what2watch/src/db_id.rs

214 lines
5.7 KiB
Rust

use std::{
borrow::Cow,
fmt::{Debug, Display},
};
use chrono::Utc;
use serde::{de::Visitor, Deserialize, Serialize};
use sqlx::{
encode::IsNull,
sqlite::{SqliteArgumentValue, SqliteValueRef},
Decode, Encode, Sqlite,
};
use ulid::Ulid;
#[derive(Default, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct DbId(pub Ulid);
impl DbId {
pub fn bytes(&self) -> [u8; 16] {
self.to_be_bytes()
}
pub fn to_be_bytes(self) -> [u8; 16] {
self.0 .0.to_be_bytes()
}
pub fn is_nil(&self) -> bool {
self.0.is_nil()
}
pub fn new() -> Self {
Self(Ulid::new())
}
pub fn from_string(s: &str) -> Result<Self, ulid::DecodeError> {
let id = Ulid::from_string(s)?;
Ok(id.into())
}
pub fn as_string(&self) -> String {
self.0.to_string()
}
pub fn created_at(&self) -> chrono::DateTime<Utc> {
self.0.datetime().into()
}
}
//-************************************************************************
// standard trait impls
//-************************************************************************
impl Display for DbId {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "{}", self.0.to_string())
}
}
impl Debug for DbId {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_tuple("DbId").field(&self.as_string()).finish()
}
}
impl From<Ulid> for DbId {
fn from(value: Ulid) -> Self {
DbId(value)
}
}
impl From<u128> for DbId {
fn from(value: u128) -> Self {
DbId(value.into())
}
}
//-************************************************************************
// sqlx traits for going in and out of the db
//-************************************************************************
impl sqlx::Type<sqlx::Sqlite> for DbId {
fn type_info() -> <sqlx::Sqlite as sqlx::Database>::TypeInfo {
<&[u8] as sqlx::Type<sqlx::Sqlite>>::type_info()
}
}
impl<'q> Encode<'q, Sqlite> for DbId {
fn encode_by_ref(&self, args: &mut Vec<SqliteArgumentValue<'q>>) -> IsNull {
args.push(SqliteArgumentValue::Blob(Cow::Owned(self.bytes().to_vec())));
IsNull::No
}
}
impl Decode<'_, Sqlite> for DbId {
fn decode(value: SqliteValueRef<'_>) -> Result<Self, sqlx::error::BoxDynError> {
let bytes = <&[u8] as Decode<Sqlite>>::decode(value)?;
let bytes: [u8; 16] = bytes.try_into().unwrap_or_default();
Ok(u128::from_be_bytes(bytes).into())
}
}
//-************************************************************************
// serde traits
//-************************************************************************
impl Serialize for DbId {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
serializer.serialize_bytes(&self.bytes())
}
}
struct DbIdVisitor;
impl<'de> Visitor<'de> for DbIdVisitor {
type Value = DbId;
fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
formatter.write_str("16 bytes")
}
fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
match std::convert::TryInto::<[u8; 16]>::try_into(v) {
Ok(v) => Ok(u128::from_be_bytes(v).into()),
Err(_) => Err(serde::de::Error::invalid_length(v.len(), &self)),
}
}
fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
DbId::from_string(&v)
.map_err(|_| serde::de::Error::invalid_value(serde::de::Unexpected::Str(&v), &self))
}
fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
DbId::from_string(v)
.map_err(|_| serde::de::Error::invalid_value(serde::de::Unexpected::Str(v), &self))
}
fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
let len = v.len();
match std::convert::TryInto::<[u8; 16]>::try_into(v) {
Ok(v) => Ok(u128::from_be_bytes(v).into()),
Err(_) => Err(serde::de::Error::invalid_length(len, &self)),
}
}
fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
where
A: serde::de::SeqAccess<'de>,
{
let mut raw_bytes_from_db = [0u8; 16];
let size = seq.size_hint().unwrap_or(0);
let mut count = 0;
while let Some(val) = seq.next_element()? {
if count > 15 {
break;
}
raw_bytes_from_db[count] = val;
count += 1;
}
if count != 16 || size > 16 {
let sz = if count < 16 { count } else { size };
Err(serde::de::Error::invalid_length(sz, &self))
} else {
Ok(u128::from_be_bytes(raw_bytes_from_db).into())
}
}
}
impl<'de> Deserialize<'de> for DbId {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: serde::Deserializer<'de>,
{
deserializer.deserialize_bytes(DbIdVisitor)
}
}
//-************************************************************************
// serialization tests
//-************************************************************************
#[cfg(test)]
mod test {
use serde_test::{assert_tokens, Token};
use super::*;
#[test]
fn test_ser_de() {
let bytes: [u8; 16] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15];
let id: DbId = u128::from_be_bytes(bytes).into();
assert_tokens(
&id,
&[Token::Bytes(&[
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
])],
);
}
}