Chore(postgres): prefer sub-crates of futures

postgres/Cargo.toml

@@ -37,7 +37,7 @@ with-time-0_3 = ["tokio-postgres/with-time-0_3"]
 [dependencies]
 bytes = "1.0"
 fallible-iterator = "0.2"
-futures = "0.3"
+futures-util = { version = "0.3", features = ["sink"] }
 tokio-postgres = { version = "0.7.6", path = "../tokio-postgres" }
 
 tokio = { version = "1.0", features = ["rt", "time"] }
@@ -45,3 +45,4 @@ log = "0.4"
 
 [dev-dependencies]
 criterion = "0.3"
+tokio = { version = "1.0", features = ["rt-multi-thread"] }

postgres/src/binary_copy.rs

@@ -4,7 +4,7 @@ use crate::connection::ConnectionRef;
 use crate::types::{BorrowToSql, ToSql, Type};
 use crate::{CopyInWriter, CopyOutReader, Error};
 use fallible_iterator::FallibleIterator;
-use futures::StreamExt;
+use futures_util::StreamExt;
 use std::pin::Pin;
 #[doc(inline)]
 pub use tokio_postgres::binary_copy::BinaryCopyOutRow;

postgres/src/connection.rs

@@ -1,6 +1,5 @@
 use crate::{Error, Notification};
-use futures::future;
-use futures::{pin_mut, Stream};
+use futures_util::{future, pin_mut, Stream};
 use std::collections::VecDeque;
 use std::future::Future;
 use std::ops::{Deref, DerefMut};

postgres/src/copy_in_writer.rs

@@ -1,7 +1,7 @@
 use crate::connection::ConnectionRef;
 use crate::lazy_pin::LazyPin;
 use bytes::{Bytes, BytesMut};
-use futures::SinkExt;
+use futures_util::SinkExt;
 use std::io;
 use std::io::Write;
 use tokio_postgres::{CopyInSink, Error};

postgres/src/copy_out_reader.rs

@@ -1,7 +1,7 @@
 use crate::connection::ConnectionRef;
 use crate::lazy_pin::LazyPin;
 use bytes::{Buf, Bytes};
-use futures::StreamExt;
+use futures_util::StreamExt;
 use std::io::{self, BufRead, Read};
 use tokio_postgres::CopyOutStream;
 

postgres/src/notifications.rs

@@ -3,7 +3,7 @@
 use crate::connection::ConnectionRef;
 use crate::{Error, Notification};
 use fallible_iterator::FallibleIterator;
-use futures::{ready, FutureExt};
+use futures_util::{ready, FutureExt};
 use std::pin::Pin;
 use std::task::Poll;
 use std::time::Duration;

postgres/src/row_iter.rs

@@ -1,6 +1,6 @@
 use crate::connection::ConnectionRef;
 use fallible_iterator::FallibleIterator;
-use futures::StreamExt;
+use futures_util::StreamExt;
 use std::pin::Pin;
 use tokio_postgres::{Error, Row, RowStream};