Struct SparseReader 

pub struct SparseReader { /* private fields */ }

A reader holding only some ranges of a file in memory (the borrowed-reader opens of a 0x06 file read what they need into one of these).

Implementations

impl SparseReader

pub fn fetch<R: RangeReader + ?Sized>( r: &R, first: Vec<u8>, ranges: &[ByteRange], ) -> Result<Self, FileError>

Fetch ranges from r (plus the first bytes first) into memory — the ones first does not already hold, in one batch.

Trait Implementations

impl RangeReader for SparseReader

fn len(&self) -> u64

Total resource length in bytes.

fn read_at(&self, offset: u64, len: u64) -> Result<Vec<u8>>

Read len bytes starting at offset. Implementations should error on an out-of-bounds range rather than truncating.

fn is_empty(&self) -> bool

True when the resource is empty.

fn read_many(&self, ranges: &[(u64, u64)]) -> Result<Vec<Vec<u8>>>

Read several (offset, len) ranges, returning each range’s bytes in request order. These ranges are independent, so a reader whose backing store is high-latency but parallelizable (an HTTP client) overrides this to issue the reads concurrently — turning N round trips into ~N/P. The default fetches them sequentially. Any range failing fails the batch.

fn concurrency(&self) -> usize

How many ranges this reader can usefully have in flight at once — the planner’s hint for probe-vs-scan and batch-size decisions (a phone’s serial sync-XHR reader reports 1; the CLI’s threaded HTTP client and the browser’s concurrent-fetch variants report their fan-out). Purely advisory: correctness never depends on it. Defaults to 1 (sequential).