Drop rustc-serialize dependency

[dtolnay]

It has been deprecated: announcement.

Is there any functionality you would require from another library before this would be possible?

[tatsuya6502]

Thanks for the heads-up. This seems an easy change. I will give it a try.

Here are some background:

• We use rmp-serialize crate to serialize/deserialize key-value metadata stored in RocksDB. rmp-serialize is the rustc-serialize binding of rmp (Rust MessagePack) crate.
  • -> rmp has a serde flavor rmp-serde from the same author, so we will switch to it.
• We also use ToHex trait in rustc-serialize to convert a [u8] value into a hexadecimal String.
  • -> If rmp-serialize's license permits, we will copy the source file (hex.rs) to this repository.
  • -> EDIT: We will use hex crate.
  • -> EDIT2: We used data-encoding crate.

[tatsuya6502]

Note: This project depends on rust-crypto, which also depends rustc-serialize. I will check if they are planning to drop the dependency.

EDIT: I found this pull request: rust-crypto - Remove rustc-serialize usage #415

[dtolnay]

Yes, here is the PR to drop rustc-serialize in rust-crypto DaGenix/rust-crypto#415. But there have been 2 commits to rust-crypto in the past 12 months so it looks abandoned to me. Maybe consider a different library?

[tatsuya6502]

But there have been 2 commits to rust-crypto in the past 12 months so it looks abandoned to me. Maybe consider a different library?

Uh, ok. We can use any crate that provides md5 digest calculation. We use it to verify the data in storage file is not corrupted. (I am not sure if md5 is the best. I need a fast and reliable digest algorithm to check data corruption)

[tatsuya6502]

(I am not sure if md5 is the best. I need a fast and reliable digest algorithm to check data corruption)

Opened #9 "Replace MD5 checksum on blob with a safe hasher".

[tatsuya6502]

Conclusion

• For RMP (Rust MessagePack): replaced rmp-serialize (rustc-serialize binding) with rmp-serde (Serde binding). This crate is used to serialize/deserialize key and metadata stored in RocksDB.
• Replaced rust-crypto crate with md-5 and data-encoding generic-array crates. These crates are used to calculate MD5 checksum for blob.
• Replaced direct dependency to rustc-serialize with data-encoding. This crate used to convert raw digest bytes to hexadecimal String.