Viewing profile — dryman

Awesome. This will be a super useful reference once I want to migrate the library to C++.

All these concerns are critical, and this is why I spent 6 months to build OPIC malloc prototype. I surveyed a lot on state of the art malloc implementations, as well as some POC p…

If I use a strict subset of C++, probably will do. However, figuring out the subset of different C++ standards and implementation that doesn't include extra pointers is hard. I mig…

I don't have a good answer to this question yet. For now I only create the heap in swap, write it to disk, and then use it as read only mmap. To ensure the written file is valid, o…

The problem is C++ brings in many extra pointers. For example, the vtable pointer used in virtual functions. All the pointers not converted to offset can be invalid in next process…

Author here. I did think about creating a programming language specialized for serialization. Fortunately, using just C seems to be sufficient for building a POC. Another advantage…

Lemire's fast range works perfectly with cuckoo, as it doesn't require probing (?). The fast mod and scale trick was invented to address this issue. It's actually pretty funny. I d…

Thanks for pointing out the thread-unsafe alternative. I'll update the benchmark with it and double I configured it with cityhash. (will update in a day or two). Speaking of cityha…

In my experiments using linear probing in robin hood doesn't give good results as well. I hope the author has tried robin hood with quadratic probing. But it's a good reference. I …

Thanks for raising this up. I spent way way more time on OPIC (almost a year) than robin hood hash map (2 weeks to complete the POC). Glad to see people noticing this project :) Th…

Wow that's a very interesting post! Maybe I should try to bring a rust binding to my project as well..

When I first see "sorted array", my first impression is it is sorted by the "original key". If we look for the hashed value in hash table, all hash tables are "sorted array" with t…

Thanks for pointing out. I used std::string mainly because I suck at C++ :(. In C I can easily define the key length to be a variable passed to the constructor, but I don't know ho…

1) I don't see why a linear probing robin hood is a sorted array? Can you explain more? Robin hood hashing doesn't limit which probing scheme you use. I end up with quadratic probi…

I found some performance numbers from Yahoo. https://yahooeng.tumblr.com/post/104861108931/mdbm-high-spee... It has random read time 0.45 μs. On my late 2013 iMac, i5 cpu, I got 0.…

Thanks for the reference. I'm collecting a list of embedded key-value store to benchmark against. I'll tryout with this one first!

Hi I'm the author for this post. My general guideline is figure out where your bottleneck is, and optimize on the hotspot first. In your description, I can only try my best to gues…