Remove deprecated API of bincode module.

[vincenzopalazzo]

This PR is an API migration from a deprecated API that is bincode::config() to
new API that is bincode::option()

The following warning is removed during the building operation

warning: use of deprecated function `bincode::config`: please use `options()` instead
    --> src/new_index/schema.rs:1442:9
     |
1442 |         bincode::config()
     |         ^^^^^^^^^^^^^^^
     |
     = note: `#[warn(deprecated)]` on by default

warning: use of deprecated function `bincode::config`: please use `options()` instead
    --> src/new_index/schema.rs:1450:18
     |
1450 |             key: bincode::config().big_endian().serialize(&self.key).unwrap(),
     |                  ^^^^^^^^^^^^^^^

warning: use of deprecated function `bincode::config`: please use `options()` instead
    --> src/new_index/schema.rs:1456:19
     |
1456 |         let key = bincode::config()
     |                   ^^^^^^^^^^^^^^^

warning: 3 warnings emitted

I hope this can be helpful

[shesek]

Hi @vincenzopalazzo, thanks for the PR!

We actually did this before and ended up reverting it because it was causing some issues. We should update the code to use the new bincode API, but it requires doing some more testing first.

[vincenzopalazzo]

Hi @shesek,

I got it, I'm waiting for the electrics indexing on my laptop, maybe I can try to reproduce the bug and try to make some test on it.

If you agree, is it possible to move this PR as a draft? or you preferer to close it?

[shesek]

It would be great if you tried to reproduce it, thanks!

It's possible that this issue only affects existing databases that were populated using bincode::config() and then read from using bincode::options(). Seeing if this works with a fresh install could help determine if that's the case or not.

[vincenzopalazzo]

@shesek,

I got it, thanks, I will restart the sync on the weekend because I had some full memory during my work 😄 .

I hope to return here with a good result

[junderw]

Sorry, I pushed something to my personal fork and for some reason it took the PR references from the mempool repo and converted them to this repo and made a mention, bumping the issue. Looks like a bug with GitHub.

[junderw]

@shesek We fixed this in mempool.

https://github.com/mempool/electrs/pull/34/files#diff-e039d452ce5039daf198e6c7a80c09121f093a7a869811de08361bc553b90577R10-R16

The issue was that the new defaults for the Options API uses VarInt and disallows trailing.

You can check the PR, but essentially:

/// This is the default settings for Options,
/// but all explicitly spelled out, except for endianness.
/// The following functions will add endianness.
#[inline]
fn options() -> impl Options {
    bincode::options()
        .with_fixint_encoding()
        .with_no_limit()
        .allow_trailing_bytes()
}

/// Adding the endian flag for big endian
#[inline]
fn big_endian() -> impl Options {
    options().with_big_endian()
}

/// Adding the endian flag for little endian
#[inline]
fn little_endian() -> impl Options {
    options().with_little_endian()
}

[shesek]

Thank you @junderw for pinning this down. I created a PR based on your suggestion and code at #70. Cheers :)