Struct quick_protobuf::reader::Reader

pub struct Reader { /* private fields */ }

A struct to read protobuf data

Contrary to BytesReader, this struct will own a buffer

Examples

// FooBar is a message generated from a proto file
// In particular it implements the `MessageRead` trait, containing a `from_reader` function.
use foo_bar::FooBar;
use quick_protobuf::Reader;

fn main() {
    // create a reader, which will parse the protobuf binary file and pop events
    // this reader will read the entire file into an internal buffer
    let mut reader = Reader::from_file("/path/to/binary/protobuf.bin")
        .expect("Cannot read input file");

    // Use the generated module fns with the reader to convert your data into rust structs.
    //
    // Depending on your input file, the message can or not be prefixed with the encoded length
    // for instance, a *stream* which contains several messages generally split them using this
    // technique (see https://developers.google.com/protocol-buffers/docs/techniques#streaming)
    //
    // To read a message without a length prefix you can directly call `FooBar::from_reader`:
    // let foobar = reader.read(FooBar::from_reader).expect("Cannot read FooBar message");
    //
    // Else to read a length then a message, you can use:
    let foobar: FooBar = reader.read(|r, b| r.read_message(b))
        .expect("Cannot read FooBar message");
    // Reader::read_message uses `FooBar::from_reader` internally through the `MessageRead`
    // trait.

    println!("Found {} foos and {} bars!", foobar.foos.len(), foobar.bars.len());
}

Implementations

impl Reader

pub fn from_reader<R: Read>(r: R, capacity: usize) -> Result<Reader>

Creates a new Reader

pub fn from_file<P: AsRef<Path>>(src: P) -> Result<Reader>

Creates a new Reader out of a file path

pub fn from_bytes(bytes: Vec<u8>) -> Reader

Creates a new reader consuming the bytes

pub fn read<'a, M, F>(&'a mut self, read: F) -> Result<M>

where F: FnMut(&mut BytesReader, &'a [u8]) -> Result<M>,

Run a BytesReader dependent function

pub fn inner(&mut self) -> &mut BytesReader

Gets the inner BytesReader

pub fn buffer(&self) -> &[u8]

Gets the buffer used internally