rust-postgres/tokio-postgres/src/query.rs

221 lines
6.1 KiB
Rust
Raw Normal View History

2019-07-25 02:18:15 +00:00
use crate::client::{InnerClient, Responses};
use crate::codec::FrontendMessage;
use crate::connection::RequestMessages;
use crate::types::{BorrowToSql, IsNull};
2019-08-02 03:43:13 +00:00
use crate::{Error, Portal, Row, Statement};
2019-10-13 00:47:47 +00:00
use bytes::{Bytes, BytesMut};
2019-10-09 00:22:56 +00:00
use futures::{ready, Stream};
2019-12-18 02:11:40 +00:00
use log::{debug, log_enabled, Level};
2019-11-19 02:12:34 +00:00
use pin_project_lite::pin_project;
2019-07-25 02:18:15 +00:00
use postgres_protocol::message::backend::Message;
use postgres_protocol::message::frontend;
use std::fmt;
2019-10-16 01:17:10 +00:00
use std::marker::PhantomPinned;
2019-07-25 02:18:15 +00:00
use std::pin::Pin;
use std::task::{Context, Poll};
2020-10-27 23:45:55 +00:00
struct BorrowToSqlParamsDebug<'a, T>(&'a [T]);
impl<'a, T> fmt::Debug for BorrowToSqlParamsDebug<'a, T>
where
T: BorrowToSql,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list()
.entries(self.0.iter().map(|x| x.borrow_to_sql()))
.finish()
}
}
pub async fn query<P, I>(
client: &InnerClient,
statement: Statement,
params: I,
) -> Result<RowStream, Error>
where
P: BorrowToSql,
I: IntoIterator<Item = P>,
I::IntoIter: ExactSizeIterator,
{
2019-12-18 02:11:40 +00:00
let buf = if log_enabled!(Level::Debug) {
let params = params.into_iter().collect::<Vec<_>>();
2019-12-18 02:11:40 +00:00
debug!(
"executing statement {} with parameters: {:?}",
statement.name(),
BorrowToSqlParamsDebug(params.as_slice()),
);
encode(client, &statement, params)?
} else {
encode(client, &statement, params)?
};
let responses = start(client, buf).await?;
Ok(RowStream {
statement,
responses,
_p: PhantomPinned,
})
2019-07-25 02:18:15 +00:00
}
2019-10-09 00:22:56 +00:00
pub async fn query_portal(
client: &InnerClient,
portal: &Portal,
2019-08-02 03:43:13 +00:00
max_rows: i32,
2019-10-09 00:22:56 +00:00
) -> Result<RowStream, Error> {
let buf = client.with_buf(|buf| {
frontend::execute(portal.name(), max_rows, buf).map_err(Error::encode)?;
frontend::sync(buf);
2019-11-27 00:32:36 +00:00
Ok(buf.split().freeze())
})?;
2019-08-02 03:43:13 +00:00
2019-10-09 00:22:56 +00:00
let responses = client.send(RequestMessages::Single(FrontendMessage::Raw(buf)))?;
2019-08-02 03:43:13 +00:00
2019-10-09 00:22:56 +00:00
Ok(RowStream {
statement: portal.statement().clone(),
responses,
_p: PhantomPinned,
2019-10-09 00:22:56 +00:00
})
2019-08-02 03:43:13 +00:00
}
pub async fn execute<P, I>(
client: &InnerClient,
statement: Statement,
params: I,
) -> Result<u64, Error>
where
P: BorrowToSql,
I: IntoIterator<Item = P>,
I::IntoIter: ExactSizeIterator,
{
2019-12-18 02:11:40 +00:00
let buf = if log_enabled!(Level::Debug) {
let params = params.into_iter().collect::<Vec<_>>();
2019-12-18 02:11:40 +00:00
debug!(
"executing statement {} with parameters: {:?}",
statement.name(),
BorrowToSqlParamsDebug(params.as_slice()),
);
encode(client, &statement, params)?
} else {
encode(client, &statement, params)?
