1️⃣🐝🏎️ The One Billion Row Challenge with Bun

About the Challenge

The One Billion Row Challenge (1BRC) is a fun exploration of how far modern Java can be pushed for aggregating one billion rows from a text file.

Later the community created a dedicated @1brc organization to pay more attention to the implementations in other languages. This repository contains and accepts Bun based implementations.

Grab all your (virtual) threads, reach out to SIMD, optimize your GC, or pull any other trick, and create the fastest implementation for solving this task!

The text file contains temperature values for a range of weather stations. Each row is one measurement in the format <string: station name>;<double: measurement>, with the measurement value having exactly one fractional digit. The following shows ten rows as an example:

Hamburg;12.0
Bulawayo;8.9
Palembang;38.8
St. John's;15.2
Cracow;12.6
Bridgetown;26.9
Istanbul;6.2
Roseau;34.4
Conakry;31.2
Istanbul;23.0

The task is to write a program which reads the file, calculates the min, mean, and max temperature value per weather station, and emits the results on stdout like this (i.e. sorted alphabetically by station name, and the result values per station in the format <min>/<mean>/<max>, rounded to one fractional digit):

{Abha=-23.0/18.0/59.2, Abidjan=-16.2/26.0/67.3, Abéché=-10.0/29.4/69.0, Accra=-10.1/26.4/66.4, Addis Ababa=-23.7/16.0/67.0, Adelaide=-27.8/17.3/58.5, ...}

Submit your implementation and become part of the leaderboard!

Results

#	Result (m:s.ms)	Implementation	Submitter	Notes
1.	02:15.064	link	Edgar Pogosyan	Potentially multi-threaded (there is a bug in Bun, which does not let us use more than one core for now, but when that gets fixed, this could potentially run in about 14s), optimized parsing, input-specific `float` to `int` parser, no mmap
	05:49.890	link	Edgar Pogosyan	The baseline, single threaded, naive implementation

See below for instructions how to enter the challenge with your own implementation.

Prerequisites

Java 21 to generate the measurements.txt files and optionally run tests.
Bun must be installed on your system.

Running the Challenge

This repository contains two programs:

dev.morling.onebrc.CreateMeasurements (invoked via create_measurements.sh): Creates the file measurements.txt in the root directory of this project with a configurable number of random measurement values
src/main/bun/baseline/index.js (invoked via calculate_average_baseline.sh): Calculates the average values for the file measurements.txt

Execute the following steps to run the challenge:

Build the project using Apache Maven:
```
./mvnw clean verify
```
Create the measurements file with 1B rows (just once):
```
./create_measurements.sh 1000000000
```
This will take a few minutes. Attention: the generated file has a size of approx. 12 GB, so make sure to have enough diskspace.
Calculate the average measurement values:
```
./calculate_average_baseline.sh
```
The provided naive example implementation uses the Bun Streams for processing the file and completes the task in ~6m16s on environment used for result evaluation. It serves as the base line for comparing your own implementation.
Optimize the heck out of it:

Adjust the src/main/bun/baseline/index.js program to speed it up, in any way you see fit (just sticking to a few rules described below). Options include parallelizing the computation, memory-mapping different sections of the file concurrently, choosing and tuning the garbage collector, and much more.

Flamegraph/Profiling

TODO: add instructions on how to profile Bun programs

Rules and limits

No external library dependencies may be used

The computation must happen at application runtime, i.e. you cannot process the measurements file at build time and just bake the result into the binary
Input value ranges are as follows:
- Station name: non null UTF-8 string of min length 1 character and max length 100 bytes (i.e. this could be 100 one-byte characters, or 50 two-byte characters, etc.)
- Temperature value: non null double between -99.9 (inclusive) and 99.9 (inclusive), always with one fractional digit
There is a maximum of 10,000 unique station names
Implementations must not rely on specifics of a given data set, e.g. any valid station name as per the constraints above and any data distribution (number of measurements per station) must be supported

Entering the Challenge

To submit your own implementation to 1BRC, follow these steps:

Create a fork of the 1brc/bun GitHub repository.
Create a copy of src/main/bun/baseline directory, rename it to src/main/bun/<your_GH_user>, e.g. src/main/bun/JohnDoe.
Make that implementation fast. Really fast.
Create a copy of calculate_average_baseline.sh, named calculate_average_<your_GH_user>.sh, e.g. calculate_average_JohnDoe.sh.
Adjust that script so that it references your implementation file. If needed, provide any Bun runtime arguments. Make sure that script does not write anything to standard output other than calculation results.
Run the test suite by executing /test.sh <your_GH_user>; if any differences are reported, fix them before submitting your implementation.
Create a pull request against the upstream repository, clearly stating
- The execution time of the program on your system and specs of the same (CPU, number of cores, RAM). This is for informative purposes only, the official runtime will be determined as described below.
I will run the program and determine its performance as described in the next section, and enter the result to the scoreboard.

Note: I reserve the right to not evaluate specific submissions if I feel doubtful about the implementation (I.e. I won't run your Bitcoin miner ;).

Evaluating Results

For now results are determined by running the program on a Apple MacBook M1 32GB (10 physical). The time program is used for measuring execution times, i.e. end-to-end times are measured. Each contender will be run five times in a row. The slowest and the fastest runs are discarded. The mean value of the remaining three runs is the result for that contender and will be added to the results table above. The exact same measurements.txt file is used for evaluating all contenders.

FAQ

Q: What is the encoding of the measurements.txt file?
A: The file is encoded with UTF-8.

Q: Can I make assumptions on the names of the weather stations showing up in the data set?
A: No, while only a fixed set of station names is used by the data set generator, any solution should work with arbitrary UTF-8 station names (for the sake of simplicity, names are guaranteed to contain no ; character).

Q: Can I copy code from other submissions?
A: Yes, you can. The primary focus of the challenge is about learning something new, rather than "winning". When you do so, please give credit to the relevant source submissions. Please don't re-submit other entries with no or only trivial improvements.

Q: Which operating system is used for evaluation?
A: macOS Sonoma 14 (see Evaluating Results)

Q: My solution runs in 2 sec on my machine. Am I the fastest 1BRC-er in the world?
A: Probably not :) 1BRC results are reported in wallclock time, thus results of different implementations are only comparable when obtained on the same machine. If for instance an implementation is faster on a 32 core workstation than on the 8 core evaluation instance, this doesn't allow for any conclusions. When sharing 1BRC results, you should also always share the result of running the baseline implementation on the same hardware.

Q: Why 1️⃣🐝🏎️ ?
A: It's the abbreviation of the project name: One Billion Row Challenge.

License

This code base is available under the Apache License, version 2.

Code of Conduct

Be excellent to each other! More than winning, the purpose of this challenge is to have fun and learn something new.

janlucaklees/1brc-bun