dda0f1c343
`ZeroCopyBuf` was convenient to use, but sometimes it did hide details that some copies were necessary in certain cases. Also it made it way to easy for the caller to pass around and convert into different values. This commit splits `ZeroCopyBuf` into `JsBuffer` (an array buffer coming from V8) and `ToJsBuffer` (a Rust buffer that will be converted into a V8 array buffer). As a result some magical conversions were removed (they were never used) limiting the API surface and preparing for changes in #19534. |
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| .. | ||
| benches | ||
| examples | ||
| magic | ||
| tests | ||
| Cargo.toml | ||
| de.rs | ||
| error.rs | ||
| keys.rs | ||
| lib.rs | ||
| payload.rs | ||
| README.md | ||
| ser.rs | ||
| serializable.rs | ||
| utils.rs | ||
serde_v8
Author: Aaron O'Mullan aaron.omullan@gmail.com
Serde support for encoding/decoding (rusty_)v8 values.
Broadly serde_v8 aims to provide an expressive but ~maximally efficient
encoding layer to biject rust & v8/js values. It's a core component of deno's
op-layer and is used to encode/decode all non-buffer values.
Original issue: denoland/deno#9540
Quickstart
serde_v8 fits naturally into the serde ecosystem, so if you've already used
serde or serde_json, serde_v8's API should be very familiar.
serde_v8 exposes two key-functions:
to_v8: mapsrust->v8, similar toserde_json::to_string, ...from_v8: mapsv8->rust, similar toserde_json::from_str, ...
Best practices
Whilst serde_v8 is compatible with serde_json::Value it's important to keep
in mind that serde_json::Value is essentially a loosely-typed value (think
nested HashMaps), so when writing ops we recommend directly using rust
structs/tuples or primitives, since mapping to serde_json::Value will add
extra overhead and result in slower ops.
I also recommend avoiding unecessary "wrappers", if your op takes a single-keyed struct, consider unwrapping that as a plain value unless you plan to add fields in the near-future.
Instead of returning "nothing" via Ok(json!({})), change your return type to
rust's unit type () and returning Ok(()), serde_v8 will efficiently encode
that as a JS null.
Advanced features
If you need to mix rust & v8 values in structs/tuples, you can use the special
serde_v8::Value type, which will passthrough the original v8 value untouched
when encoding/decoding.
TODO
- Experiment with KeyCache to optimize struct keys
- Experiment with external v8 strings
- Explore using json-stringifier.cc's fast-paths for arrays
- Improve tests to test parity with
serde_json(should be mostly interchangeable) - Consider a
Payloadtype that's deserializable by itself (holds scope & value) - Ensure we return errors instead of panicking on
.unwrap()s