fix #370

examples/log_to_file_with_rolling_and_time_trigger.rs

@@ -0,0 +1,119 @@
+//! Example showing how to use logging with a rolling trigger based on size
+//!
+//! NB: The size used in the example is intentionally small so multiple file
+//! will be created in the 2 seconds that the example is set to run and is not
+//! intended for practical for usage
+
+/// This is the size at which a new file should be created. For the demo it is
+/// set to 2s which is very small and only for demo purposes
+const TIME_TRIGGER_CONFIG: TimeTriggerConfig = TimeTriggerConfig {
+    interval: TimeTriggerInterval::Second(2),
+    max_random_delay: 0,
+    modulate: false,
+};
+
+/// Delay between log messages for demo purposes
+const TIME_BETWEEN_LOG_MESSAGES: Duration = Duration::from_millis(10);
+
+/// Number of archive log files to keep
+const LOG_FILE_COUNT: u32 = 3;
+
+/// Time demo is set to run for (Set to be long enough for multiple files to be created)
+const RUN_TIME: Duration = Duration::from_secs(6);
+
+/// Location where logs will be written to
+const FILE_PATH: &str = "/tmp/foo.log";
+
+/// Location where log archives will be moved to
+/// For Pattern info See:
+///     https://docs.rs/log4rs/*/log4rs/append/rolling_file/policy/compound/roll/fixed_window/struct.FixedWindowRollerBuilder.html#method.build
+const ARCHIVE_PATTERN: &str = "/tmp/archive/foo.{}.log";
+
+use std::{
+    thread::sleep,
+    time::{Duration, Instant},
+};
+
+use log::{debug, error, info, trace, warn, LevelFilter, SetLoggerError};
+use log4rs::{
+    append::{
+        console::{ConsoleAppender, Target},
+        rolling_file::policy::compound::{
+            roll::fixed_window::FixedWindowRoller,
+            trigger::time::{TimeTrigger, TimeTriggerConfig, TimeTriggerInterval},
+            CompoundPolicy,
+        },
+    },
+    config::{Appender, Config, Root},
+    encode::pattern::PatternEncoder,
+    filter::threshold::ThresholdFilter,
+};
+
+fn main() -> Result<(), SetLoggerError> {
+    let level = log::LevelFilter::Info;
+
+    // Build a stderr logger.
+    let stderr = ConsoleAppender::builder().target(Target::Stderr).build();
+
+    // Create a policy to use with the file logging
+    // let time_trigger_config = TimeTriggerConfig {
+    //     interval: Duration::from_secs(1),
+    //     delay: Duration::from_secs(0),
+    //     modulate: false,
+    // };
+    let trigger = TimeTrigger::new(TIME_TRIGGER_CONFIG);
+    let roller = FixedWindowRoller::builder()
+        .base(0) // Default Value (line not needed unless you want to change from 0 (only here for demo purposes)
+        .build(ARCHIVE_PATTERN, LOG_FILE_COUNT) // Roll based on pattern and max 3 archive files
+        .unwrap();
+    let policy = CompoundPolicy::new(Box::new(trigger), Box::new(roller));
+
+    // Logging to log file. (with rolling)
+    let logfile = log4rs::append::rolling_file::RollingFileAppender::builder()
+        // Pattern: https://docs.rs/log4rs/*/log4rs/encode/pattern/index.html
+        .encoder(Box::new(PatternEncoder::new("{l} - {m}\n")))
+        .build(FILE_PATH, Box::new(policy))
+        .unwrap();
+
+    // Log Trace level output to file where trace is the default level
+    // and the programmatically specified level to stderr.
+    let config = Config::builder()
+        .appender(Appender::builder().build("logfile", Box::new(logfile)))
+        .appender(
+            Appender::builder()
+                .filter(Box::new(ThresholdFilter::new(level)))
+                .build("stderr", Box::new(stderr)),
+        )
+        .build(
+            Root::builder()
+                .appender("logfile")
+                .appender("stderr")
+                .build(LevelFilter::Trace),
+        )
+        .unwrap();
+
+    // Use this to change log levels at runtime.
+    // This means you can change the default log level to trace
+    // if you are trying to debug an issue and need more logs on then turn it off
+    // once you are done.
+    let _handle = log4rs::init_config(config)?;
+
+    error!("Goes to stderr and file");
+    warn!("Goes to stderr and file");
+    info!("Goes to stderr and file");
+    debug!("Goes to file only");
+    trace!("Goes to file only");
+
+    // Generate some log messages to trigger rolling
+    let instant = Instant::now();
+    while instant.elapsed() < RUN_TIME {
+        info!("Running for {:?}", instant.elapsed());
+        sleep(TIME_BETWEEN_LOG_MESSAGES);
+    }
+    info!(
+        "See '{}' for log and '{}' for archived logs",
+        FILE_PATH, ARCHIVE_PATTERN
+    );
+
+    Ok(())
+}

src/append/rolling_file/policy/compound/trigger/time.rs

@@ -23,9 +23,12 @@ use crate::config::{Deserialize, Deserializers};
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug, Default, serde::Deserialize)]
 #[serde(deny_unknown_fields)]
 pub struct TimeTriggerConfig {
+    /// The date/time interval between log file rolls.
     interval: TimeTriggerInterval,
+    /// Whether to modulate the interval.
     #[serde(default)]
     modulate: bool,
+    /// The maximum random delay in seconds.
     #[serde(default)]
     max_random_delay: u64,
 }
@@ -34,9 +37,12 @@ pub struct TimeTriggerConfig {
 /// Configuration for the time trigger.
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug, Default)]
 pub struct TimeTriggerConfig {
-    interval: TimeTriggerInterval,
-    modulate: bool,
-    max_random_delay: u64,
+    /// The date/time interval between log file rolls.Q
+    pub interval: TimeTriggerInterval,
+    /// Whether to modulate the interval.
+    pub modulate: bool,
+    /// The maximum random delay in seconds.
+    pub max_random_delay: u64,
 }
 
 /// A trigger which rolls the log once it has passed a certain time.