Further reduce dependency on futures and futures-util

Cargo.toml

@@ -169,7 +169,7 @@ sqlx-sqlite = { workspace = true, optional = true }
 [dev-dependencies]
 anyhow = "1.0.52"
 time_ = { version = "0.3.2", package = "time" }
-futures = "0.3.19"
+futures-util = { version = "0.3.19", default-features = false, features = ["alloc"] }
 env_logger = "0.11"
 async-std = { workspace = true, features = ["attributes"] }
 tokio = { version = "1.15.0", features = ["full"] }

README.md

@@ -326,7 +326,7 @@ The `fetch` query finalizer returns a stream-like type that iterates through the
 
 ```rust
 // provides `try_next`
-use futures::TryStreamExt;
+use futures_util::TryStreamExt;
 // provides `try_get`
 use sqlx::Row;
 

examples/mysql/todos/Cargo.toml

@@ -6,7 +6,6 @@ workspace = "../../../"
 
 [dependencies]
 anyhow = "1.0"
-futures = "0.3"
 sqlx = { path = "../../../", features = [ "mysql", "runtime-tokio", "tls-native-tls" ] }
 clap = { version = "4", features = ["derive"] }
 tokio = { version = "1.20.0", features = ["rt", "macros"]}

examples/postgres/chat/Cargo.toml

@@ -6,7 +6,6 @@ workspace = "../../../"
 
 [dependencies]
 sqlx = { path = "../../../", features = [ "postgres", "runtime-tokio", "tls-native-tls" ] }
-futures = "0.3.1"
 tokio = { version = "1.20.0", features = [ "rt-multi-thread", "macros" ] }
 ratatui = "0.27.0"
 crossterm = "0.27.0"

examples/postgres/json/Cargo.toml

@@ -7,7 +7,6 @@ workspace = "../../../"
 [dependencies]
 anyhow = "1.0"
 dotenvy = "0.15.0"
-futures = "0.3"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 sqlx = { path = "../../../", features = [ "runtime-tokio", "postgres", "json" ] }

examples/postgres/listen/Cargo.toml

@@ -6,5 +6,5 @@ workspace = "../../../"
 
 [dependencies]
 sqlx = { path = "../../../", features = [ "runtime-tokio", "postgres" ] }
-futures = "0.3.1"
+futures-util = { version = "0.3.1", default-features = false }
 tokio = { version = "1.20.0", features = ["rt-multi-thread", "macros", "time"]}

examples/postgres/listen/src/main.rs

@@ -1,4 +1,4 @@
-use futures::TryStreamExt;
+use futures_util::TryStreamExt;
 use sqlx::postgres::PgListener;
 use sqlx::{Executor, PgPool};
 use std::pin::pin;

examples/postgres/mockable-todos/Cargo.toml

@@ -6,7 +6,6 @@ workspace = "../../../"
 
 [dependencies]
 anyhow = "1.0"
-futures = "0.3"
 sqlx = { path = "../../../", features = [ "postgres", "runtime-tokio", "tls-native-tls" ] }
 clap = { version = "4", features = ["derive"] }
 tokio = { version = "1.20.0", features = ["rt", "macros"]}

examples/postgres/todos/Cargo.toml

@@ -6,7 +6,6 @@ workspace = "../../../"
 
 [dependencies]
 anyhow = "1.0"
-futures = "0.3"
 sqlx = { path = "../../../", features = [ "postgres", "runtime-tokio", "tls-native-tls" ] }
 clap = { version = "4", features = ["derive"] }
 tokio = { version = "1.20.0", features = ["rt", "macros"]}

examples/postgres/transaction/Cargo.toml

@@ -6,5 +6,4 @@ workspace = "../../../"
 
 [dependencies]
 sqlx = { path = "../../../", features = [ "postgres", "runtime-tokio", "tls-native-tls" ] }
-futures = "0.3.1"
 tokio = { version = "1.20.0", features = ["rt-multi-thread", "macros"]}

examples/sqlite/todos/Cargo.toml

@@ -6,7 +6,6 @@ workspace = "../../../"
 
 [dependencies]
 anyhow = "1.0"
-futures = "0.3"
 sqlx = { path = "../../../", features = [ "sqlite", "runtime-tokio", "tls-native-tls" ] }
 clap = { version = "4", features = ["derive"] }
 tokio = { version = "1.20.0", features = ["rt", "macros"]}

sqlx-cli/Cargo.toml

@@ -33,7 +33,7 @@ sqlx = { workspace = true, default-features = false, features = [
     "migrate",
     "any",
 ] }
-futures = "0.3.19"
+futures-util = { version = "0.3.19", features = ["alloc"] }
 clap = { version = "4.3.10", features = ["derive", "env", "wrap_help"] }
