use std::{
borrow::Cow,
cmp::Ordering,
fmt::{Display, Write},
hash::Hash,
ops::Deref,
str::FromStr,
};
use actionable::Identifier;
use serde::{de::Visitor, Deserialize, Serialize};
use crate::key::{Key, KeyEncoding};
#[derive(Clone, Copy)]
pub struct DocumentId {
length: u8,
bytes: [u8; Self::MAX_LENGTH],
}
impl Deref for DocumentId {
type Target = [u8];
fn deref(&self) -> &[u8] {
&self.bytes[..usize::from(self.length)]
}
}
impl Ord for DocumentId {
fn cmp(&self, other: &Self) -> Ordering {
(**self).cmp(&**other)
}
}
impl PartialOrd for DocumentId {
fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
Some(self.cmp(other))
}
}
impl Eq for DocumentId {}
impl PartialEq for DocumentId {
fn eq(&self, other: &Self) -> bool {
**self == **other
}
}
impl std::fmt::Debug for DocumentId {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.write_str("DocumentId(")?;
arc_bytes::print_bytes(self, f)?;
f.write_char(')')
}
}
impl Display for DocumentId {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
if let Ok(string) = std::str::from_utf8(self.as_ref()) {
if string.bytes().all(|b| (32..=127).contains(&b)) {
return f.write_str(string);
}
}
if let Some((first_nonzero_byte, _)) = self
.as_ref()
.iter()
.copied()
.enumerate()
.find(|(_index, b)| *b != 0)
{
if first_nonzero_byte > 0 {
write!(f, "{:x}$", first_nonzero_byte)?;
} else {
f.write_char('$')?;
}
for (index, byte) in self[first_nonzero_byte..].iter().enumerate() {
if index > 0 {
write!(f, "{:02x}", byte)?;
} else {
write!(f, "{:x}", byte)?;
}
}
Ok(())
} else {
write!(f, "{:x}$", self.len())
}
}
}
impl Hash for DocumentId {
fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
(**self).hash(state);
}
}
impl<'a> From<DocumentId> for Identifier<'a> {
fn from(id: DocumentId) -> Self {
Identifier::from(id.to_vec())
}
}
impl<'a> From<&'a DocumentId> for Identifier<'a> {
fn from(id: &'a DocumentId) -> Self {
Identifier::from(&**id)
}
}
#[test]
fn document_id_identifier_tests() {
assert_eq!(
Identifier::from(DocumentId::new(String::from("hello")).unwrap()),
Identifier::from("hello")
);
assert_eq!(
Identifier::from(DocumentId::from_u64(1)),
Identifier::from(1)
);
}
#[derive(thiserror::Error, Debug)]
#[error("invalid hexadecimal bytes")]
pub struct InvalidHexadecimal;
const fn decode_hex_nibble(byte: u8) -> Result<u8, InvalidHexadecimal> {
match byte {
b'0'..=b'9' => Ok(byte - b'0'),
b'A'..=b'F' => Ok(byte - b'A' + 10),
b'a'..=b'f' => Ok(byte - b'a' + 10),
_ => Err(InvalidHexadecimal),
}
}
impl FromStr for DocumentId {
type Err = crate::Error;
fn from_str(s: &str) -> Result<Self, Self::Err> {
if s.is_empty() {
return Ok(Self::default());
}
let mut id = Self::default();
let bytes = s.as_bytes();
if let Some((pound_offset, _)) = s.bytes().enumerate().find(|(_index, b)| *b == b'$') {
if pound_offset > 2 {
return Err(crate::Error::DocumentIdTooLong);
}
let preceding_zeroes = if pound_offset > 0 {
let mut length = [0_u8];
decode_big_endian_hex(&bytes[0..pound_offset], &mut length)?;
usize::from(length[0])
} else {
0
};
let decoded_length = decode_big_endian_hex(&bytes[pound_offset + 1..], &mut id.bytes)?;
if preceding_zeroes > 0 {
let total_length = preceding_zeroes + usize::from(decoded_length);
if total_length > Self::MAX_LENGTH {
return Err(crate::Error::DocumentIdTooLong);
}
id.bytes
.copy_within(0..usize::from(decoded_length), preceding_zeroes);
id.bytes[0..preceding_zeroes].fill(0);
id.length = u8::try_from(total_length).unwrap();
} else {
id.length = decoded_length;
}
} else if bytes.len() > Self::MAX_LENGTH {
return Err(crate::Error::DocumentIdTooLong);
} else {
id.length = u8::try_from(bytes.len()).unwrap();
id.bytes[0..bytes.len()].copy_from_slice(bytes);
}
Ok(id)
}
}
fn decode_big_endian_hex(bytes: &[u8], output: &mut [u8]) -> Result<u8, crate::Error> {
