Copy out support

postgres-protocol/src/message/backend.rs

@@ -1,6 +1,6 @@
 #![allow(missing_docs)]
 
-use byteorder::{ReadBytesExt, BigEndian};
+use byteorder::{BigEndian, ReadBytesExt};
 use bytes::{Bytes, BytesMut};
 use fallible_iterator::FallibleIterator;
 use memchr::memchr;
@@ -148,17 +148,14 @@ impl Message {
                 let storage = buf.read_all();
                 Message::NoticeResponse(NoticeResponseBody { storage: storage })
             }
-            b'R' => {
-                match buf.read_i32::<BigEndian>()? {
+            b'R' => match buf.read_i32::<BigEndian>()? {
                 0 => Message::AuthenticationOk,
                 2 => Message::AuthenticationKerberosV5,
                 3 => Message::AuthenticationCleartextPassword,
                 5 => {
                     let mut salt = [0; 4];
                     buf.read_exact(&mut salt)?;
-                        Message::AuthenticationMd5Password(
-                            AuthenticationMd5PasswordBody { salt: salt },
-                        )
+                    Message::AuthenticationMd5Password(AuthenticationMd5PasswordBody { salt: salt })
                 }
                 6 => Message::AuthenticationScmCredential,
                 7 => Message::AuthenticationGss,
@@ -185,8 +182,7 @@ impl Message {
                         format!("unknown authentication tag `{}`", tag),
                     ));
                 }
-                }
-            }
+            },
             b's' => Message::PortalSuspended,
             b'S' => {
                 let name = buf.read_cstr()?;
@@ -394,6 +390,11 @@ impl CopyDataBody {
     pub fn data(&self) -> &[u8] {
         &self.storage
     }
+
+    #[inline]
+    pub fn into_bytes(self) -> Bytes {
+        self.storage
+    }
 }
 
 pub struct CopyInResponseBody {

tokio-postgres/src/lib.rs

@@ -21,6 +21,7 @@ extern crate state_machine_future;
 #[cfg(unix)]
 extern crate tokio_uds;
 
+use bytes::Bytes;
 use futures::{Async, Future, Poll, Stream};
 use postgres_shared::rows::RowIndex;
 use std::fmt;
@@ -95,6 +96,10 @@ impl Client {
         Query(self.0.query(&statement.0, params))
     }
 
+    pub fn copy_out(&mut self, statement: &Statement, params: &[&ToSql]) -> CopyOut {
+        CopyOut(self.0.copy_out(&statement.0, params))
+    }
+
     pub fn transaction<T>(&mut self, future: T) -> Transaction<T>
     where
         T: Future,
@@ -222,6 +227,18 @@ impl Stream for Query {
     }
 }
 
+#[must_use = "streams do nothing unless polled"]
+pub struct CopyOut(proto::CopyOutStream);
+
+impl Stream for CopyOut {
+    type Item = Bytes;
+    type Error = Error;
+
+    fn poll(&mut self) -> Poll<Option<Bytes>, Error> {
+        self.0.poll()
+    }
+}
+
 pub struct Row(proto::Row);
 
 impl Row {

tokio-postgres/src/proto/client.rs

@@ -9,6 +9,7 @@ use std::sync::{Arc, Weak};
 use disconnected;
 use error::{self, Error};
 use proto::connection::Request;
+use proto::copy_out::CopyOutStream;
 use proto::execute::ExecuteFuture;
 use proto::prepare::PrepareFuture;
 use proto::query::QueryStream;
@@ -130,6 +131,11 @@ impl Client {
         QueryStream::new(self.clone(), pending, statement.clone())
     }
 
+    pub fn copy_out(&self, statement: &Statement, params: &[&ToSql]) -> CopyOutStream {
+        let pending = self.pending_execute(statement, params);
+        CopyOutStream::new(self.clone(), pending, statement.clone())
+    }
+
     pub fn close_statement(&self, name: &str) {
         let mut buf = vec![];
         frontend::close(b'S', name, &mut buf).expect("statement name not valid");

