Struct CarWriter 

pub struct CarWriter<W: Write> { /* private fields */ }

Write blocks to CAR format.

CAR files contain a CBOR-encoded header followed by length-prefixed blocks. Optionally supports block compression for reduced archive sizes.

Implementations

impl<W: Write> CarWriter<W>

pub fn new(writer: W, roots: Vec<Cid>) -> Result<Self>

Create a new CAR writer with the given root CIDs.

For compression support, use CarWriterBuilder instead.

Arguments

• writer - The writer to output CAR data to
• roots - Vector of root CIDs for the CAR file

Examples

use ipfrs_core::{CidBuilder, car::CarWriter};

let cid = CidBuilder::new().build(b"root").unwrap();
let mut output = Vec::new();
let writer = CarWriter::new(&mut output, vec![cid]).unwrap();

pub fn write_block(&mut self, block: &Block) -> Result<()>

Write a block to the CAR file.

If compression is enabled, the block data will be compressed before writing.

Arguments

• block - The block to write

Examples

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

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

pub fn stats(&self) -> &CarCompressionStats

Get the compression statistics for this writer.

Examples

use ipfrs_core::{Block, car::CarWriterBuilder, compression::CompressionAlgorithm};
use bytes::Bytes;

let block = Block::new(Bytes::from(vec![0u8; 1000])).unwrap();
let mut output = Vec::new();
let mut writer = CarWriterBuilder::new(vec![*block.cid()])
    .with_compression(CompressionAlgorithm::Zstd, 3)
    .build(&mut output)
    .unwrap();
writer.write_block(&block).unwrap();
let stats = writer.stats();
assert_eq!(stats.blocks_processed, 1);

pub fn finish(self) -> Result<()>

Finish writing and flush the writer.