Tera groundwork

Cargo.toml

@@ -52,6 +52,12 @@ params = "0.8"
 staticfile = { version = "0.4", features = [ "cache" ] }
 tempfile = "3.1.0"
 
+# Templating
+tera = { version = "1.3.0", features = ["builtins"] }
+
+# Template hot-reloading
+arc-swap = "0.4.6"
+
 [target.'cfg(not(windows))'.dependencies]
 libc = "0.2"
 

src/bin/cratesfyi.rs

@@ -52,6 +52,10 @@ enum CommandLine {
     StartWebServer {
         #[structopt(name = "SOCKET_ADDR", default_value = "0.0.0.0:3000")]
         socket_addr: String,
+
+        /// Reload templates when they're changed
+        #[structopt(long = "reload")]
+        reload: bool,
     },
 
     /// Starts cratesfyi daemon
@@ -78,8 +82,11 @@ impl CommandLine {
     pub fn handle_args(self) {
         match self {
             Self::Build(build) => build.handle_args(),
-            Self::StartWebServer { socket_addr } => {
-                Server::start(Some(&socket_addr));
+            Self::StartWebServer {
+                socket_addr,
+                reload,
+            } => {
+                Server::start(Some(&socket_addr), reload);
             }
             Self::Daemon { foreground } => cratesfyi::utils::start_daemon(!foreground),
             Self::Database { subcommand } => subcommand.handle_args(),

src/utils/daemon.rs

@@ -260,7 +260,7 @@ pub fn start_daemon(background: bool) {
     // at least start web server
     info!("Starting web server");
 
-    crate::Server::start(None);
+    crate::Server::start(None, false);
 }
 
 fn opts() -> DocBuilderOptions {

src/web/mod.rs

@@ -346,7 +346,12 @@ pub struct Server {
 }
 
 impl Server {
-    pub fn start(addr: Option<&str>) -> Self {
+    pub fn start(addr: Option<&str>, reload_templates: bool) -> Self {
+        page::TEMPLATE_DATA.poke().expect("This returns Ok(())");
+        if reload_templates {
+            page::TemplateData::start_template_reloading();
+        }
+
         let server = Self::start_inner(addr.unwrap_or(DEFAULT_BIND), Pool::new());
         info!("Running docs.rs web server on http://{}", server.addr());
         server

src/web/page.rs → src/web/page/mod.rs

@@ -3,7 +3,10 @@
 use handlebars_iron::Template;
 use iron::response::Response;
 use iron::{status, IronResult, Set};
-use serde::ser::{Serialize, SerializeStruct, Serializer};
+use serde::{
+    ser::{SerializeStruct, Serializer},
+    Serialize,
+};
 use serde_json::Value;
 use std::collections::BTreeMap;
 
@@ -32,14 +35,6 @@ fn load_rustc_resource_suffix() -> Result<String, failure::Error> {
     failure::bail!("failed to parse the rustc version");
 }
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq, serde::Serialize)]
-pub(crate) struct GlobalAlert {
-    pub(crate) url: &'static str,
-    pub(crate) text: &'static str,
-    pub(crate) css_class: &'static str,
-    pub(crate) fa_icon: &'static str,
-}
-
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Page<T: Serialize> {
     title: Option<String>,
@@ -268,3 +263,47 @@ mod tests {
         assert!(Url::parse(&safe).is_ok());
     }
 }
+
+// --- Tera ---
+
+mod templates;
+
+pub(crate) use templates::TemplateData;
+
+lazy_static::lazy_static! {
+    /// Holds all data relevant to templating
+    pub(crate) static ref TEMPLATE_DATA: TemplateData = TemplateData::new().expect("Failed to load template data");
+}
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Serialize)]
+pub(crate) struct GlobalAlert {
+    pub(crate) url: &'static str,
+    pub(crate) text: &'static str,
+    pub(crate) css_class: &'static str,
+    pub(crate) fa_icon: &'static str,
+}
+
+#[cfg(test)]
+mod tera_tests {
+    use super::*;
+    use serde_json::json;
+
+    #[test]
+    fn serialize_global_alert() {
+        let alert = GlobalAlert {
+            url: "http://www.hasthelargehadroncolliderdestroyedtheworldyet.com/",
+            text: "THE WORLD WILL SOON END",
+            css_class: "THE END IS NEAR",
+            fa_icon: "https://gph.is/1uOvmqR",
+        };
+
+        let correct_json = json!({
+            "url": "http://www.hasthelargehadroncolliderdestroyedtheworldyet.com/",
+            "text": "THE WORLD WILL SOON END",
+            "css_class": "THE END IS NEAR",
+            "fa_icon": "https://gph.is/1uOvmqR"
+        });
+
+        assert_eq!(correct_json, serde_json::to_value(&alert).unwrap());
+    }
+}

