ref(metrics): Add normalization and update set metrics hashing (#658)

Add metrics normalization in accordance with the metrics developer docs.
Add metric name, unit, and tag truncation to adhere to the metrics user docs.
Add to_envelope for a single Metric instance to facilitate sending metrics from sentry-cli.
Change hash function to crc32 as described here, this ensures compatibility between different SDKs using the same metric.
Use clone_from instead of clone and clone_into instead of to_owned in a couple of places as suggested by clippy.

sentry-core/Cargo.toml

@@ -31,9 +31,12 @@ UNSTABLE_cadence = ["dep:cadence", "UNSTABLE_metrics"]
 
 [dependencies]
 cadence = { version = "0.29.0", optional = true }
+crc32fast = "1.4.0"
+itertools = "0.13.0"
 log = { version = "0.4.8", optional = true, features = ["std"] }
 once_cell = "1"
 rand = { version = "0.8.1", optional = true }
+regex = "1.7.3"
 sentry-types = { version = "0.32.3", path = "../sentry-types" }
 serde = { version = "1.0.104", features = ["derive"] }
 serde_json = { version = "1.0.46" }

sentry-core/src/cadence.rs

@@ -154,9 +154,10 @@ mod tests {
 
         println!("{metrics}");
 
-        assert!(metrics.contains("sentry.test.count.with.tags:1|c|#foo:bar|T"));
-        assert!(metrics.contains("sentry.test.some.count:11|c|T"));
-        assert!(metrics.contains("sentry.test.some.distr:1:2:3|d|T"));
+        assert!(metrics
+            .contains("sentry.test.count.with.tags@none:1|c|#environment:production,foo:bar|T"));
+        assert!(metrics.contains("sentry.test.some.count@none:11|c|#environment:production|T"));
+        assert!(metrics.contains("sentry.test.some.distr@none:1:2:3|d|#environment:production|T"));
         assert_eq!(items.next(), None);
     }
 }

sentry-core/src/client.rs

@@ -207,13 +207,13 @@ impl Client {
         }
 
         if event.release.is_none() {
-            event.release = self.options.release.clone();
+            event.release.clone_from(&self.options.release);
         }
         if event.environment.is_none() {
-            event.environment = self.options.environment.clone();
+            event.environment.clone_from(&self.options.environment);
         }
         if event.server_name.is_none() {
-            event.server_name = self.options.server_name.clone();
+            event.server_name.clone_from(&self.options.server_name);
         }
         if &event.platform == "other" {
             event.platform = "native".into();