sc_tracing/logging/
event_format.rs

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
// This file is part of Substrate.

// Copyright (C) Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.

use crate::logging::fast_local_time::FastLocalTime;
use console::style;
use std::fmt;
use tracing::{Event, Level, Subscriber};
use tracing_log::NormalizeEvent;
use tracing_subscriber::{
	fmt::{format, time::FormatTime, FmtContext, FormatEvent, FormatFields},
	registry::LookupSpan,
};

/// A pre-configured event formatter.
pub struct EventFormat<T = FastLocalTime> {
	/// Use the given timer for log message timestamps.
	pub timer: T,
	/// Sets whether or not an event's target is displayed.
	pub display_target: bool,
	/// Sets whether or not an event's level is displayed.
	pub display_level: bool,
	/// Sets whether or not the name of the current thread is displayed when formatting events.
	pub display_thread_name: bool,
	/// Duplicate INFO, WARN and ERROR messages to stdout.
	pub dup_to_stdout: bool,
}

impl<T> EventFormat<T>
where
	T: FormatTime,
{
	// NOTE: the following code took inspiration from tracing-subscriber
	//
	//       https://github.com/tokio-rs/tracing/blob/2f59b32/tracing-subscriber/src/fmt/format/mod.rs#L449
	pub(crate) fn format_event_custom<'b, 'w, S, N>(
		&self,
		ctx: &FmtContext<'b, S, N>,
		mut writer: format::Writer<'w>,
		event: &Event,
	) -> fmt::Result
	where
		S: Subscriber + for<'a> LookupSpan<'a>,
		N: for<'a> FormatFields<'a> + 'static,
	{
		let normalized_meta = event.normalized_metadata();
		let meta = normalized_meta.as_ref().unwrap_or_else(|| event.metadata());
		time::write(&self.timer, &mut format::Writer::new(&mut writer))?;

		if self.display_level {
			let fmt_level = FmtLevel::new(meta.level());
			write!(writer, "{} ", fmt_level)?;
		}

		if self.display_thread_name {
			let current_thread = std::thread::current();
			match current_thread.name() {
				Some(name) => {
					write!(&mut writer, "{} ", FmtThreadName::new(name))?;
				},
				// fall-back to thread id when name is absent and ids are not enabled
				None => {
					write!(&mut writer, "{:0>2?} ", current_thread.id())?;
				},
			}
		}

		if self.display_target {
			write!(&mut writer, "{}: ", meta.target())?;
		}

		// Custom code to display node name
		if let Some(span) = ctx.lookup_current() {
			for span in span.scope() {
				let exts = span.extensions();
				if let Some(prefix) = exts.get::<super::layers::Prefix>() {
					write!(&mut writer, "{}", prefix.as_str())?;
					break
				}
			}
		}

		ctx.format_fields(format::Writer::new(&mut writer), event)?;
		writeln!(&mut writer)?;

		Ok(())
	}
}

// NOTE: the following code took inspiration from tracing-subscriber
//
//       https://github.com/tokio-rs/tracing/blob/2f59b32/tracing-subscriber/src/fmt/format/mod.rs#L449
impl<S, N, T> FormatEvent<S, N> for EventFormat<T>
where
	S: Subscriber + for<'a> LookupSpan<'a>,
	N: for<'a> FormatFields<'a> + 'static,
	T: FormatTime,
{
	fn format_event(
		&self,
		ctx: &FmtContext<S, N>,
		mut writer: format::Writer<'_>,
		event: &Event,
	) -> fmt::Result {
		if self.dup_to_stdout &&
			(event.metadata().level() == &Level::INFO ||
				event.metadata().level() == &Level::WARN ||
				event.metadata().level() == &Level::ERROR)
		{
			let mut out = String::new();
			let buf_writer = format::Writer::new(&mut out);
			self.format_event_custom(ctx, buf_writer, event)?;
			writer.write_str(&out)?;
			print!("{}", out);
			Ok(())
		} else {
			self.format_event_custom(ctx, writer, event)
		}
	}
}

struct FmtLevel<'a> {
	level: &'a Level,
}

impl<'a> FmtLevel<'a> {
	pub(crate) fn new(level: &'a Level) -> Self {
		Self { level }
	}
}

const TRACE_STR: &str = "TRACE";
const DEBUG_STR: &str = "DEBUG";
const INFO_STR: &str = " INFO";
const WARN_STR: &str = " WARN";
const ERROR_STR: &str = "ERROR";

impl<'a> fmt::Display for FmtLevel<'a> {
	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
		match *self.level {
			Level::TRACE => write!(f, "{}", style(TRACE_STR).magenta()),
			Level::DEBUG => write!(f, "{}", style(DEBUG_STR).blue()),
			Level::INFO => write!(f, "{}", style(INFO_STR).green()),
			Level::WARN => write!(f, "{}", style(WARN_STR).yellow()),
			Level::ERROR => write!(f, "{}", style(ERROR_STR).red()),
		}
	}
}

struct FmtThreadName<'a> {
	name: &'a str,
}

impl<'a> FmtThreadName<'a> {
	pub(crate) fn new(name: &'a str) -> Self {
		Self { name }
	}
}

// NOTE: the following code has been duplicated from tracing-subscriber
//
//       https://github.com/tokio-rs/tracing/blob/2f59b32/tracing-subscriber/src/fmt/format/mod.rs#L845
impl<'a> fmt::Display for FmtThreadName<'a> {
	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
		use std::sync::atomic::{
			AtomicUsize,
			Ordering::{AcqRel, Acquire, Relaxed},
		};

		// Track the longest thread name length we've seen so far in an atomic,
		// so that it can be updated by any thread.
		static MAX_LEN: AtomicUsize = AtomicUsize::new(0);
		let len = self.name.len();
		// Snapshot the current max thread name length.
		let mut max_len = MAX_LEN.load(Relaxed);

		while len > max_len {
			// Try to set a new max length, if it is still the value we took a
			// snapshot of.
			match MAX_LEN.compare_exchange(max_len, len, AcqRel, Acquire) {
				// We successfully set the new max value
				Ok(_) => break,
				// Another thread set a new max value since we last observed
				// it! It's possible that the new length is actually longer than
				// ours, so we'll loop again and check whether our length is
				// still the longest. If not, we'll just use the newer value.
				Err(actual) => max_len = actual,
			}
		}

		// pad thread name using `max_len`
		write!(f, "{:>width$}", self.name, width = max_len)
	}
}

// NOTE: the following code has been duplicated from tracing-subscriber
//
//       https://github.com/tokio-rs/tracing/blob/2f59b32/tracing-subscriber/src/fmt/time/mod.rs#L252
mod time {
	use std::fmt;
	use tracing_subscriber::fmt::{format, time::FormatTime};

	pub(crate) fn write<T>(timer: T, writer: &mut format::Writer<'_>) -> fmt::Result
	where
		T: FormatTime,
	{
		if console::colors_enabled() {
			write!(writer, "\x1B[2m")?;
			timer.format_time(writer)?;
			write!(writer, "\x1B[0m")?;
		} else {
			timer.format_time(writer)?;
		}

		writer.write_char(' ')?;
		Ok(())
	}
}