runtime: add executor builder

crates/crank-runtime/src/executor_builder.rs

@@ -0,0 +1,52 @@
+use std::sync::Arc;
+
+use crank_adapter_rest::RestAdapter;
+use crank_core::{AdapterRegistry, ResponseCacheStore, SharedProtocolAdapter};
+
+use crate::{RuntimeExecutor, RuntimeLimits};
+
+pub struct RuntimeExecutorBuilder {
+    limits: RuntimeLimits,
+    adapters: AdapterRegistry,
+    response_cache: Option<Arc<dyn ResponseCacheStore>>,
+}
+
+impl RuntimeExecutorBuilder {
+    pub fn new() -> Self {
+        Self {
+            limits: RuntimeLimits::default(),
+            adapters: AdapterRegistry::empty(),
+            response_cache: None,
+        }
+    }
+
+    pub fn with_limits(mut self, limits: RuntimeLimits) -> Self {
+        self.limits = limits;
+        self
+    }
+
+    pub fn register_adapter(mut self, adapter: SharedProtocolAdapter) -> Self {
+        self.adapters = self.adapters.register(adapter);
+        self
+    }
+
+    pub fn with_response_cache(mut self, store: Arc<dyn ResponseCacheStore>) -> Self {
+        self.response_cache = Some(store);
+        self
+    }
+
+    pub fn build(self) -> RuntimeExecutor {
+        RuntimeExecutor::from_builder_parts(self.limits, self.adapters, self.response_cache)
+    }
+}
+
+impl Default for RuntimeExecutorBuilder {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+pub fn community_default() -> RuntimeExecutorBuilder {
+    RuntimeExecutorBuilder::new()
+        .register_adapter(Arc::new(RestAdapter::new()) as SharedProtocolAdapter)
+}