alamb commented on code in PR #7633: URL: https://github.com/apache/arrow-datafusion/pull/7633#discussion_r1335742738
########## datafusion/wasmtest/README.md: ########## @@ -0,0 +1,59 @@ +<!--- + Licensed to the Apache Software Foundation (ASF) under one + or more contributor license agreements. See the NOTICE file + distributed with this work for additional information + regarding copyright ownership. The ASF licenses this file + to you under the Apache License, Version 2.0 (the + "License"); you may not use this file except in compliance + with the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, + software distributed under the License is distributed on an + "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + KIND, either express or implied. See the License for the + specific language governing permissions and limitations + under the License. +--> + +## wasmtest + +Library crate to verify that various DataFusion crates compile successfully to the `wasm32-unknown-unknown` target with wasm-pack. Review Comment: It might help to add a little more context in this comment about the "why do we care about compiling with WASM" ```suggestion Library crate to verify that various DataFusion crates compile successfully to the `wasm32-unknown-unknown` target with wasm-pack. Some of DataFusion's downstream projects compile to WASM to run in the browser. Doing so requires special care that certain library dependencies are not included in DataFusion. ``` ########## datafusion/wasmtest/README.md: ########## @@ -0,0 +1,59 @@ +<!--- + Licensed to the Apache Software Foundation (ASF) under one + or more contributor license agreements. See the NOTICE file + distributed with this work for additional information + regarding copyright ownership. The ASF licenses this file + to you under the Apache License, Version 2.0 (the + "License"); you may not use this file except in compliance + with the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, + software distributed under the License is distributed on an + "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + KIND, either express or implied. See the License for the + specific language governing permissions and limitations + under the License. +--> + +## wasmtest + +Library crate to verify that various DataFusion crates compile successfully to the `wasm32-unknown-unknown` target with wasm-pack. + +## Setup + +First, [install wasm-pack](https://rustwasm.github.io/wasm-pack/installer/) + +Then use wasm-pack to compile the crate from within this directory + +``` +wasm-pack build +``` + +## Try it out + +The `datafusion-wasm-app` directory contains a simple app (created with [`create-wasm-app`](https://github.com/rustwasm/create-wasm-app) and then manually updated to WebPack 5) that invokes DataFusion and writes results to the browser console. + +From within the `datafusion/wasmtest/datafusion-wasm-app` directory: + +``` +npm install +npm run start +``` + +Then open http://localhost:8080/ in a web browser and check the console to see the results of using various DataFusion crates. + +**Note:** In GitHub Actions we test the compilation with `wasm-build`, but we don't currently invoke `datafusion-wasm-app`. In the future we may want to test the behavior of the WASM build using [`wasm-pack test`](https://rustwasm.github.io/wasm-pack/book/tutorials/npm-browser-packages/testing-your-project.html). + +## Compatibility + +The following DataFusion crates are verified to work in a wasm-pack environment using the default `wasm32-unknown-unknown` target: + +- `datafusion-common` with default-features disabled to remove the `parquet` dependency (see below) +- `datafusion-expr` +- `datafusion-optimizer` +- `datafusion-physical-expr` +- `datafusion-sql` + +The difficulty with getting the remaining DataFusion crates compiled to WASM is that they have non-optional dependencies on the [`parquet`](https://docs.rs/crate/parquet/) crate with its default features enabled. Several of the default parquet crate features require native dependencies that are not compatible with WASM, in particular the `lz4` and `zstd` features. If we can arrange our feature flags to make it possible to depend on parquet with these features disabled, then it should be possible to compile the core `datafusion` crate to WASM as well. Review Comment: @tustvold do you have any thoughts about finagling the parquet crate's dependencies so it can compile, by default, on wasm? Should we perhaps change datafusion to disable the `parquet` default features? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
