sea_orm/database/stream/
transaction.rs

1#![allow(missing_docs)]
2
3use std::{ops::DerefMut, pin::Pin, task::Poll};
4use tracing::instrument;
5
6#[cfg(feature = "sqlx-dep")]
7use futures_util::TryStreamExt;
8use futures_util::{Stream, lock::MutexGuard};
9
10#[cfg(feature = "sqlx-dep")]
11use sqlx::Executor;
12
13use super::metric::MetricStream;
14#[cfg(feature = "sqlx-dep")]
15use crate::driver::*;
16use crate::{DbErr, InnerConnection, QueryResult, Statement};
17
18/// `TransactionStream` cannot be used in a `transaction` closure as it does not impl `Send`.
19/// It seems to be a Rust limitation right now, and solution to work around this deemed to be extremely hard.
20#[ouroboros::self_referencing]
21pub struct TransactionStream<'a> {
22    stmt: Statement,
23    conn: MutexGuard<'a, InnerConnection>,
24    metric_callback: Option<crate::metric::Callback>,
25    #[borrows(mut conn, stmt, metric_callback)]
26    #[not_covariant]
27    stream: MetricStream<'this>,
28}
29
30impl std::fmt::Debug for TransactionStream<'_> {
31    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
32        write!(f, "TransactionStream")
33    }
34}
35
36impl TransactionStream<'_> {
37    #[instrument(level = "trace", skip(metric_callback))]
38    #[allow(unused_variables)]
39    pub(crate) fn build(
40        conn: MutexGuard<'_, InnerConnection>,
41        stmt: Statement,
42        metric_callback: Option<crate::metric::Callback>,
43    ) -> TransactionStream<'_> {
44        TransactionStreamBuilder {
45            stmt,
46            conn,
47            metric_callback,
48            stream_builder: |conn, stmt, _metric_callback| match conn.deref_mut() {
49                #[cfg(feature = "sqlx-mysql")]
50                InnerConnection::MySql(c) => {
51                    let query = crate::driver::sqlx_mysql::sqlx_query(stmt);
52                    let start = _metric_callback.is_some().then(std::time::SystemTime::now);
53                    let stream = c
54                        .fetch(query)
55                        .map_ok(Into::into)
56                        .map_err(sqlx_error_to_query_err);
57                    let elapsed = start.map(|s| s.elapsed().unwrap_or_default());
58                    MetricStream::new(_metric_callback, stmt, elapsed, stream)
59                }
60                #[cfg(feature = "sqlx-postgres")]
61                InnerConnection::Postgres(c) => {
62                    let query = crate::driver::sqlx_postgres::sqlx_query(stmt);
63                    let start = _metric_callback.is_some().then(std::time::SystemTime::now);
64                    let stream = c
65                        .fetch(query)
66                        .map_ok(Into::into)
67                        .map_err(sqlx_error_to_query_err);
68                    let elapsed = start.map(|s| s.elapsed().unwrap_or_default());
69                    MetricStream::new(_metric_callback, stmt, elapsed, stream)
70                }
71                #[cfg(feature = "sqlx-sqlite")]
72                InnerConnection::Sqlite(c) => {
73                    let query = crate::driver::sqlx_sqlite::sqlx_query(stmt);
74                    let start = _metric_callback.is_some().then(std::time::SystemTime::now);
75                    let stream = c
76                        .fetch(query)
77                        .map_ok(Into::into)
78                        .map_err(sqlx_error_to_query_err);
79                    let elapsed = start.map(|s| s.elapsed().unwrap_or_default());
80                    MetricStream::new(_metric_callback, stmt, elapsed, stream)
81                }
82                #[cfg(feature = "mock")]
83                InnerConnection::Mock(c) => {
84                    let start = _metric_callback.is_some().then(std::time::SystemTime::now);
85                    let stream = c.fetch(stmt);
86                    let elapsed = start.map(|s| s.elapsed().unwrap_or_default());
87                    MetricStream::new(_metric_callback, stmt, elapsed, stream)
88                }
89                #[cfg(feature = "proxy")]
90                InnerConnection::Proxy(c) => {
91                    let start = _metric_callback.is_some().then(std::time::SystemTime::now);
92                    let stream = futures_util::stream::once(async {
93                        Err(DbErr::BackendNotSupported {
94                            db: "Proxy",
95                            ctx: "TransactionStream",
96                        })
97                    });
98                    let elapsed = start.map(|s| s.elapsed().unwrap_or_default());
99                    MetricStream::new(_metric_callback, stmt, elapsed, stream)
100                }
101                #[allow(unreachable_patterns)]
102                _ => unreachable!(),
103            },
104        }
105        .build()
106    }
107}
108
109impl Stream for TransactionStream<'_> {
110    type Item = Result<QueryResult, DbErr>;
111
112    fn poll_next(
113        self: Pin<&mut Self>,
114        cx: &mut std::task::Context<'_>,
115    ) -> Poll<Option<Self::Item>> {
116        let this = self.get_mut();
117        this.with_stream_mut(|stream| Pin::new(stream).poll_next(cx))
118    }
119}
sea_orm/database/stream/transaction.rs

sea_orm/database/stream/
transaction.rs
