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StorageBackend

hexz_core::store

Trait StorageBackend 

Source 
pub trait StorageBackend:
    Send
    + Sync
    + Debug {
    // Required methods
    fn read_exact(&self, offset: u64, len: usize) -> Result<Bytes>;
    fn len(&self) -> u64;

    // Provided method
    fn is_empty(&self) -> bool { ... }
}
Expand description

Abstract interface for all byte-addressable snapshot storage backends.

Architectural intent: Decouples the snapshot decoding logic from the physical storage medium so that files, HTTP endpoints, memory maps, or object stores can be swapped without changing higher layers.

Constraints: Implementations must be thread-safe (Send + Sync) and provide stable, random-access reads over an immutable byte region whose length does not change during the lifetime of the backend.

Side effects: Individual calls may perform disk or network I/O and may block the calling thread; callers are responsible for scheduling behavior.

Required Methods§

Source

fn read_exact(&self, offset: u64, len: usize) -> Result<Bytes>

Reads exactly len bytes starting at offset from the underlying store.

Architectural intent: Provides the minimal primitive needed by the format layer to fetch headers, indices, and compressed blocks.

Constraints: offset + len must not exceed self.len(); callers should treat short reads or I/O errors as fatal for the current operation.

Side effects: May perform synchronous I/O and allocate a new Bytes buffer per call; repeated small reads can be expensive.

Source

fn len(&self) -> u64

Returns the total logical size of the underlying snapshot in bytes.

Architectural intent: Allows upper layers to validate range requests and compute offsets into the header and index regions.

Constraints: The length is assumed to be immutable for the lifetime of the backend; changing it concurrently is undefined behavior.

Provided Methods§

Source

fn is_empty(&self) -> bool

Returns true if the underlying store has zero length.

Architectural intent: Convenience helper to avoid repeated len() comparisons in call sites that need to quickly reject empty inputs.

Constraints: Equivalent to self.len() == 0; implementations should not override the default semantics.

Implementors§