add TimePadding with Right and AddZeros

src/config.rs

@@ -58,6 +58,17 @@ pub(crate) enum TimeFormat {
     Custom(&'static [time::format_description::FormatItem<'static>]),
 }
 
+#[derive(Debug, Clone, Copy)]
+/// Padding to be used for logging the time
+pub enum TimePadding {
+    /// Add spaces on the right side, up to usize many
+    Right(usize),
+    /// Do not pad the time
+    Off,
+    /// If appliciable, add zeros to the subseconds
+    AddZeros
+}
+
 /// Configuration for the Loggers
 ///
 /// All loggers print the message in the following form:
@@ -82,6 +93,7 @@ pub struct Config {
     pub(crate) module: LevelFilter,
     pub(crate) time_format: TimeFormat,
     pub(crate) time_offset: UtcOffset,
+    pub(crate) time_padding: TimePadding,
     pub(crate) filter_allow: Cow<'static, [Cow<'static, str>]>,
     pub(crate) filter_ignore: Cow<'static, [Cow<'static, str>]>,
     #[cfg(feature = "termcolor")]
@@ -226,6 +238,12 @@ impl ConfigBuilder {
         self
     }
 
+    /// Set how the time should be padded
+    pub fn set_time_padding(&mut self, padding: TimePadding) -> &mut ConfigBuilder {
+        self.0.time_padding = padding;
+        self
+    }
+
     /// Sets the offset used to the current local time offset
     /// (overriding values previously set by [`ConfigBuilder::set_time_offset`]).
     ///
@@ -345,6 +363,7 @@ impl Default for Config {
             module: LevelFilter::Off,
             time_format: TimeFormat::Custom(format_description!("[hour]:[minute]:[second]")),
             time_offset: UtcOffset::UTC,
+            time_padding: TimePadding::AddZeros,
             filter_allow: Cow::Borrowed(&[]),
             filter_ignore: Cow::Borrowed(&[]),
             write_log_enable_colors: false,

src/loggers/logging.rs

@@ -1,4 +1,4 @@
-use crate::config::{TargetPadding, TimeFormat};
+use crate::config::{TargetPadding, TimeFormat, TimePadding};
 use crate::{Config, LevelPadding, ThreadLogMode, ThreadPadding};
 use log::{LevelFilter, Record};
 use std::io::{Error, Write};
@@ -72,22 +72,35 @@ pub fn write_time<W>(write: &mut W, config: &Config) -> Result<(), Error>
 where
     W: Write + Sized,
 {
-    use time::error::Format;
     use time::format_description::well_known::*;
 
     let time = time::OffsetDateTime::now_utc().to_offset(config.time_offset);
-    let res = match config.time_format {
-        TimeFormat::Rfc2822 => time.format_into(write, &Rfc2822),
-        TimeFormat::Rfc3339 => time.format_into(write, &Rfc3339),
-        TimeFormat::Custom(format) => time.format_into(write, &format),
+    let formatted = match config.time_format {
+        TimeFormat::Rfc2822 => time.format(&Rfc2822),
+        TimeFormat::Rfc3339 => time.format(&Rfc3339),
+        TimeFormat::Custom(format) => time.format(&format),
     };
-    match res {
-        Err(Format::StdIo(err)) => return Err(err),
-        Err(err) => panic!("Invalid time format: {}", err),
-        _ => {}
+    let mut formatted: String =
+        formatted.unwrap_or_else(|err| panic!("Invalid time format: {}", err));
+
+    formatted = match config.time_padding {
+        TimePadding::Right(offset) => format!("{: <1$}", formatted, offset),
+        TimePadding::AddZeros => {
+            if matches!(config.time_format, TimeFormat::Rfc3339) {
+                // only appliciable with Rfc3339
+                //
+                // the rfc3339 timestamp is 30 characters long, if it would not end with a 0 in the
+                // subseconds part. To fix this inconsistency, we add zeros before the Z.
+                while formatted.len() < 30 {
+                    formatted.insert(formatted.len() - 1, '0')
+                }
+            }
+            format!("{}", formatted)
+        }
+        TimePadding::Off => format!("{}", formatted),
     };
 
-    write!(write, " ")?;
+    write!(write, "{} ", formatted)?;
     Ok(())
 }