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

/*
 * https://github.com/postgres/postgres/blob/REL_12_0/src/include/utils/array.h
 */

use byteorder::ReadBytesExt;
use std::convert::TryInto;

/**
 * Rust type for [array](https://www.postgresql.org/docs/current/arrays.html).
 */
#[derive(Clone, Debug)]
pub struct Array<T> {
    ndim: usize,
    elemtype: crate::pq::Type,
    has_nulls: bool,
    dimensions: Vec<i32>,
    lower_bounds: Vec<i32>,
    data: Vec<u8>,
    maker: std::marker::PhantomData<T>,
}

impl<T: crate::FromSql> Iterator for Array<T> {
    type Item = T;

    fn next(&mut self) -> Option<T> {
        use bytes::Buf;

        if self.data.is_empty() {
            return None;
        }

        let mut buf = &self.data.clone()[..];

        let mut len = buf.get_u32() as usize;
        let value = if len == 0xFFFF_FFFF {
            len = 0;
            None
        } else {
            Some(&buf[..len])
        };
        self.data = buf[len..].to_vec();

        match T::from_sql(&self.elemtype, crate::pq::Format::Binary, value) {
            Ok(x) => Some(x),
            Err(err) => {
                log::error!("Unable to convert array element from SQL: {}", err);
                None
            }
        }
    }
}

impl<T: crate::FromSql> crate::FromSql for Array<T> {
    fn from_text(_ty: &crate::pq::Type, _raw: Option<&str>) -> crate::Result<Self> {
        todo!()
    }

    fn from_binary(_: &crate::pq::Type, raw: Option<&[u8]>) -> crate::Result<Self> {
        let mut data = crate::not_null(raw)?;

        let ndim = data.read_i32::<byteorder::BigEndian>()?;
        if ndim < 0 {
            panic!("Invalid array");
        }

        let has_nulls = data.read_i32::<byteorder::BigEndian>()? != 0;

        let oid = data.read_u32::<byteorder::BigEndian>()?;
        let elemtype: crate::pq::Type = oid.try_into().unwrap_or(crate::pq::Type {
            oid,
            descr: "Custom type",
            name: "custom",
            kind: libpq::types::Kind::Composite,
        });

        let mut dimensions = Vec::new();
        let mut lower_bounds = Vec::new();

        for _ in 0..ndim {
            let dimension = data.read_i32::<byteorder::BigEndian>()?;
            dimensions.push(dimension);

            let lower_bound = data.read_i32::<byteorder::BigEndian>()?;
            lower_bounds.push(lower_bound);
        }

        let array = Self {
            ndim: ndim as usize,
            elemtype,
            has_nulls,
            dimensions,
            lower_bounds,
            data: data.to_vec(),
            maker: std::marker::PhantomData,
        };

        Ok(array)
    }
}

impl<T: crate::FromSql> From<Array<T>> for Vec<T> {
    fn from(array: Array<T>) -> Self {
        if array.ndim > 1 {
            panic!(
                "Unable to transform {} dimension array as vector",
                array.ndim
            );
        }

        array.collect()
    }
}

#[cfg(test)]
mod test {
    #[test]
    fn bin_vec() -> crate::Result {
        let elephantry = crate::test::new_conn()?;
        let results: Vec<i32> = elephantry.query_one("SELECT '{1, 2}'::int4[]", &[])?;

        assert_eq!(results, vec![1, 2]);

        Ok(())
    }

    #[test]
    fn bin_array_str() -> crate::Result {
        let elephantry = crate::test::new_conn()?;
        let results: Vec<Option<String>> =
            elephantry.query_one("SELECT '{null, str}'::text[]", &[])?;

        assert_eq!(results, vec![None, Some("str".to_string())]);

        Ok(())
    }
}