mirror of
https://github.com/logos-messaging/nim-ffi.git
synced 2026-06-20 16:29:31 +00:00
474 lines
18 KiB
C++
474 lines
18 KiB
C++
#pragma once
|
|
#include <string>
|
|
#include <cstdint>
|
|
#include <chrono>
|
|
#include <stdexcept>
|
|
#include <mutex>
|
|
#include <condition_variable>
|
|
#include <memory>
|
|
#include <functional>
|
|
#include <future>
|
|
#include <vector>
|
|
#include <optional>
|
|
#include <type_traits>
|
|
#include <cstring>
|
|
extern "C" {
|
|
#include <tinycbor/cbor.h>
|
|
}
|
|
|
|
// ── encode_cbor overloads (primitives + containers) ─────────────────────
|
|
// Per-struct encode_cbor / decode_cbor are emitted by cpp.nim next to each
|
|
// generated struct; these helpers cover the leaf types they defer into.
|
|
// Guarded so two nim-ffi headers can share a translation unit.
|
|
#ifndef NIM_FFI_CBOR_HELPERS_HPP_INCLUDED
|
|
#define NIM_FFI_CBOR_HELPERS_HPP_INCLUDED
|
|
|
|
inline CborError encode_cbor(CborEncoder& e, bool v) {
|
|
return cbor_encode_boolean(&e, v);
|
|
}
|
|
inline CborError encode_cbor(CborEncoder& e, int64_t v) {
|
|
return cbor_encode_int(&e, v);
|
|
}
|
|
inline CborError encode_cbor(CborEncoder& e, int32_t v) {
|
|
return cbor_encode_int(&e, static_cast<int64_t>(v));
|
|
}
|
|
inline CborError encode_cbor(CborEncoder& e, uint64_t v) {
|
|
return cbor_encode_uint(&e, v);
|
|
}
|
|
inline CborError encode_cbor(CborEncoder& e, double v) {
|
|
return cbor_encode_double(&e, v);
|
|
}
|
|
inline CborError encode_cbor(CborEncoder& e, const std::string& v) {
|
|
return cbor_encode_text_string(&e, v.data(), v.size());
|
|
}
|
|
|
|
template<typename T>
|
|
inline CborError encode_cbor(CborEncoder& e, const std::vector<T>& v) {
|
|
CborEncoder arr;
|
|
CborError err = cbor_encoder_create_array(&e, &arr, v.size());
|
|
if (err) return err;
|
|
for (const auto& item : v) {
|
|
err = encode_cbor(arr, item);
|
|
if (err) return err;
|
|
}
|
|
return cbor_encoder_close_container(&e, &arr);
|
|
}
|
|
|
|
template<typename T>
|
|
inline CborError encode_cbor(CborEncoder& e, const std::optional<T>& v) {
|
|
if (!v) return cbor_encode_null(&e);
|
|
return encode_cbor(e, *v);
|
|
}
|
|
|
|
// ── decode_cbor overloads ───────────────────────────────────────────────
|
|
|
|
inline CborError decode_cbor(CborValue& it, bool& out) {
|
|
if (!cbor_value_is_boolean(&it)) return CborErrorImproperValue;
|
|
CborError err = cbor_value_get_boolean(&it, &out);
|
|
if (err) return err;
|
|
return cbor_value_advance(&it);
|
|
}
|
|
inline CborError decode_cbor(CborValue& it, int64_t& out) {
|
|
if (!cbor_value_is_integer(&it)) return CborErrorImproperValue;
|
|
