sea_orm/database/stream/
query.rs

1#![allow(missing_docs, unreachable_code, unused_variables)]
2
3use futures_util::Stream;
4use std::{pin::Pin, task::Poll};
5use tracing::instrument;
6
7#[cfg(feature = "sqlx-dep")]
8use futures_util::TryStreamExt;
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/// Creates a stream from a [QueryResult]
19#[ouroboros::self_referencing]
20pub struct QueryStream {
21    stmt: Statement,
22    conn: InnerConnection,
23    metric_callback: Option<crate::metric::Callback>,
24    #[borrows(mut conn, stmt, metric_callback)]
25    #[not_covariant]
26    stream: MetricStream<'this>,
27}
28
29impl std::fmt::Debug for QueryStream {
30    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
31        write!(f, "QueryStream")
32    }
33}
34
35impl QueryStream {
36    #[allow(dead_code)]
37    #[instrument(level = "trace", skip(metric_callback))]
38    pub(crate) fn build(
39        stmt: Statement,
40        conn: InnerConnection,
41        metric_callback: Option<crate::metric::Callback>,
42    ) -> QueryStream {
43        QueryStreamBuilder {
44            stmt,
45            conn,
46            metric_callback,
47            stream_builder: |conn, stmt, _metric_callback| match conn {
48                #[cfg(feature = "sqlx-mysql")]
49                InnerConnection::MySql(c) => {
50                    let query = crate::driver::sqlx_mysql::sqlx_query(stmt);
51                    let start = _metric_callback.is_some().then(std::time::SystemTime::now);
52                    let stream = c
53                        .fetch(query)
54                        .map_ok(Into::into)
55                        .map_err(sqlx_error_to_query_err);
56                    let elapsed = start.map(|s| s.elapsed().unwrap_or_default());
57                    MetricStream::new(_metric_callback, stmt, elapsed, stream)
58                }
59                #[cfg(feature = "sqlx-postgres")]
60                InnerConnection::Postgres(c) => {
61                    let query = crate::driver::sqlx_postgres::sqlx_query(stmt);
62                    let start = _metric_callback.is_some().then(std::time::SystemTime::now);
63                    let stream = c
64                        .fetch(query)
65                        .map_ok(Into::into)
66                        .map_err(sqlx_error_to_query_err);
67                    let elapsed = start.map(|s| s.elapsed().unwrap_or_default());
68                    MetricStream::new(_metric_callback, stmt, elapsed, stream)
69                }
70                #[cfg(feature = "sqlx-sqlite")]
71                InnerConnection::Sqlite(c) => {
72                    let query = crate::driver::sqlx_sqlite::sqlx_query(stmt);
73                    let start = _metric_callback.is_some().then(std::time::SystemTime::now);
74                    let stream = c
75                        .fetch(query)
76                        .map_ok(Into::into)
77                        .map_err(sqlx_error_to_query_err);
78                    let elapsed = start.map(|s| s.elapsed().unwrap_or_default());
79                    MetricStream::new(_metric_callback, stmt, elapsed, stream)
80                }
81                #[cfg(feature = "rusqlite")]
82                InnerConnection::Rusqlite(conn) => {
83                    use itertools::Either;
84                    let start = _metric_callback.is_some().then(std::time::SystemTime::now);
85                    let stream = match conn.stream(stmt) {
86                        Ok(rows) => Either::Left(rows.into_iter().map(Ok)),
87                        Err(err) => Either::Right(std::iter::once(Err(err))),
88                    };
89                    let elapsed = start.map(|s| s.elapsed().unwrap_or_default());
90                    MetricStream::new(_metric_callback, stmt, elapsed, stream)
91                }
92                #[cfg(feature = "mock")]
93                InnerConnection::Mock(c) => {
94                    let start = _metric_callback.is_some().then(std::time::SystemTime::now);
95                    let stream = c.fetch(stmt);
96                    let elapsed = start.map(|s| s.elapsed().unwrap_or_default());
97                    MetricStream::new(_metric_callback, stmt, elapsed, stream)
98                }
99                #[cfg(feature = "proxy")]
100                InnerConnection::Proxy(c) => {
101                    let start = _metric_callback.is_some().then(std::time::SystemTime::now);
102                    let stream = futures_util::stream::once(async {
103                        Err(DbErr::BackendNotSupported {
104                            db: "Proxy",
105                            ctx: "QueryStream",
106                        })
107                    });
108                    let elapsed = start.map(|s| s.elapsed().unwrap_or_default());
109                    MetricStream::new(_metric_callback, stmt, elapsed, stream)
110                }
111                #[allow(unreachable_patterns)]
112                _ => unreachable!(),
113            },
114        }
115        .build()
116    }
117}
118
119#[cfg(not(feature = "sync"))]
120impl Stream for QueryStream {
121    type Item = Result<QueryResult, DbErr>;
122
123    fn poll_next(
124        self: Pin<&mut Self>,
125        cx: &mut std::task::Context<'_>,
126    ) -> Poll<Option<Self::Item>> {
127        let this = self.get_mut();
128        this.with_stream_mut(|stream| Pin::new(stream).poll_next(cx))
129    }
130}
131
132#[cfg(feature = "sync")]
133impl Iterator for QueryStream {
134    type Item = Result<QueryResult, DbErr>;
135
136    fn next(&mut self) -> Option<Self::Item> {
137        self.with_stream_mut(|stream| stream.next())
138    }
139}
sea_orm/database/stream/query.rs

sea_orm/database/stream/
query.rs
