I have a CAR file object in javascript and want to read it using js-car github. But I keep getting unexpected end of the file error. Here is my code I am trying
let arrayBuffer = await files[0].arrayBuffer();
let bytes=new Uint8Array(carFile);
const reader = await CarReader.fromBytes(bytes) //throws error here
const indexer = await CarIndexer.fromBytes(bytes) //throws error here
I also tired this
let str = await files[0].stream()
const reader = await CarReader.fromIterable(files[0].stream()) //throws error here
and none of them work. However with the same file this code works
const inStream = fs.createReadStream('test.car')
const reader = await CarReader.fromIterable(inStream)
I checked and I know that CarReader.fromBytes needs a Unit8Arrey and I am sure files[0] is not null. Does anyone knows what I am missing here?
for the people might face similar issue in future this is my solution:
I used res.body directly and converted it to an async stream and read it using fromIterable
async function* streamAsyncIterator(stream) {
// Get a lock on the stream
const reader = stream.getReader();
try {
while (true) {
// Read from the stream
const { done, value } = await reader.read();
// Exit if we're done
if (done) return;
// Else yield the chunk
yield value;
}
}
finally {
reader.releaseLock();
}
}
const info = await w3StorageClient.status(response)
if (info) {
// Fetch and verify files from web3.storage
const res = await w3StorageClient.get(response);
const reader = await CarReader.fromIterable(streamAsyncIterator(res.body))
// read the list of roots from the header
const roots = await reader.getRoots()
// retrieve a block, as a { cid:CID, bytes:UInt8Array } pair from the archive
const got = await reader.get(roots[0])
// also possible: for await (const { cid, bytes } of CarIterator.fromIterable(inStream)) { ... }
let decoded = cbor.decode(got.bytes)
console.log('Retrieved [%s] from example.car with CID [%s]',
decoded,
roots[0].toString())
}