1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
use byteorder::*;
use std::io::Write;
use std::num::NonZeroU32;

use crate::deserialize::{self, FromSql, Queryable};
use crate::expression::{
    AppearsOnTable, AsExpression, Expression, SelectableExpression, TypedExpressionType,
    ValidGrouping,
};
use crate::pg::{Pg, PgValue};
use crate::query_builder::{AstPass, QueryFragment, QueryId};
use crate::result::QueryResult;
use crate::serialize::{self, IsNull, Output, ToSql, WriteTuple};
use crate::sql_types::{HasSqlType, Record, SqlType};

macro_rules! tuple_impls {
    ($(
        $Tuple:tt {
            $(($idx:tt) -> $T:ident, $ST:ident, $TT:ident,)+
        }
    )+) => {$(
        impl<$($T,)+ $($ST,)+> FromSql<Record<($($ST,)+)>, Pg> for ($($T,)+)
        where
            $($T: FromSql<$ST, Pg>,)+
        {
            // Yes, we're relying on the order of evaluation of subexpressions
            // but the only other option would be to use `mem::uninitialized`
            // and `ptr::write`.
            #[allow(clippy::eval_order_dependence)]
            fn from_sql(value: PgValue<'_>) -> deserialize::Result<Self> {
                let mut bytes = value.as_bytes();
                let num_elements = bytes.read_i32::<NetworkEndian>()?;

                if num_elements != $Tuple {
                    return Err(format!(
                        "Expected a tuple of {} elements, got {}",
                        $Tuple,
                        num_elements,
                    ).into());
                }

                let result = ($({
                    // We could in theory validate the OID here, but that
                    // ignores cases like text vs varchar where the
                    // representation is the same and we don't care which we
                    // got.
                    let oid = NonZeroU32::new(bytes.read_u32::<NetworkEndian>()?).expect("Oid's aren't zero");
                    let num_bytes = bytes.read_i32::<NetworkEndian>()?;

                    if num_bytes == -1 {
                        $T::from_nullable_sql(None)?
                    } else {
                        let (elem_bytes, new_bytes) = bytes.split_at(num_bytes as usize);
                        bytes = new_bytes;
                        $T::from_sql(PgValue::new(
                            elem_bytes,
                            oid,
                        ))?
                    }
                },)+);

                if bytes.is_empty() {
                    Ok(result)
                } else {
                    Err("Received too many bytes. This tuple likely contains \
                        an element of the wrong SQL type.".into())
                }
            }
        }

        impl<$($T,)+ $($ST,)+> Queryable<Record<($($ST,)+)>, Pg> for ($($T,)+)
        where Self: FromSql<Record<($($ST,)+)>, Pg>
        {
            type Row = Self;

            fn build(row: Self::Row) -> deserialize::Result<Self> {
                Ok(row)
            }
        }

        impl<$($T,)+ $($ST,)+> AsExpression<Record<($($ST,)+)>> for ($($T,)+)
        where
            $($ST: SqlType + TypedExpressionType,)+
            $($T: AsExpression<$ST>,)+
            PgTuple<($($T::Expression,)+)>: Expression<SqlType = Record<($($ST,)+)>>,
        {
            type Expression = PgTuple<($($T::Expression,)+)>;

            fn as_expression(self) -> Self::Expression {
                PgTuple(($(
                    self.$idx.as_expression(),
                )+))
            }
        }

        impl<$($T,)+ $($ST,)+> WriteTuple<($($ST,)+)> for ($($T,)+)
        where
            $($T: ToSql<$ST, Pg>,)+
            $(Pg: HasSqlType<$ST>),+
        {
            fn write_tuple<_W: Write>(&self, out: &mut Output<_W, Pg>) -> serialize::Result {
                let mut buffer = Vec::new();
                out.write_i32::<NetworkEndian>($Tuple)?;

                $(
                    let oid = <Pg as HasSqlType<$ST>>::metadata(out.metadata_lookup()).oid()?;
                    out.write_u32::<NetworkEndian>(oid)?;
                    let is_null = {
                        let mut temp_buffer = Output::new(buffer, out.metadata_lookup());
                        let is_null = self.$idx.to_sql(&mut temp_buffer)?;
                        buffer = temp_buffer.into_inner();
                        is_null
                    };

                    if let IsNull::No = is_null {
                        out.write_i32::<NetworkEndian>(buffer.len() as i32)?;
                        out.write_all(&buffer)?;
                        buffer.clear();
                    } else {
                        out.write_i32::<NetworkEndian>(-1)?;
                    }
                )+

