Minor refactor: switch to BoxFuture whenever applicable.

src/builder/analyzed_flow.rs

@@ -1,4 +1,4 @@
-use std::{future::Future, pin::Pin, sync::Arc};
+use std::sync::Arc;
 
 use super::{analyzer, plan};
 use crate::{
@@ -9,16 +9,18 @@ use crate::{
     setup::{self, ObjectSetupStatusCheck},
 };
 use anyhow::Result;
-use futures::{future::Shared, FutureExt};
+use futures::{
+    future::{BoxFuture, Shared},
+    FutureExt,
+};
 
 pub struct AnalyzedFlow {
     pub flow_instance: spec::FlowInstanceSpec,
     pub data_schema: schema::DataSchema,
     pub desired_state: setup::FlowSetupState<setup::DesiredMode>,
     /// It's None if the flow is not up to date
-    pub execution_plan: Option<
-        Shared<Pin<Box<dyn Future<Output = Result<Arc<plan::ExecutionPlan>, SharedError>> + Send>>>,
-    >,
+    pub execution_plan:
+        Option<Shared<BoxFuture<'static, Result<Arc<plan::ExecutionPlan>, SharedError>>>>,
 }
 
 impl AnalyzedFlow {

src/builder/analyzer.rs

@@ -1,6 +1,6 @@
 use std::collections::{BTreeMap, HashSet};
 use std::sync::Mutex;
-use std::{collections::HashMap, future::Future, pin::Pin, sync::Arc};
+use std::{collections::HashMap, future::Future, sync::Arc};
 
 use super::plan::*;
 use crate::execution::db_tracking_setup;
@@ -16,7 +16,7 @@ use crate::{
     utils::immutable::RefList,
 };
 use anyhow::{anyhow, bail, Context, Result};
-use futures::future::try_join3;
+use futures::future::{try_join3, BoxFuture};
 use futures::{future::try_join_all, FutureExt};
 use indexmap::IndexMap;
 use log::{trace, warn};
@@ -678,7 +678,7 @@ impl AnalyzerContext<'_> {
         scope: &mut ExecutionScope<'_>,
         reactive_op: &NamedSpec<ReactiveOpSpec>,
         parent_scopes: RefList<'_, &'_ ExecutionScope<'_>>,
-    ) -> Result<Pin<Box<dyn Future<Output = Result<AnalyzedReactiveOp>> + Send>>> {
+    ) -> Result<BoxFuture<'static, Result<AnalyzedReactiveOp>>> {
         let result_fut = match &reactive_op.spec {
             ReactiveOpSpec::Transform(op) => {
                 let input_field_schemas =

src/ops/factory_bases.rs

@@ -5,6 +5,7 @@ use std::sync::Arc;
 
 use anyhow::Result;
 use axum::async_trait;
+use futures::future::BoxFuture;
 use serde::de::DeserializeOwned;
 use serde::Serialize;
 
@@ -208,7 +209,7 @@ impl<T: SourceFactoryBase> SourceFactory for T {
         context: Arc<FlowInstanceContext>,
     ) -> Result<(
         EnrichedValueType,
-        ExecutorFuture<'static, Box<dyn SourceExecutor>>,
+        BoxFuture<'static, Result<Box<dyn SourceExecutor>>>,
     )> {
         let spec: T::Spec = serde_json::from_value(spec)?;
         let output_schema = self.get_output_schema(&spec, &context)?;
@@ -259,7 +260,7 @@ impl<T: SimpleFunctionFactoryBase> SimpleFunctionFactory for T {
         context: Arc<FlowInstanceContext>,
     ) -> Result<(
         EnrichedValueType,
-        ExecutorFuture<'static, Box<dyn SimpleFunctionExecutor>>,
+        BoxFuture<'static, Result<Box<dyn SimpleFunctionExecutor>>>,
     )> {
         let spec: T::Spec = serde_json::from_value(spec)?;
         let mut args_resolver = OpArgsResolver::new(&input_schema)?;
@@ -288,7 +289,7 @@ pub trait StorageFactoryBase: ExportTargetFactory + Send + Sync + 'static {
         context: Arc<FlowInstanceContext>,
     ) -> Result<(
         (Self::Key, Self::SetupState),
-        ExecutorFuture<'static, (Arc<dyn ExportTargetExecutor>, Option<Arc<dyn QueryTarget>>)>,
+        BoxFuture<'static, Result<(Arc<dyn ExportTargetExecutor>, Option<Arc<dyn QueryTarget>>)>>,
     )>;
 
     fn check_setup_status(
@@ -388,7 +389,7 @@ impl<T: StorageFactoryBase> ExportTargetFactory for T {
         context: Arc<FlowInstanceContext>,
     ) -> Result<(
         (serde_json::Value, serde_json::Value),
-        ExecutorFuture<'static, (Arc<dyn ExportTargetExecutor>, Option<Arc<dyn QueryTarget>>)>,
+        BoxFuture<'static, Result<(Arc<dyn ExportTargetExecutor>, Option<Arc<dyn QueryTarget>>)>>,
     )> {
         let spec: T::Spec = serde_json::from_value(spec)?;
         let ((setup_key, setup_state), executors) = StorageFactoryBase::build(

src/ops/interface.rs

@@ -6,15 +6,14 @@ use crate::base::{
 use crate::setup;
 use anyhow::Result;
 use async_trait::async_trait;
+use futures::future::BoxFuture;
 use serde::Serialize;
-use std::{fmt::Debug, future::Future, pin::Pin, sync::Arc};
+use std::sync::Arc;
 
 pub struct FlowInstanceContext {
     pub flow_instance_name: String,
 }
 
-pub type ExecutorFuture<'a, E> = Pin<Box<dyn Future<Output = Result<E>> + Send + 'a>>;
-
 #[async_trait]
 pub trait SourceExecutor: Send + Sync {
     /// Get the list of keys for the source.
@@ -31,7 +30,7 @@ pub trait SourceFactory {
         context: Arc<FlowInstanceContext>,
     ) -> Result<(
         EnrichedValueType,
-        ExecutorFuture<'static, Box<dyn SourceExecutor>>,
+        BoxFuture<'static, Result<Box<dyn SourceExecutor>>>,
     )>;
 }
 
