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crates/matrix-sdk-crypto/src/utilities.rsRust85 lines3.1 KB
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// Copyright 2020 The Matrix.org Foundation C.I.C.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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//     http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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use std::num::NonZeroU8;
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use ruma::MilliSecondsSinceUnixEpoch;
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use time::{
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    OffsetDateTime,
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    format_description::well_known::{Iso8601, iso8601},
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};
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#[cfg(test)]
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pub(crate) fn json_convert<T, U>(value: &T) -> serde_json::Result<U>
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where
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    T: serde::Serialize,
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    U: serde::de::DeserializeOwned,
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{
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    let json = serde_json::to_string(value)?;
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    serde_json::from_str(&json)
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}
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const ISO8601_WITH_MILLIS: iso8601::EncodedConfig = iso8601::Config::DEFAULT
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    .set_time_precision(iso8601::TimePrecision::Second { decimal_digits: NonZeroU8::new(3) })
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    .encode();
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/// Format the given timestamp into a human-readable timestamp.
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///
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/// # Returns
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///
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/// Provided the timestamp fits within an `OffsetDateTime` (ie, it is on or
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/// before year 9999), a string that looks like `1970-01-01T00:00:00.000Z`.
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/// Otherwise, `None`.
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pub fn timestamp_to_iso8601(ts: MilliSecondsSinceUnixEpoch) -> Option<String> {
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    let nanos_since_epoch = i128::from(ts.get()) * 1_000_000;
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    // OffsetDateTime has a max year of 9999, whereas MilliSecondsSinceUnixEpoch has
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    // a max year of 285427, so `from_unix_timestamp_nanos` can overflow for very
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    // large timestamps. (The Y10K problem!)
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    let dt = OffsetDateTime::from_unix_timestamp_nanos(nanos_since_epoch).ok()?;
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    // SAFETY: `format` can fail if:
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    //   * The input lacks information on a component we have asked it to format
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    //     (eg, it is given a `Time` and we ask it for a date), or
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    //   * The input contains an invalid component (eg 30th February), or
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    //   * An `io::Error` is raised internally.
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    //
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    // The first two cannot occur because we know we are giving it a valid
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    // OffsetDateTime that has all the components we are asking it to print.
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    //
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    // The third should not occur because we are formatting a short string to an
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    // in-memory buffer.
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    Some(dt.format(&Iso8601::<ISO8601_WITH_MILLIS>).unwrap())
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}
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#[cfg(test)]
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pub(crate) mod tests {
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    use ruma::{MilliSecondsSinceUnixEpoch, UInt};
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    use super::timestamp_to_iso8601;
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    #[test]
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    fn test_timestamp_to_iso8601() {
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        assert_eq!(
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            timestamp_to_iso8601(MilliSecondsSinceUnixEpoch(UInt::new_saturating(0))),
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            Some("1970-01-01T00:00:00.000Z".to_owned())
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        );
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        assert_eq!(
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            timestamp_to_iso8601(MilliSecondsSinceUnixEpoch(UInt::new_saturating(1709657033012))),
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            Some("2024-03-05T16:43:53.012Z".to_owned())
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        );
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        assert_eq!(timestamp_to_iso8601(MilliSecondsSinceUnixEpoch(UInt::MAX)), None);
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    }
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}