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#[cfg(feature = "specfile")]
use notify_debouncer_mini::{notify::RecommendedWatcher, Debouncer};
use crate::primary_writer::PrimaryWriter;
use crate::util::{eprint_err, ERRCODE};
use crate::writers::{FileLogWriterBuilder, FileLogWriterConfig, LogWriter};
use crate::{FlexiLoggerError, LogSpecification};
use std::collections::HashMap;
use std::sync::{Arc, RwLock};
/// Shuts down the logger when its last instance is dropped
/// (in case you use `LoggerHandle::clone()` you can have multiple instances),
/// and allows reconfiguring the logger programmatically.
///
/// A `LoggerHandle` is returned from `Logger::start()` and from `Logger::start_with_specfile()`.
/// Keep it alive until the very end of your program if you use one of
/// `Logger::log_to_file`, `Logger::log_to_writer`, or `Logger::log_to_file_and_writer`.
///
/// `LoggerHandle` offers methods to modify the log specification programmatically,
/// to flush() the logger explicitly, and even to reconfigure the used `FileLogWriter` --
/// if one is used.
///
/// # Examples
///
/// Since dropping the `LoggerHandle` has no effect if you use
/// `Logger::log_to_stderr` (which is the default) or `Logger::log_to_stdout`.
/// you can then safely ignore the return value of `Logger::start()`:
///
/// ```rust
/// # use flexi_logger::Logger;
/// # fn main() -> Result<(), Box<dyn std::error::Error>> {
/// Logger::try_with_str("info")?
/// .start()?;
/// // ...
/// # Ok(())
/// # }
/// ```
///
/// When logging to a file or another writer, keep the `LoggerHandle` alive until the program ends:
///
/// ```rust
/// use flexi_logger::{FileSpec, Logger};
/// fn main() -> Result<(), Box<dyn std::error::Error>> {
/// let _logger = Logger::try_with_str("info")?
/// .log_to_file(FileSpec::default())
/// .start()?;
///
/// // do work
/// Ok(())
/// }
/// ```
///
/// You can use the logger handle to permanently exchange the log specification programmatically,
/// anywhere in your code:
///
/// ```rust
/// # fn main() -> Result<(), Box<dyn std::error::Error>> {
/// let mut logger = flexi_logger::Logger::try_with_str("info")?
/// .start()
/// .unwrap();
/// // ...
/// logger.parse_new_spec("warn");
/// // ...
/// # Ok(())
/// # }
/// ```
///
/// However, when debugging, you often want to modify the log spec only temporarily, for
/// one or few method calls only; this is easier done with the following method, because
/// it allows switching back to the previous spec:
///
/// ```rust
/// # fn main() -> Result<(), Box<dyn std::error::Error>> {
/// # let mut logger = flexi_logger::Logger::try_with_str("info")?
/// # .start()?;
/// logger.parse_and_push_temp_spec("trace");
/// // ...
/// // critical calls
/// // ...
/// logger.pop_temp_spec();
/// // Continue with the log spec you had before.
/// // ...
/// # Ok(())
/// # }
/// ```
#[derive(Clone)]
pub struct LoggerHandle {
pub(crate) writers_handle: WritersHandle,
#[cfg(feature = "specfile")]
pub(crate) ao_specfile_watcher: Option<Arc<Debouncer<RecommendedWatcher>>>,
}
impl LoggerHandle {
pub(crate) fn new(
spec: Arc<RwLock<LogSpecification>>,
primary_writer: Arc<PrimaryWriter>,
other_writers: Arc<HashMap<String, Box<dyn LogWriter>>>,
) -> Self {
Self {
writers_handle: WritersHandle {
spec,
spec_stack: Vec::default(),
primary_writer,
other_writers,
},
#[cfg(feature = "specfile")]
ao_specfile_watcher: None,
}
}
//
pub(crate) fn reconfigure(&self, max_level: log::LevelFilter) {
self.writers_handle.reconfigure(max_level);
}
/// Replaces the active `LogSpecification`.
