refactor: codegen out of build.rs

See http-rs/http-types#504 (comment)

Cargo.toml

@@ -1,3 +1,8 @@
+[workspace]
+members = [
+  "generate-database"
+]
+
 [package]
 name = "tide-compress"
 version = "0.10.5"
@@ -22,11 +27,9 @@ brotli = ["async-compression/brotli"]
 gzip = ["async-compression/gzip"]
 deflate = ["async-compression/deflate"]
 
-db-check = ["regex-check", "phf", "_build_deps"]
+db-check = ["regex-check", "phf"]
 regex-check = ["regex"]
 
-_build_deps = ["async-std", "phf_codegen", "serde", "serde_json", "surf"]
-
 [dependencies]
 async-compression = { version = "0.3", features = ["futures-bufread"] }
 futures-lite = "1.11"
@@ -44,14 +47,6 @@ version = "1"
 default-features = false # Disable features which are enabled by default
 features = ["user-hooks"]
 
-[build-dependencies]
-async-std = { version = "1.11", features = ["attributes"], optional = true }
-cfg-if = "1"
-phf_codegen = { version = "0.10", optional = true }
-serde = { version = "1", features = ["derive"], optional = true }
-serde_json = { version = "1", optional = true }
-surf = { version = "2.3.2", default-features = false, features = ["h1-client-rustls"], optional = true }
-
 [package.metadata.docs.rs]
 # Prevent docs.rs from trying to pull down the database...
 no-default-features = true

generate-database/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "generate-database"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+async-std = { version = "1.11", features = ["attributes"] }
+cfg-if = "1"
+phf_codegen = "0.10"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1" 
+surf = { version = "2.3.2", default-features = false, features = ["h1-client-rustls"] }

generate-database/src/main.rs

@@ -0,0 +1,44 @@
+use std::collections::HashMap;
+use std::env;
+use std::path::Path;
+
+use async_std::fs::File;
+use async_std::io::BufWriter;
+use async_std::io::WriteExt;
+use serde::Deserialize;
+
+#[derive(Debug, Deserialize, Clone)]
+struct MimeInfo {
+    compressible: Option<bool>,
+}
+
+#[async_std::main]
+async fn main() -> surf::Result<()> {
+    let path = Path::new(&env::var("CARGO_MANIFEST_DIR").unwrap())
+        .join("..")
+        .join("src")
+        .join("codegen_database.rs");
+    let mut file = BufWriter::new(File::create(&path).await?);
+
+    let mime_db: HashMap<String, MimeInfo> =
+        surf::get("https://raw.githubusercontent.com/jshttp/mime-db/master/db.json")
+            .recv_json()
+            .await?;
+
+    let mut builder = phf_codegen::Set::new();
+
+    for (key, info) in mime_db {
+        if matches!(info.compressible, Some(yes) if yes) {
+            builder.entry(key);
+        }
+    }
+
+    writeln!(
+        &mut file,
+        "pub(crate) const MIME_DB: phf::Set<&'static str> =\n{};\n",
+        builder.build()
+    )
+    .await?;
+
+    Ok(())
+}