00:00 UTC | 3 | 1 | 2 |
| 2020 | 2020-01-01 00:00:00 UTC | 2021-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2021 | 2021-01-01 00:00:00 UTC | 2022-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2022 | 2022-01-01 00:00:00 UTC | 2023-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2023 | 2023-01-01 00:00:00 UTC | 2024-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2024 | 2024-01-01 00:00:00 UTC | 2025-01-01 00:00:00 UTC | 1 | 1 | 0 |
What Hacker News says
4 sourcesThe code overall is pretty clever, but at the core of all this they completely ignore strict aliasing to dump stuff into a char* buffer indiscriminately... Look at this function:
https://github.com/PlatformLab/NanoLog/blob/master/runtime/N...
T argument = *reinterpret_cast<T*>(*in);
...
uint32_t stringBytes = *reinterpret_cast<uint32_t*>(*in);
A total of 6 reinterpret_casts in that file alone.
I didn't see any indication that you have to turn off strict aliasing to use this library (and would you really want to make all your remaining code slower just so your logging has better benchmark scores?). Which makes all this code UB as far as the C++ standard is concerned (no, their allocator does not magically placement-new the correct object types into the right places).
They could just inspect their T values as char* and/or me
Read the rest
mcpy them around instead of all this pointer aliasing (well, as long as their values are trivial types - I couldn't figure out whether you can log non-trivial stuff here?) at virtually no additional cost.
Edit: And this right here convinces me that I definitely wouldn't want to use this library in production... Adding a volatile to fix a threading bug is just a big no-no.
https://github.com/PlatformLab/NanoLog/commit/e9691246ede6da...
NanoLog – a nanosecond scale logging system for C++
144 points · Open discussionYou could check out Nanolog [1] for inspiration.
[1] https://github.com/PlatformLab/NanoLog
In Is C++ fast?