type-erased-table

type-erased-table

A column-oriented based raw data storage
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About The Project

Allow to create Table like structure represented by a structure of Arrays maintaining multiple arrays of different types while maintaining the same size for all the arrays and a shared index for each attribute created throughout its lifetime.

Provide a Table struct that allows to store rows of data composed of different types. This structure can be represented as a Structure of arrays and is built has an HashMap where keys are column identifiers and values are Column. Each Column is a contiguous array and every row component can be accessed with the same index on each Column.

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Built With

• Nohash to create hashmap without hashing algorithm (keys are u32) - https://github.com/tetcoin/nohash
• Based on bevy BlobVec implementation - https://github.com/bevyengine/bevy/blob/main/crates/bevy_ecs

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Getting Started

This is an example of how you use this crate to to create a table struct with a simple columns.

Installation

Add dependency to you cargo.toml

[dependencies]
type-erased-table = "0.1.0"

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Usage

After creating a table just add a column and start filling it with un-typed data.

let mut table = Table::new(1);

let value: u32 = 2;

// Get Layout from concrete type
let layout = Layout::for_value(&value);

// Create column with u32 identifier
let column_info = ColumnInfo::new(1, layout);

table.add_column(column_info);

let column = table.get_column_mut(1).unwrap();

// Push data into row of column by passing pointer as *const u8
unsafe { column.push(ptr::addr_of!(value) as *const u8) }

// Read value of row 0
let row_ptr = unsafe { column.get(0) };
let row_value: u32 = unsafe { (*row_ptr).into() };

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Contributing

Contributions are what make the open source community such an amazing place to learn, inspire, and create. Any contributions you make are greatly appreciated.

If you have a suggestion that would make this better, please fork the repo and create a pull request. Don't forget to give the project a star! Thanks again!

1. Fork the Project
2. Create your Feature Branch (git checkout -b feature/AmazingFeature)
3. Commit your Changes (git commit -m 'Add some AmazingFeature')
4. Push to the Branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

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License

Distributed under the MIT License.

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Contact

Project Link: https://github.com/ValentinRio/type-erased-table

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