                Ok(IsNull::No)
            }
        }
    )+}
}

__diesel_for_each_tuple!(tuple_impls);

#[derive(Debug, Clone, Copy, QueryId, ValidGrouping)]
pub struct PgTuple<T>(T);

impl<T> QueryFragment<Pg> for PgTuple<T>
where
    T: QueryFragment<Pg>,
{
    fn walk_ast(&self, mut out: AstPass<Pg>) -> QueryResult<()> {
        out.push_sql("(");
        self.0.walk_ast(out.reborrow())?;
        out.push_sql(")");
        Ok(())
    }
}

impl<T> Expression for PgTuple<T>
where
    T: Expression,
{
    type SqlType = Record<T::SqlType>;
}

impl<T, QS> SelectableExpression<QS> for PgTuple<T>
where
    T: SelectableExpression<QS>,
    Self: AppearsOnTable<QS>,
{
}

impl<T, QS> AppearsOnTable<QS> for PgTuple<T>
where
    T: AppearsOnTable<QS>,
    Self: Expression,
{
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::dsl::sql;
    use crate::prelude::*;
    use crate::sql_types::*;
    use crate::test_helpers::*;

    #[test]
    fn record_deserializes_correctly() {
        let conn = &mut pg_connection();

        let tup =
            sql::<Record<(Integer, Text)>>("SELECT (1, 'hi')").get_result::<(i32, String)>(conn);
        assert_eq!(Ok((1, String::from("hi"))), tup);

        let tup = sql::<Record<(Record<(Integer, Text)>, Integer)>>("SELECT ((2, 'bye'), 3)")
            .get_result::<((i32, String), i32)>(conn);
        assert_eq!(Ok(((2, String::from("bye")), 3)), tup);

        let tup = sql::<
            Record<(
                Record<(Nullable<Integer>, Nullable<Text>)>,
                Nullable<Integer>,
            )>,
        >("SELECT ((4, NULL), NULL)")
        .get_result::<((Option<i32>, Option<String>), Option<i32>)>(conn);
        assert_eq!(Ok(((Some(4), None), None)), tup);
    }

    #[test]
    fn record_kinda_sorta_not_really_serializes_correctly() {
        let conn = &mut pg_connection();

        let tup = sql::<Record<(Integer, Text)>>("(1, 'hi')");
        let res = crate::select(tup.eq((1, "hi"))).get_result(conn);
        assert_eq!(Ok(true), res);

        let tup = sql::<Record<(Record<(Integer, Text)>, Integer)>>("((2, 'bye'::text), 3)");
        let res = crate::select(tup.eq(((2, "bye"), 3))).get_result(conn);
        assert_eq!(Ok(true), res);

        let tup = sql::<
            Record<(
                Record<(Nullable<Integer>, Nullable<Text>)>,
                Nullable<Integer>,
            )>,
        >("((4, NULL::text), NULL::int4)");
        let res = crate::select(tup.is_not_distinct_from(((Some(4), None::<&str>), None::<i32>)))
            .get_result(conn);
        assert_eq!(Ok(true), res);
    }

    #[test]
    fn serializing_named_composite_types() {
        #[derive(SqlType, QueryId, Debug, Clone, Copy)]
        #[postgres(type_name = "my_type")]
        struct MyType;

        #[derive(Debug, AsExpression)]
        #[sql_type = "MyType"]
        struct MyStruct<'a>(i32, &'a str);

        impl<'a> ToSql<MyType, Pg> for MyStruct<'a> {
            fn to_sql<W: Write>(&self, out: &mut Output<W, Pg>) -> serialize::Result {
                WriteTuple::<(Integer, Text)>::write_tuple(&(self.0, self.1), out)
            }
        }

        let conn = &mut pg_connection();

        crate::sql_query("CREATE TYPE my_type AS (i int4, t text)")
            .execute(conn)
            .unwrap();
        let sql = sql::<Bool>("(1, 'hi')::my_type = ").bind::<MyType, _>(MyStruct(1, "hi"));
        let res = crate::select(sql).get_result(conn);
        assert_eq!(Ok(true), res);
    }
}