CborError err = cbor_value_get_int64_checked(&it, &out);
|
|
if (err) return err;
|
|
return cbor_value_advance(&it);
|
|
}
|
|
inline CborError decode_cbor(CborValue& it, int32_t& out) {
|
|
int64_t tmp = 0;
|
|
CborError err = decode_cbor(it, tmp);
|
|
if (err) return err;
|
|
out = static_cast<int32_t>(tmp);
|
|
return CborNoError;
|
|
}
|
|
inline CborError decode_cbor(CborValue& it, uint64_t& out) {
|
|
if (!cbor_value_is_unsigned_integer(&it)) return CborErrorImproperValue;
|
|
CborError err = cbor_value_get_uint64(&it, &out);
|
|
if (err) return err;
|
|
return cbor_value_advance(&it);
|
|
}
|
|
inline CborError decode_cbor(CborValue& it, double& out) {
|
|
if (cbor_value_is_double(&it)) {
|
|
CborError err = cbor_value_get_double(&it, &out);
|
|
if (err) return err;
|
|
return cbor_value_advance(&it);
|
|
}
|
|
if (cbor_value_is_float(&it)) {
|
|
float f = 0.0f;
|
|
CborError err = cbor_value_get_float(&it, &f);
|
|
if (err) return err;
|
|
out = static_cast<double>(f);
|
|
return cbor_value_advance(&it);
|
|
}
|
|
return CborErrorImproperValue;
|
|
}
|
|
inline CborError decode_cbor(CborValue& it, std::string& out) {
|
|
if (!cbor_value_is_text_string(&it)) return CborErrorImproperValue;
|
|
size_t len = 0;
|
|
CborError err = cbor_value_get_string_length(&it, &len);
|
|
if (err) return err;
|
|
out.resize(len);
|
|
err = cbor_value_copy_text_string(&it, out.empty() ? nullptr : &out[0], &len, nullptr);
|
|
if (err) return err;
|
|
return cbor_value_advance(&it);
|
|
}
|
|
|
|
template<typename T>
|
|
inline CborError decode_cbor(CborValue& it, std::vector<T>& out) {
|
|
if (!cbor_value_is_array(&it)) return CborErrorImproperValue;
|
|
size_t len = 0;
|
|
CborError err = cbor_value_get_array_length(&it, &len);
|
|
if (err) return err;
|
|
out.clear();
|
|
out.resize(len);
|
|
CborValue inner;
|
|
err = cbor_value_enter_container(&it, &inner);
|
|
if (err) return err;
|
|
for (size_t i = 0; i < len; ++i) {
|
|
err = decode_cbor(inner, out[i]);
|
|
if (err) return err;
|
|
}
|
|
return cbor_value_leave_container(&it, &inner);
|
|
}
|
|
|
|
template<typename T>
|
|
inline CborError decode_cbor(CborValue& it, std::optional<T>& out) {
|
|
if (cbor_value_is_null(&it)) {
|
|
out = std::nullopt;
|
|
return cbor_value_advance(&it);
|
|
}
|
|
T tmp{};
|
|
CborError err = decode_cbor(it, tmp);
|
|
if (err) return err;
|
|
out = std::move(tmp);
|
|
return CborNoError;
|
|
}
|
|
|
|
// ── Public entry points ─────────────────────────────────────────────────
|
|
|
|
template<typename T>
|
|
inline std::vector<std::uint8_t> encodeCborFFI(const T& value) {
|
|
// Start with a generous 4 KiB buffer; double on overflow until it fits.
