1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135

use sentry_core::protocol::{Breadcrumb, Event};
use slog::{Drain, OwnedKVList, Record};

use crate::{breadcrumb_from_record, event_from_record, exception_from_record};

/// The action that Sentry should perform for a [`slog::Level`].
#[derive(Debug)]
pub enum LevelFilter {
    /// Ignore the [`Record`].
    Ignore,
    /// Create a [`Breadcrumb`] from this [`Record`].
    Breadcrumb,
    /// Create a message [`Event`] from this [`Record`].
    Event,
    /// Create an exception [`Event`] from this [`Record`].
    Exception,
}

/// The type of Data Sentry should ingest for a [`slog::Record`].
#[allow(clippy::large_enum_variant)]
pub enum RecordMapping {
    /// Ignore the [`Record`].
    Ignore,
    /// Adds the [`Breadcrumb`] to the Sentry scope.
    Breadcrumb(Breadcrumb),
    /// Captures the [`Event`] to Sentry.
    Event(Event<'static>),
}

/// The default slog filter.
///
/// By default, an exception event is captured for `critical` logs,
/// a regular event for `error` and `warning` logs and a breadcrumb for `info`,
/// `debug` and `trace`.
pub fn default_filter(level: slog::Level) -> LevelFilter {
    match level {
        slog::Level::Critical => LevelFilter::Exception,
        slog::Level::Error | slog::Level::Warning => LevelFilter::Event,
        slog::Level::Info | slog::Level::Debug | slog::Level::Trace => LevelFilter::Breadcrumb,
    }
}

/// A Drain which passes all [`Record`]s to Sentry.
pub struct SentryDrain<D: Drain> {
    drain: D,
    filter: Box<dyn Fn(slog::Level) -> LevelFilter + Send + Sync>,
    #[allow(clippy::type_complexity)]
    mapper: Option<Box<dyn Fn(&Record, &OwnedKVList) -> RecordMapping + Send + Sync>>,
}

impl<D: slog::SendSyncRefUnwindSafeDrain> std::panic::RefUnwindSafe for SentryDrain<D> {}
impl<D: slog::SendSyncUnwindSafeDrain> std::panic::UnwindSafe for SentryDrain<D> {}

impl<D: Drain> SentryDrain<D> {
    /// Creates a new `SentryDrain`, wrapping a `slog::Drain`.
    pub fn new(drain: D) -> Self {
        Self {
            drain,
            filter: Box::new(default_filter),
            mapper: None,
        }
    }

    /// Sets a custom filter function.
    ///
    /// The filter classifies how sentry should handle [`Record`]s based on
    /// their [`slog::Level`].
    #[must_use]
    pub fn filter<F>(mut self, filter: F) -> Self
    where
        F: Fn(slog::Level) -> LevelFilter + Send + Sync + 'static,
    {
        self.filter = Box::new(filter);
        self
    }

    /// Sets a custom mapper function.
    ///
    /// The mapper is responsible for creating either breadcrumbs or events
    /// from [`Record`]s.
    ///
    /// # Examples
    ///
    /// ```
    /// use sentry_slog::{breadcrumb_from_record, RecordMapping, SentryDrain};
    ///
    /// let drain = SentryDrain::new(slog::Discard).mapper(|record, kv| match record.level() {
    ///     slog::Level::Trace => RecordMapping::Ignore,
    ///     _ => RecordMapping::Breadcrumb(breadcrumb_from_record(record, kv)),
    /// });
    /// ```
    #[must_use]
    pub fn mapper<M>(mut self, mapper: M) -> Self
    where
        M: Fn(&Record, &OwnedKVList) -> RecordMapping + Send + Sync + 'static,
    {
        self.mapper = Some(Box::new(mapper));
        self
    }
}

impl<D: Drain> slog::Drain for SentryDrain<D> {
    type Ok = D::Ok;
    type Err = D::Err;

    fn log(&self, record: &Record, values: &OwnedKVList) -> Result<Self::Ok, Self::Err> {
        let item: RecordMapping = match &self.mapper {
            Some(mapper) => mapper(record, values),
            None => match (self.filter)(record.level()) {
                LevelFilter::Ignore => RecordMapping::Ignore,
                LevelFilter::Breadcrumb => {
                    RecordMapping::Breadcrumb(breadcrumb_from_record(record, values))
                }
                LevelFilter::Event => RecordMapping::Event(event_from_record(record, values)),
                LevelFilter::Exception => {
                    RecordMapping::Event(exception_from_record(record, values))
                }
            },
        };

        match item {
            RecordMapping::Ignore => {}
            RecordMapping::Breadcrumb(b) => sentry_core::add_breadcrumb(b),
            RecordMapping::Event(e) => {
                sentry_core::capture_event(e);
            }
        }

        self.drain.log(record, values)
    }

    fn is_enabled(&self, level: slog::Level) -> bool {
        self.drain.is_enabled(level) || !matches!((self.filter)(level), LevelFilter::Ignore)
    }
}