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ps_datachunk/
lib.rs

1#![allow(clippy::missing_errors_doc)]
2#![allow(clippy::module_name_repetitions)]
3pub mod aligned;
4pub mod borrowed;
5pub mod cow;
6pub mod encrypted;
7pub mod error;
8pub mod mbuf;
9pub mod owned;
10pub mod typed;
11pub mod utils;
12pub use aligned::AlignedDataChunk;
13pub use borrowed::BorrowedDataChunk;
14pub use bytes::Bytes;
15pub use cow::CowDataChunk;
16pub use encrypted::EncryptedDataChunk;
17pub use error::DataChunkError;
18pub use error::Result;
19pub use mbuf::MbufDataChunk;
20pub use owned::OwnedDataChunk;
21pub use ps_hash::Hash;
22pub use ps_mbuf::Mbuf;
23pub use typed::ToDataChunk;
24pub use typed::ToTypedDataChunk;
25pub use typed::TypedDataChunk;
26
27use std::sync::Arc;
28
29/// Represents any representation of a chunk of data.
30///
31/// # Invariants
32///
33/// Implementers must treat the bytes and hash exposed through `&self` as immutable and stable.
34/// In practice this means:
35/// - Repeated calls to [`Self::data_ref`] must point to the same logical bytes while `self` is borrowed.
36/// - Repeated calls to [`Self::hash_ref`] must return the hash for those same bytes.
37/// - Neither value may change through interior mutability while `self` is borrowed.
38///
39/// `TypedDataChunk` relies on this contract for its unchecked deref fast path.
40pub trait DataChunk
41where
42    Self: Sized,
43{
44    /// Returns a stable view of the underlying bytes.
45    fn data_ref(&self) -> &[u8];
46    /// Returns a stable view of the hash corresponding to [`Self::data_ref`].
47    fn hash_ref(&self) -> &Hash;
48
49    fn hash(&self) -> Hash {
50        *self.hash_ref()
51    }
52
53    fn encrypt(&self) -> Result<EncryptedDataChunk> {
54        Ok(ps_cypher::encrypt(self.data_ref())?.into())
55    }
56
57    fn decrypt(&self, key: &Hash) -> Result<OwnedDataChunk> {
58        utils::decrypt(self.data_ref(), key)
59    }
60
61    fn borrow(&self) -> BorrowedDataChunk<'_> {
62        BorrowedDataChunk::from_parts_unchecked(self.data_ref(), self.hash())
63    }
64
65    /// Transforms this [`DataChunk`] into [`Bytes`].
66    fn into_bytes(self) -> Bytes {
67        Bytes::from_owner(Arc::from(self.data_ref()))
68    }
69
70    /// Copies this [`DataChunk`] into a new [`OwnedDataChunk`].
71    fn into_owned(self) -> OwnedDataChunk {
72        OwnedDataChunk::from_data_and_hash_unchecked(Arc::from(self.data_ref()), self.hash())
73    }
74
75    fn try_as<T: rkyv::Archive>(self) -> Result<TypedDataChunk<Self, T>>
76    where
77        T::Archived:
78            for<'a> rkyv::bytecheck::CheckBytes<rkyv::api::high::HighValidator<'a, rancor::Error>>,
79    {
80        TypedDataChunk::<Self, T>::from_data_chunk(self)
81    }
82}
83
84#[cfg(test)]
85mod tests {
86    use super::*;
87
88    // Keep crate-root tests for cross-module flow behavior.
89    #[test]
90    fn test_encryption_decryption() -> Result<()> {
91        let original_data = "Neboť tak Bůh miluje svět, že dal [svého] jediného Syna, aby žádný, kdo v něho věří, nezahynul, ale měl život věčný. Vždyť Bůh neposlal [svého] Syna na svět, aby svět odsoudil, ale aby byl svět skrze něj zachráněn.".as_bytes().to_owned();
92
93        let data_chunk = BorrowedDataChunk::from_data(&original_data)?;
94
95        let encrypted_chunk = data_chunk.encrypt()?;
96        let decrypted_chunk = encrypted_chunk.decrypt()?;
97
98        assert_eq!(decrypted_chunk.data_ref(), original_data);
99
100        Ok(())
101    }
102}