tracing.rs

use serde::Serialize;
use tracing::Level;

const CLIENT: &str = "jsonrpsee-client";
const SERVER: &str = "jsonrpsee-server";

/// Logging with jsonrpsee client target.
pub mod client {
	use super::*;

	/// Helper for writing trace logs from str.
	pub fn tx_log_from_str(s: impl AsRef<str>, max: u32) {
		if tracing::enabled!(Level::TRACE) {
			let msg = truncate_at_char_boundary(s.as_ref(), max as usize);
			tracing::trace!(target: CLIENT, send = msg);
		}
	}

	/// Helper for writing trace logs from JSON.
	pub fn tx_log_from_json(s: &impl Serialize, max: u32) {
		if tracing::enabled!(Level::TRACE) {
			let json = serde_json::to_string(s).unwrap_or_default();
			let msg = truncate_at_char_boundary(&json, max as usize);
			tracing::trace!(target: CLIENT, send = msg);
		}
	}

	/// Helper for writing trace logs from str.
	pub fn rx_log_from_str(s: impl AsRef<str>, max: u32) {
		if tracing::enabled!(Level::TRACE) {
			let msg = truncate_at_char_boundary(s.as_ref(), max as usize);
			tracing::trace!(target: CLIENT, recv = msg);
		}
	}

	/// Helper for writing trace logs from JSON.
	pub fn rx_log_from_json(s: &impl Serialize, max: u32) {
		if tracing::enabled!(Level::TRACE) {
			let res = serde_json::to_string(s).unwrap_or_default();
			let msg = truncate_at_char_boundary(res.as_str(), max as usize);
			tracing::trace!(target: CLIENT, recv = msg);
		}
	}

	/// Helper for writing trace logs from bytes.
	pub fn rx_log_from_bytes(bytes: &[u8], max: u32) {
		if tracing::enabled!(Level::TRACE) {
			let res = serde_json::from_slice::<serde_json::Value>(bytes).unwrap_or_default();
			rx_log_from_json(&res, max);
		}
	}
}

/// Logging with jsonrpsee server target.
pub mod server {
	use super::*;

	/// Helper for writing trace logs from str.
	pub fn tx_log_from_str(s: impl AsRef<str>, max: u32) {
		if tracing::enabled!(Level::TRACE) {
			let msg = truncate_at_char_boundary(s.as_ref(), max as usize);
			tracing::trace!(target: SERVER, send = msg);
		}
	}

	/// Helper for writing trace logs from JSON.
	pub fn tx_log_from_json(s: &impl Serialize, max: u32) {
		if tracing::enabled!(Level::TRACE) {
			let json = serde_json::to_string(s).unwrap_or_default();
			let msg = truncate_at_char_boundary(&json, max as usize);
			tracing::trace!(target: SERVER, send = msg);
		}
	}

	/// Helper for writing trace logs from str.
	pub fn rx_log_from_str(s: impl AsRef<str>, max: u32) {
		if tracing::enabled!(Level::TRACE) {
			let msg = truncate_at_char_boundary(s.as_ref(), max as usize);
			tracing::trace!(target: SERVER, recv = msg);
		}
	}

	/// Helper for writing trace logs from JSON.
	pub fn rx_log_from_json(s: &impl Serialize, max: u32) {
		if tracing::enabled!(Level::TRACE) {
			let res = serde_json::to_string(s).unwrap_or_default();
			let msg = truncate_at_char_boundary(res.as_str(), max as usize);
			tracing::trace!(target: SERVER, recv = msg);
		}
	}

	/// Helper for writing trace logs from bytes.
	pub fn rx_log_from_bytes(bytes: &[u8], max: u32) {
		if tracing::enabled!(Level::TRACE) {
			let res = serde_json::from_slice::<serde_json::Value>(bytes).unwrap_or_default();
			rx_log_from_json(&res, max);
		}
	}
}

/// Find the next char boundary to truncate at.
fn truncate_at_char_boundary(s: &str, max: usize) -> &str {
	if s.len() < max {
		return s;
	}

	match s.char_indices().nth(max) {
		None => s,
		Some((idx, _)) => &s[..idx],
	}
}

#[cfg(test)]
mod tests {
	use super::truncate_at_char_boundary;

	#[test]
	fn truncate_at_char_boundary_works() {
		assert_eq!(truncate_at_char_boundary("ボルテックス", 0), "");
		assert_eq!(truncate_at_char_boundary("ボルテックス", 4), "ボルテッ");
		assert_eq!(truncate_at_char_boundary("ボルテックス", 100), "ボルテックス");
		assert_eq!(truncate_at_char_boundary("hola-hola", 4), "hola");
	}
}