Oxigraph WASM with C Bindings

A WebAssembly library that provides raw C bindings for the Oxigraph RDF store, designed for use in sandboxed WASM environments that don't support JavaScript.

Features

• Store Management: Create, destroy, and clear RDF stores
• Triple Operations: Add, check existence, and count triples
• SPARQL Queries: Execute SPARQL queries with string results
• RDF Serialization: Load and serialize Turtle format
• WASM Optimized: Built for wasm32-unknown-unknown target
• Custom Random: Deterministic random number generation for WASM
• FFI Safe: All functions use C-compatible types

API Functions

Store Management

• oxigraph_create_store() - Create a new store
• oxigraph_destroy_store(store) - Destroy a store
• oxigraph_clear_store(store) - Clear all triples
• oxigraph_count_triples(store) - Get triple count

Triple Operations

• oxigraph_add_triple(store, subject, predicate, object) - Add a triple
• oxigraph_contains_triple(store, subject, predicate, object) - Check if triple exists

SPARQL

• oxigraph_query_sparql(store, query, result, result_len) - Execute SPARQL query

RDF Serialization

• oxigraph_load_turtle(store, turtle_data, base_iri) - Load Turtle data
• oxigraph_serialize_turtle(store, result, result_len) - Export as Turtle

Building

# Install WASM target
rustup target add wasm32-unknown-unknown

# Build release version
cargo build --release --target wasm32-unknown-unknown

# Or use the build script
./build.sh

Generated Files

• target/wasm32-unknown-unknown/release/oxigraph_wasm.wasm - WASM module
• target/wasm32-unknown-unknown/release/liboxigraph_wasm.a - Static library
• oxigraph_wasm.h - C header file

Usage

Include the header file in your C/C++ code:

#include "oxigraph_wasm.h"

// Create store
Store* store = oxigraph_create_store();

// Add a triple
int result = oxigraph_add_triple(store,
    "http://example.org/subject",
    "http://example.org/predicate",
    "example value");

// Query
char buffer[1024];
int len = oxigraph_query_sparql(store,
    "SELECT ?s ?p ?o WHERE { ?s ?p ?o }",
    buffer, sizeof(buffer));

// Cleanup
oxigraph_destroy_store(store);

Dependencies

• Oxigraph (Deepthought-Solutions fork with WASM support)
• getrandom 0.3 (with custom backend for WASM)

Error Codes

All functions return negative values on error:

• -1: NULL pointer or invalid arguments
• -2: Invalid UTF-8 encoding
• -3: RDF/SPARQL parse error
• -4: Store operation error
• -5: Serialization error
• -6: Buffer too small

WASM Environment

This crate is specifically designed for sandboxed WASM environments and includes:

• Custom deterministic random number generation
• Fixed time functions
• No JavaScript dependencies
• Optimized build configuration