summaryrefslogtreecommitdiffstats
path: root/third_party/rust/toml/src/datetime.rs
blob: e980e6abc086b5ce024eb320ca2996510160b8f1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
use std::error;
use std::fmt;
use std::str::{self, FromStr};

use serde::{de, ser};

/// A parsed TOML datetime value
///
/// This structure is intended to represent the datetime primitive type that can
/// be encoded into TOML documents. This type is a parsed version that contains
/// all metadata internally.
///
/// Currently this type is intentionally conservative and only supports
/// `to_string` as an accessor. Over time though it's intended that it'll grow
/// more support!
///
/// Note that if you're using `Deserialize` to deserialize a TOML document, you
/// can use this as a placeholder for where you're expecting a datetime to be
/// specified.
///
/// Also note though that while this type implements `Serialize` and
/// `Deserialize` it's only recommended to use this type with the TOML format,
/// otherwise encoded in other formats it may look a little odd.
///
/// Depending on how the option values are used, this struct will correspond
/// with one of the following four datetimes from the [TOML v1.0.0 spec]:
///
/// | `date`    | `time`    | `offset`  | TOML type          |
/// | --------- | --------- | --------- | ------------------ |
/// | `Some(_)` | `Some(_)` | `Some(_)` | [Offset Date-Time] |
/// | `Some(_)` | `Some(_)` | `None`    | [Local Date-Time]  |
/// | `Some(_)` | `None`    | `None`    | [Local Date]       |
/// | `None`    | `Some(_)` | `None`    | [Local Time]       |
///
/// **1. Offset Date-Time**: If all the optional values are used, `Datetime`
/// corresponds to an [Offset Date-Time]. From the TOML v1.0.0 spec:
///
/// > To unambiguously represent a specific instant in time, you may use an
/// > RFC 3339 formatted date-time with offset.
/// >
/// > ```toml
/// > odt1 = 1979-05-27T07:32:00Z
/// > odt2 = 1979-05-27T00:32:00-07:00
/// > odt3 = 1979-05-27T00:32:00.999999-07:00
/// > ```
/// >
/// > For the sake of readability, you may replace the T delimiter between date
/// > and time with a space character (as permitted by RFC 3339 section 5.6).
/// >
/// > ```toml
/// > odt4 = 1979-05-27 07:32:00Z
/// > ```
///
/// **2. Local Date-Time**: If `date` and `time` are given but `offset` is
/// `None`, `Datetime` corresponds to a [Local Date-Time]. From the spec:
///
/// > If you omit the offset from an RFC 3339 formatted date-time, it will
/// > represent the given date-time without any relation to an offset or
/// > timezone. It cannot be converted to an instant in time without additional
/// > information. Conversion to an instant, if required, is implementation-
/// > specific.
/// >
/// > ```toml
/// > ldt1 = 1979-05-27T07:32:00
/// > ldt2 = 1979-05-27T00:32:00.999999
/// > ```
///
/// **3. Local Date**: If only `date` is given, `Datetime` corresponds to a
/// [Local Date]; see the docs for [`Date`].
///
/// **4. Local Time**: If only `time` is given, `Datetime` corresponds to a
/// [Local Time]; see the docs for [`Time`].
///
/// [TOML v1.0.0 spec]: https://toml.io/en/v1.0.0
/// [Offset Date-Time]: https://toml.io/en/v1.0.0#offset-date-time
/// [Local Date-Time]: https://toml.io/en/v1.0.0#local-date-time
/// [Local Date]: https://toml.io/en/v1.0.0#local-date
/// [Local Time]: https://toml.io/en/v1.0.0#local-time
#[derive(PartialEq, Eq, Clone)]
pub struct Datetime {
    /// Optional date.
    /// Required for: *Offset Date-Time*, *Local Date-Time*, *Local Date*.
    pub date: Option<Date>,

    /// Optional time.
    /// Required for: *Offset Date-Time*, *Local Date-Time*, *Local Time*.
    pub time: Option<Time>,

    /// Optional offset.
    /// Required for: *Offset Date-Time*.
    pub offset: Option<Offset>,
}

