You are viewing a plain text version of this content. The canonical link for it is here.
Posted to github@arrow.apache.org by "doki23 (via GitHub)" <gi...@apache.org> on 2023/03/06 13:18:04 UTC
[GitHub] [arrow-rs] doki23 commented on a diff in pull request #3762: Support for casting `Utf8` and `LargeUtf8` --> `Interval`
doki23 commented on code in PR #3762:
URL: https://github.com/apache/arrow-rs/pull/3762#discussion_r1126402464
##########
arrow-cast/src/parse.rs:
##########
@@ -445,6 +446,231 @@ impl Parser for Date64Type {
}
}
+pub(crate) fn parse_interval_year_month(
+ value: &str,
+) -> Result<<IntervalYearMonthType as ArrowPrimitiveType>::Native, ArrowError> {
+ let (result_months, result_days, result_nanos) = parse_interval("years", value)?;
+ if result_days != 0 || result_nanos != 0 {
+ return Err(ArrowError::CastError(format!(
+ "Cannot cast {value} to IntervalYearMonth because the value isn't multiple of months"
+ )));
+ }
+ Ok(IntervalYearMonthType::make_value(0, result_months))
+}
+
+pub(crate) fn parse_interval_day_time(
+ value: &str,
+) -> Result<<IntervalDayTimeType as ArrowPrimitiveType>::Native, ArrowError> {
+ let (result_months, mut result_days, result_nanos) = parse_interval("days", value)?;
+ if result_nanos % 1_000_000 != 0 {
+ return Err(ArrowError::CastError(format!(
+ "Cannot cast {value} to IntervalDayTime because the nanos part isn't multiple of milliseconds"
+ )));
+ }
+ result_days += result_months * 30;
+ Ok(IntervalDayTimeType::make_value(
+ result_days,
+ (result_nanos / 1_000_000) as i32,
+ ))
+}
+
+pub(crate) fn parse_interval_month_day_nano(
+ value: &str,
+) -> Result<<IntervalMonthDayNanoType as ArrowPrimitiveType>::Native, ArrowError> {
+ let (result_months, result_days, result_nanos) = parse_interval("months", value)?;
+ Ok(IntervalMonthDayNanoType::make_value(
+ result_months,
+ result_days,
+ result_nanos,
+ ))
+}
+
+const SECONDS_PER_HOUR: f64 = 3_600_f64;
+const NANOS_PER_MILLIS: f64 = 1_000_000_f64;
+const NANOS_PER_SECOND: f64 = 1_000_f64 * NANOS_PER_MILLIS;
+const NANOS_PER_MINUTE: f64 = 60_f64 * NANOS_PER_SECOND;
+const NANOS_PER_HOUR: f64 = 60_f64 * NANOS_PER_MINUTE;
+const NANOS_PER_DAY: f64 = 24_f64 * NANOS_PER_HOUR;
+
+#[derive(Clone, Copy)]
+#[repr(u16)]
+enum IntervalType {
+ Century = 0b_00_0000_0001,
+ Decade = 0b_00_0000_0010,
+ Year = 0b_00_0000_0100,
+ Month = 0b_00_0000_1000,
+ Week = 0b_00_0001_0000,
+ Day = 0b_00_0010_0000,
+ Hour = 0b_00_0100_0000,
+ Minute = 0b_00_1000_0000,
+ Second = 0b_01_0000_0000,
+ Millisecond = 0b_10_0000_0000,
+}
+
+impl FromStr for IntervalType {
+ type Err = ArrowError;
+
+ fn from_str(s: &str) -> Result<Self, ArrowError> {
+ match s.to_lowercase().as_str() {
+ "century" | "centuries" => Ok(Self::Century),
+ "decade" | "decades" => Ok(Self::Decade),
+ "year" | "years" => Ok(Self::Year),
+ "month" | "months" => Ok(Self::Month),
+ "week" | "weeks" => Ok(Self::Week),
+ "day" | "days" => Ok(Self::Day),
+ "hour" | "hours" => Ok(Self::Hour),
+ "minute" | "minutes" => Ok(Self::Minute),
+ "second" | "seconds" => Ok(Self::Second),
+ "millisecond" | "milliseconds" => Ok(Self::Millisecond),
+ _ => Err(ArrowError::NotYetImplemented(format!(
+ "Unknown interval type: {s}"
+ ))),
+ }
+ }
+}
+
+pub type MonthDayNano = (i32, i32, i64);
+
+/// parse string value to a triple of aligned months, days, nanos
+pub fn parse_interval(
+ leading_field: &str,
+ value: &str,
+) -> Result<MonthDayNano, ArrowError> {
+ let mut used_interval_types = 0;
+
+ let mut calculate_from_part = |interval_period_str: &str,
+ interval_type: &str|
+ -> Result<(i64, i64, f64), ArrowError> {
+ // @todo It's better to use Decimal in order to protect rounding errors