 clap_complete = { version = "4.3.1", optional = true }
 chrono = { version = "0.4.19", default-features = false, features = ["clock"] }

sqlx-cli/src/lib.rs

@@ -1,8 +1,9 @@
+use std::future::Future;
 use std::io;
 use std::time::Duration;
 
 use anyhow::Result;
-use futures::{Future, TryFutureExt};
+use futures_util::TryFutureExt;
 
 use sqlx::{AnyConnection, Connection};
 use tokio::{select, signal};

sqlx-core/src/acquire.rs

@@ -111,7 +111,7 @@ macro_rules! impl_acquire {
                 self,
             ) -> futures_core::future::BoxFuture<'c, Result<Self::Connection, $crate::error::Error>>
             {
-                Box::pin(futures_util::future::ok(self))
+                Box::pin(std::future::ready(Ok(self)))
             }
 
             #[inline]

sqlx-core/src/any/transaction.rs

@@ -1,4 +1,4 @@
-use futures_util::future::BoxFuture;
+use futures_core::future::BoxFuture;
 use std::borrow::Cow;
 
 use crate::any::{Any, AnyConnection};

sqlx-core/src/executor.rs

@@ -5,8 +5,8 @@ use crate::error::{BoxDynError, Error};
 use either::Either;
 use futures_core::future::BoxFuture;
 use futures_core::stream::BoxStream;
-use futures_util::{future, FutureExt, StreamExt, TryFutureExt, TryStreamExt};
-use std::fmt::Debug;
+use futures_util::{FutureExt, StreamExt, TryFutureExt, TryStreamExt};
+use std::{fmt::Debug, future};
 
 /// A type that contains or can provide a database
 /// connection to use for executing queries against the database.
@@ -121,9 +121,11 @@ pub trait Executor<'c>: Send + Debug + Sized {
         E: 'q + Execute<'q, Self::Database>,
     {
         self.fetch_optional(query)
-            .and_then(|row| match row {
-                Some(row) => future::ok(row),
-                None => future::err(Error::RowNotFound),
+            .and_then(|row| {
+                future::ready(match row {
+                    Some(row) => Ok(row),
+                    None => Err(Error::RowNotFound),
+                })
             })
             .boxed()
     }

sqlx-core/src/ext/async_stream.rs

@@ -3,7 +3,7 @@
 //! This was created initially to get around some weird compiler errors we were getting with
 //! `async-stream`, and now it'd just be more work to replace.
 
-use std::future::Future;
+use std::future::{self, Future};
 use std::pin::Pin;
 use std::sync::{Arc, Mutex};
 use std::task::{Context, Poll};
@@ -76,7 +76,7 @@ impl<T> Yielder<T> {
         //
         // Note that because this has no way to schedule a wakeup, this could deadlock the task
         // if called in the wrong place.
-        futures_util::future::poll_fn(|_cx| {
+        future::poll_fn(|_cx| {
             if !yielded {
                 yielded = true;
                 Poll::Pending

sqlx-core/src/net/tls/tls_rustls.rs

@@ -1,7 +1,7 @@
-use futures_util::future;
+use std::future;
 use std::io::{self, Read, Write};
 use std::sync::Arc;
-use std::task::{Context, Poll};
+use std::task::{ready, Context, Poll};
 
 use rustls::{
     client::{
@@ -33,7 +33,7 @@ impl<S: Socket> RustlsSocket<S> {
         loop {
             match self.state.complete_io(&mut self.inner) {
                 Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
-                    futures_util::ready!(self.inner.poll_ready(cx))?;
+                    ready!(self.inner.poll_ready(cx))?;
                 }
                 ready => return Poll::Ready(ready.map(|_| ())),
             }
@@ -76,12 +76,12 @@ impl<S: Socket> Socket for RustlsSocket<S> {
             self.close_notify_sent = true;
         }
 
-        futures_util::ready!(self.poll_complete_io(cx))?;
+        ready!(self.poll_complete_io(cx))?;
 
         // Server can close socket as soon as it receives the connection shutdown request.
