nim-ffi/examples/timer/c_bindings/my_timer_cbor.h

// Generated by nim-ffi C codegen. Do not edit by hand.
//
// CBOR ABI (`<name>_cbor`). Use this for callers that cross a process or machine
// boundary (the request has to be serialized anyway) or any generic / cross-
// language caller. Build the request with the FfiCbor helpers below — a CBOR map
// whose keys are the Nim parameter names (listed per proc) — call the matching
// `<name>_cbor`, and decode the RET_OK response (a CBOR-encoded value; for
// string-returning procs a CBOR text string) with ffi_decode_text. RET_ERR
// delivers raw error text. For same-process callers, prefer the native `<name>`
// ABI in the companion <lib>.h header.
#ifndef NIM_FFI_GEN_MY_TIMER_CBOR_H
#define NIM_FFI_GEN_MY_TIMER_CBOR_H

#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

#ifdef __cplusplus
extern "C" {
#endif

#ifndef NIM_FFI_RET_CODES
#define NIM_FFI_RET_CODES
#define RET_OK 0
#define RET_ERR 1
#define RET_MISSING_CALLBACK 2
#endif

#ifndef NIM_FFI_CALLBACK_T
#define NIM_FFI_CALLBACK_T
typedef void (*FFICallBack)(int callerRet, const char *msg, size_t len, void *userData);
#endif

#ifndef NIM_FFI_CBOR_HELPERS
#define NIM_FFI_CBOR_HELPERS
// --- minimal growable CBOR request encoder --------------------------------
typedef struct {
  uint8_t *buf;
  size_t cap;
  size_t len;
} FfiCbor;

static inline FfiCbor ffi_cbor_new(void) {
  FfiCbor c;
  c.cap = 256;
  c.len = 0;
  c.buf = (uint8_t *)malloc(c.cap);
  return c;
}
static inline void ffi_cbor_free(FfiCbor *c) {
  free(c->buf);
  c->buf = NULL;
}
static inline void ffi_cbor_put(FfiCbor *c, uint8_t b) {
  if (c->len >= c->cap) {
    c->cap *= 2;
    c->buf = (uint8_t *)realloc(c->buf, c->cap);
  }
  c->buf[c->len++] = b;
}
static inline void ffi_cbor_head(FfiCbor *c, uint8_t major, uint64_t arg) {
  uint8_t mt = (uint8_t)(major << 5);
  if (arg < 24) {
    ffi_cbor_put(c, mt | (uint8_t)arg);
  } else if (arg <= 0xff) {
    ffi_cbor_put(c, mt | 24);
    ffi_cbor_put(c, (uint8_t)arg);
  } else if (arg <= 0xffff) {
    ffi_cbor_put(c, mt | 25);
    ffi_cbor_put(c, (uint8_t)(arg >> 8));
    ffi_cbor_put(c, (uint8_t)arg);
  } else if (arg <= 0xffffffffULL) {
    ffi_cbor_put(c, mt | 26);
    ffi_cbor_put(c, (uint8_t)(arg >> 24));
    ffi_cbor_put(c, (uint8_t)(arg >> 16));
    ffi_cbor_put(c, (uint8_t)(arg >> 8));
    ffi_cbor_put(c, (uint8_t)arg);
  } else {
    ffi_cbor_put(c, mt | 27);
    for (int s = 56; s >= 0; s -= 8) ffi_cbor_put(c, (uint8_t)(arg >> s));
  }
}
static inline void ffi_cbor_map(FfiCbor *c, size_t n) { ffi_cbor_head(c, 5, n); }
static inline void ffi_cbor_text(FfiCbor *c, const char *s) {
  size_t n = s ? strlen(s) : 0;
  ffi_cbor_head(c, 3, n);
  for (size_t i = 0; i < n; i++) ffi_cbor_put(c, (uint8_t)s[i]);
}
static inline void ffi_cbor_kv_text(FfiCbor *c, const char *k, const char *v) {
  ffi_cbor_text(c, k);
  ffi_cbor_text(c, v);
}
static inline void ffi_cbor_kv_uint(FfiCbor *c, const char *k, uint64_t v) {
  ffi_cbor_text(c, k);
  ffi_cbor_head(c, 0, v);
}
static inline void ffi_cbor_kv_int(FfiCbor *c, const char *k, int64_t v) {
  ffi_cbor_text(c, k);
  if (v >= 0)
    ffi_cbor_head(c, 0, (uint64_t)v);
  else
    ffi_cbor_head(c, 1, (uint64_t)(-(v + 1)));
}

// --- response decoding -----------------------------------------------------
// Zero-copy view of a top-level CBOR text string (the RET_OK payload). Sets
// *out/*outLen to point INTO `data` (no allocation; valid only while `data` is)
// and returns 1; returns 0 for a non-text-string payload.
static inline int ffi_text_view(const uint8_t *data, size_t len,
                                const uint8_t **out, size_t *outLen) {
  if (len < 1 || (data[0] >> 5) != 3) return 0;
  uint8_t info = data[0] & 0x1f;
  size_t p = 1;
  uint64_t slen = 0;
  if (info < 24) {
    slen = info;
  } else if (info == 24) {
    if (len < p + 1) return 0;
    slen = data[p++];
  } else if (info == 25) {
    if (len < p + 2) return 0;
    slen = ((uint64_t)data[p] << 8) | data[p + 1];
    p += 2;
  } else if (info == 26) {
    if (len < p + 4) return 0;
    slen = ((uint64_t)data[p] << 24) | ((uint64_t)data[p + 1] << 16) |
           ((uint64_t)data[p + 2] << 8) | data[p + 3];
    p += 4;
  } else {
    return 0;
  }
  if (len < p + slen) return 0;
  *out = data + p;
  *outLen = (size_t)slen;
  return 1;
}

// Owning variant: malloc a NUL-terminated copy. NULL for a non-text payload.
// Caller frees.
static inline char *ffi_decode_text(const uint8_t *data, size_t len) {
  const uint8_t *view;
  size_t slen;
  if (!ffi_text_view(data, len, &view, &slen)) return NULL;
  char *out = (char *)malloc(slen + 1);
  if (!out) return NULL;
  memcpy(out, view, slen);
  out[slen] = '\0';
  return out;
}
#endif // NIM_FFI_CBOR_HELPERS


// request map keys: {"config": TimerConfig}
void *my_timer_create_cbor(const uint8_t *reqCbor, size_t reqCborLen, FFICallBack callback, void *userData);

// request map keys: {"req": EchoRequest}
int my_timer_echo_cbor(void *ctx, FFICallBack callback, void *userData, const uint8_t *reqCbor, size_t reqCborLen);

// request: empty CBOR map (0xA0)
int my_timer_version_cbor(void *ctx, FFICallBack callback, void *userData, const uint8_t *reqCbor, size_t reqCborLen);

// request map keys: {"req": ComplexRequest}
int my_timer_complex_cbor(void *ctx, FFICallBack callback, void *userData, const uint8_t *reqCbor, size_t reqCborLen);

// request map keys: {"job": JobSpec, "retry": RetryPolicy, "schedule": ScheduleConfig}
int my_timer_schedule_cbor(void *ctx, FFICallBack callback, void *userData, const uint8_t *reqCbor, size_t reqCborLen);

int my_timer_destroy(void *ctx);

uint64_t my_timer_add_event_listener(void *ctx, const char *eventName, FFICallBack callback, void *userData);
int my_timer_remove_event_listener(void *ctx, uint64_t listenerId);

#ifdef __cplusplus
} // extern "C"
#endif

#endif /* NIM_FFI_GEN_MY_TIMER_CBOR_H */