logging - 在 Rust 中删除调试宏

Question

我正在编写一个应用程序，它在执行期间使用 slog 记录多项内容。因此，我广泛使用了 info!、error!、warn! 和 debug! 宏。

但是，正如预期的那样，debug! 调用可以帮助我调试应用程序，我不希望这些调用在实际使用应用程序时污染日志。

我一直在尝试编译它们，但没有成功。这是我正在使用的行:RUSTFLAGS="$RUSTFLAGS -C debug-assertions"cargo build --release

编译进行得很顺利，但在执行时我看到了所有的调试调用。

以下是我的问题的一个工作示例:

cargo .toml:

[dependencies]
slog = { version = "1.5", features = ["max_level_trace", "release_max_level_warn"] }
slog-stream = "1.2.0"
slog-term = "1.5.0"
slog-json = "1.2.1"
slog-stdlog = "1.1.0"
log = "0.3.7"

主要.rs:

#[macro_use]
extern crate slog;
extern crate slog_stream;
extern crate slog_term;
extern crate slog_json;
extern crate slog_stdlog;
#[macro_use]
extern crate log;

use std::path::Path;
use std::fs::OpenOptions;
use slog::DrainExt;

fn init_logger(work_dir : &Path) {
    let mut log_dir_buf = work_dir.to_path_buf();
    log_dir_buf.push("log");

    if !log_dir_buf.exists() {
        std::fs::create_dir(log_dir_buf.as_path()).unwrap();
    }

    log_dir_buf.push("the_log_file.log");
    let log_file_name = log_dir_buf.to_str().unwrap();

    let log_file = OpenOptions::new()
                        .create(true)
                        .write(true)
                        .truncate(true)
                        .open(log_file_name).unwrap();

    let console_drain = slog_term::streamer().build();
    let file_drain = slog_stream::stream(log_file, slog_json::default());
    let logger = slog::Logger::root(slog::duplicate(console_drain, file_drain).fuse(), o!());
    slog_stdlog::set_logger(logger).unwrap();
} 

fn main() {
    init_logger(Path::new("."));

    info!("This is an info message");
    warn!("This is a warn message");
    error!("This is an error message");
    debug!("This is a debug message");
}

现在，如上所述构建发布版本并运行二进制文件，我得到以下输出:

Jan 23 17:20:56.640 INFO This is an info message
Jan 23 17:20:56.641 WARN This is a warn message
Jan 23 17:20:56.641 ERRO This is an error message
Jan 23 17:20:56.641 DEBG This is a debug message

最后，rust 版本: rustc 1.31.0 (abe02cefd 2018-12-04)

我知道我使用的 slog 版本很旧，但目前升级依赖不是当务之急。然而，version's documentation指出日志过滤应该是可能的，正如@shepmaster 在 linked answer 中描述的那样，它似乎对我不起作用。我错过了什么？

Answer 1

为了简化问题，我使用当前版本的 slog (2.4.1) 制作了另一个工作示例，它设置了一个全局范围的记录器，问题仍然重现。这是代码示例:

extern crate slog;
extern crate slog_async;
extern crate slog_json;
extern crate slog_term;
extern crate slog_scope;
extern crate slog_stdlog;
#[macro_use]
extern crate log;

fn complex_logging() -> Result<(), log::SetLoggerError> {
    //Create the output file
    let log_path = "your_log_file_path.log";
    let file = OpenOptions::new()
        .create(true)
        .write(true)
        .truncate(true)
        .open(log_path)
        .unwrap();

    //Create the terminal drain
    let decorator = slog_term::TermDecorator::new().build();
    let d1 = slog_term::FullFormat::new(decorator).build().fuse();
    let d1 = slog_async::Async::new(d1).build().fuse();

    //Create the file drain
    let d2 = slog_json::Json::new(file)
        .add_default_keys()
        .build()
        .fuse();
    let d2 = slog_async::Async::new(d2).build().fuse();

    //Fuse the drains and create the logger
    let logger = slog::Logger::root(slog::Duplicate::new(d1, d2).fuse(), o!());
    let _guard = slog_scope::set_global_logger(logger);

    //register slog_stdlog as the log handler with the log crate
    slog_stdlog::init().unwrap();


    trace!("logging a trace message");
    debug!("debug values \"x\" => 1, \"y\" => -1");
    info!("some interesting info; where => right here");
    warn!("be cautious!; why => you never know...");
    error!("wrong, foobar; type => unknown");

    Ok(())
}

fn main() {
  let _res = complex_logging();    
}

在构建发布后运行上面的示例会产生以下结果:

Jan 30 13:53:52.398 TRCE logging a trace message
Jan 30 13:53:52.399 DEBG debug values "x" => 1, "y" => -1
Jan 30 13:53:52.399 INFO some interesting info; where => right here
Jan 30 13:53:52.399 WARN be cautious!; why => you never know...
Jan 30 13:53:52.399 ERRO wrong, foobar; type => unknown

但是，一个传递记录器的新示例解决了这个问题。这是工作示例:

#[macro_use]
extern crate slog;
extern crate slog_async;
extern crate slog_json;
extern crate slog_term;
extern crate slog_scope;
extern crate slog_stdlog;

use slog::Drain;
use std::fs::OpenOptions;
use std::io;
use std::sync::Mutex;

fn duplicate_log() {
    let plain = slog_term::PlainSyncDecorator::new(std::io::stdout());
    let d1 = slog_term::FullFormat::new(plain).build().fuse();
    let d2 = Mutex::new(slog_json::Json::default(io::stdout())).fuse();
    let log = slog::Logger::root(slog::Duplicate::new(d1, d2).fuse(), o!("version" => env!("CARGO_PKG_VERSION")));

    trace!(log, "logging a trace message");
    debug!(log, "debug values"; "x" => 1, "y" => -1);
    info!(log, "some interesting info"; "where" => "right here");
    warn!(log, "be cautious!"; "why" => "you never know...");
    error!(log, "wrong {}", "foobar"; "type" => "unknown");
    crit!(log, "abandoning test");
}

fn main() {
   duplicate_log();
}

运行工作示例会产生以下结果:

Jan 30 13:56:30.839 INFO some interesting info, where: right here, version: 0.1.0
{"msg":"some interesting info","level":"INFO","ts":"2019-01-30T13:56:30.839762+00:00","version":"0.1.0","where":"right here"}
Jan 30 13:56:30.839 WARN be cautious!, why: you never know..., version: 0.1.0
{"msg":"be cautious!","level":"WARN","ts":"2019-01-30T13:56:30.839787+00:00","version":"0.1.0","why":"you never know..."}
Jan 30 13:56:30.839 ERRO wrong foobar, type: unknown, version: 0.1.0
{"msg":"wrong foobar","level":"ERRO","ts":"2019-01-30T13:56:30.839802+00:00","version":"0.1.0","type":"unknown"}
Jan 30 13:56:30.839 CRIT abandoning test, version: 0.1.0
{"msg":"abandoning test","level":"CRIT","ts":"2019-01-30T13:56:30.839815+00:00","version":"0.1.0"}

如果您遇到与我类似的问题，我的问题是设置全局范围记录器。传递记录器解决了这个问题。