debugging and single provider compime

src/util/flow_debug.rs

@@ -0,0 +1,43 @@
+use std::sync::atomic::{AtomicU64, Ordering};
+use std::time::{SystemTime, UNIX_EPOCH};
+
+static NEXT_TRACE_ID: AtomicU64 = AtomicU64::new(1);
+
+pub fn next_trace_id(prefix: &str) -> String {
+    let id = NEXT_TRACE_ID.fetch_add(1, Ordering::Relaxed);
+    format!("{prefix}-{id:06}")
+}
+
+#[cfg(feature = "debug")]
+pub fn emit(module: &str, line: u32, message: String) {
+    let millis = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map(|duration| duration.as_millis())
+        .unwrap_or_default();
+    eprintln!("[debug][{millis}][{module}:{line}] {message}");
+}
+
+#[cfg(not(feature = "debug"))]
+pub fn emit(_module: &str, _line: u32, _message: String) {}
+
+pub fn preview(value: &str, limit: usize) -> String {
+    if value.len() <= limit {
+        return value.to_string();
+    }
+
+    let mut end = limit;
+    while !value.is_char_boundary(end) {
+        end -= 1;
+    }
+    format!("{}...", &value[..end])
+}
+
+#[macro_export]
+macro_rules! flow_debug {
+    ($($arg:tt)*) => {{
+        #[cfg(feature = "debug")]
+        {
+            $crate::util::flow_debug::emit(module_path!(), line!(), format!($($arg)*));
+        }
+    }};
+}