node/src/util.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_UTIL_H_
#define SRC_UTIL_H_

#include "v8.h"

#include <assert.h>
#include <stddef.h>
#include <stdlib.h>

namespace node {

#define FIXED_ONE_BYTE_STRING(isolate, string)                                \
  (node::OneByteString((isolate), (string), sizeof(string) - 1))

#define DISALLOW_COPY_AND_ASSIGN(TypeName)                                    \
  void operator=(const TypeName&);                                            \
  TypeName(const TypeName&)

#if defined(NDEBUG)
# define ASSERT(expression)
# define CHECK(expression)                                                    \
  do {                                                                        \
    if (!(expression)) abort();                                               \
  } while (0)
#else
# define ASSERT(expression)  assert(expression)
# define CHECK(expression)   assert(expression)
#endif

#define CHECK_EQ(a, b) CHECK((a) == (b))
#define CHECK_GE(a, b) CHECK((a) >= (b))
#define CHECK_GT(a, b) CHECK((a) > (b))
#define CHECK_LE(a, b) CHECK((a) <= (b))
#define CHECK_LT(a, b) CHECK((a) < (b))
#define CHECK_NE(a, b) CHECK((a) != (b))

#define UNREACHABLE() abort()

// The helper is for doing safe downcasts from base types to derived types.
template <typename Inner, typename Outer>
class ContainerOfHelper {
 public:
  inline ContainerOfHelper(Inner Outer::*field, Inner* pointer);
  template <typename TypeName>
  inline operator TypeName*() const;
 private:
  Outer* const pointer_;
};

// Calculate the address of the outer (i.e. embedding) struct from
// the interior pointer to a data member.
template <typename Inner, typename Outer>
inline ContainerOfHelper<Inner, Outer> ContainerOf(Inner Outer::*field,
                                                   Inner* pointer);

// If persistent.IsWeak() == false, then do not call persistent.Reset()
// while the returned Local<T> is still in scope, it will destroy the
// reference to the object.
template <class TypeName>
inline v8::Local<TypeName> PersistentToLocal(
    v8::Isolate* isolate,
    const v8::Persistent<TypeName>& persistent);

// Unchecked conversion from a non-weak Persistent<T> to Local<TLocal<T>,
// use with care!
//
// Do not call persistent.Reset() while the returned Local<T> is still in
// scope, it will destroy the reference to the object.
template <class TypeName>
inline v8::Local<TypeName> StrongPersistentToLocal(
    const v8::Persistent<TypeName>& persistent);

template <class TypeName>
inline v8::Local<TypeName> WeakPersistentToLocal(
    v8::Isolate* isolate,
    const v8::Persistent<TypeName>& persistent);

// Convenience wrapper around v8::String::NewFromOneByte().
inline v8::Local<v8::String> OneByteString(v8::Isolate* isolate,
                                           const char* data,
                                           int length = -1);

// For the people that compile with -funsigned-char.
inline v8::Local<v8::String> OneByteString(v8::Isolate* isolate,
                                           const signed char* data,
                                           int length = -1);

inline v8::Local<v8::String> OneByteString(v8::Isolate* isolate,
                                           const unsigned char* data,
                                           int length = -1);

inline void Wrap(v8::Local<v8::Object> object, void* pointer);

inline void ClearWrap(v8::Local<v8::Object> object);

template <typename TypeName>
inline TypeName* Unwrap(v8::Local<v8::Object> object);

class Utf8Value {
  public:
    explicit Utf8Value(v8::Handle<v8::Value> value);

    ~Utf8Value() {
      free(str_);
    }

    char* operator*() {
      return str_;
    };

    const char* operator*() const {
      return str_;
    };

    size_t length() const {
      return length_;
    };

  private:
    size_t length_;
    char* str_;
};

}  // namespace node

#endif  // SRC_UTIL_H_