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AwkwardForth: Speeding Up ROOT Data Reading

AwkwardForth enhances Uproot for faster ROOT file processing.

― 5 min read


AwkwardForth Boosts ROOTAwkwardForth Boosts ROOTFile Speedwith new tools.Transforming data reading efficiency
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In the world of particle physics, Data is often stored in a specific format called Root. This format has been around for years, and it has its own way of organizing information. One common way ROOT organizes data is through structures called TTrees. TTrees can hold complex data types, making them useful for scientists working with large datasets. However, reading these TTrees efficiently can be tricky, especially when the data is complicated.

Uproot is a library in Python that helps users read ROOT files without needing any extra compiled code. It’s user-friendly and accessible, but it struggles with certain types of data, especially those that are more complex. For example, when data has nested lists, Uproot can become very slow. This is because it has to read through the data one piece at a time, which takes a lot of time when the data structure is complex.

To address this problem, a new approach was developed using a special programming language called AwkwardForth. This language is based on Forth, a simpler programming language known for its speed and efficiency. AwkwardForth was designed specifically to handle the unique needs of reading ROOT files, especially when it comes to processing complex data types quickly.

The Challenge with Complex Data

When working with ROOT files, especially older formats, data can be organized in different ways. Some types of data are stored in a simple column format, which makes them easier to read. However, more complicated data types, like those that contain nested lists, are often stored in a way that requires lots of back-and-forth reading. This can slow down the reading process dramatically.

For instance, if a data type contains elements that are themselves lists, the program cannot simply read the entire structure all at once. Instead, it has to read each list and then read the contents of those lists one by one. This back-and-forth process can slow down the overall reading speed significantly.

Introducing AwkwardForth

AwkwardForth was created to tackle the slow reading speeds encountered with complex data types in Uproot. This new language allows for faster execution because it operates differently than Python. While Python checks types and follows pointers during execution, AwkwardForth streamlines these processes. It treats all data as integers and only focuses on the essential operations necessary for reading the data efficiently.

The design of AwkwardForth makes it lightweight and easy to use. There’s no need for additional complicated tools or installations, which means that anyone using Uproot can access these improvements without needing special setup. This accessibility is a big deal for scientists and researchers who may not be well-versed in programming.

How AwkwardForth Works

AwkwardForth operates on a principle called a stack. This means that it handles information in a series of layers, pushing and popping data off the stack as needed. This is much simpler than the complex checks and balances that languages like Python have to perform, leading to a significant speed increase.

When Uproot is used with AwkwardForth, the library can generate code specific to the type of data being read. This means that the reading process is tailored to fit the needs of the data, rather than relying on a one-size-fits-all approach. This customization is key to making the reading process much faster.

Performance Improvements

Thanks to AwkwardForth, users can expect to see a dramatic increase in reading speeds-up to 400 times faster when processing complex data types. This level of improvement means that scientists can work with larger datasets more efficiently, allowing them to draw conclusions and make discoveries faster than ever before.

One of the significant improvements comes from the ability to use multiple threads when reading data. While Python has limitations due to its Global Interpreter Lock (GIL), AwkwardForth’s design allows for multi-threading. This means that different parts of the data can be read simultaneously, further speeding up the process. When multiple threads are used, even larger files can be processed at a much quicker pace.

Future Directions and Enhancements

As technology continues to advance, there’s always room for improvement. One area of interest is the potential to incorporate Just-In-Time (JIT) compilation into AwkwardForth. This means that if a user has access to certain tools, the code could be compiled while it’s running, making it even faster.

The basic structure of AwkwardForth already allows for significant performance increases, but by standing on the shoulders of existing tools, further optimization could be achieved. For scientists working with vast amounts of data, even small improvements can lead to major time savings.

Conclusion

In summary, the introduction of AwkwardForth into the Uproot library has opened the door to faster, more efficient reading of ROOT TTrees, particularly when dealing with complex data structures. This development is a game changer for researchers and scientists, allowing them to handle data more effectively and get results quicker. By minimizing the time spent on data reading, AwkwardForth empowers scientists to spend more time analyzing results and making new discoveries.

The advancements seen with AwkwardForth are just the beginning. As more features and enhancements are implemented, the landscape of data handling in particle physics will continue to evolve, helping researchers push the boundaries of what’s possible with data analysis. The integration of simple, fast tools like AwkwardForth into existing libraries like Uproot showcases the power of innovative thinking in tackling complex problems in the world of science.

Original Source

Title: Using a DSL to read ROOT TTrees faster in Uproot

Abstract: Uproot reads ROOT TTrees using pure Python. For numerical and (singly) jagged arrays, this is fast because a whole block of data can be interpreted as an array without modifying the data. For other cases, such as arrays of std::vector, numerical data are interleaved with structure, and the only way to deserialize them is with a sequential algorithm. When written in Python, such algorithms are very slow. We solve this problem by writing the same logic in a language that can be executed quickly. AwkwardForth is a Domain Specific Language (DSL), based on Standard Forth with I/O extensions for making Awkward Arrays, and it can be interpreted as a fast virtual machine without requiring LLVM as a dependency. We generate code as late as possible to take advantage of optimization opportunities. All ROOT types previously implemented with Python have been converted to AwkwardForth. Double and triple-jagged arrays, for example, are 400x faster in AwkwardForth than in Python, with multithreaded scaling up to 1 second/GB because AwkwardForth releases the Python GIL. We also investigate the possibility of JIT-compiling the generated AwkwardForth code using LLVM to increase the performance gains. In this paper, we describe design aspects, performance studies, and future directions in accelerating Uproot with AwkwardForth.

Authors: Aryan Roy, Jim Pivarski

Last Update: 2023-03-03 00:00:00

Language: English

Source URL: https://arxiv.org/abs/2303.02202

Source PDF: https://arxiv.org/pdf/2303.02202

Licence: https://creativecommons.org/licenses/by/4.0/

Changes: This summary was created with assistance from AI and may have inaccuracies. For accurate information, please refer to the original source documents linked here.

Thank you to arxiv for use of its open access interoperability.

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