Trait NativeLogStorage 

pub trait NativeLogStorage: Send + Sync {
    // Required methods
    fn read_chunk(
        &self,
        name: &str,
        version: u64,
        chunk: u64,
    ) -> Result<Option<Vec<u8>>, LogError>;
    fn cas_chunk(
        &self,
        name: &str,
        version: u64,
        chunk: u64,
        expected: Option<&[u8]>,
        new: &[u8],
    ) -> Result<(), LogError>;
    fn list_chunks(&self, name: &str) -> Result<Vec<(u64, u64)>, LogError>;
    fn delete_all(&self, name: &str) -> Result<(), LogError>;
}

Synchronous byte store for chunked transaction-log objects.

Implementations usually adapt the same native storage system used for blobs and roots. A database’s log for one lease version is a sequence of chunk objects (name, version, chunk), each a run of framed records; a writer appends to the highest chunk and rolls to the next once it fills, so no single object grows without bound. Chunk 0 of a version is the whole-log object earlier releases wrote, so existing logs read back as their chunk 0.

Required Methods

fn read_chunk( &self, name: &str, version: u64, chunk: u64, ) -> Result<Option<Vec<u8>>, LogError>

Reads the encoded bytes for one (name, version, chunk) object.

Errors

Returns an error when the native backend cannot read the chunk object or when backend data cannot be represented as log bytes.

fn cas_chunk( &self, name: &str, version: u64, chunk: u64, expected: Option<&[u8]>, new: &[u8], ) -> Result<(), LogError>

Compare-and-swap writes encoded bytes for one (name, version, chunk) object.

Errors

Returns an error when the compare-and-swap fails, the native backend cannot publish the chunk object, or the backend reports invalid data.

fn list_chunks(&self, name: &str) -> Result<Vec<(u64, u64)>, LogError>

Lists every (version, chunk) pair present for name.

Errors

Returns an error when the native backend cannot enumerate log objects or returns an invalid identifier.

fn delete_all(&self, name: &str) -> Result<(), LogError>

Deletes every chunk of every version for name.

Errors

Returns an error when the native backend cannot remove a chunk object.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors