Reimplement notice file generation for third-party licenses through Rust, now with CEF credits (#3808)

tools/third-party-licenses/src/cef.rs

@@ -0,0 +1,105 @@
+use lzma_rust2::XzReader;
+use scraper::{Html, Selector};
+use std::hash::Hash;
+use std::io::Read;
+use std::path::PathBuf;
+use std::{fs, process};
+
+use crate::{LicenceSource, LicenseEntry, Package};
+
+pub struct CefLicenseSource;
+
+impl CefLicenseSource {
+	pub fn new() -> Self {
+		Self {}
+	}
+}
+
+impl LicenceSource for CefLicenseSource {
+	fn licenses(&self) -> Vec<LicenseEntry> {
+		let html = read();
+		parse(&html)
+	}
+}
+
+impl Hash for CefLicenseSource {
+	fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+		read().hash(state)
+	}
+}
+
+fn parse(html: &str) -> Vec<LicenseEntry> {
+	let document = Html::parse_document(html);
+
+	let product_sel = Selector::parse("div.product").unwrap();
+	let title_sel = Selector::parse("span.title").unwrap();
+	let homepage_sel = Selector::parse("span.homepage a").unwrap();
+	let license_sel = Selector::parse("div.license pre").unwrap();
+
+	document
+		.select(&product_sel)
+		.filter_map(|product| {
+			let name: String = product.select(&title_sel).next().map(|el| el.text().collect()).unwrap_or_default();
+
+			if name.is_empty() {
+				return None;
+			}
+
+			let homepage = product.select(&homepage_sel).next().and_then(|el| el.value().attr("href").map(String::from));
+
+			let license_text: String = product.select(&license_sel).next().map(|el| el.text().collect::<String>()).unwrap_or_default().trim().to_string();
+
+			let pkg = Package {
+				name,
+				url: homepage,
+				authors: Vec::new(),
+			};
+
+			Some(LicenseEntry {
+				name: None,
+				text: license_text,
+				packages: vec![pkg],
+			})
+		})
+		.collect()
+}
+
+fn read() -> String {
+	let cef_path = PathBuf::from(env!("CEF_PATH"));
+	let cef_credits = std::fs::read_dir(&cef_path)
+		.unwrap_or_else(|e| {
+			eprintln!("Failed to read CEF_PATH directory {}: {e}", cef_path.display());
+			process::exit(1);
+		})
+		.filter_map(|entry| entry.ok())
+		.find(|entry| {
+			let name = entry.file_name();
+			name.eq_ignore_ascii_case("credits.html") || name.eq_ignore_ascii_case("credits.html.xz")
+		})
+		.map(|entry| entry.path())
+		.unwrap_or_else(|| {
+			eprintln!("Could not find CREDITS.html or CREDITS.html.xz in {}", cef_path.display());
+			process::exit(1);
+		});
+
+	let decompress_xz = cef_credits.extension().map(|ext| ext.eq_ignore_ascii_case("xz")).unwrap_or(false);
+
+	if decompress_xz {
+		let file = fs::File::open(&cef_credits).unwrap_or_else(|e| {
+			eprintln!("Failed to open CEF credits file {}: {e}", cef_credits.display());
+			process::exit(1);
+		});
+		let mut reader = XzReader::new(file, false);
+		let mut html = String::new();
+		reader.read_to_string(&mut html).unwrap_or_else(|e| {
+			eprintln!("Failed to decompress CEF credits file {}: {e}", cef_credits.display());
+			process::exit(1);
+		});
+		html
+	} else {
+		fs::read_to_string(&cef_credits).unwrap_or_else(|e| {
+			eprintln!("Failed to read CEF credits file {}: {e}", cef_credits.display());
+			process::exit(1);
+		})
+	}
+}