cdbc_pg/
value.rs

1use cdbc::error::{BoxDynError, UnexpectedNullError};
2use crate::{PgTypeInfo, Postgres};
3use cdbc::value::{Value, ValueRef};
4use bytes::{Buf, Bytes};
5use std::borrow::Cow;
6use std::str::from_utf8;
7
8#[derive(Debug, Clone, Copy, Eq, PartialEq)]
9#[repr(u8)]
10pub enum PgValueFormat {
11    Text = 0,
12    Binary = 1,
13}
14
15/// Implementation of [`ValueRef`] for PostgreSQL.
16#[derive(Clone)]
17pub struct PgValueRef<'r> {
18    pub(crate) value: Option<&'r [u8]>,
19    pub(crate) row: Option<&'r Bytes>,
20    pub(crate) type_info: PgTypeInfo,
21    pub(crate) format: PgValueFormat,
22}
23
24/// Implementation of [`Value`] for PostgreSQL.
25#[derive(Clone)]
26pub struct PgValue {
27    pub(crate) value: Option<Bytes>,
28    pub(crate) type_info: PgTypeInfo,
29    pub(crate) format: PgValueFormat,
30}
31
32impl<'r> PgValueRef<'r> {
33    pub(crate) fn get(buf: &mut &'r [u8], format: PgValueFormat, ty: PgTypeInfo) -> Self {
34        let mut element_len = buf.get_i32();
35
36        let element_val = if element_len == -1 {
37            element_len = 0;
38            None
39        } else {
40            Some(&buf[..(element_len as usize)])
41        };
42
43        buf.advance(element_len as usize);
44
45        PgValueRef {
46            value: element_val,
47            row: None,
48            type_info: ty,
49            format,
50        }
51    }
52
53    pub(crate) fn format(&self) -> PgValueFormat {
54        self.format
55    }
56
57    pub(crate) fn as_bytes(&self) -> Result<&'r [u8], BoxDynError> {
58        match &self.value {
59            Some(v) => Ok(v),
60            None => Err(UnexpectedNullError.into()),
61        }
62    }
63
64    pub(crate) fn as_str(&self) -> Result<&'r str, BoxDynError> {
65        Ok(from_utf8(self.as_bytes()?)?)
66    }
67}
68
69impl Value for PgValue {
70    type Database = Postgres;
71
72    #[inline]
73    fn as_ref(&self) -> PgValueRef<'_> {
74        PgValueRef {
75            value: self.value.as_deref(),
76            row: None,
77            type_info: self.type_info.clone(),
78            format: self.format,
79        }
80    }
81
82    fn type_info(&self) -> Cow<'_, PgTypeInfo> {
83        Cow::Borrowed(&self.type_info)
84    }
85
86    fn is_null(&self) -> bool {
87        self.value.is_none()
88    }
89}
90
91impl<'r> ValueRef<'r> for PgValueRef<'r> {
92    type Database = Postgres;
93
94    fn to_owned(&self) -> PgValue {
95        let value = match (self.row, self.value) {
96            (Some(row), Some(value)) => Some(row.slice_ref(value)),
97
98            (None, Some(value)) => Some(Bytes::copy_from_slice(value)),
99
100            _ => None,
101        };
102
103        PgValue {
104            value,
105            format: self.format,
106            type_info: self.type_info.clone(),
107        }
108    }
109
110    fn type_info(&self) -> Cow<'_, PgTypeInfo> {
111        Cow::Borrowed(&self.type_info)
112    }
113
114    fn is_null(&self) -> bool {
115        self.value.is_none()
116    }
117}
cdbc_pg/value.rs

cdbc_pg/
value.rs
