swift-yyjson-benchmark

Benchmarks for swift-yyjson, comparing performance against Foundation's JSON APIs.

Prerequisites

• Swift 6.1+
• macOS 26+

Setup

Download the JSON test fixtures:

make fixtures

This downloads standard JSON benchmark files from nativejson-benchmark:

• twitter.json (~632KB) - Twitter API response with nested objects and CJK text
• citm_catalog.json (~1.7MB) - Large catalog with many string keys
• canada.json (~2.2MB) - GeoJSON with many floating-point coordinates
• tokenizer.json (~11MB) - HuggingFace tokenizer (mlx-community/Qwen3-0.6B-Base-DQ5) with large vocab and merges arrays

Running Benchmarks

Run all benchmarks:

swift package benchmark

Run specific benchmark groups:

# Encoder/Decoder comparisons
swift package benchmark run --filter "Encoder"
swift package benchmark run --filter "Decoder"

# Serialization API comparisons
swift package benchmark run --filter "Serialization"

# Real-world fixture benchmarks
swift package benchmark run --filter "Fixture"

# Direct Value API benchmarks
swift package benchmark run --filter "Value"

List all available benchmarks:

swift package benchmark list

Benchmark Categories

Encoder/Decoder Benchmarks

Compares YYJSONEncoder/YYJSONDecoder against Foundation's JSONEncoder/JSONDecoder using the Codable protocol.

• Simple: Small struct with basic types (string, int, double, bool)
• Nested: Struct with nested objects, arrays, and dictionaries
• Large: Deeply nested structure with multiple levels

Serialization Benchmarks

Compares YYJSONSerialization against JSONSerialization for reading/writing untyped JSON ([String: Any]).

Value API Benchmarks

Benchmarks for YYJSONValue direct parsing and access:

• Parsing JSON to value representation
• Key/index-based access
• Object/array iteration
• Deep nested traversal

Fixture Benchmarks

Real-world JSON files commonly used in JSON parser benchmarks.

Baseline Comparisons

Save a baseline:

swift package --allow-writing-to-package-directory benchmark baseline update default

Compare against baseline:

swift package benchmark baseline compare default

Makefile Commands

make fixtures        # Download test fixtures
make clean           # Remove fixtures
make benchmark       # Download fixtures and run benchmarks