|
|
std::vector<std::uint8_t> buf(4096);
|
|
while (true) {
|
|
CborEncoder enc;
|
|
cbor_encoder_init(&enc, buf.data(), buf.size(), 0);
|
|
CborError err = encode_cbor(enc, value);
|
|
if (err == CborNoError) {
|
|
const size_t used = cbor_encoder_get_buffer_size(&enc, buf.data());
|
|
buf.resize(used);
|
|
return buf;
|
|
}
|
|
if (err == CborErrorOutOfMemory) {
|
|
const size_t extra = cbor_encoder_get_extra_bytes_needed(&enc);
|
|
buf.resize(buf.size() + (extra > 0 ? extra : buf.size()));
|
|
continue;
|
|
}
|
|
throw std::runtime_error(std::string("FFI CBOR encode failed: ") +
|
|
cbor_error_string(err));
|
|
}
|
|
}
|
|
|
|
template<typename T>
|
|
inline T decodeCborFFI(const std::vector<std::uint8_t>& bytes) {
|
|
CborParser parser;
|
|
CborValue it;
|
|
CborError err = cbor_parser_init(bytes.data(), bytes.size(), 0, &parser, &it);
|
|
if (err != CborNoError) {
|
|
throw std::runtime_error(std::string("FFI CBOR parse init failed: ") +
|
|
cbor_error_string(err));
|
|
}
|
|
T out{};
|
|
err = decode_cbor(it, out);
|
|
if (err != CborNoError) {
|
|
throw std::runtime_error(std::string("FFI CBOR decode failed: ") +
|
|
cbor_error_string(err));
|
|
}
|
|
return out;
|
|
}
|
|
|
|
#endif // NIM_FFI_CBOR_HELPERS_HPP_INCLUDED
|
|
|
|
// ============================================================
|
|
// User-declared FFI types
|
|
// ============================================================
|
|
|
|
struct EchoConfig {
|
|
std::string prefix;
|
|
};
|
|
inline CborError encode_cbor(CborEncoder& e, const EchoConfig& v) {
|
|
CborEncoder m;
|
|
CborError err = cbor_encoder_create_map(&e, &m, 1);
|
|
if (err) return err;
|
|
err = cbor_encode_text_stringz(&m, "prefix"); if (err) return err;
|
|
err = encode_cbor(m, v.prefix); if (err) return err;
|
|
return cbor_encoder_close_container(&e, &m);
|
|
}
|
|
inline CborError decode_cbor(CborValue& it, EchoConfig& v) {
|
|
if (!cbor_value_is_map(&it)) return CborErrorImproperValue;
|
|
CborValue field;
|
|
CborError err;
|
|
err = cbor_value_map_find_value(&it, "prefix", &field); if (err) return err;
|
|
if (!cbor_value_is_valid(&field)) return CborErrorImproperValue;
|
|
err = decode_cbor(field, v.prefix); if (err) return err;
|
|
return cbor_value_advance(&it);
|
|
}
|
|
|
|
struct ShoutRequest {
|
|
std::string text;
|
|
};
|
|
inline CborError encode_cbor(CborEncoder& e, const ShoutRequest& v) {
|
|
CborEncoder m;
|
|
CborError err = cbor_encoder_create_map(&e, &m, 1);
|
|
if (err) return err;
|
|
err = cbor_encode_text_stringz(&m, "text"); if (err) return err;
|
|
err = encode_cbor(m, v.text); if (err) return err;
|
|
return cbor_encoder_close_container(&e, &m);
|
|
}
|
|
inline CborError decode_cbor(CborValue& it, ShoutRequest& v) {
|
|
if (!cbor_value_is_map(&it)) return CborErrorImproperValue;
|
|
CborValue field;
|
|
CborError err;
|
|
err = cbor_value_map_find_value(&it, "text", &field); if (err) return err;
|
|
if (!cbor_value_is_valid(&field)) return CborErrorImproperValue;
|
|
err = decode_cbor(field, v.text); if (err) return err;
|
|
return cbor_value_advance(&it);
|
|
}
|
|
|
|
struct ShoutResponse {
|
|
std::string shouted;
|
|
std::string prefix;
|
|
};
|
|
inline CborError encode_cbor(CborEncoder& e, const ShoutResponse& v) {
|
|
CborEncoder m;
|
|
CborError err = cbor_encoder_create_map(&e, &m, 2);
|
|
if (err) return err;
|
|
err = cbor_encode_text_stringz(&m, "shouted"); if (err) return err;
|
|
err = encode_cbor(m, v.shouted); if (err) return err;
|
|
err = cbor_encode_text_stringz(&m, "prefix"); if (err) return err;
|
|
err = encode_cbor(m, v.prefix); if (err) return err;
|
|
return cbor_encoder_close_container(&e, &m);
|
|
}
|
|
inline CborError decode_cbor(CborValue& it, ShoutResponse& v) {
|
|
if (!cbor_value_is_map(&it)) return CborErrorImproperValue;
|
|
CborValue field;
