diesel/pg/types/
array.rs

1use byteorder::{NetworkEndian, ReadBytesExt, WriteBytesExt};
2use std::fmt;
3use std::io::Write;
4
5use crate::deserialize::{self, FromSql};
6use crate::pg::{Pg, PgTypeMetadata, PgValue};
7use crate::query_builder::bind_collector::ByteWrapper;
8use crate::serialize::{self, IsNull, Output, ToSql};
9use crate::sql_types::{Array, HasSqlType, Nullable};
10
11#[cfg(feature = "postgres_backend")]
12impl<T> HasSqlType<Array<T>> for Pg
13where
14    Pg: HasSqlType<T>,
15{
16    fn metadata(lookup: &mut Self::MetadataLookup) -> PgTypeMetadata {
17        match <Pg as HasSqlType<T>>::metadata(lookup).0 {
18            Ok(tpe) => PgTypeMetadata::new(tpe.array_oid, 0),
19            c @ Err(_) => PgTypeMetadata(c),
20        }
21    }
22}
23
24#[cfg(feature = "postgres_backend")]
25impl<T, ST> FromSql<Array<ST>, Pg> for Vec<T>
26where
27    T: FromSql<ST, Pg>,
28{
29    fn from_sql(value: PgValue<'_>) -> deserialize::Result<Self> {
30        let mut bytes = value.as_bytes();
31        let num_dimensions = bytes.read_i32::<NetworkEndian>()?;
32        let has_null = bytes.read_i32::<NetworkEndian>()? != 0;
33        let _oid = bytes.read_i32::<NetworkEndian>()?;
34
35        if num_dimensions == 0 {
36            return Ok(Vec::new());
37        }
38
39        let num_elements = bytes.read_i32::<NetworkEndian>()?;
40        let _lower_bound = bytes.read_i32::<NetworkEndian>()?;
41
42        if num_dimensions != 1 {
43            return Err("multi-dimensional arrays are not supported".into());
44        }
45
46        (0..num_elements)
47            .map(|_| {
48                let elem_size = bytes.read_i32::<NetworkEndian>()?;
49                if has_null && elem_size == -1 {
50                    T::from_nullable_sql(None)
51                } else {
52                    let (elem_bytes, new_bytes) = bytes.split_at(elem_size.try_into()?);
53                    bytes = new_bytes;
54                    T::from_sql(PgValue::new_internal(elem_bytes, &value))
55                }
56            })
57            .collect()
58    }
59}
60
61use crate::expression::bound::Bound;
62use crate::expression::AsExpression;
63
64macro_rules! array_as_expression {
65    ($ty:ty, $sql_type:ty) => {
66        #[cfg(feature = "postgres_backend")]
67        // this simplifies the macro implementation
68        // as some macro calls use this lifetime
69        #[allow(clippy::extra_unused_lifetimes)]
70        impl<'a, 'b, ST: 'static, T> AsExpression<$sql_type> for $ty {
71            type Expression = Bound<$sql_type, Self>;
72
73            fn as_expression(self) -> Self::Expression {
74                Bound::new(self)
75            }
76        }
77    };
78}
79
80array_as_expression!(&'a [T], Array<ST>);
81array_as_expression!(&'a [T], Nullable<Array<ST>>);
82array_as_expression!(&'a &'b [T], Array<ST>);
83array_as_expression!(&'a &'b [T], Nullable<Array<ST>>);
84array_as_expression!(Vec<T>, Array<ST>);
85array_as_expression!(Vec<T>, Nullable<Array<ST>>);
86array_as_expression!(&'a Vec<T>, Array<ST>);
87array_as_expression!(&'a Vec<T>, Nullable<Array<ST>>);
88array_as_expression!(&'a &'b Vec<T>, Array<ST>);
89array_as_expression!(&'a &'b Vec<T>, Nullable<Array<ST>>);
90
91#[cfg(feature = "postgres_backend")]
92impl<ST, T> ToSql<Array<ST>, Pg> for [T]
93where
94    Pg: HasSqlType<ST>,
95    T: ToSql<ST, Pg>,
96{
97    fn to_sql<'b>(&'b self, out: &mut Output<'b, '_, Pg>) -> serialize::Result {
98        let num_dimensions = 1;
99        out.write_i32::<NetworkEndian>(num_dimensions)?;
100        let flags = 0;
101        out.write_i32::<NetworkEndian>(flags)?;
102        let element_oid = Pg::metadata(out.metadata_lookup()).oid()?;
103        out.write_u32::<NetworkEndian>(element_oid)?;
104        out.write_i32::<NetworkEndian>(self.len().try_into()?)?;
105        let lower_bound = 1;
106        out.write_i32::<NetworkEndian>(lower_bound)?;
107
108        // This buffer is created outside of the loop to reuse the underlying memory allocation
109        // For most cases all array elements will have the same serialized size
110        let mut buffer = Vec::new();
111
112        for elem in self.iter() {
113            let is_null = {
114                let mut temp_buffer = Output::new(ByteWrapper(&mut buffer), out.metadata_lookup());
115                elem.to_sql(&mut temp_buffer)?
116            };
117
118            if let IsNull::No = is_null {
119                out.write_i32::<NetworkEndian>(buffer.len().try_into()?)?;
120                out.write_all(&buffer)?;
121                buffer.clear();
122            } else {
123                // https://github.com/postgres/postgres/blob/82f8107b92c9104ec9d9465f3f6a4c6dab4c124a/src/backend/utils/adt/arrayfuncs.c#L1461
124                out.write_i32::<NetworkEndian>(-1)?;
125            }
126        }
127
128        Ok(IsNull::No)
129    }
130}
131
132#[cfg(feature = "postgres_backend")]
133impl<ST, T> ToSql<Nullable<Array<ST>>, Pg> for [T]
134where
135    [T]: ToSql<Array<ST>, Pg>,
136    ST: 'static,
137{
138    fn to_sql<'b>(&'b self, out: &mut Output<'b, '_, Pg>) -> serialize::Result {
139        ToSql::<Array<ST>, Pg>::to_sql(self, out)
140    }
141}
142
143#[cfg(feature = "postgres_backend")]
144impl<ST, T> ToSql<Array<ST>, Pg> for Vec<T>
145where
146    ST: 'static,
147    [T]: ToSql<Array<ST>, Pg>,
148    T: fmt::Debug,
149{
150    fn to_sql<'b>(&'b self, out: &mut Output<'b, '_, Pg>) -> serialize::Result {
151        (self as &[T]).to_sql(out)
152    }
153}
154
155#[cfg(feature = "postgres_backend")]
156impl<ST, T> ToSql<Nullable<Array<ST>>, Pg> for Vec<T>
157where
158    ST: 'static,
159    Vec<T>: ToSql<Array<ST>, Pg>,
160{
161    fn to_sql<'b>(&'b self, out: &mut Output<'b, '_, Pg>) -> serialize::Result {
162        ToSql::<Array<ST>, Pg>::to_sql(self, out)
163    }
164}
diesel/pg/types/array.rs

diesel/pg/types/
array.rs
