Struct WindowReader 

pub struct WindowReader { /* private fields */ }

An I/O-free decoder retaining only the current window and current entry.

Binding. Done means every entry yielded across the whole run chain (the original run and every resume through its cursors) is an entry, in order, of the one pack whose bytes hash to the verified pack id: the trailer, and expected_pack_id when set. A cursor from pack A used on a source that yields different bytes for any not-yet-verified range fails with PackfileCorrupted, never Done. The reader does not re-read ranges it has already verified. Keeping the source immutable across resumes is the caller’s job (informative: WP-4.8 binds R2 range reads to the object’s etag). A source whose already-verified prefix changed after verification can still reach Done, but only with entries of the verified pack.

Implementations

impl WindowReader

pub fn new( pack_len: u64, window_size: u64, limits: DecodeLimits, expected_pack_id: Option<Hash>, ) -> Result<Self, PackError>

Start a pack with power-of-two windows between 64 KiB and 64 MiB.

Errors

Short pack lengths give PackfileTooShort; invalid geometry gives PackfileCorrupted.

pub fn resume( cursor: &WindowCursor, limits: DecodeLimits, ) -> Result<Self, PackError>

Restore an entry boundary. The first request contains the next entry.

Errors

Inconsistent cursors give PackfileCorrupted.

pub fn step(&mut self) -> Result<Step, PackError>

Advance to a request, an entry, or verified completion.

Errors

Malformed packs, resource limits, and failed integrity checks use the errors documented at module level. A parsing error makes the reader inert.

pub fn feed(&mut self, offset: u64, bytes: &[u8]) -> Result<(), PackError>

Supply exactly the outstanding range. Wrong ranges leave it pending.

Errors

Wrong ranges give PackfileCorrupted; failed allocations give PackfileTooLarge.

pub fn feed_owned( &mut self, offset: u64, bytes: Vec<u8>, ) -> Result<(), PackError>

Supply a range by transferring its buffer, avoiding two full-window copies.

Errors

Wrong ranges give PackfileCorrupted; allocation failure gives PackfileTooLarge.

pub fn last_frame(&self) -> Option<FrameInfo>

The frame of the entry the latest Step::Entry returned, or None before the first one. A resumed reader starts with None.

pub fn checkpoint(&self) -> Option<WindowCursor>

A compact checkpoint only at an entry boundary, never within an entry.

Hashes the current window prefix lazily on this call. Returns None if the reader has released the bytes needed for that prefix, including while fetching a split trailer or awaiting a resumed window. Keep the previous cursor in that case. No bytes are needed when the boundary is exactly at a window start. Mid-entry states, including carried straddling entries, never produce a checkpoint.

Trait Implementations

impl Debug for WindowReader

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

Formats the value using the given formatter.