src/web/page/templates.rs

@@ -0,0 +1,191 @@
+use super::TEMPLATE_DATA;
+use crate::error::Result;
+use arc_swap::ArcSwap;
+use serde_json::Value;
+use std::collections::HashMap;
+use tera::{Result as TeraResult, Tera};
+
+/// Holds all data relevant to templating
+pub(crate) struct TemplateData {
+    /// The actual templates, stored in an `ArcSwap` so that they're hot-swappable
+    // TODO: Conditional compilation so it's not always wrapped, the `ArcSwap` is unneeded overhead for prod
+    pub templates: ArcSwap<Tera>,
+    /// The current global alert, serialized into a json value
+    global_alert: Value,
+    /// The version of docs.rs, serialized into a json value
+    docsrs_version: Value,
+    /// The current resource suffix of rustc, serialized into a json value
+    resource_suffix: Value,
+}
+
+impl TemplateData {
+    pub fn new() -> Result<Self> {
+        log::trace!("Loading templates");
+
+        let data = Self {
+            templates: ArcSwap::from_pointee(load_templates()?),
+            global_alert: serde_json::to_value(crate::GLOBAL_ALERT)?,
+            docsrs_version: Value::String(crate::BUILD_VERSION.to_owned()),
+            resource_suffix: Value::String(load_rustc_resource_suffix().unwrap_or_else(|err| {
+                log::error!("Failed to load rustc resource suffix: {:?}", err);
+                String::from("???")
+            })),
+        };
+
+        log::trace!("Finished loading templates");
+
+        Ok(data)
+    }
+
+    pub fn start_template_reloading() {
+        use std::{sync::Arc, thread, time::Duration};
+
+        thread::spawn(|| loop {
+            match load_templates() {
+                Ok(templates) => {
+                    log::info!("Reloaded templates");
+                    TEMPLATE_DATA.templates.swap(Arc::new(templates));
+                    thread::sleep(Duration::from_secs(10));
+                }
+
+                Err(err) => {
+                    log::info!("Error Loading Templates:\n{}", err);
+                    thread::sleep(Duration::from_secs(5));
+                }
+            }
+        });
+    }
+
+    /// Used to initialize a `TemplateData` instance in a `lazy_static`.
+    /// Loading tera takes a second, so it's important that this is done before any
+    /// requests start coming in
+    pub fn poke(&self) -> Result<()> {
+        Ok(())
+    }
+}
+
+// TODO: Is there a reason this isn't fatal? If the rustc version is incorrect (Or "???" as used by default), then
+//       all pages will be served *really* weird because they'll lack all CSS
+fn load_rustc_resource_suffix() -> Result<String> {
+    let conn = crate::db::connect_db()?;
+
+    let res = conn.query(
+        "SELECT value FROM config WHERE name = 'rustc_version';",
+        &[],
+    )?;
+    if res.is_empty() {
+        failure::bail!("missing rustc version");
+    }
+
+    if let Some(Ok(vers)) = res.get(0).get_opt::<_, Value>("value") {
+        if let Some(vers_str) = vers.as_str() {
+            return Ok(crate::utils::parse_rustc_version(vers_str)?);
+        }
+    }
+
+    failure::bail!("failed to parse the rustc version");
+}
+
+pub(super) fn load_templates() -> TeraResult<Tera> {
+    let mut tera = Tera::new("templates/**/*")?;
