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• Quick Start

This package is a C# wrapper around delta-rs and implements the FFI (Foreign Function Interface) for delta-kernel-rs.

It uses the tokio-rs runtime to provide asynchronous behavior. This allows the usage of .NET Tasks and async/await to take advantage of the same behavior provided by the underlying rust library. This library also takes advantage of the Apache Arrow C Data Interface to minimize the amount of copying required to move data between runtimes.

The bridge library incorporates delta-rs, delta-kernel-rs and tokio-rs as shown in the image below.

The Delta Kernel FFI integration is pinned to releases of the Kernel, as new support is added to Kernel, support in C# will be easily extended as a fast follower. The library also benefits from Apache DataFusion SQL support, which is part of delta-rs

NOTE: On unix systems, there is the possibility of a stack overflow due to small stack sizes for the .NET framework. The default size should correspond to ulimit -s, but we can override this by setting the environment variable DOTNET_DefaultStackSize to a hexadecimal number of bytes. The unit tests use 180000.

Quick Start

This section explains how build and run Delta Dotnet locally from scratch on a fresh Linux Machine.

If you're on windows, WSL provides a great way to spinup Linux VMs rapidly for testing.

Step 1: Clone this repo, and initiate the delta-kernel-rs submodule:

cd ~/
git clone https://github.com/delta-incubator/delta-dotnet.git
cd delta-dotnet

GIT_ROOT=$(git rev-parse --show-toplevel)

chmod +x ${GIT_ROOT}/.scripts/checkout-delta-kernel-rs.sh && ${GIT_ROOT}/.scripts/checkout-delta-kernel-rs.sh

Step 2: Install dev dependencies:

chmod +x ${GIT_ROOT}/.scripts/bootstrap-dev-env.sh && ${GIT_ROOT}/.scripts/bootstrap-dev-env.sh
source ~/.bashrc

Step 3: Run the unit tests, which also builds the Rust binaries:

dotnet test -c Debug --logger "console;verbosity=detailed"

All tests should run green ✅

Step 4: Run the example project, which writes delta tables to Azure Storage and reads it back as a DataFrame:

az login --use-device-code
dotnet run --project ${GIT_ROOT}/examples/local/local.csproj -- "abfss://[email protected]/a/b/demo-table" "20"

# Table root path: abfss://[email protected]/a/b/demo-table
# Table partition columns: colHostTest
# Table version before transaction: 0
# Table version after transaction: 1
# Table: 3 columns by 20 rows
#
# colStringTest | colIntegerTest | colHostTest
# --------------|----------------|-------------
# yUnmZGYdeY    | 568935462      | Desktop    
# PfAc0LT7ZQ    | 683443233      | Desktop    
# Tg5xBKy3N3    | 897232561      | Desktop    
# pGMIGfmtRI    | 415054756      | Desktop    
# ormadktrAp    | 1114613767     | Desktop    
# OUYjEQpMxs    | 1159354204     | Desktop    
# J3mECDWmoc    | 1059212885     | Desktop    
# KSlaMMYiaT    | 525569187      | Desktop    
# KA5ZiD1ZTq    | 274902831      | Desktop    
# GRcqxFnF87    | 727541254      | Desktop    
# ZjFFAx6LZt    | 704318687      | Desktop    
# GUBZOqmRU9    | 62468794       | Desktop    
# 6sZdWl5xeV    | 439777191      | Desktop    
# 3oDrKCMZ9c    | 330135342      | Desktop    
# Goiltladv2    | 350043751      | Desktop    
# ts0v56YIDN    | 1381983219     | Desktop    
# 1dyWhaM7SU    | 1935291772     | Desktop    
# 7lBUQeMdeQ    | 1339188314     | Desktop    
# QFfm4Y7Q3w    | 498941470      | Desktop    
# 9yRU65qBy1    | 1105953095     | Desktop