glean_core/metrics/
text.rs

1// This Source Code Form is subject to the terms of the Mozilla Public
2// License, v. 2.0. If a copy of the MPL was not distributed with this
3// file, You can obtain one at https://mozilla.org/MPL/2.0/.
4
5use std::sync::Arc;
6
7use crate::common_metric_data::{CommonMetricDataInternal, DynamicLabelType};
8use crate::error_recording::{test_get_num_recorded_errors, ErrorType};
9use crate::metrics::Metric;
10use crate::metrics::MetricType;
11use crate::storage::StorageManager;
12use crate::util::truncate_string_at_boundary_with_error;
13use crate::Glean;
14use crate::{CommonMetricData, TestGetValue};
15
16// The maximum number of characters for text.
17const MAX_LENGTH_VALUE: usize = 200 * 1024;
18
19/// A text metric.
20///
21/// Records a single long Unicode text,
22/// used when the limits on `String` are too low.
23/// Text is length-limited to `MAX_LENGTH_VALUE` bytes.
24#[derive(Clone, Debug)]
25pub struct TextMetric {
26    meta: Arc<CommonMetricDataInternal>,
27}
28
29impl MetricType for TextMetric {
30    fn meta(&self) -> &CommonMetricDataInternal {
31        &self.meta
32    }
33
34    fn with_name(&self, name: String) -> Self {
35        let mut meta = (*self.meta).clone();
36        meta.inner.name = name;
37        Self {
38            meta: Arc::new(meta),
39        }
40    }
41
42    fn with_dynamic_label(&self, label: DynamicLabelType) -> Self {
43        let mut meta = (*self.meta).clone();
44        meta.inner.dynamic_label = Some(label);
45        Self {
46            meta: Arc::new(meta),
47        }
48    }
49}
50
51// IMPORTANT:
52//
53// When changing this implementation, make sure all the operations are
54// also declared in the related trait in `../traits/`.
55impl TextMetric {
56    /// Creates a new text metric.
57    pub fn new(meta: CommonMetricData) -> Self {
58        Self {
59            meta: Arc::new(meta.into()),
60        }
61    }
62
63    /// Sets to the specified value.
64    ///
65    /// # Arguments
66    ///
67    /// * `value` - The text to set the metric to.
68    ///
69    /// ## Notes
70    ///
71    /// Truncates the value (at codepoint boundaries) if it is longer than `MAX_LENGTH_VALUE` bytes
72    /// and logs an error.
73    pub fn set(&self, value: String) {
74        let metric = self.clone();
75        crate::launch_with_glean(move |glean| metric.set_sync(glean, &value))
76    }
77
78    /// Sets to the specified value synchronously,
79    /// truncating and recording an error if longer than `MAX_LENGTH_VALUE`.
80    #[doc(hidden)]
81    pub fn set_sync<S: Into<String>>(&self, glean: &Glean, value: S) {
82        if !self.should_record(glean) {
83            return;
84        }
85
86        let s = truncate_string_at_boundary_with_error(glean, &self.meta, value, MAX_LENGTH_VALUE);
87
88        let value = Metric::Text(s);
89        glean.storage().record(glean, &self.meta, &value)
90    }
91
92    /// Gets the currently-stored value as a string, or None if there is no value.
93    #[doc(hidden)]
94    pub fn get_value<'a, S: Into<Option<&'a str>>>(
95        &self,
96        glean: &Glean,
97        ping_name: S,
98    ) -> Option<String> {
99        let queried_ping_name = ping_name
100            .into()
101            .unwrap_or_else(|| &self.meta().inner.send_in_pings[0]);
102
103        match StorageManager.snapshot_metric_for_test(
104            glean.storage(),
105            queried_ping_name,
106            &self.meta.identifier(glean),
107            self.meta.inner.lifetime,
108        ) {
109            Some(Metric::Text(s)) => Some(s),
110            _ => None,
111        }
112    }
113
114    /// **Exported for test purposes.**
115    ///
116    /// Gets the number of recorded errors for the given metric and error type.
117    ///
118    /// # Arguments
119    ///
120    /// * `error` - The type of error
121    ///
122    /// # Returns
123    ///
124    /// The number of errors reported.
125    pub fn test_get_num_recorded_errors(&self, error: ErrorType) -> i32 {
126        crate::block_on_dispatcher();
127
128        crate::core::with_glean(|glean| {
129            test_get_num_recorded_errors(glean, self.meta(), error).unwrap_or(0)
130        })
131    }
132}
133
134impl TestGetValue<String> for TextMetric {
135    /// **Test-only API (exported for FFI purposes).**
136    ///
137    /// Gets the currently stored value as a string.
138    ///
139    /// This doesn't clear the stored value.
140    ///
141    /// # Arguments
142    ///
143    /// * `ping_name` - the optional name of the ping to retrieve the metric
144    ///                 for. Defaults to the first value in `send_in_pings`.
145    ///
146    /// # Returns
147    ///
148    /// The stored value or `None` if nothing stored.
149    fn test_get_value(&self, ping_name: Option<String>) -> Option<String> {
150        crate::block_on_dispatcher();
151        crate::core::with_glean(|glean| self.get_value(glean, ping_name.as_deref()))
152    }
153}
154
155#[cfg(test)]
156mod test {
157    use super::*;
158    use crate::tests::new_glean;
159    use crate::util::truncate_string_at_boundary;
160    use crate::Lifetime;
161
162    #[test]
163    fn setting_a_long_string_records_an_error() {
164        let (glean, _t) = new_glean(None);
165
166        let metric = TextMetric::new(CommonMetricData {
167            name: "text_metric".into(),
168            category: "test".into(),
169            send_in_pings: vec!["store1".into()],
170            lifetime: Lifetime::Application,
171            disabled: false,
172            dynamic_label: None,
173        });
174
175        let sample_string = "0123456789".repeat(200 * 1024);
176        metric.set_sync(&glean, sample_string.clone());
177
178        let truncated = truncate_string_at_boundary(sample_string, MAX_LENGTH_VALUE);
179        assert_eq!(truncated, metric.get_value(&glean, "store1").unwrap());
180
181        assert_eq!(
182            1,
183            test_get_num_recorded_errors(&glean, metric.meta(), ErrorType::InvalidOverflow)
184                .unwrap()
185        );
186    }
187}
glean_core/metrics/text.rs

glean_core/metrics/
text.rs