+ // Wait https://github.com/apache/arrow/pull/9232
+ let interval_period = match f64::from_str(interval_period_str) {
+ Ok(n) => n,
+ Err(_) => {
+ return Err(ArrowError::NotYetImplemented(format!(
+ "Unsupported Interval Expression with value {value:?}"
+ )));
+ }
+ };
+
+ if interval_period > (i64::MAX as f64) {
+ return Err(ArrowError::ParseError(format!(
+ "Interval field value out of range: {value:?}"
+ )));
+ }
+
+ let it = IntervalType::from_str(interval_type).map_err(|_| {
+ ArrowError::ParseError(format!(
+ "Invalid input syntax for type interval: {value:?}"
+ ))
+ })?;
+
+ // Disallow duplicate interval types
+ if used_interval_types & (it as u16) != 0 {
+ return Err(ArrowError::ParseError(format!(
+ "Invalid input syntax for type interval: {value:?}. Repeated type '{interval_type}'"
+ )));
+ } else {
+ used_interval_types |= it as u16;
+ }
+
+ match it {
+ IntervalType::Century => {
+ Ok(align_interval_parts(interval_period * 1200_f64, 0.0, 0.0))
+ }
+ IntervalType::Decade => {
+ Ok(align_interval_parts(interval_period * 120_f64, 0.0, 0.0))
+ }
+ IntervalType::Year => {
+ Ok(align_interval_parts(interval_period * 12_f64, 0.0, 0.0))
+ }
+ IntervalType::Month => Ok(align_interval_parts(interval_period, 0.0, 0.0)),
+ IntervalType::Week => {
+ Ok(align_interval_parts(0.0, interval_period * 7_f64, 0.0))
+ }
+ IntervalType::Day => Ok(align_interval_parts(0.0, interval_period, 0.0)),
+ IntervalType::Hour => {
+ Ok((0, 0, interval_period * SECONDS_PER_HOUR * NANOS_PER_SECOND))
+ }
+ IntervalType::Minute => {
+ Ok((0, 0, interval_period * 60_f64 * NANOS_PER_SECOND))
+ }
+ IntervalType::Second => Ok((0, 0, interval_period * NANOS_PER_SECOND)),
+ IntervalType::Millisecond => Ok((0, 0, interval_period * 1_000_000f64)),
+ }
+ };
+
+ let mut result_month: i64 = 0;
+ let mut result_days: i64 = 0;
+ let mut result_nanos: i128 = 0;
+
+ let mut parts = value.split_whitespace();
+
+ loop {
+ let interval_period_str = parts.next();
+ if interval_period_str.is_none() {
+ break;
+ }
+
+ let unit = parts.next().unwrap_or(leading_field);
+
+ let (diff_month, diff_days, diff_nanos) =
+ calculate_from_part(interval_period_str.unwrap(), unit)?;
+
+ result_month += diff_month;
+
+ if result_month > (i32::MAX as i64) {
+ return Err(ArrowError::ParseError(format!(
+ "Interval field value out of range: {value:?}"
+ )));
+ }
+
+ result_days += diff_days;
+
+ if result_days > (i32::MAX as i64) {
+ return Err(ArrowError::ParseError(format!(
+ "Interval field value out of range: {value:?}"
+ )));
+ }
+
+ result_nanos += diff_nanos as i128;
+
+ if result_nanos > (i64::MAX as i128) {
+ return Err(ArrowError::ParseError(format!(
+ "Interval field value out of range: {value:?}"
+ )));
+ }
+ }
+
+ Ok((result_month as i32, result_days as i32, result_nanos as i64))
+}
+
+/// We are storing parts as integers, it's why we need to align parts fractional
+/// INTERVAL '0.5 MONTH' = 15 days, INTERVAL '1.5 MONTH' = 1 month 15 days
+/// INTERVAL '0.5 DAY' = 12 hours, INTERVAL '1.5 DAY' = 1 day 12 hours
+/// INTERVAL '30 DAYS' = 1 month
+fn align_interval_parts(
+ mut month_part: f64,
+ mut day_part: f64,
+ mut nanos_part: f64,
+) -> (i64, i64, f64) {
+ // Convert fractional month to days, It's not supported by Arrow types, but anyway
Review Comment:
According to [this doc](https://www.postgresql.org/docs/current/datatype-datetime.html#DATATYPE-INTERVAL-INPUT:~:text=Field%20values%20can,fractional%20on%20output.) it's correct. But you remind me that maybe it's incorrect to spill smaller units to larger units.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: github-unsubscribe@arrow.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org