build(deps): keep in-process mode off the RPC and HTTP stacks

benchmark/src/lib.rs

@@ -8,7 +8,7 @@ use fastrace::Span;
 use fastrace::future::FutureExt as _;
 use liquid_cache::cache::CacheStats;
 use liquid_cache::cache::{Evict, EvictionPolicy, TranscodeEvict};
-use liquid_cache_common::rpc::ExecutionMetricsResponse;
+use liquid_cache_common::metrics::ExecutionMetricsResponse;
 use liquid_cache_datafusion_server::{ApiResponse, ExecutionStats};
 use log::info;
 use serde::Serialize;

src/common/Cargo.toml

@@ -7,18 +7,26 @@ readme = "README.md"
 description = { workspace = true }
 repository = { workspace = true }
 
+[features]
+# Arrow Flight RPC message types used between the client and the server.
+rpc = ["dep:arrow-flight", "dep:prost"]
+
 [dependencies]
-arrow-flight = { workspace = true }
+arrow-flight = { workspace = true, optional = true }
 async-trait = { workspace = true }
 bytes = { workspace = true }
 chrono = "0.4.45"
 futures = { workspace = true }
 object_store = { workspace = true }
-prost = { workspace = true }
+prost = { workspace = true, optional = true }
 serde = { workspace = true }
 thiserror = "2.0.18"
 tokio = { workspace = true }
 url = { workspace = true }
 
 [dev-dependencies]
 tempfile = { workspace = true }
+tokio = { workspace = true, features = ["macros"] }
+
+[package.metadata.docs.rs]
+features = ["rpc"]

src/common/README.md

@@ -3,3 +3,5 @@
 Common types and utilities shared across LiquidCache components.
 
 This crate contains shared data structures, enums, and utility functions used throughout the LiquidCache ecosystem. It defines the core abstractions for cache modes, schema transformations, and RPC message types that enable communication between client and server components.
+
+The RPC message types (`rpc` module) are behind the `rpc` feature, which is off by default. The client and server crates enable it; in-process use through `liquid-cache-datafusion-local` does not need it, and so does not depend on Arrow Flight or gRPC.

src/common/src/lib.rs

@@ -1,5 +1,7 @@
 #![doc = include_str!("../README.md")]
 
+pub mod metrics;
 pub mod mock_store;
+#[cfg(feature = "rpc")]
 pub mod rpc;
 pub mod utils;

src/common/src/metrics.rs

@@ -0,0 +1,18 @@
+//! Execution metrics reported for a query plan.
+
+#[derive(Clone, PartialEq, serde::Serialize, serde::Deserialize, Debug)]
+pub struct ExecutionMetricsResponse {
+    pub pushdown_eval_time: u64,
+    pub cache_memory_usage: u64,
+    pub liquid_cache_usage: u64,
+}
+
+impl ExecutionMetricsResponse {
+    pub fn zero() -> Self {
+        Self {
+            pushdown_eval_time: 0,
+            cache_memory_usage: 0,
+            liquid_cache_usage: 0,
+        }
+    }
+}

src/common/src/rpc.rs

@@ -246,20 +246,3 @@ impl ProstMessageExt for FetchResults {
         }
     }
 }
-
-#[derive(Clone, PartialEq, serde::Serialize, serde::Deserialize, Debug)]
-pub struct ExecutionMetricsResponse {
-    pub pushdown_eval_time: u64,
-    pub cache_memory_usage: u64,
-    pub liquid_cache_usage: u64,
-}
-
-impl ExecutionMetricsResponse {
-    pub fn zero() -> Self {
-        Self {
-            pushdown_eval_time: 0,
-            cache_memory_usage: 0,
-            liquid_cache_usage: 0,
-        }
-    }
-}

src/datafusion-client/Cargo.toml

@@ -17,13 +17,13 @@ arrow-schema = { workspace = true }
 futures = { workspace = true }
 tonic = { workspace = true }
 uuid = { workspace = true }
-liquid-cache-common = { workspace = true }
+liquid-cache-common = { workspace = true, features = ["rpc"] }
 liquid-cache-datafusion = { workspace = true }
 fastrace = { workspace = true }
 fastrace-tonic = { workspace = true }
 tower = "0.5.3"
 tokio = { workspace = true }
-object_store = { workspace = true }
+object_store = { workspace = true, features = ["http"] }
 
 [dev-dependencies]
 insta = { workspace = true }

src/datafusion-server/Cargo.toml

@@ -21,7 +21,7 @@ tokio = { workspace = true }
 url = { workspace = true }
 liquid-cache-datafusion = { workspace = true }
 object_store = { workspace = true, features = ["aws", "http"] }
-liquid-cache-common = { workspace = true }
+liquid-cache-common = { workspace = true, features = ["rpc"] }
 tempfile = { workspace = true }
 axum = "0.8.9"
 serde = { workspace = true }

src/datafusion-server/src/admin_server/handlers.rs

@@ -17,7 +17,7 @@ use datafusion::{
     datasource::physical_plan::FileScanConfig,
     physical_plan::{ExecutionPlan, StatisticsArgs, StatisticsContext},
 };
-use liquid_cache_common::rpc::ExecutionMetricsResponse;
+use liquid_cache_common::metrics::ExecutionMetricsResponse;
 use liquid_cache_datafusion::LiquidParquetSource;
 use log::info;
 use serde::Serialize;

src/datafusion-server/src/service.rs

@@ -7,7 +7,7 @@ use datafusion::{
 };
 use liquid_cache::{ByteCache, cache::EvictionPolicy};
 use liquid_cache::{cache::HydrationPolicy, cache_policies::CachePolicy};
-use liquid_cache_common::rpc::ExecutionMetricsResponse;
+use liquid_cache_common::metrics::ExecutionMetricsResponse;
 use liquid_cache_datafusion::{
     cache::{ColumnLineages, LiquidCacheParquet, LiquidCacheParquetRef},
     extract_execution_metrics,

src/datafusion/Cargo.toml

@@ -17,7 +17,7 @@ futures = { workspace = true }
 tokio = { workspace = true }
 ahash = { workspace = true }
 log = { workspace = true }
-object_store = { workspace = true, features = ["http"] }
+object_store = { workspace = true }
 liquid-cache-common = { workspace = true }
 liquid-cache = { workspace = true }
 fastrace = { workspace = true }

src/datafusion/src/utils.rs

@@ -9,7 +9,7 @@ use datafusion::{
     datasource::source::DataSourceExec,
     physical_plan::{ExecutionPlan, metrics::MetricValue},
 };
-use liquid_cache_common::rpc::ExecutionMetricsResponse;
+use liquid_cache_common::metrics::ExecutionMetricsResponse;
 use parquet::arrow::arrow_reader::RowSelector;
 
 use crate::cache::LiquidCacheParquetRef;