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Added additional functionality to DateTime.
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@mdecimus
mdecimus committed Oct 16, 2022
1 parent be32ba6 commit fbd53cb
Showing 1 changed file with 232 additions and 13 deletions.
245 changes: 232 additions & 13 deletions src/parsers/fields/date.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,11 @@ use std::fmt;

use crate::{parsers::MessageStream, DateTime, HeaderValue};

pub static DOW: &[&str] = &["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"];
pub static MONTH: &[&str] = &[
"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
];

impl DateTime {
/// Parses an RFC822 date
pub fn parse_rfc822(&self, value: &str) -> Option<Self> {
Expand All @@ -22,6 +27,123 @@ impl DateTime {
}
}

/// Parses an RFC3339 date
pub fn parse_rfc3339(value: &str) -> Option<Self> {
// 2004 - 06 - 28 T 23 : 43 : 45 . 000 Z
// 1969 - 02 - 13 T 23 : 32 : 00 - 03 : 30
// 0 1 2 3 4 5 6 7

let mut pos = 0;
let mut parts = [0u32; 8];
let mut parts_sizes = [
4u32, // Year (0)
2u32, // Month (1)
2u32, // Day (2)
2u32, // Hour (3)
2u32, // Minute (4)
2u32, // Second (5)
2u32, // TZ Hour (6)
2u32, // TZ Minute (7)
];
let mut skip_digits = false;
let mut is_plus = true;

for ch in value.as_bytes() {
match ch {
b'0'..=b'9' if !skip_digits => {
if parts_sizes[pos] > 0 {
parts_sizes[pos] -= 1;
parts[pos] += (*ch - b'0') as u32 * u32::pow(10, parts_sizes[pos]);
} else {
return None;
}
}
b'-' => {
if pos <= 1 {
pos += 1;
} else if pos == 5 {
pos += 1;
is_plus = false;
skip_digits = false;
} else {
return None;
}
}
b'T' => {
if pos == 2 {
pos += 1;
} else {
return None;
}
}
b':' => {
if [3, 4, 6].contains(&pos) {
pos += 1;
} else {
return None;
}
}
b'+' => {
if pos == 5 {
pos += 1;
skip_digits = false;
} else {
return None;
}
}
b'.' => {
if pos == 5 {
skip_digits = true;
} else {
return None;
}
}

_ => (),
}
}

if pos >= 5 {
DateTime {
year: parts[0] as u16,
month: parts[1] as u8,
day: parts[2] as u8,
hour: parts[3] as u8,
minute: parts[4] as u8,
second: parts[5] as u8,
tz_hour: parts[6] as u8,
tz_minute: parts[7] as u8,
tz_before_gmt: !is_plus,
}
.into()
} else {
None
}
}

/// Return an RFC822 date
pub fn to_rfc822(&self) -> String {
format!(
"{}, {} {} {:04} {:02}:{:02}:{:02} {}{:02}{:02}",
DOW[self.day_of_week() as usize],
self.day,
MONTH
.get(self.month.saturating_sub(1) as usize)
.unwrap_or(&""),
self.year,
self.hour,
self.minute,
self.second,
if self.tz_before_gmt && (self.tz_hour > 0 || self.tz_minute > 0) {
"-"
} else {
"+"
},
self.tz_hour,
self.tz_minute
)
}

/// Returns an RFC3339 representation of the parsed RFC5322 datetime field
pub fn to_rfc3339(&self) -> String {
if self.tz_hour != 0 || self.tz_minute != 0 {
Expand Down Expand Up @@ -52,7 +174,7 @@ impl DateTime {
/// Returns true if the date is valid
pub fn is_valid(&self) -> bool {
(0..=23).contains(&self.tz_hour)
&& (1970..=3000).contains(&self.year)
&& (1900..=3000).contains(&self.year)
&& (0..=59).contains(&self.tz_minute)
&& (1..=12).contains(&self.month)
&& (1..=31).contains(&self.day)
Expand All @@ -64,6 +186,14 @@ impl DateTime {
/// Returns the numbers of seconds since 1970-01-01T00:00:00Z (Unix epoch)
/// or None if the date is invalid.
pub fn to_timestamp(&self) -> i64 {
self.to_timestamp_local()
+ ((self.tz_hour as i64 * 3600 + self.tz_minute as i64 * 60)
* if self.tz_before_gmt { 1 } else { -1 })
}

/// Returns the numbers of seconds since 1970-01-01T00:00:00Z (Unix epoch) in local time
/// or None if the date is invalid.
pub fn to_timestamp_local(&self) -> i64 {
// Ported from https://github.com/protocolbuffers/upb/blob/22182e6e/upb/json_decode.c#L982-L992
let month = self.month as u32;
let year_base = 4800; /* Before min year, multiple of 400. */
Expand All @@ -77,8 +207,61 @@ impl DateTime {
+ self.hour as i64 * 3600
+ self.minute as i64 * 60
+ self.second as i64
+ ((self.tz_hour as i64 * 3600 + self.tz_minute as i64 * 60)
* if self.tz_before_gmt { 1 } else { -1 })
}