tokio-postgres/src/proto/copy_out.rs

@@ -0,0 +1,106 @@
+use bytes::Bytes;
+use futures::sync::mpsc;
+use futures::{Async, Poll, Stream};
+use postgres_protocol::message::backend::Message;
+use std::mem;
+
+use error::{self, Error};
+use proto::client::{Client, PendingRequest};
+use proto::statement::Statement;
+use {bad_response, disconnected};
+
+enum State {
+    Start {
+        client: Client,
+        request: PendingRequest,
+        statement: Statement,
+    },
+    ReadingCopyOutResponse {
+        receiver: mpsc::Receiver<Message>,
+    },
+    ReadingCopyData {
+        receiver: mpsc::Receiver<Message>,
+    },
+    Done,
+}
+
+pub struct CopyOutStream(State);
+
+impl Stream for CopyOutStream {
+    type Item = Bytes;
+    type Error = Error;
+
+    fn poll(&mut self) -> Poll<Option<Bytes>, Error> {
+        loop {
+            match mem::replace(&mut self.0, State::Done) {
+                State::Start {
+                    client,
+                    request,
+                    statement,
+                } => {
+                    let receiver = client.send(request)?;
+                    // it's ok for the statement to close now that we've queued the query
+                    drop(statement);
+                    self.0 = State::ReadingCopyOutResponse { receiver };
+                }
+                State::ReadingCopyOutResponse { mut receiver } => {
+                    let message = match receiver.poll() {
+                        Ok(Async::Ready(message)) => message,
+                        Ok(Async::NotReady) => {
+                            self.0 = State::ReadingCopyOutResponse { receiver };
+                            break Ok(Async::NotReady);
+                        }
+                        Err(()) => unreachable!("mpsc::Receiver doesn't return errors"),
+                    };
+
+                    match message {
+                        Some(Message::BindComplete) => {
+                            self.0 = State::ReadingCopyOutResponse { receiver };
+                        }
+                        Some(Message::CopyOutResponse(_)) => {
+                            self.0 = State::ReadingCopyData { receiver };
+                        }
+                        Some(Message::ErrorResponse(body)) => break Err(error::__db(body)),
+                        Some(_) => break Err(bad_response()),
+                        None => break Err(disconnected()),
+                    }
+                }
+                State::ReadingCopyData { mut receiver } => {
+                    let message = match receiver.poll() {
+                        Ok(Async::Ready(message)) => message,
+                        Ok(Async::NotReady) => {
+                            self.0 = State::ReadingCopyData { receiver };
+                            break Ok(Async::NotReady);
+                        }
+                        Err(()) => unreachable!("mpsc::Reciever doesn't return errors"),
+                    };
+
+                    match message {
+                        Some(Message::CopyData(body)) => {
+                            self.0 = State::ReadingCopyData { receiver };
+                            break Ok(Async::Ready(Some(body.into_bytes())));
+                        }
+                        Some(Message::CopyDone) | Some(Message::CommandComplete(_)) => {
+                            self.0 = State::ReadingCopyData { receiver };
+                        }
+                        Some(Message::ReadyForQuery(_)) => break Ok(Async::Ready(None)),
+                        Some(Message::ErrorResponse(body)) => break Err(error::__db(body)),
+                        Some(_) => break Err(bad_response()),
+                        None => break Err(disconnected()),
+                    }
+                }
+                State::Done => break Ok(Async::Ready(None)),
+            }
+        }
+    }
+}
+
+impl CopyOutStream {
+    pub fn new(client: Client, request: PendingRequest, statement: Statement) -> CopyOutStream {
+        CopyOutStream(State::Start {
+            client,
+            request,
+            statement,
+        })
+    }
+}

tokio-postgres/src/proto/mod.rs

@@ -13,6 +13,7 @@ mod client;
 mod codec;
 mod connect;
 mod connection;
+mod copy_out;
 mod execute;
 mod handshake;
 mod prepare;
@@ -30,6 +31,7 @@ pub use proto::cancel::CancelFuture;
 pub use proto::client::Client;
 pub use proto::codec::PostgresCodec;
 pub use proto::connection::Connection;
+pub use proto::copy_out::CopyOutStream;
 pub use proto::execute::ExecuteFuture;
 pub use proto::handshake::HandshakeFuture;
 pub use proto::prepare::PrepareFuture;

tokio-postgres/tests/test.rs

@@ -480,7 +480,7 @@ fn notifications() {
 }
 
 #[test]
-fn test_transaction_commit() {
+fn transaction_commit() {
     let _ = env_logger::try_init();
     let mut runtime = Runtime::new().unwrap();
 
@@ -518,7 +518,7 @@ fn test_transaction_commit() {
 }
 
 #[test]
-fn test_transaction_abort() {
+fn transaction_abort() {
     let _ = env_logger::try_init();
     let mut runtime = Runtime::new().unwrap();
 
@@ -556,3 +556,37 @@ fn test_transaction_abort() {
 
     assert_eq!(rows.len(), 0);
 }
+
+#[test]
+fn copy_out() {
+    let _ = env_logger::try_init();
+    let mut runtime = Runtime::new().unwrap();
+
+    let (mut client, connection) = runtime
+        .block_on(tokio_postgres::connect(
+            "postgres://postgres@localhost:5433".parse().unwrap(),
+            TlsMode::None,
+        ))
+        .unwrap();
+    let connection = connection.map_err(|e| panic!("{}", e));
+    runtime.handle().spawn(connection).unwrap();
+
+    runtime
+        .block_on(client.batch_execute(
+            "CREATE TEMPORARY TABLE foo (
+                id SERIAL,
+                name TEXT
+            );
+            INSERT INTO foo (name) VALUES ('jim'), ('joe');",
+        ))
+        .unwrap();
+
+    let data = runtime
+        .block_on(
+            client
+                .prepare("COPY foo TO STDOUT")
+                .and_then(|s| client.copy_out(&s, &[]).concat2()),
+        )
+        .unwrap();
+    assert_eq!(&data[..], b"1\tjim\n2\tjoe\n");
+}