Struct flexi_logger::writers::FileLogWriterBuilder

pub struct FileLogWriterBuilder { /* private fields */ }

Builder for FileLogWriter.

Implementations

impl FileLogWriterBuilder

Simple methods for influencing the behavior of the FileLogWriter.

pub fn print_message(self) -> FileLogWriterBuilder

Makes the FileLogWriter print an info message to stdout when a new file is used for log-output.

pub fn format(self, format: FormatFunction) -> FileLogWriterBuilder

Makes the FileLogWriter use the provided format function for the log entries, rather than the default (formats::default_format).

pub fn directory<S: Into<String>>(self, directory: S) -> FileLogWriterBuilder

Specifies a folder for the log files.

If the specified folder does not exist, the initialization will fail. By default, the log files are created in the folder where the program was started.

pub fn suffix<S: Into<String>>(self, suffix: S) -> FileLogWriterBuilder

Specifies a suffix for the log files. The default is “log”.

pub fn suppress_timestamp(self) -> FileLogWriterBuilder

Makes the logger not include a timestamp into the names of the log files

pub fn rotate_over_size(self, rotate_over_size: usize) -> FileLogWriterBuilder

Prevents indefinite growth of log files.

By default, the log file is fixed while your program is running and will grow indefinitely. With this option being used, when the log file reaches or exceeds the specified file size, the file will be closed and a new file will be opened.

The rotate-over-size is given in bytes, e.g. rotate_over_size(1_000) will rotate files once they reach a size of 1000 bytes.

Note that also the filename pattern changes:

• by default, no timestamp is added to the filename
• the logs are always written to a file with infix _rCURRENT
• if this file exceeds the specified rotate-over-size, it is closed and renamed to a file with a sequential number infix, and then the logging continues again to the (fresh) file with infix _rCURRENT

Example:

After some logging with your program my_prog, you will find files like

my_prog_r00000.log
my_prog_r00001.log
my_prog_r00002.log
my_prog_rCURRENT.log

pub fn append(self) -> FileLogWriterBuilder

Makes the logger append to the given file, if it exists; by default, the file would be truncated.

pub fn discriminant<S: Into<String>>(
    self,
    discriminant: S
) -> FileLogWriterBuilder

The specified String is added to the log file name.

pub fn create_symlink<S: Into<String>>(self, symlink: S) -> FileLogWriterBuilder

The specified String will be used on linux systems to create in the current folder a symbolic link to the current log file.

pub fn instantiate(self) -> Result<FileLogWriter, FlexiLoggerError>

Produces the FileLogWriter.

impl FileLogWriterBuilder

Alternative set of methods to control the behavior of the FileLogWriterBuilder. Use these methods when you want to control the settings flexibly, e.g. with commandline arguments via docopts or clap.

pub fn o_print_message(self, print_message: bool) -> FileLogWriterBuilder

With true, makes the FileLogWriterBuilder print an info message to stdout, each time when a new file is used for log-output.

pub fn o_directory<S: Into<String>>(
    self,
    directory: Option<S>
) -> FileLogWriterBuilder

Specifies a folder for the log files.

If the specified folder does not exist, the initialization will fail. With None, the log files are created in the folder where the program was started.

pub fn o_timestamp(self, use_timestamp: bool) -> FileLogWriterBuilder

With true, makes the FileLogWriterBuilder include a timestamp into the names of the log files.

pub fn o_rotate_over_size(
    self,
    rotate_over_size: Option<usize>
) -> FileLogWriterBuilder

By default, and with None, the log file will grow indefinitely. If a size is set, when the log file reaches or exceeds the specified size, the file will be closed and a new file will be opened. Also the filename pattern changes: instead of the timestamp, a serial number is included into the filename.

The size is given in bytes, e.g. o_rotate_over_size(Some(1_000)) will rotate files once they reach a size of 1 kB.

pub fn o_append(self, append: bool) -> FileLogWriterBuilder

If append is set to true, makes the logger append to the given file, if it exists. By default, or with false, the file would be truncated.

pub fn o_discriminant<S: Into<String>>(
    self,
    discriminant: Option<S>
) -> FileLogWriterBuilder

The specified String is added to the log file name.

pub fn o_create_symlink<S: Into<String>>(
    self,
    symlink: Option<S>
) -> FileLogWriterBuilder

If a String is specified, it will be used on linux systems to create in the current folder a symbolic link with this name to the current log file.