Struct flexi_logger::LoggerHandle
source · [−]pub struct LoggerHandle { /* private fields */ }
Expand description
Shuts down the logger when dropped, and allows reconfiguring the logger programmatically.
A LoggerHandle
is returned from Logger::start()
and from Logger::start_with_specfile()
.
When the logger handle is dropped, then it shuts down the Logger!
This matters if you use one of Logger::log_to_file
, Logger::log_to_writer
, or
Logger::log_to_file_and_writer
. It is then important to keep the logger handle alive
until the very end of your program!
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()
:
Logger::try_with_str("info")?
.start()?;
// ...
When logging to a file or another writer, keep the LoggerHandle
alive until the program ends:
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:
let mut logger = flexi_logger::Logger::try_with_str("info")?
.start()
.unwrap();
// ...
logger.parse_new_spec("warn");
// ...
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:
logger.parse_and_push_temp_spec("trace");
// ...
// critical calls
// ...
logger.pop_temp_spec();
// Continue with the log spec you had before.
// ...
Implementations
sourceimpl LoggerHandle
impl LoggerHandle
sourcepub fn set_new_spec(&mut self, new_spec: LogSpecification)
pub fn set_new_spec(&mut self, new_spec: LogSpecification)
Replaces the active LogSpecification
.
sourcepub fn parse_new_spec(&mut self, spec: &str) -> Result<(), FlexiLoggerError>
pub fn parse_new_spec(&mut self, spec: &str) -> Result<(), FlexiLoggerError>
Tries to replace the active LogSpecification
with the result from parsing the given String.
Errors
FlexiLoggerError::Parse
if the input is malformed.
sourcepub fn push_temp_spec(&mut self, new_spec: LogSpecification)
pub fn push_temp_spec(&mut self, new_spec: LogSpecification)
Replaces the active LogSpecification
and pushes the previous one to a Stack.
sourcepub fn parse_and_push_temp_spec<S: AsRef<str>>(
&mut self,
new_spec: S
) -> Result<(), FlexiLoggerError>
pub fn parse_and_push_temp_spec<S: AsRef<str>>(
&mut self,
new_spec: S
) -> Result<(), FlexiLoggerError>
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.
sourcepub fn pop_temp_spec(&mut self)
pub fn pop_temp_spec(&mut self)
Reverts to the previous LogSpecification
, if any.
sourcepub fn reset_flw(
&self,
flwb: &FileLogWriterBuilder
) -> Result<(), FlexiLoggerError>
pub fn reset_flw(
&self,
flwb: &FileLogWriterBuilder
) -> Result<(), FlexiLoggerError>
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
.
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.
sourcepub fn flw_config(&self) -> Result<FileLogWriterConfig, FlexiLoggerError>
pub fn flw_config(&self) -> Result<FileLogWriterConfig, FlexiLoggerError>
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.
sourcepub fn reopen_outputfile(&self) -> Result<(), FlexiLoggerError>
pub fn reopen_outputfile(&self) -> Result<(), FlexiLoggerError>
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
,
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.
sourcepub fn shutdown(&self)
pub fn shutdown(&self)
Shutdown all participating writers.
This method is supposed to be called at the very end of your program, if
- you use some
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
.
Trait Implementations
sourceimpl Clone for LoggerHandle
impl Clone for LoggerHandle
sourcefn clone(&self) -> LoggerHandle
fn clone(&self) -> LoggerHandle
Returns a copy of the value. Read more
1.0.0 · sourcefn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from source
. Read more
sourceimpl Drop for LoggerHandle
impl Drop for LoggerHandle
sourceimpl LogSpecSubscriber for LoggerHandle
impl LogSpecSubscriber for LoggerHandle
sourcefn set_new_spec(
&mut self,
new_spec: LogSpecification
) -> Result<(), FlexiLoggerError>
fn set_new_spec(
&mut self,
new_spec: LogSpecification
) -> Result<(), FlexiLoggerError>
Apply a new LogSpecification
. Read more
sourcefn initial_spec(&self) -> Result<LogSpecification, FlexiLoggerError>
fn initial_spec(&self) -> Result<LogSpecification, FlexiLoggerError>
Provide the current log spec. Read more
Auto Trait Implementations
impl !RefUnwindSafe for LoggerHandle
impl Send for LoggerHandle
impl Sync for LoggerHandle
impl Unpin for LoggerHandle
impl !UnwindSafe for LoggerHandle
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<T> Instrument for T
impl<T> Instrument for T
sourcefn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
sourcefn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
sourceimpl<T> WithSubscriber for T
impl<T> WithSubscriber for T
sourcefn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self> where
S: Into<Dispatch>,
fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self> where
S: Into<Dispatch>,
Attaches the provided Subscriber
to this type, returning a
WithDispatch
wrapper. Read more
sourcefn with_current_subscriber(self) -> WithDispatch<Self>
fn with_current_subscriber(self) -> WithDispatch<Self>
Attaches the current default Subscriber
to this type, returning a
WithDispatch
wrapper. Read more