continuwuity/src/core/utils/mod.rs
Jason Volk 90d9a997a5 split / cleanup core utils.
Signed-off-by: Jason Volk <jason@zemos.net>
2024-06-02 20:17:45 +00:00

126 lines
3.3 KiB
Rust

pub mod content_disposition;
pub mod debug;
pub mod defer;
pub mod html;
pub mod json;
pub mod sys;
use std::{
cmp,
cmp::Ordering,
time::{SystemTime, UNIX_EPOCH},
};
pub use debug::slice_truncated as debug_slice_truncated;
pub use html::Escape as HtmlEscape;
pub use json::{deserialize_from_str, to_canonical_object};
use rand::prelude::*;
use ring::digest;
use ruma::OwnedUserId;
pub use sys::available_parallelism;
use crate::{Error, Result};
pub fn clamp<T: Ord>(val: T, min: T, max: T) -> T { cmp::min(cmp::max(val, min), max) }
#[must_use]
#[allow(clippy::as_conversions)]
pub fn millis_since_unix_epoch() -> u64 {
SystemTime::now()
.duration_since(UNIX_EPOCH)
.expect("time is valid")
.as_millis() as u64
}
pub fn increment(old: Option<&[u8]>) -> Vec<u8> {
let number = match old.map(TryInto::try_into) {
Some(Ok(bytes)) => {
let number = u64::from_be_bytes(bytes);
number + 1
},
_ => 1, // Start at one. since 0 should return the first event in the db
};
number.to_be_bytes().to_vec()
}
#[must_use]
pub fn generate_keypair() -> Vec<u8> {
let mut value = random_string(8).as_bytes().to_vec();
value.push(0xFF);
value.extend_from_slice(
&ruma::signatures::Ed25519KeyPair::generate().expect("Ed25519KeyPair generation always works (?)"),
);
value
}
/// Parses the bytes into an u64.
pub fn u64_from_bytes(bytes: &[u8]) -> Result<u64, std::array::TryFromSliceError> {
let array: [u8; 8] = bytes.try_into()?;
Ok(u64::from_be_bytes(array))
}
/// Parses the bytes into a string.
pub fn string_from_bytes(bytes: &[u8]) -> Result<String, std::string::FromUtf8Error> {
String::from_utf8(bytes.to_vec())
}
/// Parses a `OwnedUserId` from bytes.
pub fn user_id_from_bytes(bytes: &[u8]) -> Result<OwnedUserId> {
OwnedUserId::try_from(
string_from_bytes(bytes).map_err(|_| Error::bad_database("Failed to parse string from bytes"))?,
)
.map_err(|_| Error::bad_database("Failed to parse user id from bytes"))
}
pub fn random_string(length: usize) -> String {
thread_rng()
.sample_iter(&rand::distributions::Alphanumeric)
.take(length)
.map(char::from)
.collect()
}
#[tracing::instrument(skip(keys))]
pub fn calculate_hash(keys: &[&[u8]]) -> Vec<u8> {
// We only hash the pdu's event ids, not the whole pdu
let bytes = keys.join(&0xFF);
let hash = digest::digest(&digest::SHA256, &bytes);
hash.as_ref().to_owned()
}
#[allow(clippy::impl_trait_in_params)]
pub fn common_elements(
mut iterators: impl Iterator<Item = impl Iterator<Item = Vec<u8>>>, check_order: impl Fn(&[u8], &[u8]) -> Ordering,
) -> Option<impl Iterator<Item = Vec<u8>>> {
let first_iterator = iterators.next()?;
let mut other_iterators = iterators.map(Iterator::peekable).collect::<Vec<_>>();
Some(first_iterator.filter(move |target| {
other_iterators.iter_mut().all(|it| {
while let Some(element) = it.peek() {
match check_order(element, target) {
Ordering::Greater => return false, // We went too far
Ordering::Equal => return true, // Element is in both iters
Ordering::Less => {
// Keep searching
it.next();
},
}
}
false
})
}))
}
/// Boilerplate for wraps which are typed to never error.
///
/// * <https://doc.rust-lang.org/std/convert/enum.Infallible.html>
#[must_use]
#[inline(always)]
pub fn unwrap_infallible<T>(result: Result<T, std::convert::Infallible>) -> T {
match result {
Ok(val) => val,
Err(err) => match err {},
}
}