feat(encoding)!: EncodeLabelSet does not consume LabelSetEncoder

see prometheus#135. this adjusts the parameter of `encode()` so that it only mutably borrows the encoder. Signed-off-by: katelyn martin <[email protected]>
cratelyn · Nov 18, 2024 · 3a88e8c · 3a88e8c
1 parent 05da98f
commit 3a88e8c
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Showing 4 changed files with 37 additions and 37 deletions.
diff --git a/derive-encode/src/lib.rs b/derive-encode/src/lib.rs
@@ -72,7 +72,7 @@ pub fn derive_encode_label_set(input: TokenStream) -> TokenStream {
 
     let gen = quote! {
         impl prometheus_client::encoding::EncodeLabelSet for #name {
-            fn encode(&self, mut encoder: prometheus_client::encoding::LabelSetEncoder) -> std::result::Result<(), std::fmt::Error> {
+            fn encode(&self, encoder: &mut prometheus_client::encoding::LabelSetEncoder) -> std::result::Result<(), std::fmt::Error> {
                 use prometheus_client::encoding::EncodeLabel;
                 use prometheus_client::encoding::EncodeLabelKey;
                 use prometheus_client::encoding::EncodeLabelValue;

diff --git a/src/encoding.rs b/src/encoding.rs
@@ -203,7 +203,7 @@ impl MetricEncoder<'_> {
 /// An encodable label set.
 pub trait EncodeLabelSet {
     /// Encode oneself into the given encoder.
-    fn encode(&self, encoder: LabelSetEncoder) -> Result<(), std::fmt::Error>;
+    fn encode(&self, encoder: &mut LabelSetEncoder) -> Result<(), std::fmt::Error>;
 }
 
 impl<'a> From<text::LabelSetEncoder<'a>> for LabelSetEncoder<'a> {
@@ -331,13 +331,13 @@ impl<'a> LabelKeyEncoder<'a> {
     }
 }
 impl<T: EncodeLabel, const N: usize> EncodeLabelSet for [T; N] {
-    fn encode(&self, encoder: LabelSetEncoder) -> Result<(), std::fmt::Error> {
+    fn encode(&self, encoder: &mut LabelSetEncoder) -> Result<(), std::fmt::Error> {
         self.as_ref().encode(encoder)
     }
 }
 
 impl<T: EncodeLabel> EncodeLabelSet for &[T] {
-    fn encode(&self, mut encoder: LabelSetEncoder) -> Result<(), std::fmt::Error> {
+    fn encode(&self, encoder: &mut LabelSetEncoder) -> Result<(), std::fmt::Error> {
         if self.is_empty() {
             return Ok(());
         }
@@ -351,13 +351,13 @@ impl<T: EncodeLabel> EncodeLabelSet for &[T] {
 }
 
 impl<T: EncodeLabel> EncodeLabelSet for Vec<T> {
-    fn encode(&self, encoder: LabelSetEncoder) -> Result<(), std::fmt::Error> {
+    fn encode(&self, encoder: &mut LabelSetEncoder) -> Result<(), std::fmt::Error> {
         self.as_slice().encode(encoder)
     }
 }
 
 impl EncodeLabelSet for NoLabelSet {
-    fn encode(&self, _encoder: LabelSetEncoder) -> Result<(), std::fmt::Error> {
+    fn encode(&self, _encoder: &mut LabelSetEncoder) -> Result<(), std::fmt::Error> {
         Ok(())
     }
 }

diff --git a/src/encoding/protobuf.rs b/src/encoding/protobuf.rs
@@ -119,12 +119,11 @@ impl DescriptorEncoder<'_> {
             ..Default::default()
         };
         let mut labels = vec![];
-        self.labels.encode(
-            LabelSetEncoder {
-                labels: &mut labels,
-            }
-            .into(),
-        )?;
+        let mut encoder = LabelSetEncoder {
+            labels: &mut labels,
+        }
+        .into();
+        self.labels.encode(&mut encoder)?;
         self.metric_families.push(family);
 