|
|
CborError err;
|
|
err = cbor_value_map_find_value(&it, "shouted", &field); if (err) return err;
|
|
if (!cbor_value_is_valid(&field)) return CborErrorImproperValue;
|
|
err = decode_cbor(field, v.shouted); if (err) return err;
|
|
err = cbor_value_map_find_value(&it, "prefix", &field); if (err) return err;
|
|
if (!cbor_value_is_valid(&field)) return CborErrorImproperValue;
|
|
err = decode_cbor(field, v.prefix); if (err) return err;
|
|
return cbor_value_advance(&it);
|
|
}
|
|
|
|
// ============================================================
|
|
// Per-proc request envelopes (CBOR encoded on the wire)
|
|
// ============================================================
|
|
|
|
struct EchoCreateCtorReq {
|
|
EchoConfig config;
|
|
};
|
|
inline CborError encode_cbor(CborEncoder& e, const EchoCreateCtorReq& v) {
|
|
CborEncoder m;
|
|
CborError err = cbor_encoder_create_map(&e, &m, 1);
|
|
if (err) return err;
|
|
err = cbor_encode_text_stringz(&m, "config"); if (err) return err;
|
|
err = encode_cbor(m, v.config); if (err) return err;
|
|
return cbor_encoder_close_container(&e, &m);
|
|
}
|
|
inline CborError decode_cbor(CborValue& it, EchoCreateCtorReq& v) {
|
|
if (!cbor_value_is_map(&it)) return CborErrorImproperValue;
|
|
CborValue field;
|
|
CborError err;
|
|
err = cbor_value_map_find_value(&it, "config", &field); if (err) return err;
|
|
if (!cbor_value_is_valid(&field)) return CborErrorImproperValue;
|
|
err = decode_cbor(field, v.config); if (err) return err;
|
|
return cbor_value_advance(&it);
|
|
}
|
|
|
|
struct EchoShoutReq {
|
|
ShoutRequest req;
|
|
};
|
|
inline CborError encode_cbor(CborEncoder& e, const EchoShoutReq& v) {
|
|
CborEncoder m;
|
|
CborError err = cbor_encoder_create_map(&e, &m, 1);
|
|
if (err) return err;
|
|
err = cbor_encode_text_stringz(&m, "req"); if (err) return err;
|
|
err = encode_cbor(m, v.req); if (err) return err;
|
|
return cbor_encoder_close_container(&e, &m);
|
|
}
|
|
inline CborError decode_cbor(CborValue& it, EchoShoutReq& v) {
|
|
if (!cbor_value_is_map(&it)) return CborErrorImproperValue;
|
|
CborValue field;
|
|
CborError err;
|
|
err = cbor_value_map_find_value(&it, "req", &field); if (err) return err;
|
|
if (!cbor_value_is_valid(&field)) return CborErrorImproperValue;
|
|
err = decode_cbor(field, v.req); if (err) return err;
|
|
return cbor_value_advance(&it);
|
|
}
|
|
|
|
struct EchoVersionReq {
|
|
};
|
|
inline CborError encode_cbor(CborEncoder& e, const EchoVersionReq&) {
|
|
CborEncoder m;
|
|
CborError err = cbor_encoder_create_map(&e, &m, 0);
|
|
if (err) return err;
|
|
return cbor_encoder_close_container(&e, &m);
|
|
}
|
|
inline CborError decode_cbor(CborValue& it, EchoVersionReq&) {
|
|
if (!cbor_value_is_map(&it)) return CborErrorImproperValue;
|
|
return cbor_value_advance(&it);
|
|
}
|
|
|
|
// ============================================================
|
|
// C FFI declarations
|
|
// ============================================================
|
|
|
|
extern "C" {
|
|
typedef void (*FFICallback)(int ret, const char* msg, size_t len, void* user_data);
|
|
|
|
void* echo_create(const uint8_t* req_cbor, size_t req_cbor_len, FFICallback callback, void* user_data);
|
|
int echo_shout(void* ctx, FFICallback callback, void* user_data, const uint8_t* req_cbor, size_t req_cbor_len);
|
|
int echo_version(void* ctx, FFICallback callback, void* user_data, const uint8_t* req_cbor, size_t req_cbor_len);
|
|
int echo_destroy(void* ctx);
|
|
void echo_set_event_callback(void* ctx, FFICallback callback, void* user_data);
|
|
} // extern "C"
|
|
|
|
// ============================================================
|
|
// Synchronous call helper
|
|
// ============================================================
|
|
// Guarded so two nim-ffi headers can share a translation unit.