/// Error returned from parsing a `Datetime` in the `FromStr` implementation.
#[derive(Debug, Clone)]
pub struct DatetimeParseError {
    _private: (),
}

// Currently serde itself doesn't have a datetime type, so we map our `Datetime`
// to a special valid in the serde data model. Namely one with these special
// fields/struct names.
//
// In general the TOML encoder/decoder will catch this and not literally emit
// these strings but rather emit datetimes as they're intended.
pub const FIELD: &str = "$__toml_private_datetime";
pub const NAME: &str = "$__toml_private_Datetime";

/// A parsed TOML date value
///
/// May be part of a [`Datetime`]. Alone, `Date` corresponds to a [Local Date].
/// From the TOML v1.0.0 spec:
///
/// > If you include only the date portion of an RFC 3339 formatted date-time,
/// > it will represent that entire day without any relation to an offset or
/// > timezone.
/// >
/// > ```toml
/// > ld1 = 1979-05-27
/// > ```
///
/// [Local Date]: https://toml.io/en/v1.0.0#local-date
#[derive(PartialEq, Eq, Clone)]
pub struct Date {
    /// Year: four digits
    pub year: u16,
    /// Month: 1 to 12
    pub month: u8,
    /// Day: 1 to {28, 29, 30, 31} (based on month/year)
    pub day: u8,
}

/// A parsed TOML time value
///
/// May be part of a [`Datetime`]. Alone, `Time` corresponds to a [Local Time].
/// From the TOML v1.0.0 spec:
///
/// > If you include only the time portion of an RFC 3339 formatted date-time,
/// > it will represent that time of day without any relation to a specific
/// > day or any offset or timezone.
/// >
/// > ```toml
/// > lt1 = 07:32:00
/// > lt2 = 00:32:00.999999
/// > ```
/// >
/// > Millisecond precision is required. Further precision of fractional
/// > seconds is implementation-specific. If the value contains greater
/// > precision than the implementation can support, the additional precision
/// > must be truncated, not rounded.
///
/// [Local Time]: https://toml.io/en/v1.0.0#local-time
#[derive(PartialEq, Eq, Clone)]
pub struct Time {
    /// Hour: 0 to 23
    pub hour: u8,
    /// Minute: 0 to 59
    pub minute: u8,
    /// Second: 0 to {58, 59, 60} (based on leap second rules)
    pub second: u8,
    /// Nanosecond: 0 to 999_999_999
    pub nanosecond: u32,
}

/// A parsed TOML time offset
///
#[derive(PartialEq, Eq, Clone)]
pub enum Offset {
    /// > A suffix which, when applied to a time, denotes a UTC offset of 00:00;
    /// > often spoken "Zulu" from the ICAO phonetic alphabet representation of
    /// > the letter "Z". --- [RFC 3339 section 2]
    ///
    /// [RFC 3339 section 2]: https://datatracker.ietf.org/doc/html/rfc3339#section-2
    Z,

    /// Offset between local time and UTC
    Custom {
        /// Hours: -12 to +12
        hours: i8,

        /// Minutes: 0 to 59
        minutes: u8,
    },
}

impl fmt::Debug for Datetime {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        fmt::Display::fmt(self, f)
    }
}

impl fmt::Display for Datetime {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        if let Some(ref date) = self.date {
            write!(f, "{}", date)?;
        }
        if let Some(ref time) = self.time {
            if self.date.is_some() {
                write!(f, "T")?;
            }
            write!(f, "{}", time)?;
        }
        if let Some(ref offset) = self.offset {
            write!(f, "{}", offset)?;
        }
        Ok(())
    }
}

impl fmt::Display for Date {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{:04}-{:02}-{:02}", self.year, self.month, self.day)
    }
}

impl fmt::Display for Time {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{:02}:{:02}:{:02}", self.hour, self.minute, self.second)?;
        if self.nanosecond != 0 {
            let s = format!("{:09}", self.nanosecond);
            write!(f, ".{}", s.trim_end_matches('0'))?;
        }
        Ok(())
    }
}

impl fmt::Display for Offset {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match *self {
            Offset::Z => write!(f, "Z"),
            Offset::Custom { hours, minutes } => write!(f, "{:+03}:{:02}", hours, minutes),
        }
    }
}

impl FromStr for Datetime {
    type Err = DatetimeParseError;

    fn from_str(date: &str) -> Result<Datetime, DatetimeParseError> {
        // Accepted formats:
        //
        // 0000-00-00T00:00:00.00Z
        // 0000-00-00T00:00:00.00
        // 0000-00-00
        // 00:00:00.00
        if date.len() < 3 {
            return Err(DatetimeParseError { _private: () });
        }
        let mut offset_allowed = true;
        let mut chars = date.chars();

