diagnostics_log/
lib.rs

1// Copyright 2021 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
3
4#![deny(missing_docs)]
5
6//! Provides the `log::Log` implementation that allows to publish `log` events to
7//! Fuchsia Logging System.
8//!
9//! This library isn't Fuchsia-specific and provides a general `log::Log` that allows
10//! the library to also be used in the host.
11
12#[cfg(target_os = "fuchsia")]
13mod fuchsia;
14#[cfg(target_os = "fuchsia")]
15use self::fuchsia as implementation;
16
17#[cfg(not(target_os = "fuchsia"))]
18mod portable;
19#[cfg(not(target_os = "fuchsia"))]
20use self::portable as implementation;
21
22pub use diagnostics_log_types::Severity;
23pub use implementation::*;
24
25/// Adds a panic hook which will log an `ERROR` log with the panic information.
26pub(crate) fn install_panic_hook(prefix: Option<&'static str>) {
27    let previous_hook = std::panic::take_hook();
28    std::panic::set_hook(Box::new(move |info| {
29        let message = format!("{info}");
30        let prefix = prefix.unwrap_or("PANIC");
31        log::logger().log(
32            &log::RecordBuilder::new()
33                .level(log::Level::Error)
34                .line(Some(info.location().unwrap().line()))
35                .file(Some(info.location().unwrap().file()))
36                .key_values(&[("info", message.as_str())])
37                .args(format_args!("{prefix}"))
38                .build(),
39        );
40        previous_hook(info);
41    }));
42}
43
44/// A type which has a `Severity`.
45pub trait SeverityExt {
46    /// Return the severity of this value.
47    fn severity(&self) -> Severity;
48
49    /// Return the raw severity of this value.
50    fn raw_severity(&self) -> u8 {
51        self.severity() as u8
52    }
53}
54
55impl SeverityExt for log::Metadata<'_> {
56    fn severity(&self) -> Severity {
57        match self.level() {
58            log::Level::Error => Severity::Error,
59            log::Level::Warn => Severity::Warn,
60            log::Level::Info => Severity::Info,
61            log::Level::Debug => Severity::Debug,
62            log::Level::Trace => Severity::Trace,
63        }
64    }
65}
66
67/// Options to configure publishing. This is for initialization of logs, it's a superset of
68/// `PublisherOptions`.
69// NOTE: `Default` is implemented by the target specific implementations.
70pub struct PublishOptions<'t> {
71    pub(crate) publisher: PublisherOptions<'t>,
72    pub(crate) install_panic_hook: bool,
73    pub(crate) panic_prefix: Option<&'static str>,
74}
75
76impl PublishOptions<'_> {
77    /// Whether or not to install a panic hook which will log an ERROR whenever a panic happens.
78    ///
79    /// Default: true.
80    pub fn install_panic_hook(mut self, enable: bool) -> Self {
81        self.install_panic_hook = enable;
82        self
83    }
84
85    /// Enable to always log file/line information, otherwise only log
86    /// when severity is ERROR or above.
87    #[cfg(target_os = "fuchsia")]
88    pub fn always_log_file_line(mut self) -> Self {
89        self.publisher.always_log_file_line = true;
90        self
91    }
92
93    /// Override the default string prefix for a logged panic message.
94    pub fn panic_prefix(mut self, prefix: &'static str) -> Self {
95        self.panic_prefix = Some(prefix);
96        self
97    }
98}
99
100macro_rules! publisher_options {
101    ($(($name:ident, $self:ident, $($self_arg:ident),*)),*) => {
102        $(
103            impl<'t> $name<'t> {
104                /// Sets the tags applied to all published events.
105                ///
106                /// When set to an empty slice (the default), events are tagged with the moniker of
107                /// the component in which they are recorded.
108                ///
109                /// Default: empty.
110                pub fn tags(mut $self, tags: &'t [&'t str]) -> Self {
111                    let this = &mut $self$(.$self_arg)*;
112                    this.tags = tags;
113                    $self
114                }
115
116                /// Enable a metatag. It'll be applied to all published events.
117                ///
118                /// Default: no metatags are enabled.
119                pub fn enable_metatag(mut $self, metatag: Metatag) -> Self {
120                    let this = &mut $self$(.$self_arg)*;
121                    this.metatags.insert(metatag);
122                    $self
123                }
124
125                /// An interest filter to apply to messages published.
126                ///
127                /// Default: EMPTY, which implies INFO.
128                pub fn minimum_severity(mut $self, severity: impl Into<Severity>) -> Self {
129                    let this = &mut $self$(.$self_arg)*;
130                    this.interest.min_severity = Some(severity.into().into());
131                    $self
132                }
133            }
134        )*
135    };
136}
137
138publisher_options!((PublisherOptions, self,), (PublishOptions, self, publisher));
diagnostics_log/lib.rs

diagnostics_log/
lib.rs