};
2019-07-27 03:11:34 +00:00
let mut responses = start(client, buf).await?;
2019-07-25 02:18:15 +00:00
let mut rows = 0;
2019-07-25 02:18:15 +00:00
loop {
match responses.next().await? {
Message::DataRow(_) => {}
Message::CommandComplete(body) => {
rows = body
2019-07-25 02:18:15 +00:00
.tag()
.map_err(Error::parse)?
.rsplit(' ')
.next()
.unwrap()
.parse()
.unwrap_or(0);
}
Message::EmptyQueryResponse => rows = 0,
Message::ReadyForQuery(_) => return Ok(rows),
2019-07-25 02:18:15 +00:00
_ => return Err(Error::unexpected_message()),
}
}
}
async fn start(client: &InnerClient, buf: Bytes) -> Result<Responses, Error> {
2019-07-27 03:11:34 +00:00
let mut responses = client.send(RequestMessages::Single(FrontendMessage::Raw(buf)))?;
match responses.next().await? {
Message::BindComplete => {}
_ => return Err(Error::unexpected_message()),
}
Ok(responses)
}
pub fn encode<P, I>(client: &InnerClient, statement: &Statement, params: I) -> Result<Bytes, Error>
2019-08-02 03:43:13 +00:00
where
P: BorrowToSql,
I: IntoIterator<Item = P>,
2019-08-02 03:43:13 +00:00
I::IntoIter: ExactSizeIterator,
{
client.with_buf(|buf| {
encode_bind(statement, params, "", buf)?;
frontend::execute("", 0, buf).map_err(Error::encode)?;
frontend::sync(buf);
2019-11-27 00:32:36 +00:00
Ok(buf.split().freeze())
})
2019-08-02 03:43:13 +00:00
}
pub fn encode_bind<P, I>(
2019-10-13 00:47:47 +00:00
statement: &Statement,
params: I,
portal: &str,
buf: &mut BytesMut,
) -> Result<(), Error>
2019-07-25 02:18:15 +00:00
where
P: BorrowToSql,
I: IntoIterator<Item = P>,
2019-07-25 02:18:15 +00:00
I::IntoIter: ExactSizeIterator,
{
let params = params.into_iter();
assert!(
statement.params().len() == params.len(),
"expected {} parameters but got {}",
statement.params().len(),
params.len()
);
let mut error_idx = 0;
let r = frontend::bind(
2019-08-02 03:43:13 +00:00
portal,
2019-07-25 02:18:15 +00:00
statement.name(),
Some(1),
params.zip(statement.params()).enumerate(),
|(idx, (param, ty)), buf| match param.borrow_to_sql().to_sql_checked(ty, buf) {
2019-07-25 02:18:15 +00:00
Ok(IsNull::No) => Ok(postgres_protocol::IsNull::No),
Ok(IsNull::Yes) => Ok(postgres_protocol::IsNull::Yes),
Err(e) => {
error_idx = idx;
Err(e)
}
},
Some(1),
buf,
2019-07-25 02:18:15 +00:00
);
match r {
Ok(()) => Ok(()),
2019-10-09 22:20:23 +00:00
Err(frontend::BindError::Conversion(e)) => Err(Error::to_sql(e, error_idx)),
Err(frontend::BindError::Serialization(e)) => Err(Error::encode(e)),
2019-07-25 02:18:15 +00:00
}
}
2019-11-19 02:12:34 +00:00
pin_project! {
/// A stream of table rows.
pub struct RowStream {
statement: Statement,
responses: Responses,
#[pin]
_p: PhantomPinned,
}
2019-07-25 02:18:15 +00:00
}
impl Stream for RowStream {
2019-07-25 02:18:15 +00:00
type Item = Result<Row, Error>;
fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
let this = self.project();
loop {
match ready!(this.responses.poll_next(cx)?) {
Message::DataRow(body) => {
return Poll::Ready(Some(Ok(Row::new(this.statement.clone(), body)?)))
}
Message::EmptyQueryResponse
| Message::CommandComplete(_)
| Message::PortalSuspended => {}
Message::ReadyForQuery(_) => return Poll::Ready(None),
_ => return Poll::Ready(Some(Err(Error::unexpected_message()))),
2019-07-25 02:18:15 +00:00
}
}
}
}