Struct png::decoder::read_decoder::ReadDecoder

pub(crate) struct ReadDecoder<R: Read> {
    reader: BufReader<R>,
    decoder: StreamingDecoder,
}

Helper for encapsulating reading input from Read and feeding it into a StreamingDecoder while hiding low-level Decoded events and only exposing a few high-level reading operations like:

• read_header_info - reading until IHDR chunk
• read_until_image_data - reading until IDAT / fdAT sequence
• decode_image_data - reading from IDAT / fdAT sequence into Vec<u8>
• finish_decoding_image_data() - discarding remaining data from IDAT / fdAT sequence
• read_until_end_of_input() - reading until IEND chunk

Fields

reader: BufReader<R>

decoder: StreamingDecoder

Implementations

impl<R: Read> ReadDecoder<R>

pub fn new(r: R) -> Self

pub fn with_options(r: R, options: DecodeOptions) -> Self

pub fn set_limits(&mut self, limits: Limits)

pub fn reserve_bytes(&mut self, bytes: usize) -> Result<(), DecodingError>

pub fn set_ignore_text_chunk(&mut self, ignore_text_chunk: bool)

pub fn set_ignore_iccp_chunk(&mut self, ignore_iccp_chunk: bool)

pub fn ignore_checksums(&mut self, ignore_checksums: bool)

fn decode_next( &mut self, image_data: &mut Vec<u8>, ) -> Result<Decoded, DecodingError>

Returns the next decoded chunk. If the chunk is an ImageData chunk, its contents are written into image_data.

fn decode_next_without_image_data(&mut self) -> Result<Decoded, DecodingError>

fn decode_next_and_discard_image_data( &mut self, ) -> Result<Decoded, DecodingError>

pub fn read_header_info(&mut self) -> Result<&Info<'static>, DecodingError>

Reads until the end of IHDR chunk.

Prerequisite: None (idempotent).

pub fn read_until_image_data(&mut self) -> Result<(), DecodingError>

Reads until the start of the next IDAT or fdAT chunk.

Prerequisite: Not within IDAT / fdAT chunk sequence.

pub fn decode_image_data( &mut self, image_data: &mut Vec<u8>, ) -> Result<ImageDataCompletionStatus, DecodingError>

Reads image_data and reports whether there may be additional data afterwards (i.e. if it is okay to call decode_image_data and/or finish_decoding_image_data again)..

Prerequisite: Input is currently positioned within IDAT / fdAT chunk sequence.

pub fn finish_decoding_image_data(&mut self) -> Result<(), DecodingError>

Consumes and discards the rest of an IDAT / fdAT chunk sequence.

Prerequisite: Input is currently positioned within IDAT / fdAT chunk sequence.

pub fn read_until_end_of_input(&mut self) -> Result<(), DecodingError>

Reads until the IEND chunk.

Prerequisite: IEND chunk hasn’t been reached yet.

pub fn info(&self) -> Option<&Info<'static>>