Decode .tar.gz archives using liblzma (via WebAssembly)

[jmillikin]

Fixes #169

[jmillikin]

Tested locally with this script:

import fs from "node:fs";
import tar from "tar";

import { decompress } from "./dist/publish-to-bcr/infrastructure/xzdec/xzdec.js";

async function main() {
	fs.mkdirSync("../../extracted-m4", {recursive: true });
	let reader = fs.createReadStream("../../rules_m4-v0.2.3.tar.xz");
	let writer = tar.x({
		cwd: "../../extracted-m4"
	});
	decompress(reader, writer);
	return;
}

main()

curl -L -O https://github.com/jmillikin/rules_m4/releases/download/v0.2.3/rules_m4-v0.2.3.tar.xz
node18 tools/clean-dist-files.js && node18 node_modules/typescript/bin/tsc && node18 tools/copy-dist-files.js && (cd dist/publish-to-bcr/ && node18 ../../testxz.js )

[kormide]

Locally I get this error when I try to build.

dyld[37073]: Library not loaded: /opt/homebrew/opt/zstd/lib/libzstd.1.dylib
  Referenced from: <4C4C4449-5555-3144-A1D4-18BC03AC1DFB> /private/var/tmp/_bazel_derek/3b365bd722e54dd93dde1a0e900c70d0/external/toolchains_llvm~~llvm~llvm_toolchain_llvm/bin/clang-19
  Reason: tried: '/opt/homebrew/opt/zstd/lib/libzstd.1.dylib' (no such file), '/System/Volumes/Preboot/Cryptexes/OS/opt/homebrew/opt/zstd/lib/libzstd.1.dylib' (no such file), '/opt/homebrew/opt/zstd/lib/libzstd.1.dylib' (no such file)

Is there a way to bring in libzstd hermetically under Bazel?

[kormide]

Are you able to add a brief README in the xzdec folder that explains what this does?

[kormide]

Tested locally with this script:

import fs from "node:fs";
import tar from "tar";

import { decompress } from "./dist/publish-to-bcr/infrastructure/xzdec/xzdec.js";

async function main() {
	fs.mkdirSync("../../extracted-m4", {recursive: true });
	let reader = fs.createReadStream("../../rules_m4-v0.2.3.tar.xz");
	let writer = tar.x({
		cwd: "../../extracted-m4"
	});
	decompress(reader, writer);
	return;
}

main()

curl -L -O https://github.com/jmillikin/rules_m4/releases/download/v0.2.3/rules_m4-v0.2.3.tar.xz
node18 tools/clean-dist-files.js && node18 node_modules/typescript/bin/tsc && node18 tools/copy-dist-files.js && (cd dist/publish-to-bcr/ && node18 ../../testxz.js )

Once this is ready I can deploy and we can test a release of your ruleset. It would be nice if there was an e2e for this but I'm not expecting you to also write a compression function.

[jmillikin]

Looks some of the macOS builds of LLVM have a known packaging problem where they pick up a stray libzstd dynamic dependency from the build machine: llvm/llvm-project#110070

% otool -L bazel-xzdec/external/toolchains_llvm~~llvm~llvm_toolchain_llvm/bin/clang-19
bazel-xzdec/external/toolchains_llvm~~llvm~llvm_toolchain_llvm/bin/clang-19:
	/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1345.120.2)
	/usr/lib/libz.1.dylib (compatibility version 1.0.0, current version 1.2.12)
	/opt/homebrew/opt/zstd/lib/libzstd.1.dylib (compatibility version 1.0.0, current version 1.5.6)
	/usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 1700.255.5)

LLVM v18.1.8 and v19.1.2 both seem to be packaged correctly, but bazel-contrib/toolchains_llvm doesn't have checksums recorded for v19.1.2 yet, so I'll go with v18.

[jmillikin]

Are you able to add a brief README in the xzdec folder that explains what this does?

Done.