@@ -59,7 +58,7 @@ pub trait SimpleFunctionFactory {
         context: Arc<FlowInstanceContext>,
     ) -> Result<(
         EnrichedValueType,
-        ExecutorFuture<'static, Box<dyn SimpleFunctionExecutor>>,
+        BoxFuture<'static, Result<Box<dyn SimpleFunctionExecutor>>>,
     )>;
 }
 
@@ -111,7 +110,7 @@ pub trait ExportTargetFactory {
         context: Arc<FlowInstanceContext>,
     ) -> Result<(
         (serde_json::Value, serde_json::Value),
-        ExecutorFuture<'static, (Arc<dyn ExportTargetExecutor>, Option<Arc<dyn QueryTarget>>)>,
+        BoxFuture<'static, Result<(Arc<dyn ExportTargetExecutor>, Option<Arc<dyn QueryTarget>>)>>,
     )>;
 
     fn check_setup_status(

src/ops/py_factory.rs

@@ -1,7 +1,7 @@
 use std::sync::Arc;
 
 use axum::async_trait;
-use futures::FutureExt;
+use futures::{future::BoxFuture, FutureExt};
 use pyo3::{
     pyclass, pymethods,
     types::{IntoPyDict, PyString, PyTuple},
@@ -16,9 +16,7 @@ use crate::{
 };
 use anyhow::Result;
 
-use super::sdk::{
-    ExecutorFuture, FlowInstanceContext, SimpleFunctionExecutor, SimpleFunctionFactory,
-};
+use super::interface::{FlowInstanceContext, SimpleFunctionExecutor, SimpleFunctionFactory};
 
 #[pyclass(name = "OpArgSchema")]
 pub struct PyOpArgSchema {
@@ -114,7 +112,7 @@ impl SimpleFunctionFactory for PyFunctionFactory {
         _context: Arc<FlowInstanceContext>,
     ) -> Result<(
         schema::EnrichedValueType,
-        ExecutorFuture<'static, Box<dyn SimpleFunctionExecutor>>,
+        BoxFuture<'static, Result<Box<dyn SimpleFunctionExecutor>>>,
     )> {
         let (result_type, executor, kw_args_names, num_positional_args) =
             Python::with_gil(|py| -> anyhow::Result<_> {

src/ops/storages/postgres.rs

@@ -1,8 +1,6 @@
 use std::borrow::Cow;
 use std::collections::{BTreeMap, HashMap};
-use std::future::Future;
 use std::ops::Bound;
-use std::pin::Pin;
 use std::sync::{Arc, Mutex};
 
 use crate::base::spec::{self, *};
@@ -13,7 +11,7 @@ use crate::{get_lib_context, setup};
 use anyhow::{anyhow, bail, Result};
 use async_trait::async_trait;
 use derivative::Derivative;
-use futures::future::Shared;
+use futures::future::{BoxFuture, Shared};
 use futures::FutureExt;
 use indexmap::{IndexMap, IndexSet};
 use itertools::Itertools;
@@ -457,12 +455,8 @@ fn distance_to_similarity(metric: VectorSimilarityMetric, distance: f64) -> f64
 }
 
 pub struct Factory {
-    db_pools: Mutex<
-        HashMap<
-            Option<String>,
-            Shared<Pin<Box<dyn Future<Output = Result<PgPool, SharedError>> + Send>>>,
-        >,
-    >,
+    db_pools:
+        Mutex<HashMap<Option<String>, Shared<BoxFuture<'static, Result<PgPool, SharedError>>>>>,
 }
 
 impl Default for Factory {
@@ -932,7 +926,7 @@ impl StorageFactoryBase for Arc<Factory> {
         context: Arc<FlowInstanceContext>,
     ) -> Result<(
         (TableId, SetupState),
-        ExecutorFuture<'static, (Arc<dyn ExportTargetExecutor>, Option<Arc<dyn QueryTarget>>)>,
+        BoxFuture<'static, Result<(Arc<dyn ExportTargetExecutor>, Option<Arc<dyn QueryTarget>>)>>,
     )> {
         let table_id = TableId {
             database_url: spec.database_url.clone(),

src/server.rs

@@ -2,9 +2,9 @@ use crate::{lib_context::LibContext, service};
 
 use anyhow::Result;
 use axum::{routing, Router};
-use futures::FutureExt;
+use futures::{future::BoxFuture, FutureExt};
 use serde::Deserialize;
-use std::{future::Future, pin::Pin, sync::Arc};
+use std::sync::Arc;
 use tower::ServiceBuilder;
 use tower_http::{
     cors::{AllowOrigin, CorsLayer},
@@ -21,7 +21,7 @@ pub struct ServerSettings {
 pub async fn init_server(
     lib_context: Arc<LibContext>,
     settings: ServerSettings,
-) -> Result<Pin<Box<dyn Future<Output = ()> + Send>>> {
+) -> Result<BoxFuture<'static, ()>> {
     let mut cors = CorsLayer::default();
     if let Some(ui_cors_origin) = &settings.cors_origin {
         cors = cors