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use "Write" with fmt_duration_string to support Formatter and Strin…
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…g, split out `iso_duration_string`
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@alexander-beedie
alexander-beedie committed Nov 13, 2024
1 parent 67e0845 commit f37f800
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30 changes: 23 additions & 7 deletions crates/polars-core/src/chunked_array/temporal/duration.rs
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Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
use crate::export::chrono::Duration as ChronoDuration;
use crate::fmt::fmt_duration_string;
use crate::fmt::{fmt_duration_string, iso_duration_string};
use crate::prelude::DataType::Duration;
use crate::prelude::*;

Expand Down Expand Up @@ -64,13 +64,29 @@ impl DurationChunked {
/// Convert from [`Duration`] to String; note that `strftime` format
/// strings are not supported, only the specifiers 'iso' and 'polars'.
pub fn to_string(&self, format: &str) -> PolarsResult<StringChunked> {
// the duration string functions below can reuse this string buffer
let mut s = String::with_capacity(32);
match format {
"iso" | "polars" => {
let out: StringChunked = self
.0
.apply_nonnull_values_generic(DataType::String, |v: i64| {
fmt_duration_string(v, self.time_unit(), format == "iso")
});
"iso" => {
let out: StringChunked =
self.0
.apply_nonnull_values_generic(DataType::String, |v: i64| {
s.clear();
iso_duration_string(&mut s, v, self.time_unit());
s.clone()
});
Ok(out)
},
"polars" => {
let out: StringChunked =
self.0
.apply_nonnull_values_generic(DataType::String, |v: i64| {
s.clear();
fmt_duration_string(&mut s, v, self.time_unit())
.map_err(|e| polars_err!(ComputeError: "{:?}", e))
.expect("failed to format duration");
s.clone()
});
Ok(out)
},
_ => {
Expand Down
202 changes: 95 additions & 107 deletions crates/polars-core/src/fmt.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -984,141 +984,129 @@ const SIZES_US: [i64; 4] = [86_400_000_000, 3_600_000_000, 60_000_000, 1_000_000
const SIZES_MS: [i64; 4] = [86_400_000, 3_600_000, 60_000, 1_000];

#[cfg(feature = "dtype-duration")]
pub fn fmt_duration_string(mut v: i64, unit: TimeUnit, iso: bool) -> String {
// take the physical/integer duration value and return either a human-readable version
// of the duration (as used in the Polars frame repr) or an ISO8601 duration string.
//
// Polars: "3d 22m 55s 1ms"
// ISO: "P3DT22M55.001S"
//
// the parts (days, hours, minutes, seconds) occur in the same order in
// each string, so we use the same code to generate each of them, with
// only the separators and the 'seconds' part differing.
//
// ref: https://en.wikipedia.org/wiki/ISO_8601#Durations
pub fn fmt_duration_string<W: Write>(f: &mut W, v: i64, unit: TimeUnit) -> fmt::Result {
// take the physical/integer duration value and return a
// friendly/readable duration string, eg: "3d 22m 55s 1ms"
if v == 0 {
return if iso {
"PT0S".to_string()
} else {
match unit {
TimeUnit::Nanoseconds => "0ns".to_string(),
TimeUnit::Microseconds => "0µs".to_string(),
TimeUnit::Milliseconds => "0ms".to_string(),
}
return match unit {
TimeUnit::Nanoseconds => f.write_str("0ns"),
TimeUnit::Microseconds => f.write_str("0µs"),
TimeUnit::Milliseconds => f.write_str("0ms"),
};
};
// iterate over dtype-specific sizes to appropriately scale
// and extract 'days', 'hours', 'minutes', and 'seconds' parts.
let sizes = match unit {
TimeUnit::Nanoseconds => SIZES_NS.as_slice(),
TimeUnit::Microseconds => SIZES_US.as_slice(),
TimeUnit::Milliseconds => SIZES_MS.as_slice(),
};

let mut s = String::with_capacity(32);
let mut buffer = itoa::Buffer::new();
let mut wrote_part = false;
if iso {
if v < 0 {
// negative sign before "P" indicates that the entire ISO duration is negative.
// the Polars version applies a negative sign to each *individual* part.
s.push_str("-P");
v = v.abs()
for (i, &size) in sizes.iter().enumerate() {
let whole_num = if i == 0 {
v / size
} else {
s.push('P');
(v % sizes[i - 1]) / size
};
if whole_num != 0 {
f.write_str(buffer.format(whole_num))?;
f.write_str(DURATION_PARTS[i])?;
if v % size != 0 {
f.write_char(' ')?;
}
}
}
// write fractional seconds as integer nano/micro/milliseconds.
let (v, units) = match unit {
TimeUnit::Nanoseconds => (v % 1_000_000_000, ["ns", "µs", "ms"]),
TimeUnit::Microseconds => (v % 1_000_000, ["µs", "ms", ""]),
TimeUnit::Milliseconds => (v % 1_000, ["ms", "", ""]),
};
if v != 0 {
let (value, suffix) = if v % 1_000 != 0 {
(v, units[0])
} else if v % 1_000_000 != 0 {
(v / 1_000, units[1])
} else {
(v / 1_000_000, units[2])
};
f.write_str(buffer.format(value))?;
f.write_str(suffix)?;
}
Ok(())
}