|
|
#ifndef NIM_FFI_SYNC_CALL_HELPER_HPP_INCLUDED
|
|
#define NIM_FFI_SYNC_CALL_HELPER_HPP_INCLUDED
|
|
|
|
namespace {
|
|
|
|
struct FFICallState_ {
|
|
std::mutex mtx;
|
|
std::condition_variable cv;
|
|
bool done{false};
|
|
bool ok{false};
|
|
std::vector<std::uint8_t> bytes;
|
|
std::string err;
|
|
};
|
|
|
|
inline void ffi_cb_(int ret, const char* msg, size_t len, void* ud) {
|
|
// ffi_call_ heap-allocated a shared_ptr and passed its address as ud;
|
|
// take ownership here so it's freed on every exit path.
|
|
std::unique_ptr<std::shared_ptr<FFICallState_>> handle(
|
|
static_cast<std::shared_ptr<FFICallState_>*>(ud));
|
|
FFICallState_& s = **handle;
|
|
|
|
std::lock_guard<std::mutex> lock(s.mtx);
|
|
s.ok = (ret == 0);
|
|
if (msg && len > 0) {
|
|
const auto* p = reinterpret_cast<const std::uint8_t*>(msg);
|
|
if (s.ok) s.bytes.assign(p, p + len);
|
|
else s.err.assign(msg, len);
|
|
}
|
|
s.done = true;
|
|
s.cv.notify_one();
|
|
}
|
|
|
|
inline std::vector<std::uint8_t> ffi_call_(std::function<int(FFICallback, void*)> f,
|
|
std::chrono::milliseconds timeout) {
|
|
auto state = std::make_shared<FFICallState_>();
|
|
auto* cb_ref = new std::shared_ptr<FFICallState_>(state);
|
|
const int ret = f(ffi_cb_, cb_ref);
|
|
if (ret == 2) {
|
|
delete cb_ref;
|
|
throw std::runtime_error("RET_MISSING_CALLBACK (internal error)");
|
|
}
|
|
std::unique_lock<std::mutex> lock(state->mtx);
|
|
const bool fired = state->cv.wait_for(lock, timeout, [&]{ return state->done; });
|
|
if (!fired)
|
|
throw std::runtime_error("FFI call timed out after " + std::to_string(timeout.count()) + "ms");
|
|
if (!state->ok)
|
|
throw std::runtime_error(state->err);
|
|
return state->bytes;
|
|
}
|
|
|
|
} // anonymous namespace
|
|
|
|
#endif // NIM_FFI_SYNC_CALL_HELPER_HPP_INCLUDED
|
|
|
|
// ============================================================
|
|
// High-level C++ context class
|
|
// ============================================================
|
|
|
|
class EchoCtx {
|
|
public:
|
|
static std::unique_ptr<EchoCtx> create(const EchoConfig& config, std::chrono::milliseconds timeout = std::chrono::seconds{30}) {
|
|
const auto ffi_req_ = EchoCreateCtorReq{config};
|
|
const auto ffi_req_bytes_ = encodeCborFFI(ffi_req_);
|
|
const auto ffi_raw_ = ffi_call_([&](FFICallback cb, void* ud) {
|
|
(void)echo_create(ffi_req_bytes_.data(), ffi_req_bytes_.size(), cb, ud);
|
|
return 0;
|
|
}, timeout);
|
|
const auto addr_str = decodeCborFFI<std::string>(ffi_raw_);
|
|
try {
|
|
const auto addr = std::stoull(addr_str);
|
|