         // We shouldn't expect it to stick around for the TLS session to close cleanly.
         // https://security.stackexchange.com/a/82034
-        let _ = futures_util::ready!(self.inner.socket.poll_shutdown(cx));
+        let _ = ready!(self.inner.socket.poll_shutdown(cx));
 
         Poll::Ready(Ok(()))
     }

sqlx-core/src/net/tls/util.rs

@@ -1,10 +1,9 @@
 use crate::net::Socket;
 
+use std::future;
 use std::io::{self, Read, Write};
 use std::task::{ready, Context, Poll};
 
-use futures_util::future;
-
 pub struct StdSocket<S> {
     pub socket: S,
     wants_read: bool,

sqlx-core/src/pool/connection.rs

@@ -1,4 +1,5 @@
 use std::fmt::{self, Debug, Formatter};
+use std::future::{self, Future};
 use std::ops::{Deref, DerefMut};
 use std::sync::Arc;
 use std::time::{Duration, Instant};
@@ -11,7 +12,6 @@ use crate::error::Error;
 
 use super::inner::{is_beyond_max_lifetime, DecrementSizeGuard, PoolInner};
 use crate::pool::options::PoolConnectionMetadata;
-use std::future::Future;
 
 const CLOSE_ON_DROP_TIMEOUT: Duration = Duration::from_secs(5);
 
@@ -183,7 +183,7 @@ impl<'c, DB: Database> crate::acquire::Acquire<'c> for &'c mut PoolConnection<DB
 
     #[inline]
     fn acquire(self) -> futures_core::future::BoxFuture<'c, Result<Self::Connection, Error>> {
-        Box::pin(futures_util::future::ok(&mut **self))
+        Box::pin(future::ready(Ok(&mut **self)))
     }
 
     #[inline]

sqlx-core/src/pool/inner.rs

@@ -9,7 +9,7 @@ use crossbeam_queue::ArrayQueue;
 use crate::sync::{AsyncSemaphore, AsyncSemaphoreReleaser};
 
 use std::cmp;
-use std::future::Future;
+use std::future::{self, Future};
 use std::pin::pin;
 use std::sync::atomic::{AtomicBool, AtomicU32, AtomicUsize, Ordering};
 use std::sync::{Arc, RwLock};
@@ -18,7 +18,6 @@ use std::task::Poll;
 use crate::logger::private_level_filter_to_trace_level;
 use crate::pool::options::PoolConnectionMetadata;
 use crate::private_tracing_dynamic_event;
-use futures_util::future::{self};
 use futures_util::FutureExt;
 use std::time::{Duration, Instant};
 use tracing::Level;

sqlx-core/src/pool/mod.rs

@@ -59,7 +59,7 @@ use std::fmt;
 use std::future::Future;
 use std::pin::{pin, Pin};
 use std::sync::Arc;
-use std::task::{Context, Poll};
+use std::task::{ready, Context, Poll};
 use std::time::{Duration, Instant};
 
 use event_listener::EventListener;
@@ -627,7 +627,7 @@ impl Future for CloseEvent {
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         if let Some(listener) = &mut self.listener {
-            futures_core::ready!(listener.poll_unpin(cx));
+            ready!(listener.poll_unpin(cx));
         }
 
         // `EventListener` doesn't like being polled after it yields, and even if it did it

sqlx-core/src/query.rs

@@ -1,8 +1,8 @@
-use std::marker::PhantomData;
+use std::{future, marker::PhantomData};
 
 use either::Either;
 use futures_core::stream::BoxStream;
-use futures_util::{future, StreamExt, TryFutureExt, TryStreamExt};
+use futures_util::{StreamExt, TryFutureExt, TryStreamExt};
 
 use crate::arguments::{Arguments, IntoArguments};
 use crate::database::{Database, HasStatementCache};
@@ -459,9 +459,11 @@ where
         O: 'e,
     {
         self.fetch_optional(executor)
-            .and_then(|row| match row {
-                Some(row) => future::ok(row),
-                None => future::err(Error::RowNotFound),
+            .and_then(|row| {
+                future::ready(match row {
+                    Some(row) => Ok(row),
+                    None => Err(Error::RowNotFound),
+                })
             })
             .await
     }