Crate json_extractor 

JSON Fragment Scanner

A high-performance two-stage JSON fragment scanner that identifies and extracts JSON objects and arrays from complete documents using SIMD acceleration.

Features

• Two-stage pipeline: Bulk character classification + fragment extraction
• SIMD-accelerated: AVX2/SSE4.2 for maximum throughput (5-10 GiB/s)
• Fragment detection: Identifies JSON objects ({}) and arrays ([])
• Error reporting: Detailed error information for invalid fragments
• Position tracking: Absolute byte offsets for each fragment
• Nesting support: Handles arbitrary levels of nesting

Quick Start

Extract the first JSON fragment from a string:

use json_extractor::extract_first;

let input = r#"some log prefix {"name": "Alice"} tail"#;
assert_eq!(extract_first(input), Some(r#"{"name": "Alice"}"#));

Advanced Usage

Use StagedScanner for repeated scans with buffer reuse:

use json_extractor::StagedScanner;

let mut scanner = StagedScanner::new();
let data = br#"{"name": "Alice"} {"age": 30}"#;
let fragments = scanner.scan_fragments(data);

assert_eq!(fragments.len(), 2);
assert!(fragments[0].is_complete());
assert_eq!(fragments[0].start, 0);

Structs

Fragment

Represents a found JSON fragment

JsonFragmentScanner

Convenience stateless API

StagedScanner

Stateful JSON fragment scanner with buffer reuse

Enums

ErrorKind

Types of errors that can occur during parsing

FragmentStatus

Fragment completion status

Functions

extract_first

Extract the first complete JSON fragment from a string.