Commit Graph

2 Commits

Author SHA1 Message Date
Jun Wu
abb8ccb346 minibytes: add serde support
Summary:
See also https://github.com/serde-rs/bytes/.

This will be used in the `dag` crate.

Reviewed By: DurhamG

Differential Revision: D19770858

fbshipit-source-id: 2a870a564e0ceecdc7a4667853b2b2a5ea4ce6e3
2020-02-07 14:21:39 -08:00
Jun Wu
108f1c947a minibytes: minimalist zero-copy Bytes with mmap support
Summary:
This crate provides the core features of the commonly known `Bytes` crate:
zero-copy slicing and cloning, while also supports mmap-backed buffers.

The main motivation is to replace `Mmap` in `indexedlog`. That has multiple
benefits:
- Handles 0-sized mmap more cleanly.
- Handles clones more cleanly.
- Gain the flexibility to zero-copy data without lifetime / reference.
- Gain the flexibility to switch to non-mmap data.

The `bytes::Bytes` crate does not yet support mmap buffers as of its latest
release (0.5.4).

Implementation wise, `minibytes::Bytes` uses `Option<Arc<dyn Trait>>` for the
"trait object". This makes implementing the mmap storage just one line.
`bytes 0.5.4` re-invents the "trait object" manually using unsafe code. It requires
about 50 lines to implement the mmap storage (in D19756122).

Reviewed By: xavierd

Differential Revision: D19770856

fbshipit-source-id: 8cfa7052a18ac2e0cd6348b77d5e2a4acc61195c
2020-02-07 14:21:38 -08:00