/// Creates a DateTime object from a timestamp
pub fn from_timestamp(timestamp: i64) -> Self {
// Ported from http://howardhinnant.github.io/date_algorithms.html#civil_from_days
let (z, seconds) = ((timestamp / 86400) + 719468, timestamp % 86400);
let era: i64 = (if z >= 0 { z } else { z - 146096 }) / 146097;
let doe: u64 = (z - era * 146097) as u64; // [0, 146096]
let yoe: u64 = (doe - doe / 1460 + doe / 36524 - doe / 146096) / 365; // [0, 399]
let y: i64 = (yoe as i64) + era * 400;
let doy: u64 = doe - (365 * yoe + yoe / 4 - yoe / 100); // [0, 365]
let mp = (5 * doy + 2) / 153; // [0, 11]
let d: u64 = doy - (153 * mp + 2) / 5 + 1; // [1, 31]
let m: u64 = if mp < 10 { mp + 3 } else { mp - 9 }; // [1, 12]
let (h, mn, s) = (seconds / 3600, (seconds / 60) % 60, seconds % 60);

DateTime {
year: (y + (if m <= 2 { 1 } else { 0 })) as u16,
month: m as u8,
day: d as u8,
hour: h as u8,
minute: mn as u8,
second: s as u8,
tz_before_gmt: false,
tz_hour: 0,
tz_minute: 0,
}
}

/// Returns the day of week where [0, 6] represents [Sun, Sat].
pub fn day_of_week(&self) -> u8 {
(((self.to_timestamp_local() as f64 / 86400.0).floor() as i64 + 4).rem_euclid(7)) as u8
}

/// Returns the julian day
pub fn julian_day(&self) -> i64 {
let day = self.day as i64;
let (month, year) = if self.month > 2 {
((self.month - 3) as i64, self.year as i64)
} else {
((self.month + 9) as i64, (self.year - 1) as i64)
};

let c = year / 100;
c * 146097 / 4 + (year - c * 100) * 1461 / 4 + (month * 153 + 2) / 5 + day + 1721119
}

/// Converts the DateTime to the given timezone
pub fn to_timezone(&self, tz: i64) -> DateTime {
let mut dt = DateTime::from_timestamp(self.to_timestamp() + tz);
dt.tz_before_gmt = tz < 0;
let tz = tz.abs();
dt.tz_hour = (tz / 3600) as u8;
dt.tz_minute = (tz % 3600) as u8;
dt
}
}

Expand Down Expand Up @@ -199,6 +382,27 @@ impl<'x> MessageStream<'x> {
continue;
}
b',' | b'\r' => (),
b';' => {
// May be parsing Received field, reset state.
pos = 0;
parts = [0u32; 7];
parts_sizes = [
2u32, // Day (0)
2u32, // Month (1)
4u32, // Year (2)
2u32, // Hour (3)
2u32, // Minute (4)
2u32, // Second (5)
4u32, // TZ (6)
];
month_hash = 0;
month_pos = 0;

is_plus = true;
is_new_token = true;
ignore = true;
continue;
}
_ => (),
}

Expand Down Expand Up @@ -265,28 +469,32 @@ mod tests {
fn parse_dates() {
let inputs = [
(
"Fri, 21 Nov 1997 09:55:06 -0600",
"1997-11-21T09:55:06-06:00",
"Tue, 1 Jul 2003 10:52:37 +0200",
"2003-07-01T10:52:37+02:00",
),
(
"Tue, 1 Jul 2003 10:52:37 +0200",
"2003-07-01T10:52:37+02:00",
),
(
"Thu, 13 Feb 1969 23:32:54 -0330",
"1969-02-13T23:32:54-03:30",
"Fri, 21 Nov 1997 09:55:06 -0600",
"1997-11-21T09:55:06-06:00",
),
(
"Mon, 24 Nov 1997 14:22:01 -0800",
"1997-11-24T14:22:01-08:00",
),
(
"Thu,\n 13\n Feb\n 1969\n 23:32\n -0330 (Newfoundland Time)\n",
"1969-02-13T23:32:00-03:30",
"Tue, 30 Dec 1969 23:32:54 -0330",
"1969-12-30T23:32:54-03:30",
),
(
"Tue, 1 Jul 2003 10:52:37 +0200",
"2003-07-01T10:52:37+02:00",
"Thu, 13 Feb 1969 23:32:54 -0330",
"1969-02-13T23:32:54-03:30",
),
(
"Thu,\n 13\n Feb\n 1969\n 23:32\n -0330 (Newfoundland Time)\n",
"1969-02-13T23:32:00-03:30",
),
(
" 1 Jul 2003 (comment about date) 10:52:37 +0200",
Expand Down Expand Up @@ -321,12 +529,23 @@ mod tests {
("11 nov 2021 09:55:06 +0200", "2021-11-11T09:55:06+02:00"),
("12 dec 2021 09:55:06 +0200", "2021-12-12T09:55:06+02:00"),
("13 zzz 2021 09:55:06 +0200", "2021-00-13T09:55:06+02:00"),
(
concat!(
"by 2002:aa7:cd10:0:b0:45c:2c83:1208 with SMTP id ",
"b16-20020aa7cd10000000b0045c2c831208mr4220805edw.81.1665423075119;\n\t",
"Mon, 10 Oct 2022 10:31:15 -0700 (PDT)"
),
"2022-10-10T10:31:15-07:00",
),
];

for (input, expected_result) in inputs {
for (pos, (input, expected_result)) in inputs.iter().enumerate() {
match MessageStream::new(input.as_bytes()).parse_date() {
HeaderValue::DateTime(datetime) => {
assert_eq!(expected_result, datetime.to_rfc3339());
if pos < 6 {
assert_eq!(*input, datetime.to_rfc822());
}
assert_eq!(*expected_result, datetime.to_rfc3339());

if datetime.is_valid() {
if let LocalResult::Single(chrono_datetime)
Expand Down

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