Update prometheus-client version

autometrics/Cargo.toml

@@ -47,7 +47,7 @@ prometheus = { version = "0.13", default-features = false, optional = true }
 const_format = { version = "0.2", features = ["rust_1_51"], optional = true }
 
 # Used for prometheus-client feature
-prometheus-client = { version = "0.20", optional = true }
+prometheus-client = { version = "0.21.1", optional = true }
 
 [dev-dependencies]
 regex = "1.7"

autometrics/src/labels.rs

@@ -1,8 +1,7 @@
 use crate::{constants::*, objectives::*};
-use prometheus_client::encoding::EncodeLabelKey;
 #[cfg(feature = "prometheus-client")]
 use prometheus_client::encoding::{
-    EncodeLabelSet, EncodeLabelValue, LabelSetEncoder, LabelValueEncoder,
+    EncodeLabelKey, EncodeLabelSet, EncodeLabelValue, LabelValueEncoder,
 };
 use std::ops::Deref;
 
@@ -58,8 +57,8 @@ pub(crate) enum ResultLabel {
 impl EncodeLabelValue for ResultLabel {
     fn encode(&self, encoder: &mut LabelValueEncoder) -> Result<(), std::fmt::Error> {
         match self {
-            ResultLabel::Ok => OK_KEY.encode(encoder),
-            ResultLabel::Error => ERROR_KEY.encode(encoder),
+            ResultLabel::Ok => EncodeLabelValue::encode(&OK_KEY, encoder),
+            ResultLabel::Error => EncodeLabelValue::encode(&ERROR_KEY, encoder),
         }
     }
 }
@@ -120,7 +119,6 @@ impl CounterLabels {
 pub struct HistogramLabels {
     pub function: &'static str,
     pub module: &'static str,
-    /// The SLO name, objective percentile, and latency threshold
     pub objective_name: &'static str,
     pub objective_percentile: ObjectivePercentile,
     pub objective_latency_threshold: ObjectiveLatency,