Struct Reader 

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

A checked cursor over a byte range of the file.

Holds the whole file buffer plus the window this reader is allowed to touch, so a BoxHeader’s absolute offsets stay meaningful when a child reader is handed to a nested parser.

Implementations

impl<'a> Reader<'a>

pub const fn new(file: &'a [u8]) -> Self

A reader over the whole of file.

pub fn window(file: &'a [u8], start: usize, end: usize) -> Self

A reader over file[start..end], clamped to the file.

Used to resolve an iloc extent, which names an absolute range that a hostile file may place outside the data it actually shipped.

pub const fn file(&self) -> &'a [u8]

The complete file this reader was cut from.

pub const fn position(&self) -> usize

The cursor’s absolute offset within the file.

pub const fn remaining(&self) -> usize

Bytes between the cursor and the end of this reader’s window.

pub const fn is_empty(&self) -> bool

Whether the cursor has reached the end of the window.

pub fn rest(&self) -> &'a [u8]

The window’s bytes from the cursor onward.

pub fn take(&mut self, len: usize) -> Result<&'a [u8]>

Take len bytes, advancing the cursor.

Errors

Returns PixelsError::Malformed if the window holds fewer than len bytes from the cursor.

pub fn skip(&mut self, len: usize) -> Result<()>

Advance the cursor by len bytes without returning them.

Errors

As Reader::take.

pub fn u8(&mut self) -> Result<u8>

Read one byte.

Errors

As Reader::take.

pub fn u16(&mut self) -> Result<u16>

Read a big-endian u16. ISOBMFF is big-endian throughout.

Errors

As Reader::take.

pub fn u32(&mut self) -> Result<u32>

Read a big-endian u32.

Errors

As Reader::take.

pub fn u64(&mut self) -> Result<u64>

Read a big-endian u64.

Errors

As Reader::take.

pub fn uint(&mut self, size: u8) -> Result<u64>

Read a big-endian unsigned integer of size bytes, where size is 0, 4 or 8.

iloc encodes its offset and length field widths this way, and a width of zero means the field is absent and reads as zero.

Errors

Returns PixelsError::Malformed for a width the specification does not allow, or as Reader::take.

pub fn fourcc(&mut self) -> Result<FourCc>

Read a four-character code.

Errors

As Reader::take.

pub fn cstring(&mut self) -> Result<&'a str>

Read a null-terminated UTF-8 string.

Used by infe for item names and by auxC for the auxiliary type URN. An unterminated string consumes the rest of the box, which is what real files with a missing terminator intend and costs nothing to allow.

Errors

Returns PixelsError::Malformed if the bytes are not UTF-8.

pub fn full_box(&mut self) -> Result<(u8, u32)>

Read the version and flags of a full box.

Errors

As Reader::take.

pub fn next_box(&mut self) -> Option<Result<BoxHeader>>

Read the next box header, positioning the cursor at its payload.

Returns None at the end of the window. A trailing run shorter than a header is treated as padding and ends iteration rather than failing: real files pad, and refusing them buys no safety.

Errors

Returns PixelsError::Malformed if a box declares a size smaller than its own header — which would make iteration loop forever — or one that runs past the end of the enclosing box.

pub fn payload(&self, header: &BoxHeader) -> Reader<'a>

A reader over header’s payload.

pub fn find(&mut self, kind: &[u8; 4]) -> Result<Option<Reader<'a>>>

Find the first child box of type kind, if any.

Scans from the cursor and leaves the cursor where it stopped, so this is for one-shot lookups rather than repeated probing of one container.

Errors

As Reader::next_box.

Trait Implementations

impl<'a> Clone for Reader<'a>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Copy for Reader<'a>

impl<'a> Debug for Reader<'a>

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

Formats the value using the given formatter.