return std::unique_ptr<EchoCtx>(new EchoCtx(reinterpret_cast<void*>(static_cast<uintptr_t>(addr)), timeout));
|
|
} catch (const std::exception&) {
|
|
throw std::runtime_error("FFI create returned non-numeric address: " + addr_str);
|
|
}
|
|
}
|
|
|
|
static std::future<std::unique_ptr<EchoCtx>> createAsync(const EchoConfig& config, std::chrono::milliseconds timeout = std::chrono::seconds{30}) {
|
|
return std::async(std::launch::async, [config, timeout]() { return create(config, timeout); });
|
|
}
|
|
|
|
// Special-member policy: this class owns a echo context, which in
|
|
// turn owns the library's worker thread(s) and internal state. Moving
|
|
// such an object out from under a caller silently tears that state
|
|
// down and is easy to misuse (e.g. storing in a container that
|
|
// relocates its elements). It also has no clean analogue in the other
|
|
// binding languages we generate. So copies and moves are both
|
|
// deleted; ownership is transferred via EchoCtx::create returning a
|
|
// std::unique_ptr<EchoCtx>. The destructor still releases the
|
|
// context.
|
|
~EchoCtx() {
|
|
if (ptr_) {
|
|
echo_destroy(ptr_);
|
|
ptr_ = nullptr;
|
|
}
|
|
}
|
|
|
|
EchoCtx(const EchoCtx&) = delete;
|
|
EchoCtx& operator=(const EchoCtx&) = delete;
|
|
EchoCtx(EchoCtx&&) = delete;
|
|
EchoCtx& operator=(EchoCtx&&) = delete;
|
|
|
|
ShoutResponse shout(const ShoutRequest& req) const {
|
|
const auto ffi_req_ = EchoShoutReq{req};
|
|
const auto ffi_req_bytes_ = encodeCborFFI(ffi_req_);
|
|
const auto ffi_raw_ = ffi_call_([&](FFICallback cb, void* ud) {
|
|
return echo_shout(ptr_, cb, ud, ffi_req_bytes_.data(), ffi_req_bytes_.size());
|
|
}, timeout_);
|
|
return decodeCborFFI<ShoutResponse>(ffi_raw_);
|
|
}
|
|
|
|
std::future<ShoutResponse> shoutAsync(const ShoutRequest& req) const {
|
|
return std::async(std::launch::async, [this, req]() { return this->shout(req); });
|
|
}
|
|
|
|
std::string version() const {
|
|
const auto ffi_req_ = EchoVersionReq{};
|
|
const auto ffi_req_bytes_ = encodeCborFFI(ffi_req_);
|
|
const auto ffi_raw_ = ffi_call_([&](FFICallback cb, void* ud) {
|
|
return echo_version(ptr_, cb, ud, ffi_req_bytes_.data(), ffi_req_bytes_.size());
|
|
}, timeout_);
|
|
return decodeCborFFI<std::string>(ffi_raw_);
|
|
}
|
|
|
|
std::future<std::string> versionAsync() const {
|
|
return std::async(std::launch::async, [this]() { return this->version(); });
|
|
}
|
|
|
|
private:
|
|
void* ptr_;
|
|
std::chrono::milliseconds timeout_;
|
|
explicit EchoCtx(void* p, std::chrono::milliseconds t) : ptr_(p), timeout_(t) {}
|
|
};
|