From 919a9b62c74513126a602c84c855dafda8ef7b2e Mon Sep 17 00:00:00 2001 From: Samuel Colvin Date: Tue, 30 Apr 2024 01:51:25 +0100 Subject: [PATCH] fix jiter readme --- crates/jiter/README.md | 152 ++++++++++++++++++++++++++++++++++++++++ crates/jiter/src/lib.rs | 2 +- 2 files changed, 153 insertions(+), 1 deletion(-) create mode 100644 crates/jiter/README.md diff --git a/crates/jiter/README.md b/crates/jiter/README.md new file mode 100644 index 00000000..fc01d46e --- /dev/null +++ b/crates/jiter/README.md @@ -0,0 +1,152 @@ +# jiter + +[![CI](https://github.com/pydantic/jiter/actions/workflows/ci.yml/badge.svg?event=push)](https://github.com/pydantic/jiter/actions/workflows/ci.yml?query=branch%3Amain) +[![Crates.io](https://img.shields.io/crates/v/jiter?color=green)](https://crates.io/crates/jiter) +[![CodSpeed Badge](https://img.shields.io/endpoint?url=https://codspeed.io/badge.json)](https://codspeed.io/pydantic/jiter) + +Fast iterable JSON parser. + +Documentation is available at [docs.rs/jiter](https://docs.rs/jiter). + +jiter has three interfaces: +* [`JsonValue`] an enum representing JSON data +* [`Jiter`] an iterator over JSON data +* [`python_parse`] which parses a JSON string into a Python object + +## JsonValue Example + +See [the `JsonValue` docs][JsonValue] for more details. + +```rust +use jiter::JsonValue; + +fn main() { + let json_data = r#" + { + "name": "John Doe", + "age": 43, + "phones": [ + "+44 1234567", + "+44 2345678" + ] + }"#; + let json_value = JsonValue::parse(json_data.as_bytes(), true).unwrap(); + println!("{:#?}", json_value); +} +``` + +returns: + +```text +Object( + { + "name": Str("John Doe"), + "age": Int(43), + "phones": Array( + [ + Str("+44 1234567"), + Str("+44 2345678"), + ], + ), + }, +) +``` + +## Jiter Example + +To use [Jiter], you need to know what schema you're expecting: + +```rust +use jiter::{Jiter, NumberInt, Peek}; + +fn main() { + let json_data = r#" + { + "name": "John Doe", + "age": 43, + "phones": [ + "+44 1234567", + "+44 2345678" + ] + }"#; + let mut jiter = Jiter::new(json_data.as_bytes(), true); + assert_eq!(jiter.next_object().unwrap(), Some("name")); + assert_eq!(jiter.next_str().unwrap(), "John Doe"); + assert_eq!(jiter.next_key().unwrap(), Some("age")); + assert_eq!(jiter.next_int().unwrap(), NumberInt::Int(43)); + assert_eq!(jiter.next_key().unwrap(), Some("phones")); + assert_eq!(jiter.next_array().unwrap(), Some(Peek::String)); + // we know the next value is a string as we just asserted so + assert_eq!(jiter.known_str().unwrap(), "+44 1234567"); + assert_eq!(jiter.array_step().unwrap(), Some(Peek::String)); + // same again + assert_eq!(jiter.known_str().unwrap(), "+44 2345678"); + // next we'll get `None` from `array_step` as the array is finished + assert_eq!(jiter.array_step().unwrap(), None); + // and `None` from `next_key` as the object is finished + assert_eq!