rssn 0.2.9

A comprehensive scientific computing library for Rust, aiming for feature parity with NumPy and SymPy.
Documentation
//! JSON-based FFI API for numerical number theory operations.

use std::ffi::CStr;
use std::ffi::CString;
use std::os::raw::c_char;

use serde::Deserialize;

use crate::ffi_apis::ffi_api::FfiResult;
use crate::numerical::number_theory as nt;

#[derive(Deserialize)]
struct FactorizeRequest {
    n: u64,
}

/// Factorizes a number from JSON.
///
/// # Safety
///
/// This function is unsafe because it dereferences raw pointers as part of the FFI boundary.
/// The caller must ensure:
/// 1. All pointer arguments are valid and point to initialized memory.
/// 2. The memory layout of passed structures matches the expected C-ABI layout.
/// 3. Any pointers returned by this function are managed according to the API's ownership rules.
///
/// # Panics
///
/// This function may panic if the FFI input is malformed, null where not expected,
/// or if internal state synchronization fails (e.g., poisoned locks).
#[unsafe(no_mangle)]
pub unsafe extern "C" fn rssn_num_nt_factorize_json(json_ptr: *const c_char) -> *mut c_char {
    if json_ptr.is_null() {
        return std::ptr::null_mut();
    }

    let json_str = match unsafe { CStr::from_ptr(json_ptr).to_str() } {
        | Ok(s) => s,
        | Err(_) => {
            return std::ptr::null_mut();
        },
    };

    let req: FactorizeRequest = match serde_json::from_str(json_str) {
        | Ok(r) => r,
        | Err(e) => {
            let res: FfiResult<Vec<u64>, String> = FfiResult {
                ok: None,
                err: Some(e.to_string()),
            };

            return CString::new(serde_json::to_string(&res).unwrap())
                .unwrap()
                .into_raw();
        },
    };

    let factors = nt::factorize(req.n);

    let ffi_res: FfiResult<Vec<u64>, String> = FfiResult {
        ok: Some(factors),
        err: None,
    };

    CString::new(serde_json::to_string(&ffi_res).unwrap())
        .unwrap()
        .into_raw()
}

#[derive(Deserialize)]
struct ModInverseRequest {
    a: i64,
    m: i64,
}

/// Modular inverse from JSON.
///
/// # Safety
///
/// This function is unsafe because it dereferences raw pointers as part of the FFI boundary.
/// The caller must ensure:
/// 1. All pointer arguments are valid and point to initialized memory.
/// 2. The memory layout of passed structures matches the expected C-ABI layout.
/// 3. Any pointers returned by this function are managed according to the API's ownership rules.
///
/// # Panics
///
/// This function may panic if the FFI input is malformed, null where not expected,
/// or if internal state synchronization fails (e.g., poisoned locks).
#[unsafe(no_mangle)]
pub unsafe extern "C" fn rssn_num_nt_mod_inverse_json(json_ptr: *const c_char) -> *mut c_char {
    if json_ptr.is_null() {
        return std::ptr::null_mut();
    }

    let json_str = match unsafe { CStr::from_ptr(json_ptr).to_str() } {
        | Ok(s) => s,
        | Err(_) => {
            return std::ptr::null_mut();
        },
    };

    let req: ModInverseRequest = match serde_json::from_str(json_str) {
        | Ok(r) => r,
        | Err(e) => {
            let res: FfiResult<i64, String> = FfiResult {
                ok: None,
                err: Some(e.to_string()),
            };

            return CString::new(serde_json::to_string(&res).unwrap())
                .unwrap()
                .into_raw();
        },
    };

    match nt::mod_inverse(req.a, req.m) {
        | Some(inv) => {
            let ffi_res: FfiResult<i64, String> = FfiResult {
                ok: Some(inv),
                err: None,
            };

            CString::new(serde_json::to_string(&ffi_res).unwrap())
                .unwrap()
                .into_raw()
        },
        | None => {
            let ffi_res: FfiResult<i64, String> = FfiResult {
                ok: None,
                err: Some(
                    "No modular \
                     inverse exists"
                        .to_string(),
                ),
            };

            CString::new(serde_json::to_string(&ffi_res).unwrap())
                .unwrap()
                .into_raw()
        },
    }
}