Struct CarReader 

pub struct CarReader<R: Read> { /* private fields */ }

Read blocks from CAR format.

CAR files are read sequentially, yielding blocks one at a time.

Implementations

impl<R: Read> CarReader<R>

pub fn new(reader: R) -> Result<Self>

Create a new CAR reader.

This reads and parses the CAR header immediately.

Arguments

• reader - The reader to read CAR data from

Examples

use ipfrs_core::{Block, car::{CarWriter, CarReader}};
use bytes::Bytes;

let block = Block::new(Bytes::from_static(b"test")).unwrap();
let mut data = Vec::new();
let mut writer = CarWriter::new(&mut data, vec![*block.cid()]).unwrap();
writer.write_block(&block).unwrap();
writer.finish().unwrap();

let reader = CarReader::new(&data[..]).unwrap();
assert_eq!(reader.roots().len(), 1);

pub fn roots(&self) -> &[Cid]

Get the root CIDs from the CAR header.

pub fn read_block(&mut self) -> Result<Option<Block>>

Read the next block from the CAR file.

Returns None when there are no more blocks. Automatically decompresses blocks if they were compressed during writing.

Examples

use ipfrs_core::{Block, car::{CarWriter, CarReader}};
use bytes::Bytes;

let block = Block::new(Bytes::from_static(b"data")).unwrap();
let mut data = Vec::new();
let mut writer = CarWriter::new(&mut data, vec![*block.cid()]).unwrap();
writer.write_block(&block).unwrap();
writer.finish().unwrap();

let mut reader = CarReader::new(&data[..]).unwrap();
let read_block = reader.read_block().unwrap().unwrap();
assert_eq!(read_block.cid(), block.cid());

pub fn read_all_blocks(&mut self) -> Result<Vec<Block>>

Read all blocks from the CAR file.

Examples

use ipfrs_core::{Block, car::{CarWriter, CarReader}};
use bytes::Bytes;

let block1 = Block::new(Bytes::from_static(b"data1")).unwrap();
let block2 = Block::new(Bytes::from_static(b"data2")).unwrap();
let mut data = Vec::new();
let mut writer = CarWriter::new(&mut data, vec![*block1.cid()]).unwrap();
writer.write_block(&block1).unwrap();
writer.write_block(&block2).unwrap();
writer.finish().unwrap();

let mut reader = CarReader::new(&data[..]).unwrap();
let blocks = reader.read_all_blocks().unwrap();
assert_eq!(blocks.len(), 2);