let mut length = 0;
let mut chunks = if bytes.len() & 1 == 0 {
bytes.chunks_exact(2)
} else {
output[0] = decode_hex_nibble(bytes[0])?;
length = 1;
bytes[1..].chunks_exact(2)
};
for chunk in &mut chunks {
let write_at = length;
length += 1;
if length > output.len() {
return Err(crate::Error::DocumentIdTooLong);
}
let upper = decode_hex_nibble(chunk[0])?;
let lower = decode_hex_nibble(chunk[1])?;
output[write_at] = upper << 4 | lower;
}
if !chunks.remainder().is_empty() {
return Err(crate::Error::from(InvalidHexadecimal));
}
Ok(u8::try_from(length).unwrap())
}
#[test]
fn document_id_parsing() {
fn test_id(bytes: &[u8], display: &str) {
let id = DocumentId::try_from(bytes).unwrap();
let as_string = id.to_string();
assert_eq!(as_string, display);
let parsed = DocumentId::from_str(&as_string).unwrap();
assert_eq!(&*parsed, bytes);
}
test_id(b"hello", "hello");
test_id(b"\x00\x0a\xaf\xfa", "1$aaffa");
test_id(&1_u128.to_be_bytes(), "f$1");
test_id(&17_u8.to_be_bytes(), "$11");
test_id(&[0_u8; 63], "3f$");
test_id(
&[0_u8; DocumentId::MAX_LENGTH],
&format!("{:x}$", DocumentId::MAX_LENGTH),
);
}
impl Default for DocumentId {
fn default() -> Self {
Self {
length: 0,
bytes: [0; Self::MAX_LENGTH],
}
}
}
impl<'a> TryFrom<&'a [u8]> for DocumentId {
type Error = crate::Error;
fn try_from(bytes: &'a [u8]) -> Result<Self, Self::Error> {
if bytes.len() <= Self::MAX_LENGTH {
let mut new_id = Self {
length: u8::try_from(bytes.len()).unwrap(),
..Self::default()
};
new_id.bytes[..bytes.len()].copy_from_slice(bytes);
Ok(new_id)
} else {
Err(crate::Error::DocumentIdTooLong)
}
}
}
impl<const N: usize> TryFrom<[u8; N]> for DocumentId {
type Error = crate::Error;
fn try_from(bytes: [u8; N]) -> Result<Self, Self::Error> {
Self::try_from(&bytes[..])
}
}
impl DocumentId {
pub const MAX_LENGTH: usize = 63;
pub fn new<PrimaryKey: for<'k> Key<'k>, PrimaryKeyRef: for<'k> KeyEncoding<'k, PrimaryKey>>(
value: PrimaryKeyRef,
) -> Result<Self, crate::Error> {
let bytes = value
.as_ord_bytes()
.map_err(|err| crate::Error::Serialization(err.to_string()))?;
Self::try_from(&bytes[..])
}
#[must_use]
#[allow(clippy::missing_panics_doc)] pub fn from_u64(id: u64) -> Self {
Self::try_from(&id.to_be_bytes()[..]).unwrap()
}
#[must_use]
#[allow(clippy::missing_panics_doc)] pub fn from_u32(id: u32) -> Self {
Self::try_from(&id.to_be_bytes()[..]).unwrap()
}
pub fn deserialize<'a, PrimaryKey: Key<'a>>(&'a self) -> Result<PrimaryKey, crate::Error> {
PrimaryKey::from_ord_bytes(self.as_ref())
.map_err(|err| crate::Error::Serialization(err.to_string()))
}
}
impl Serialize for DocumentId {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
serializer.serialize_bytes(self.as_ref())
}
}
impl<'de> Deserialize<'de> for DocumentId {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: serde::Deserializer<'de>,
{
deserializer.deserialize_byte_buf(DocumentIdVisitor)
}
}
struct DocumentIdVisitor;
impl<'de> Visitor<'de> for DocumentIdVisitor {
type Value = DocumentId;
fn expecting(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
formatter.write_str("a document id (bytes)")
}
fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
if v.len() <= DocumentId::MAX_LENGTH {
let mut document_id = DocumentId {
length: u8::try_from(v.len()).unwrap(),
..DocumentId::default()
};
document_id.bytes[..v.len()].copy_from_slice(v);
Ok(document_id)
} else {
Err(E::invalid_length(v.len(), &"< 64 bytes"))
}
}
}
impl<'k> Key<'k> for DocumentId {
fn from_ord_bytes(bytes: &'k [u8]) -> Result<Self, Self::Error> {
Self::try_from(bytes)
}
}
impl<'k, PrimaryKey> KeyEncoding<'k, PrimaryKey> for DocumentId
where
PrimaryKey: for<'a> Key<'a>,
{
type Error = crate::Error;
const LENGTH: Option<usize> = None;
fn as_ord_bytes(&'k self) -> Result<Cow<'k, [u8]>, Self::Error> {
Ok(Cow::Borrowed(self))
}
}