         Ok(MetricEncoder {
@@ -209,12 +208,11 @@ impl MetricEncoder<'_> {
         label_set: &impl super::EncodeLabelSet,
     ) -> Result<(), std::fmt::Error> {
         let mut info_labels = vec![];
-        label_set.encode(
-            LabelSetEncoder {
-                labels: &mut info_labels,
-            }
-            .into(),
-        )?;
+        let mut encoder = LabelSetEncoder {
+            labels: &mut info_labels,
+        }
+        .into();
+        label_set.encode(&mut encoder)?;
 
         self.family.push(openmetrics_data_model::Metric {
             labels: self.labels.clone(),
@@ -234,12 +232,11 @@ impl MetricEncoder<'_> {
         label_set: &S,
     ) -> Result<MetricEncoder, std::fmt::Error> {
         let mut labels = self.labels.clone();
-        label_set.encode(
-            LabelSetEncoder {
-                labels: &mut labels,
-            }
-            .into(),
-        )?;
+        let mut encoder = LabelSetEncoder {
+            labels: &mut labels,
+        }
+        .into();
+        label_set.encode(&mut encoder)?;
 
         Ok(MetricEncoder {
             metric_type: self.metric_type,
@@ -302,12 +299,11 @@ impl<S: EncodeLabelSet, V: EncodeExemplarValue> TryFrom<&Exemplar<S, V>>
             .encode(ExemplarValueEncoder { value: &mut value }.into())?;
 
         let mut labels = vec![];
-        exemplar.label_set.encode(
-            LabelSetEncoder {
-                labels: &mut labels,
-            }
-            .into(),
-        )?;
+        let mut encoder = LabelSetEncoder {
+            labels: &mut labels,
+        }
+        .into();
+        exemplar.label_set.encode(&mut encoder)?;
 
         Ok(openmetrics_data_model::Exemplar {
             value,

diff --git a/src/encoding/text.rs b/src/encoding/text.rs
@@ -297,7 +297,8 @@ impl<'a> std::fmt::Debug for MetricEncoder<'a> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let mut labels = String::new();
         if let Some(l) = self.family_labels {
-            l.encode(LabelSetEncoder::new(&mut labels).into())?;
+            let mut encoder = LabelSetEncoder::new(&mut labels).into();
+            l.encode(&mut encoder)?;
         }
 
         f.debug_struct("Encoder")
@@ -451,7 +452,7 @@ impl<'a> MetricEncoder<'a> {
         self.writer.write_str(" # {")?;
         exemplar
             .label_set
-            .encode(LabelSetEncoder::new(self.writer).into())?;
+            .encode(&mut LabelSetEncoder::new(self.writer).into())?;
         self.writer.write_str("} ")?;
         exemplar.value.encode(
             ExemplarValueEncoder {
@@ -502,14 +503,15 @@ impl<'a> MetricEncoder<'a> {
         self.writer.write_str("{")?;
 
         self.const_labels
-            .encode(LabelSetEncoder::new(self.writer).into())?;
+            .encode(&mut LabelSetEncoder::new(self.writer).into())?;
 
         if let Some(additional_labels) = additional_labels {
             if !self.const_labels.is_empty() {
                 self.writer.write_str(",")?;
             }
 
-            additional_labels.encode(LabelSetEncoder::new(self.writer).into())?;
+            let mut encoder = LabelSetEncoder::new(self.writer).into();
+            additional_labels.encode(&mut encoder)?;
         }
 
         /// Writer impl which prepends a comma on the first call to write output to the wrapped writer
@@ -539,9 +541,11 @@ impl<'a> MetricEncoder<'a> {
                     writer: self.writer,
                     should_prepend: true,
                 };
-                labels.encode(LabelSetEncoder::new(&mut writer).into())?;
+                let mut encoder = LabelSetEncoder::new(&mut writer).into();
+                labels.encode(&mut encoder)?;
             } else {
-                labels.encode(LabelSetEncoder::new(self.writer).into())?;
+                let mut encoder = LabelSetEncoder::new(self.writer).into();
+                labels.encode(&mut encoder)?;
             };
         }
 
@@ -936,7 +940,7 @@ mod tests {
         struct EmptyLabels {}
 
         impl EncodeLabelSet for EmptyLabels {
-            fn encode(&self, _encoder: crate::encoding::LabelSetEncoder) -> Result<(), Error> {
+            fn encode(&self, _encoder: &mut crate::encoding::LabelSetEncoder) -> Result<(), Error> {
                 Ok(())
             }
         }