+
+    // Custom functions
+    tera.register_function("global_alert", global_alert);
+    tera.register_function("docsrs_version", docsrs_version);
+    tera.register_function("rustc_resource_suffix", rustc_resource_suffix);
+
+    // Custom filters
+    tera.register_filter("timeformat", timeformat);
+    tera.register_filter("dbg", dbg);
+    tera.register_filter("dedent", dedent);
+
+    Ok(tera)
+}
+
+/// Returns an `Option<GlobalAlert>` in json form for templates
+fn global_alert(args: &HashMap<String, Value>) -> TeraResult<Value> {
+    debug_assert!(args.is_empty(), "global_alert takes no args");
+
+    Ok(TEMPLATE_DATA.global_alert.clone())
+}
+
+/// Returns the version of docs.rs, takes the `safe` parameter which can be `true` to get a url-safe version
+fn docsrs_version(args: &HashMap<String, Value>) -> TeraResult<Value> {
+    debug_assert!(
+        args.is_empty(),
+        "docsrs_version only takes no args, to get a safe version use `docsrs_version() | slugify`",
+    );
+
+    Ok(TEMPLATE_DATA.docsrs_version.clone())
+}
+
+/// Returns the current rustc resource suffix
+fn rustc_resource_suffix(args: &HashMap<String, Value>) -> TeraResult<Value> {
+    debug_assert!(args.is_empty(), "rustc_resource_suffix takes no args");
+
+    Ok(TEMPLATE_DATA.resource_suffix.clone())
+}
+
+/// Prettily format a timestamp
+// TODO: This can be replaced by chrono
+fn timeformat(value: &Value, args: &HashMap<String, Value>) -> TeraResult<Value> {
+    let fmt = if let Some(Value::Bool(true)) = args.get("relative") {
+        let value = time::strptime(value.as_str().unwrap(), "%Y-%m-%dT%H:%M:%S%z").unwrap();
+
+        super::super::duration_to_str(value.to_timespec())
+    } else {
+        const TIMES: &[&str] = &["seconds", "minutes", "hours"];
+
+        let mut value = value.as_f64().unwrap();
+        let mut chosen_time = &TIMES[0];
+
+        for time in &TIMES[1..] {
+            if value / 60.0 >= 1.0 {
+                chosen_time = time;
+                value /= 60.0;
+            } else {
+                break;
+            }
+        }
+
+        // TODO: This formatting section can be optimized, two string allocations aren't needed
+        let mut value = format!("{:.1}", value);
+        if value.ends_with(".0") {
+            value.truncate(value.len() - 2);
+        }
+
+        format!("{} {}", value, chosen_time)
+    };
+
+    Ok(Value::String(fmt))
+}
+
+/// Print a tera value to stdout
+fn dbg(value: &Value, _args: &HashMap<String, Value>) -> TeraResult<Value> {
+    println!("{:?}", value);
+
+    Ok(value.clone())
+}
+
+/// Dedent a string by removing all leading whitespace
+fn dedent(value: &Value, _args: &HashMap<String, Value>) -> TeraResult<Value> {
+    let string = value.as_str().expect("dedent takes a string");
+
+    Ok(Value::String(
+        string
+            .lines()
+            .map(|l| l.trim_start())
+            .collect::<Vec<&str>>()
+            .join("\n"),
+    ))
+}
+
+#[cfg(test)]
+mod tests {
+    // TODO: This will fail as long as there are `.hbs` files in `templates/`
+    // #[test]
+    // fn test_templates_are_valid() {
+    //     let tera = load_templates().unwrap();
+    //     tera.check_macro_files().unwrap();
+    // }
+}