metrics: add metrics module and protos

This change adds a metrics module containing proto definitions to mirror datafusion metrics. These will be used for EXPLAIN ANALYZE. It also adds roundtrip serialization tests.

Informs #123.

Author: jayshrivastava

Cargo.lock

@@ -38,6 +38,7 @@ parquet = { version = "55.2.0", optional = true }
 arrow = { version = "55.2.0", optional = true }
 tokio-stream = { version = "0.1.17", optional = true }
 hyper-util = { version = "0.1.16", optional = true }
+chrono = "0.4.42"
 
 [features]
 integration = [

Cargo.toml

@@ -8,6 +8,9 @@ mod distributed_physical_optimizer_rule;
 mod errors;
 mod execution_plans;
 mod flight_service;
+mod metrics;
+
+pub use metrics::proto::*;
 
 mod protobuf;
 #[cfg(any(feature = "integration", test))]

src/lib.rs

@@ -0,0 +1 @@
+pub(crate) mod proto;