1 个不稳定版本
0.3.0 | 2020 年 8 月 4 日 |
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#7 in #logrotate
16KB
213 行代码(不含注释)
将输出写入文件,当超过限制时旋转文件。
定义了一个简单的 std::io::Write 对象,您可以将其作为中间件插入到您的写入器中。
按行旋转
我们可以通过行数作为限制来旋转日志文件。
use file_rotate::{FileRotate, RotationMode};
use std::{fs, io::Write};
// Create a directory to store our logs, this is not strictly needed but shows how we can
// arbitrary paths.
fs::create_dir("target/my-log-directory-lines");
// Create a new log writer. The first argument is anything resembling a path. The
// basename is used for naming the log files.
//
// Here we choose to limit logs by 10 lines, and have at most 2 rotated log files. This
// makes the total amount of log files 4, since the original file is present as well as
// file 0.
let mut log = FileRotate::new("target/my-log-directory-lines/my-log-file", RotationMode::Lines(3), 2);
// Write a bunch of lines
writeln!(log, "Line 1: Hello World!");
for idx in 2..11 {
writeln!(log, "Line {}", idx);
}
assert_eq!("Line 10\n", fs::read_to_string("target/my-log-directory-lines/my-log-file").unwrap());
assert_eq!("Line 1: Hello World!\nLine 2\nLine 3\n", fs::read_to_string("target/my-log-directory-lines/my-log-file.0").unwrap());
assert_eq!("Line 4\nLine 5\nLine 6\n", fs::read_to_string("target/my-log-directory-lines/my-log-file.1").unwrap());
assert_eq!("Line 7\nLine 8\nLine 9\n", fs::read_to_string("target/my-log-directory-lines/my-log-file.2").unwrap());
fs::remove_dir_all("target/my-log-directory-lines");
按字节旋转
另一种旋转方法是按字节而不是按行。
use file_rotate::{FileRotate, RotationMode};
use std::{fs, io::Write};
fs::create_dir("target/my-log-directory-bytes");
let mut log = FileRotate::new("target/my-log-directory-bytes/my-log-file", RotationMode::Bytes(5), 2);
writeln!(log, "Test file");
assert_eq!("Test ", fs::read_to_string("target/my-log-directory-bytes/my-log-file.0").unwrap());
assert_eq!("file\n", fs::read_to_string("target/my-log-directory-bytes/my-log-file").unwrap());
fs::remove_dir_all("target/my-log-directory-bytes");
旋转方法
使用的旋转方法是始终写入基本路径,然后在超过限制时将文件移动到新位置。移动顺序为 0, 1, 2, n, 0, 1, 2...
以下是一个 1 字节限制的示例
use file_rotate::{FileRotate, RotationMode};
use std::{fs, io::Write};
fs::create_dir("target/my-log-directory-small");
let mut log = FileRotate::new("target/my-log-directory-small/my-log-file", RotationMode::Bytes(1), 3);
write!(log, "A");
assert_eq!("A", fs::read_to_string("target/my-log-directory-small/my-log-file").unwrap());
write!(log, "B");
assert_eq!("A", fs::read_to_string("target/my-log-directory-small/my-log-file.0").unwrap());
assert_eq!("B", fs::read_to_string("target/my-log-directory-small/my-log-file").unwrap());
write!(log, "C");
assert_eq!("A", fs::read_to_string("target/my-log-directory-small/my-log-file.0").unwrap());
assert_eq!("B", fs::read_to_string("target/my-log-directory-small/my-log-file.1").unwrap());
assert_eq!("C", fs::read_to_string("target/my-log-directory-small/my-log-file").unwrap());
write!(log, "D");
assert_eq!("A", fs::read_to_string("target/my-log-directory-small/my-log-file.0").unwrap());
assert_eq!("B", fs::read_to_string("target/my-log-directory-small/my-log-file.1").unwrap());
assert_eq!("C", fs::read_to_string("target/my-log-directory-small/my-log-file.2").unwrap());
assert_eq!("D", fs::read_to_string("target/my-log-directory-small/my-log-file").unwrap());
write!(log, "E");
assert_eq!("A", fs::read_to_string("target/my-log-directory-small/my-log-file.0").unwrap());
assert_eq!("B", fs::read_to_string("target/my-log-directory-small/my-log-file.1").unwrap());
assert_eq!("C", fs::read_to_string("target/my-log-directory-small/my-log-file.2").unwrap());
assert_eq!("D", fs::read_to_string("target/my-log-directory-small/my-log-file.3").unwrap());
assert_eq!("E", fs::read_to_string("target/my-log-directory-small/my-log-file").unwrap());
// Here we overwrite the 0 file since we're out of log files, restarting the sequencing
write!(log, "F");
assert_eq!("E", fs::read_to_string("target/my-log-directory-small/my-log-file.0").unwrap());
assert_eq!("B", fs::read_to_string("target/my-log-directory-small/my-log-file.1").unwrap());
assert_eq!("C", fs::read_to_string("target/my-log-directory-small/my-log-file.2").unwrap());
assert_eq!("D", fs::read_to_string("target/my-log-directory-small/my-log-file.3").unwrap());
assert_eq!("F", fs::read_to_string("target/my-log-directory-small/my-log-file").unwrap());
fs::remove_dir_all("target/my-log-directory-small");
文件系统错误
如果日志所在的目录被删除或无法访问,则旋转器将简单地继续无故障地运行。在旋转发生时,它尝试在目录中打开一个文件。如果可以,它将继续记录。如果不行,则将写入的日期发送到空地。
此日志记录器永远不会崩溃。