#[allow(clippy::missing_panics_doc)]
pub fn set_new_spec(&self, new_spec: LogSpecification) {
self.writers_handle
.set_new_spec(new_spec)
.map_err(|e| eprint_err(ERRCODE::Poison, "rwlock on log spec is poisoned", &e))
.ok();
}
/// Tries to replace the active `LogSpecification` with the result from parsing the given String.
///
/// # Errors
///
/// [`FlexiLoggerError::Parse`] if the input is malformed.
pub fn parse_new_spec(&mut self, spec: &str) -> Result<(), FlexiLoggerError> {
self.set_new_spec(LogSpecification::parse(spec)?);
Ok(())
}
/// Replaces the active `LogSpecification` and pushes the previous one to a Stack.
#[allow(clippy::missing_panics_doc)]
pub fn push_temp_spec(&mut self, new_spec: LogSpecification) {
self.writers_handle
.spec_stack
.push(self.writers_handle.spec.read().unwrap(/* catch and expose error? */).clone());
self.set_new_spec(new_spec);
}
/// Tries to replace the active `LogSpecification` with the result from parsing the given String
/// and pushes the previous one to a Stack.
///
/// # Errors
///
/// [`FlexiLoggerError::Parse`] if the input is malformed.
pub fn parse_and_push_temp_spec<S: AsRef<str>>(
&mut self,
new_spec: S,
) -> Result<(), FlexiLoggerError> {
self.writers_handle.spec_stack.push(
self.writers_handle
.spec
.read()
.map_err(|_| FlexiLoggerError::Poison)?
.clone(),
);
self.set_new_spec(LogSpecification::parse(new_spec)?);
Ok(())
}
/// Reverts to the previous `LogSpecification`, if any.
pub fn pop_temp_spec(&mut self) {
if let Some(previous_spec) = self.writers_handle.spec_stack.pop() {
self.set_new_spec(previous_spec);
}
}
/// Flush all writers.
pub fn flush(&self) {
self.writers_handle.primary_writer.flush().ok();
for writer in self.writers_handle.other_writers.values() {
writer.flush().ok();
}
}
/// Replaces parts of the configuration of the file log writer.
///
/// Note that neither the write mode nor the format function can be reset and
/// that the provided `FileLogWriterBuilder` must have the same values for these as the
/// currently used `FileLogWriter`.
///
/// # Example
///
/// See [`code_examples`](code_examples/index.html#reconfigure-the-file-log-writer).
///
/// # Errors
///
/// `FlexiLoggerError::NoFileLogger` if no file log writer is configured.
///
/// `FlexiLoggerError::Reset` if a reset was tried with a different write mode.
///
/// `FlexiLoggerError::Io` if the specified path doesn't work.
///
/// `FlexiLoggerError::Poison` if some mutex is poisoned.
pub fn reset_flw(&self, flwb: &FileLogWriterBuilder) -> Result<(), FlexiLoggerError> {
if let PrimaryWriter::Multi(ref mw) = &*self.writers_handle.primary_writer {
mw.reset_file_log_writer(flwb)
} else {
Err(FlexiLoggerError::NoFileLogger)
}
}
/// Returns the current configuration of the file log writer.
///
/// # Errors
///
/// `FlexiLoggerError::NoFileLogger` if no file log writer is configured.
///
/// `FlexiLoggerError::Poison` if some mutex is poisoned.
pub fn flw_config(&self) -> Result<FileLogWriterConfig, FlexiLoggerError> {
if let PrimaryWriter::Multi(ref mw) = &*self.writers_handle.primary_writer {
mw.flw_config()
} else {
Err(FlexiLoggerError::NoFileLogger)
}
}
/// Makes the logger re-open the current log file.
///
/// If the log is written to a file, `flexi_logger` expects that nobody else modifies the file,
/// and offers capabilities to rotate, compress, and clean up log files.
