Rust - Download a piece - unexpected EOF

[latisaron]

In this setup, I’m trying a read a piece whose length is 262144;

As per the challenge, I’m breaking it up into pieces of 16384 bytes.

For some examples, after reaching a specific part (16kb) that is NOT the last one, and sending the associated request, I’m getting an EOF error.

Is the error related to the fact that I’m using read_exact which expects to read all of the data in one go? Because in terms of the length of the piece I’m trying to read, I’m pretty sure that’s not an issue.

[EDIT] Given that I’m not allowed to add multiple photos to this, I’ll drop the code below:

    let mut fin_vec: Vec<u8> = Vec::<u8>::new();
    for i in 0..((self.piece_length +  Self::DEFAULT_PIECE_BYTE_SIZE - 1) / Self::DEFAULT_PIECE_BYTE_SIZE) {
        self.send_part_request(i).await?;
        let part = self.recv_part_piece().await?;
        fin_vec.extend_from_slice(&part[8..]);
    }

I am doing the rest of the bitfield/ interest/ unchoke shenanigans.

[andy1li]

For some examples, after reaching a specific part (16kb) that is NOT the last one

Hey @latisaron, I tried running your code, and it consistently failed on the last piece, which can be shorter than plength.

In the example above, piece 3 is actually the 4th and last piece, so it’s much shorter:

Piece 0: 262,144
Piece 1: 262,144
Piece 2: 262,144
Piece 3:  34,460 = 820,892 - 262,144 * 3

You might want to double-check the math to ensure the last piece is handled correctly.

[latisaron]

Hi there @andy1li

Thank you for clarifying. Somehow, what I gathered from the documentation is that all the pieces are divided in such a manner that all of them have the same length, thus being plength. I didn’t think of checking the position of the piece.

I thought the last piece was referrring to the breakapart in 16KBs.

I’ll try this again and reach out