        // First up, parse the full date if we can
        let full_date = if chars.clone().nth(2) == Some(':') {
            offset_allowed = false;
            None
        } else {
            let y1 = u16::from(digit(&mut chars)?);
            let y2 = u16::from(digit(&mut chars)?);
            let y3 = u16::from(digit(&mut chars)?);
            let y4 = u16::from(digit(&mut chars)?);

            match chars.next() {
                Some('-') => {}
                _ => return Err(DatetimeParseError { _private: () }),
            }

            let m1 = digit(&mut chars)?;
            let m2 = digit(&mut chars)?;

            match chars.next() {
                Some('-') => {}
                _ => return Err(DatetimeParseError { _private: () }),
            }

            let d1 = digit(&mut chars)?;
            let d2 = digit(&mut chars)?;

            let date = Date {
                year: y1 * 1000 + y2 * 100 + y3 * 10 + y4,
                month: m1 * 10 + m2,
                day: d1 * 10 + d2,
            };

            if date.month < 1 || date.month > 12 {
                return Err(DatetimeParseError { _private: () });
            }
            if date.day < 1 || date.day > 31 {
                return Err(DatetimeParseError { _private: () });
            }

            Some(date)
        };

        // Next parse the "partial-time" if available
        let next = chars.clone().next();
        let partial_time = if full_date.is_some()
            && (next == Some('T') || next == Some('t') || next == Some(' '))
        {
            chars.next();
            true
        } else {
            full_date.is_none()
        };

        let time = if partial_time {
            let h1 = digit(&mut chars)?;
            let h2 = digit(&mut chars)?;
            match chars.next() {
                Some(':') => {}
                _ => return Err(DatetimeParseError { _private: () }),
            }
            let m1 = digit(&mut chars)?;
            let m2 = digit(&mut chars)?;
            match chars.next() {
                Some(':') => {}
                _ => return Err(DatetimeParseError { _private: () }),
            }
            let s1 = digit(&mut chars)?;
            let s2 = digit(&mut chars)?;

            let mut nanosecond = 0;
            if chars.clone().next() == Some('.') {
                chars.next();
                let whole = chars.as_str();

                let mut end = whole.len();
                for (i, byte) in whole.bytes().enumerate() {
                    match byte {
                        b'0'..=b'9' => {
                            if i < 9 {
                                let p = 10_u32.pow(8 - i as u32);
                                nanosecond += p * u32::from(byte - b'0');
                            }
                        }
                        _ => {
                            end = i;
                            break;
                        }
                    }
                }
                if end == 0 {
                    return Err(DatetimeParseError { _private: () });
                }
                chars = whole[end..].chars();
            }

            let time = Time {
                hour: h1 * 10 + h2,
                minute: m1 * 10 + m2,
                second: s1 * 10 + s2,
                nanosecond,
            };

            if time.hour > 24 {
                return Err(DatetimeParseError { _private: () });
            }
            if time.minute > 59 {
                return Err(DatetimeParseError { _private: () });
            }
            if time.second > 59 {
                return Err(DatetimeParseError { _private: () });
            }
            if time.nanosecond > 999_999_999 {
                return Err(DatetimeParseError { _private: () });
            }

            Some(time)
        } else {
            offset_allowed = false;
            None
        };