///
/// However, if you use tools like linux' `logrotate`
/// to rename or delete the current output file, you need to inform `flexi_logger` about
/// such actions by calling this method. Otherwise `flexi_logger` will not stop
/// writing to the renamed or even deleted file!
///
/// # Example
///
/// `logrotate` e.g. can be configured to send a `SIGHUP` signal to your program. You need to
/// handle `SIGHUP` in your program explicitly,
/// e.g. using a crate like [`ctrlc`](https://docs.rs/ctrlc/latest/ctrlc/),
/// and call this function from the registered signal handler.
///
/// # Errors
///
/// `FlexiLoggerError::NoFileLogger` if no file log writer is configured.
///
/// `FlexiLoggerError::Poison` if some mutex is poisoned.
pub fn reopen_outputfile(&self) -> Result<(), FlexiLoggerError> {
if let PrimaryWriter::Multi(ref mw) = &*self.writers_handle.primary_writer {
mw.reopen_outputfile()
} else {
Err(FlexiLoggerError::NoFileLogger)
}
}
/// Shutdown all participating writers.
///
/// This method is supposed to be called at the very end of your program, if
///
/// - you use some [`Cleanup`](crate::Cleanup) strategy with compression:
/// then you want to ensure that a termination of your program
/// does not interrput the cleanup-thread when it is compressing a log file,
/// which could leave unexpected files in the filesystem
/// - you use your own writer(s), and they need to clean up resources
///
/// See also [`writers::LogWriter::shutdown`](crate::writers::LogWriter::shutdown).
pub fn shutdown(&self) {
self.writers_handle.primary_writer.shutdown();
for writer in self.writers_handle.other_writers.values() {
writer.shutdown();
}
}
// Allows checking the logs written so far to the writer
#[doc(hidden)]
pub fn validate_logs(&self, expected: &[(&'static str, &'static str, &'static str)]) {
self.writers_handle.primary_writer.validate_logs(expected);
}
}
#[derive(Clone)]
pub(crate) struct WritersHandle {
spec: Arc<RwLock<LogSpecification>>,
spec_stack: Vec<LogSpecification>,
primary_writer: Arc<PrimaryWriter>,
other_writers: Arc<HashMap<String, Box<dyn LogWriter>>>,
}
impl WritersHandle {
fn set_new_spec(&self, new_spec: LogSpecification) -> Result<(), FlexiLoggerError> {
let max_level = new_spec.max_level();
self.spec
.write()
.map_err(|_| FlexiLoggerError::Poison)?
.update_from(new_spec);
self.reconfigure(max_level);
Ok(())
}
pub(crate) fn reconfigure(&self, mut max_level: log::LevelFilter) {
for w in self.other_writers.as_ref().values() {
max_level = std::cmp::max(max_level, w.max_log_level());
}
log::set_max_level(max_level);
}
}
impl Drop for WritersHandle {
fn drop(&mut self) {
self.primary_writer.shutdown();
for writer in self.other_writers.values() {
writer.shutdown();
}
}
}
/// Trait that allows to register for changes to the log specification.
#[cfg(feature = "specfile_without_notification")]
pub trait LogSpecSubscriber: 'static + Send {
/// Apply a new `LogSpecification`.
///
/// # Errors
fn set_new_spec(&mut self, new_spec: LogSpecification) -> Result<(), FlexiLoggerError>;
/// Provide the current log spec.
///
/// # Errors
fn initial_spec(&self) -> Result<LogSpecification, FlexiLoggerError>;
}
#[cfg(feature = "specfile_without_notification")]
impl LogSpecSubscriber for WritersHandle {
fn set_new_spec(&mut self, new_spec: LogSpecification) -> Result<(), FlexiLoggerError> {
WritersHandle::set_new_spec(self, new_spec)
}
fn initial_spec(&self) -> Result<LogSpecification, FlexiLoggerError> {
Ok((*self.spec.read().map_err(|_e| FlexiLoggerError::Poison)?).clone())
}
}