Struct ChunkNode 

pub struct ChunkNode<'a> { /* private fields */ }

A lightweight cursor pointing to a specific node in the dependency graph.

This struct contains the logic to read, decompress, and navigate from this node. It is a “view” into the ParcodeReader and holds a lifetime reference to it.

Implementations

impl<'a> ChunkNode<'a>

pub fn read_raw(&self) -> Result<Cow<'a, [u8]>>

Reads and decompresses the local payload of this chunk.

This returns Cow, so if no compression was used, it returns a direct reference to the mmap (Zero-Copy). If compressed, it allocates the decompressed buffer.

pub fn children(&self) -> Result<Vec<Self>>

Returns a list of all direct child nodes.

This allows manual traversal of the dependency graph (e.g., iterating over specific shards). Note: This does not deserialize the children, only loads their metadata (offsets).

pub fn decode<T: DeserializeOwned>(&self) -> Result<T>

Standard single-threaded deserialization. Use this for leaf nodes or simple structs that fit in memory.

pub fn decode_parallel_collection<T>(&self) -> Result<Vec<T>>

where T: ParcodeItem,

Parallel Shard Reconstruction

Reconstructs a Vec<T> by deserializing shards concurrently.

Safety

This function uses unsafe to write directly into an uninitialized buffer. To ensure safety:

1. We pre-calculate correct offsets using RLE metadata.
2. We cast the buffer pointer to usize to safely pass it to Rayon threads.
3. We verify that the number of items read from a shard matches the RLE expectation (expected_count). If not, we abort before writing, preventing partial initialization UB.

pub fn len(&self) -> u64

Returns the logical number of items in this container.

pub fn is_empty(&self) -> bool

Checks if the container is empty.

pub fn get<T: ParcodeItem>(&self, index: usize) -> Result<T>

Retrieves item at index using RLE arithmetic.

This calculates which shard holds the item, loads ONLY that shard, and returns the specific item.

pub fn iter<T: ParcodeItem>(self) -> Result<ChunkIterator<'a, T>>

Creates a streaming iterator over the collection. Memory usage is constant (size of one shard) regardless of total size.

pub fn get_child_by_index(&self, index: usize) -> Result<Self>

Retrieves a child ChunkNode by its index in the footer.

pub fn offset(&self) -> u64

Returns the absolute file offset of this chunk.

pub fn length(&self) -> u64

Returns the total physical length of this chunk.

pub fn child_count(&self) -> u32

Returns the number of children.

pub fn meta(&self) -> MetaByte

Returns the metadata flags.

pub fn payload_len(&self) -> u64

Calculates the size of the payload (excluding metadata/footer).

Trait Implementations

impl<'a> Clone for ChunkNode<'a>

fn clone(&self) -> ChunkNode<'a>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Debug for ChunkNode<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.