Atomic Posts
I’m using the term atomic post in reference to the concept of atomic habits. The idea is for posts to be as narrow as possible in scope, while still being self-contained.
NP-Incompleteness |
Kunigami's Technical Blog
Latest posts
Folly F14 Map
F14Map is Folly’s alternative to std::unordered_map and in this post we’ll explore this data structure in detail. We’ll start with std::unordered_map which implements a more textbook version of hash maps using linked lists to handle collisions and then cover F14FastMap which uses a chunked (14 entries / chunk) open addressing implementation and leverages SIMD instructions for efficiency.
Velox: Memory
Velox is an open source C++ library by Meta that can be used to perform computation common to distributed engines like Presto. Its offerings include columnar operations, a rich type system, an expression parser and a smart resource management such as memory [1]. In this series of posts we’ll go over different components of Velox. In this post we’ll study memory management done by Velox.
On Doing Things Manually
In my last post about KD-tree, I vibe-coded a JavaScript application to demonstrate visually, step-by-step, how to construct and query a KD-tree. Codex one-shotted it in a few minutes; I spent a few minutes linking it to the blog post but did not even take a look at the code. I’ve been using AI more and more both at work and for personal stuff but I also deliberately avoid using AI for specific…
KD-Tree
Jon Bentley is an American computer scientist, famously known for his book Programming Pearls. He also came up with the data structure called k-d tree while an undergrad at Stanford and published it in a paper titled Multidimensional Binary Search Trees Used for Associative Searching in 1975. In this post we study the kd-tree data structure, how to construct and perform queries on it. Then we…
Velox: UDFs
Velox is an open source C++ library by Meta that can be used to perform computation common to distributed engines like Presto. Its offerings include columnar operations, a rich type system, an expression parser and a smart resource management such as memory [1]. In this series of posts we’ll go over different components of Velox. In this post we’ll study user defined functions, UDFs, including the…
Delaunay Triangulation
Boris Nikolayevich Delaunay was a Russian mathematician (1890 – 1980), who is best known for inventing the Delaunay triangulation. Boris was the descendant of a French army officer de Launay, who was captured in Russia during Napoleon’s failed attempt to invade Russia. After his release, De Launay stayed back in Russia and married into a noble Russian family. In this post we’ll study the Delaunay…
Velox: A Simple Application
Velox is an open source C++ library by Meta that can be used to perform computation common to distributed engines like Presto. Its offerings include columnar operations, a rich type system, an expression parser and a smart resource management such as memory [1]. In this series of posts we’ll go over different components of Velox. In this post we’ll cover a high level application that reads from a…
Lagrangian Mechanics
I’ve been reading the book The Theoretical Minimum [1] by Leonard Susskind and George Hrabovsky and the first topic I don’t recall learning in school is Lagrangian mechanics. In this post I’d like to cover this formulation and connect it with the mathematical concepts we studied previously.
Velox: The Vector
Velox is an open source C++ library by Meta that can be used to perform computation common to distributed engines like Presto. Its offerings include columnar operations, a rich type system, an expression parser and a smart resource management such as memory [1]. In this series of posts we’ll go over different components of Velox. In this inaugural post we cover the vector data structure which is…