hdbconnect_impl/types_impl/
seconddate.rs

1use crate::{HdbResult, HdbValue, impl_err};
2use byteorder::{LittleEndian, ReadBytesExt};
3
4const NULL_REPRESENTATION: i64 = 315_538_070_401;
5
6const SECOND_FACTOR: i64 = 1;
7const MINUTE_FACTOR: i64 = 60;
8const HOUR_FACTOR: i64 = 3_600;
9const DAY_FACTOR: i64 = 86_400;
10
11const ZEITENWENDE: i64 = 1_721_424;
12const JGREG: i64 = 2_299_161;
13// const IGREG: i64 = 18_994;             // Julian day of 01.01.0001 n. Chr.
14
15/// Implementation of HANA's `SecondDate`.
16///
17/// The type is used internally to implement deserialization from the wire.
18/// It is agnostic of timezones.
19#[derive(Clone, Debug, Serialize)]
20pub struct SecondDate(i64);
21
22impl std::fmt::Display for SecondDate {
23    // The format chosen supports the conversion to chrono types.
24    fn fmt(&self, fmt: &mut std::fmt::Formatter) -> std::fmt::Result {
25        let (year, month, day, hour, minute, second) = self.as_ymd_hms();
26        write!(
27            fmt,
28            "{year:04}-{month:02}-{day:02}T{hour:02}:{minute:02}:{second:02}",
29        )
30    }
31}
32
33impl std::cmp::PartialEq<SecondDate> for SecondDate {
34    fn eq(&self, other: &Self) -> bool {
35        self.0 == other.0
36    }
37}
38
39impl SecondDate {
40    pub(crate) fn new(raw: i64) -> Self {
41        Self(raw)
42    }
43
44    pub(crate) fn ref_raw(&self) -> &i64 {
45        &self.0
46    }
47
48    // Convert into tuple of "elements".
49    #[allow(clippy::cast_possible_truncation)]
50    #[allow(clippy::cast_precision_loss)]
51    #[allow(clippy::cast_sign_loss)]
52    pub(crate) fn as_ymd_hms(&self) -> (i32, u8, u8, u8, u8, u8) {
53        let value = match self.0 {
54            0 => 0, // maps the special value '' == 0 to '0001-01-01 00:00:00.000000000' = 1
55            v => v - 1,
56        };
57
58        let datevalue = value / DAY_FACTOR;
59        let mut timevalue = value - (datevalue * DAY_FACTOR);
60        let hour: u8 = (timevalue / HOUR_FACTOR) as u8;
61        timevalue -= HOUR_FACTOR * (i64::from(hour));
62        let minute: u8 = (timevalue / MINUTE_FACTOR) as u8;
63        timevalue -= MINUTE_FACTOR * (i64::from(minute));
64        let second: u8 = (timevalue / SECOND_FACTOR) as u8;
65
66        let julian: i64 = datevalue + ZEITENWENDE;
67        let ja: i64 = if julian >= JGREG {
68            let jalpha: i64 = (((julian - 1_867_216) as f64 - 0.25_f64) / 36_524.25_f64) as i64;
69            julian + 1 + jalpha - ((0.25_f64 * jalpha as f64) as i64)
70        } else {
71            julian
72        };
73
74        let jb: i64 = ja + 1524;
75        let jc: i64 = (6680_f64 + ((jb - 2_439_870) as f64 - 122.1_f64) / 365.25_f64) as i64;
76        let jd: i64 = ((365 * jc) as f64 + (0.25_f64 * jc as f64)) as i64;
77        let je: i64 = ((jb - jd) as f64 / 30.6001) as i64;
78
79        let day: u8 = (jb - jd - ((30.6001 * je as f64) as i64)) as u8;
80        let mut month: u8 = je as u8 - 1;
81        let mut year: i32 = jc as i32 - 4715;
82
83        if month > 12 {
84            month -= 12;
85        }
86        if month > 2 {
87            year -= 1;
88        }
89        if year <= 0 {
90            year -= 1;
91        }
92        (year, month, day, hour, minute, second)
93    }
94}
95
96pub(crate) fn parse_seconddate(
97    nullable: bool,
98    rdr: &mut dyn std::io::Read,
99) -> HdbResult<HdbValue<'static>> {
100    let i = rdr.read_i64::<LittleEndian>()?;
101    if i == NULL_REPRESENTATION {
102        if nullable {
103            Ok(HdbValue::NULL)
104        } else {
105            Err(impl_err!("found NULL value for NOT NULL SECONDDATE column",))
106        }
107    } else {
108        Ok(HdbValue::SECONDDATE(SecondDate::new(i)))
109    }
110}
hdbconnect_impl/types_impl/seconddate.rs

hdbconnect_impl/types_impl/
seconddate.rs