#[cfg(feature = "dtype-duration")]
pub fn iso_duration_string(s: &mut String, mut v: i64, unit: TimeUnit) {
if v == 0 {
s.push_str("PT0S");
return;
}
let mut buffer = itoa::Buffer::new();
let mut wrote_part = false;
if v < 0 {
// negative sign before "P" indicates entire ISO duration is negative.
s.push_str("-P");
v = v.abs();
} else {
s.push('P');
}
// iterate over dtype-specific sizes to appropriately scale
// and extract 'days', 'hours', 'minutes', and 'seconds' parts.
let sizes = match unit {
TimeUnit::Nanoseconds => SIZES_NS.as_slice(),
TimeUnit::Microseconds => SIZES_US.as_slice(),
TimeUnit::Milliseconds => SIZES_MS.as_slice(),
};
for (i, &size) in sizes.iter().enumerate() {
let whole_num = if i == 0 {
v / size
} else {
(v % sizes[i - 1]) / size
};
if whole_num != 0 || (iso && i == 3) {
if iso {
if i != 3 {
// days, hours, minutes
s.push_str(buffer.format(whole_num));
s.push_str(ISO_DURATION_PARTS[i]);
if whole_num != 0 || i == 3 {
if i != 3 {
// days, hours, minutes
s.push_str(buffer.format(whole_num));
s.push_str(ISO_DURATION_PARTS[i]);
} else {
// (index 3 => 'seconds' part): the ISO version writes
// fractional seconds, not integer nano/micro/milliseconds.
// if zero, only write out if no other parts written yet.
let fractional_part = v % size;
if whole_num == 0 && fractional_part == 0 {
if !wrote_part {
s.push_str("0S")
}
} else {
// (index 3 => 'seconds' part): the ISO version writes
// fractional seconds, not integer nano/micro/milliseconds.
// if zero, only write out if no other parts written yet.
let fractional_part = v % size;
if whole_num == 0 && fractional_part == 0 {
if !wrote_part {
s.push_str("0S")
}
} else {
s.push_str(buffer.format(whole_num));
if fractional_part != 0 {
let secs = match unit {
TimeUnit::Nanoseconds => format!(".{:09}", fractional_part),
TimeUnit::Microseconds => format!(".{:06}", fractional_part),
TimeUnit::Milliseconds => format!(".{:03}", fractional_part),
};
s.push_str(secs.trim_end_matches('0'));
}
s.push_str(ISO_DURATION_PARTS[i]);
s.push_str(buffer.format(whole_num));
if fractional_part != 0 {
let secs = match unit {
TimeUnit::Nanoseconds => format!(".{:09}", fractional_part),
TimeUnit::Microseconds => format!(".{:06}", fractional_part),
TimeUnit::Milliseconds => format!(".{:03}", fractional_part),
};
s.push_str(secs.trim_end_matches('0'));
}
s.push_str(ISO_DURATION_PARTS[i]);
}
// (index 0 => 'days' part): after writing days above (if non-zero)
// the ISO duration string requires a `T` before the time part.
if i == 0 {
s.push('T');
}
} else {
s.push_str(buffer.format(whole_num));
s.push_str(DURATION_PARTS[i]);
if v % size != 0 {
s.push(' ');
}
}
// (index 0 => 'days' part): after writing days above (if non-zero)
// the ISO duration string requires a `T` before the time part.
if i == 0 {
s.push('T');
}
wrote_part = true;
} else if iso && i == 0 {
} else if i == 0 {
// always need to write the `T` separator for ISO
// durations, even if there is no 'days' part.
s.push('T');
}
}
if iso {
// if there was only a 'days' component, no need for time separator.
if s.ends_with('T') {
s.pop();
}
} else {
// write out fractional seconds as integer nano/micro/milliseconds.
match unit {
TimeUnit::Nanoseconds => {
if v % 1000 != 0 {
s.push_str(buffer.format(v % 1_000_000_000));
s.push_str("ns");
} else if v % 1_000_000 != 0 {
s.push_str(buffer.format((v % 1_000_000_000) / 1000));
s.push_str("µs");
} else if v % 1_000_000_000 != 0 {
s.push_str(buffer.format((v % 1_000_000_000) / 1_000_000));
s.push_str("ms");
}
},
TimeUnit::Microseconds => {
if v % 1000 != 0 {
s.push_str(buffer.format(v % 1_000_000));
s.push_str("µs");
} else if v % 1_000_000 != 0 {
s.push_str(buffer.format((v % 1_000_000) / 1_000));
s.push_str("ms");
}
},
TimeUnit::Milliseconds => {
if v % 1000 != 0 {
s.push_str(buffer.format(v % 1_000));
s.push_str("ms");
}
},
}
// if there was only a 'days' component, no need for time separator.
if s.ends_with('T') {
s.pop();
}
s
}

fn format_blob(f: &mut Formatter<'_>, bytes: &[u8]) -> fmt::Result {
Expand All @@ -1133,9 +1121,9 @@ fn format_blob(f: &mut Formatter<'_>, bytes: &[u8]) -> fmt::Result {
}
}
if bytes.len() > width {
write!(f, "\"…")?;
f.write_str("\"…")?;
} else {
write!(f, "\"")?;
f.write_str("\"")?;
}
Ok(())
}
Expand Down Expand Up @@ -1169,7 +1157,7 @@ impl Display for AnyValue<'_> {
fmt_datetime(f, *v, *tu, tz.as_ref().map(|v| v.as_ref()))
},
#[cfg(feature = "dtype-duration")]
AnyValue::Duration(v, tu) => write!(f, "{}", fmt_duration_string(*v, *tu, false)),
AnyValue::Duration(v, tu) => fmt_duration_string(f, *v, *tu),
#[cfg(feature = "dtype-time")]
AnyValue::Time(_) => {
let nt: chrono::NaiveTime = self.into();
Expand Down

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