(jiter.next_key().unwrap(), None); + // and we check there's nothing else in the input + jiter.finish().unwrap(); +} +``` + +## Benchmarks + +_There are lies, damned lies and benchmarks._ + +In particular, serde-json benchmarks use `serde_json::Value` which is significantly slower than deserializing +to a string. + +For more details, see [the benchmarks](https://github.com/pydantic/jiter/tree/main/benches). + +```text +running 48 tests +test big_jiter_iter ... bench: 3,662,616 ns/iter (+/- 88,878) +test big_jiter_value ... bench: 6,998,605 ns/iter (+/- 292,383) +test big_serde_value ... bench: 29,793,191 ns/iter (+/- 576,173) +test bigints_array_jiter_iter ... bench: 11,836 ns/iter (+/- 414) +test bigints_array_jiter_value ... bench: 28,979 ns/iter (+/- 938) +test bigints_array_serde_value ... bench: 129,797 ns/iter (+/- 5,096) +test floats_array_jiter_iter ... bench: 19,302 ns/iter (+/- 631) +test floats_array_jiter_value ... bench: 31,083 ns/iter (+/- 921) +test floats_array_serde_value ... bench: 208,932 ns/iter (+/- 6,167) +test lazy_map_lookup_1_10 ... bench: 615 ns/iter (+/- 15) +test lazy_map_lookup_2_20 ... bench: 1,776 ns/iter (+/- 36) +test lazy_map_lookup_3_50 ... bench: 4,291 ns/iter (+/- 77) +test massive_ints_array_jiter_iter ... bench: 62,244 ns/iter (+/- 1,616) +test massive_ints_array_jiter_value ... bench: 82,889 ns/iter (+/- 1,916) +test massive_ints_array_serde_value ... bench: 498,650 ns/iter (+/- 47,759) +test medium_response_jiter_iter ... bench: 0 ns/iter (+/- 0) +test medium_response_jiter_value ... bench: 3,521 ns/iter (+/- 101) +test medium_response_jiter_value_owned ... bench: 6,088 ns/iter (+/- 180) +test medium_response_serde_value ... bench: 9,383 ns/iter (+/- 342) +test pass1_jiter_iter ... bench: 0 ns/iter (+/- 0) +test pass1_jiter_value ... bench: 3,048 ns/iter (+/- 79) +test pass1_serde_value ... bench: 6,588 ns/iter (+/- 232) +test pass2_jiter_iter ... bench: 384 ns/iter (+/- 9) +test pass2_jiter_value ... bench: 1,259 ns/iter (+/- 44) +test pass2_serde_value ... bench: 1,237 ns/iter (+/- 38) +test sentence_jiter_iter ... bench: 283 ns/iter (+/- 10) +test sentence_jiter_value ... bench: 357 ns/iter (+/- 15) +test sentence_serde_value ... bench: 428 ns/iter (+/- 9) +test short_numbers_jiter_iter ... bench: 0 ns/iter (+/- 0) +test short_numbers_jiter_value ... bench: 18,085 ns/iter (+/- 613) +test short_numbers_serde_value ... bench: 87,253 ns/iter (+/- 1,506) +test string_array_jiter_iter ... bench: 615 ns/iter (+/- 18) +test string_array_jiter_value ... bench: 1,410 ns/iter (+/- 44) +test string_array_jiter_value_owned ... bench: 2,863 ns/iter (+/- 151) +test string_array_serde_value ... bench: 3,467 ns/iter (+/- 60) +test true_array_jiter_iter ... bench: 299 ns/iter (+/- 8) +test true_array_jiter_value ... bench: 995 ns/iter (+/- 29) +test true_array_serde_value ... bench: 1,207 ns/iter (+/- 36) +test true_object_jiter_iter ... bench: 2,482 ns/iter (+/- 84) +test true_object_jiter_value ... bench: 2,058 ns/iter (+/- 45) +test true_object_serde_value ... bench: 7,991 ns/iter (+/- 370) +test unicode_jiter_iter ... bench: 315 ns/iter (+/- 7) +test unicode_jiter_value ... bench: 389 ns/iter (+/- 6) +test unicode_serde_value ... bench: 445 ns/iter (+/- 6) +test x100_jiter_iter ... bench: 12 ns/iter (+/- 0) +test x100_jiter_value ... bench: 20 ns/iter (+/- 1) +test x100_serde_iter ... bench: 72 ns/iter (+/- 3) +test x100_serde_value ... bench: 83 ns/iter (+/- 3) +``` diff --git a/crates/jiter/src/lib.rs b/crates/jiter/src/lib.rs index 9c6262a1..3e9e0fb9 100644 --- a/crates/jiter/src/lib.rs +++ b/crates/jiter/src/lib.rs @@ -1,4 +1,4 @@ -#![doc = include_str!("../../../README.md")] +#![doc = include_str!("../README.md")] mod errors; mod jiter;