node_internals.h

// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

#ifndef SRC_NODE_INTERNALS_H_
#define SRC_NODE_INTERNALS_H_

#include <stdlib.h>

#include "v8.h"

namespace node {

#ifdef _WIN32
// emulate snprintf() on windows, _snprintf() doesn't zero-terminate the buffer
// on overflow...
#include <stdarg.h>
inline static int snprintf(char* buf, unsigned int len, const char* fmt, ...) {
  va_list ap;
  va_start(ap, fmt);
  int n = _vsprintf_p(buf, len, fmt, ap);
  if (len) buf[len - 1] = '\0';
  va_end(ap);
  return n;
}
#endif

#ifndef offset_of
// g++ in strict mode complains loudly about the system offsetof() macro
// because it uses NULL as the base address.
# define offset_of(type, member) \
  ((intptr_t) ((char *) &(((type *) 8)->member) - 8))
#endif

#ifndef container_of
# define container_of(ptr, type, member) \
  ((type *) ((char *) (ptr) - offset_of(type, member)))
#endif

#ifndef ARRAY_SIZE
# define ARRAY_SIZE(a) (sizeof((a)) / sizeof((a)[0]))
#endif

#ifndef ROUND_UP
# define ROUND_UP(a, b) ((a) % (b) ? ((a) + (b)) - ((a) % (b)) : (a))
#endif

// this would have been a template function were it not for the fact that g++
// sometimes fails to resolve it...
#define THROW_ERROR(fun)                                                      \
  do {                                                                        \
    v8::HandleScope scope;                                                    \
    return v8::ThrowException(fun(v8::String::New(errmsg)));                  \
  }                                                                           \
  while (0)

inline static v8::Handle<v8::Value> ThrowError(const char* errmsg) {
  THROW_ERROR(v8::Exception::Error);
}

inline static v8::Handle<v8::Value> ThrowTypeError(const char* errmsg) {
  THROW_ERROR(v8::Exception::TypeError);
}

inline static v8::Handle<v8::Value> ThrowRangeError(const char* errmsg) {
  THROW_ERROR(v8::Exception::RangeError);
}

#define UNWRAP(type)                                                        \
  assert(!args.Holder().IsEmpty());                                         \
  assert(args.Holder()->InternalFieldCount() > 0);                          \
  type* wrap =                                                              \
      static_cast<type*>(args.Holder()->GetPointerFromInternalField(0));    \
  if (!wrap) {                                                              \
    fprintf(stderr, #type ": Aborting due to unwrap failure at %s:%d\n",    \
            __FILE__, __LINE__);                                            \
    abort();                                                                \
  }

} // namespace node

#endif // SRC_NODE_INTERNALS_H_