perf: Cache environment variables at startup

1 files changed, 56 insertions, 0 deletions

diff --git a/src/environment.rs b/src/environment.rs
new file mode 100644
index 0000000..dd10171
--- /dev/null
+++ b/src/environment.rs
@@ -0,0 +1,56 @@
+use std::sync::LazyLock;
+
+pub static ENVIRONMENT: LazyLock<Environment> =
+  LazyLock::new(Environment::from_environment);
+
+pub struct Environment {
+  pub root:                       String,
+  pub css_external:               Option<String>,
+  pub primary_colour:             Option<String>,
+  pub favicon_external:           Option<String>,
+  pub mathjax:                    bool,
+  pub head:                       Option<String>,
+  pub header:                     Option<String>,
+  pub plain_text_route:           Option<String>,
+  pub condense_links:             Vec<String>,
+  pub condense_links_at_headings: Vec<String>,
+  pub proxy_by_default:           bool,
+  pub keep_gemini:                Option<Vec<String>>,
+  pub embed_images:               Option<String>,
+}
+
+impl Environment {
+  fn from_environment() -> Self {
+    Self {
+      root:                       std::env::var("ROOT").unwrap_or_else(|_| {
+        log::warn!(
+          "could not use ROOT from environment variables, proceeding with \
+           default root: gemini://fuwn.me"
+        );
+        "gemini://fuwn.me".to_string()
+      }),
+      css_external:               std::env::var("CSS_EXTERNAL").ok(),
+      primary_colour:             std::env::var("PRIMARY_COLOUR").ok(),
+      favicon_external:           std::env::var("FAVICON_EXTERNAL").ok(),
+      mathjax:                    std::env::var("MATHJAX")
+        .map(|v| v.to_lowercase() == "true")
+        .unwrap_or(true),
+      head:                       std::env::var("HEAD").ok(),
+      header:                     std::env::var("HEADER").ok(),
+      plain_text_route:           std::env::var("PLAIN_TEXT_ROUTE").ok(),
+      condense_links:             std::env::var("CONDENSE_LINKS")
+        .map(|s| s.split(',').map(String::from).collect())
+        .unwrap_or_default(),
+      condense_links_at_headings: std::env::var("CONDENSE_LINKS_AT_HEADINGS")
+        .map(|s| s.split(',').map(String::from).collect())
+        .unwrap_or_default(),
+      proxy_by_default:           std::env::var("PROXY_BY_DEFAULT")
+        .map(|v| v.to_lowercase() == "true")
+        .unwrap_or(true),
+      keep_gemini:                std::env::var("KEEP_GEMINI")
+        .ok()
+        .map(|s| s.split(',').map(String::from).collect()),
+      embed_images:               std::env::var("EMBED_IMAGES").ok(),
+    }
+  }
+}