        // And finally, parse the offset
        let offset = if offset_allowed {
            let next = chars.clone().next();
            if next == Some('Z') || next == Some('z') {
                chars.next();
                Some(Offset::Z)
            } else if next.is_none() {
                None
            } else {
                let sign = match next {
                    Some('+') => 1,
                    Some('-') => -1,
                    _ => return Err(DatetimeParseError { _private: () }),
                };
                chars.next();
                let h1 = digit(&mut chars)? as i8;
                let h2 = digit(&mut chars)? as i8;
                match chars.next() {
                    Some(':') => {}
                    _ => return Err(DatetimeParseError { _private: () }),
                }
                let m1 = digit(&mut chars)?;
                let m2 = digit(&mut chars)?;

                Some(Offset::Custom {
                    hours: sign * (h1 * 10 + h2),
                    minutes: m1 * 10 + m2,
                })
            }
        } else {
            None
        };

        // Return an error if we didn't hit eof, otherwise return our parsed
        // date
        if chars.next().is_some() {
            return Err(DatetimeParseError { _private: () });
        }

        Ok(Datetime {
            date: full_date,
            time,
            offset,
        })
    }
}

fn digit(chars: &mut str::Chars<'_>) -> Result<u8, DatetimeParseError> {
    match chars.next() {
        Some(c) if ('0'..='9').contains(&c) => Ok(c as u8 - b'0'),
        _ => Err(DatetimeParseError { _private: () }),
    }
}

impl ser::Serialize for Datetime {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: ser::Serializer,
    {
        use serde::ser::SerializeStruct;

        let mut s = serializer.serialize_struct(NAME, 1)?;
        s.serialize_field(FIELD, &self.to_string())?;
        s.end()
    }
}

impl<'de> de::Deserialize<'de> for Datetime {
    fn deserialize<D>(deserializer: D) -> Result<Datetime, D::Error>
    where
        D: de::Deserializer<'de>,
    {
        struct DatetimeVisitor;

        impl<'de> de::Visitor<'de> for DatetimeVisitor {
            type Value = Datetime;

            fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
                formatter.write_str("a TOML datetime")
            }

            fn visit_map<V>(self, mut visitor: V) -> Result<Datetime, V::Error>
            where
                V: de::MapAccess<'de>,
            {
                let value = visitor.next_key::<DatetimeKey>()?;
                if value.is_none() {
                    return Err(de::Error::custom("datetime key not found"));
                }
                let v: DatetimeFromString = visitor.next_value()?;
                Ok(v.value)
            }
        }

        static FIELDS: [&str; 1] = [FIELD];
        deserializer.deserialize_struct(NAME, &FIELDS, DatetimeVisitor)
    }
}

struct DatetimeKey;

impl<'de> de::Deserialize<'de> for DatetimeKey {
    fn deserialize<D>(deserializer: D) -> Result<DatetimeKey, D::Error>
    where
        D: de::Deserializer<'de>,
    {
        struct FieldVisitor;

        impl<'de> de::Visitor<'de> for FieldVisitor {
            type Value = ();

            fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
                formatter.write_str("a valid datetime field")
            }

            fn visit_str<E>(self, s: &str) -> Result<(), E>
            where
                E: de::Error,
            {
                if s == FIELD {
                    Ok(())
                } else {
                    Err(de::Error::custom("expected field with custom name"))
                }
            }
        }

        deserializer.deserialize_identifier(FieldVisitor)?;
        Ok(DatetimeKey)
    }
}

pub struct DatetimeFromString {
    pub value: Datetime,
}

impl<'de> de::Deserialize<'de> for DatetimeFromString {
    fn deserialize<D>(deserializer: D) -> Result<DatetimeFromString, D::Error>
    where
        D: de::Deserializer<'de>,
    {
        struct Visitor;

        impl<'de> de::Visitor<'de> for Visitor {
            type Value = DatetimeFromString;

            fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
                formatter.write_str("string containing a datetime")
            }

            fn visit_str<E>(self, s: &str) -> Result<DatetimeFromString, E>
            where
                E: de::Error,
            {
                match s.parse() {
                    Ok(date) => Ok(DatetimeFromString { value: date }),
                    Err(e) => Err(de::Error::custom(e)),
                }
            }
        }

        deserializer.deserialize_str(Visitor)
    }
}

impl fmt::Display for DatetimeParseError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        "failed to parse datetime".fmt(f)
    }
}

impl error::Error for DatetimeParseError {}