v0.1.3-pre.006

crates/ksp-logging-lib/src/domain.rs

@@ -0,0 +1,181 @@
+// file: crates/ksp-logging-lib/src/domain.rs
+// version: 1
+
+std::thread_local! {
+    static CURRENT_DOMAIN: std::cell::RefCell<std::option::Option<std::string::String>> = const { std::cell::RefCell::new(std::option::Option::None) };
+}
+
+#[derive(Clone, Debug, Default, Eq, PartialEq)]
+struct SpanDomain {
+    value: std::option::Option<std::string::String>,
+}
+
+#[derive(Default)]
+struct DomainVisitor {
+    value: std::option::Option<std::string::String>,
+}
+
+impl tracing::field::Visit for DomainVisitor {
+    fn record_str(&mut self, field: &tracing::field::Field, value: &str) {
+        if field.name() == "domain" {
+            self.value = std::option::Option::Some(value.to_string());
+        }
+    }
+
+    fn record_debug(&mut self, field: &tracing::field::Field, value: &dyn std::fmt::Debug) {
+        if field.name() == "domain" {
+            self.value = std::option::Option::Some(format!("{value:?}"));
+        }
+    }
+}
+
+pub(crate) struct DomainContextLayer;
+
+impl DomainContextLayer {
+    pub(crate) const fn new() -> Self {
+        return Self;
+    }
+}
+
+impl<S> tracing_subscriber::Layer<S> for DomainContextLayer
+where
+    S: tracing::Subscriber + for<'lookup> tracing_subscriber::registry::LookupSpan<'lookup>,
+{
+    fn on_new_span(&self, attrs: &tracing::span::Attributes<'_>, id: &tracing::span::Id, ctx: tracing_subscriber::layer::Context<'_, S>) {
+        let mut visitor = DomainVisitor::default();
+        attrs.record(&mut visitor);
+        let effective_domain = match visitor.value {
+            std::option::Option::Some(domain) => std::option::Option::Some(domain),
+            std::option::Option::None => span_parent_domain(id, &ctx),
+        };
+        if let std::option::Option::Some(span) = ctx.span(id) {
+            span.extensions_mut().insert(SpanDomain { value: effective_domain.clone() });
+        }
+        set_current_domain(effective_domain.as_deref());
+    }
+
+    fn on_record(&self, id: &tracing::span::Id, values: &tracing::span::Record<'_>, ctx: tracing_subscriber::layer::Context<'_, S>) {
+        let mut visitor = DomainVisitor::default();
+        values.record(&mut visitor);
+        if let std::option::Option::Some(domain) = visitor.value {
+            if let std::option::Option::Some(span) = ctx.span(id) {
+                let mut extensions = span.extensions_mut();
+                if let std::option::Option::Some(stored) = extensions.get_mut::<SpanDomain>() {
+                    stored.value = std::option::Option::Some(domain.clone());
+                } else {
+                    extensions.insert(SpanDomain { value: std::option::Option::Some(domain.clone()) });
+                }
+            }
+            set_current_domain(std::option::Option::Some(domain.as_str()));
+            return;
+        }
+        let domain = span_domain(id, &ctx);
+        set_current_domain(domain.as_deref());
+    }
+
+    fn on_event(&self, event: &tracing::Event<'_>, ctx: tracing_subscriber::layer::Context<'_, S>) {
+        let mut visitor = DomainVisitor::default();
+        event.record(&mut visitor);
+        let effective_domain = match visitor.value {
+            std::option::Option::Some(domain) => std::option::Option::Some(domain),
+            std::option::Option::None => event_parent_domain(event, &ctx),
+        };
+        set_current_domain(effective_domain.as_deref());
+    }
+
+    fn on_enter(&self, id: &tracing::span::Id, ctx: tracing_subscriber::layer::Context<'_, S>) {
+        let domain = span_domain(id, &ctx);
+        set_current_domain(domain.as_deref());
+    }
+
+    fn on_exit(&self, id: &tracing::span::Id, ctx: tracing_subscriber::layer::Context<'_, S>) {
+        let domain = span_domain(id, &ctx);
+        set_current_domain(domain.as_deref());
+    }
+
+    fn on_close(&self, id: tracing::span::Id, ctx: tracing_subscriber::layer::Context<'_, S>) {
+        let domain = span_domain(&id, &ctx);
+        set_current_domain(domain.as_deref());
+    }
+}
+
+pub(crate) fn current_domain_matches(selectors: &[std::string::String]) -> bool {
+    if let [selector] = selectors
+        && selector == "*"
+    {
+        return true;
+    }
+    return CURRENT_DOMAIN.with(|current| -> bool {
+        let borrow_result = current.try_borrow();
+        let current = match borrow_result {
+            std::result::Result::Ok(current) => current,
+            std::result::Result::Err(_) => return false,
+        };
+        let domain = match current.as_ref() {
+            std::option::Option::Some(domain) => domain,
+            std::option::Option::None => return false,
+        };
+        return selectors.iter().any(|selector| -> bool {
+            return domain.starts_with(selector.as_str());
+        });
+    });
+}
+
+fn set_current_domain(domain: std::option::Option<&str>) {
+    CURRENT_DOMAIN.with(|current| {
+        let borrow_result = current.try_borrow_mut();
+        if let std::result::Result::Ok(mut current) = borrow_result {
+            *current = domain.map(std::borrow::ToOwned::to_owned);
+        }
+    });
+}
+
+fn span_parent_domain<S>(id: &tracing::span::Id, ctx: &tracing_subscriber::layer::Context<'_, S>) -> std::option::Option<std::string::String>
+where
+    S: tracing::Subscriber + for<'lookup> tracing_subscriber::registry::LookupSpan<'lookup>,
+{
+    let span = match ctx.span(id) {
+        std::option::Option::Some(span) => span,
+        std::option::Option::None => return std::option::Option::None,
+    };
+    let parent = match span.parent() {
+        std::option::Option::Some(parent) => parent,
+        std::option::Option::None => return std::option::Option::None,
+    };
+    let extensions = parent.extensions();
+    return extensions.get::<SpanDomain>().and_then(|domain| -> std::option::Option<std::string::String> {
+        return domain.value.clone();
+    });
+}
+
+fn span_domain<S>(id: &tracing::span::Id, ctx: &tracing_subscriber::layer::Context<'_, S>) -> std::option::Option<std::string::String>
+where
+    S: tracing::Subscriber + for<'lookup> tracing_subscriber::registry::LookupSpan<'lookup>,
+{
+    let span = match ctx.span(id) {
+        std::option::Option::Some(span) => span,
+        std::option::Option::None => return std::option::Option::None,
+    };
+    let extensions = span.extensions();
+    return extensions.get::<SpanDomain>().and_then(|domain| -> std::option::Option<std::string::String> {
+        return domain.value.clone();
+    });
+}
+
+fn event_parent_domain<S>(event: &tracing::Event<'_>, ctx: &tracing_subscriber::layer::Context<'_, S>) -> std::option::Option<std::string::String>
+where
+    S: tracing::Subscriber + for<'lookup> tracing_subscriber::registry::LookupSpan<'lookup>,
+{
+    let parent = match ctx.event_span(event) {
+        std::option::Option::Some(parent) => parent,
+        std::option::Option::None => return std::option::Option::None,
+    };
+    let extensions = parent.extensions();
+    return extensions.get::<SpanDomain>().and_then(|domain| -> std::option::Option<std::string::String> {
+        return domain.value.clone();
+    });
+}
+
+#[cfg(test)]
+#[path = "../unit_tests/domain.rs"]
+mod tests;