v8.h.svn-base

Google浏览器V8内核代码

 * Ignore
 */
class EXPORT DeclareExtension {
 public:
  inline DeclareExtension(Extension* extension) {
    RegisterExtension(extension);
  }
};


// --- S t a t i c s ---


Handle<Primitive> EXPORT Undefined();
Handle<Primitive> EXPORT Null();
Handle<Boolean> EXPORT True();
Handle<Boolean> EXPORT False();


/**
 * A set of constraints that specifies the limits of the runtime's
 * memory use.
 */
class EXPORT ResourceConstraints {
 public:
  ResourceConstraints();
  int max_young_space_size() { return max_young_space_size_; }
  void set_max_young_space_size(int value) { max_young_space_size_ = value; }
  int max_old_space_size() { return max_old_space_size_; }
  void set_max_old_space_size(int value) { max_old_space_size_ = value; }
  uint32_t* stack_limit() { return stack_limit_; }
  void set_stack_limit(uint32_t* value) { stack_limit_ = value; }
 private:
  int max_young_space_size_;
  int max_old_space_size_;
  uint32_t* stack_limit_;
};


bool SetResourceConstraints(ResourceConstraints* constraints);


// --- E x c e p t i o n s ---


typedef void (*FatalErrorCallback)(const char* location, const char* message);


typedef void (*MessageCallback)(Handle<Message> message, Handle<Value> data);


/**
 * Schedules an exception to be thrown when returning to JavaScript.  When an
 * exception has been scheduled it is illegal to invoke any JavaScript
 * operation; the caller must return immediately and only after the exception
 * has been handled does it become legal to invoke JavaScript operations.
 */
Handle<Value> EXPORT ThrowException(Handle<Value> exception);

/**
 * Create new error objects by calling the corresponding error object
 * constructor with the message.
 */
class EXPORT Exception {
 public:
  static Local<Value> RangeError(Handle<String> message);
  static Local<Value> ReferenceError(Handle<String> message);
  static Local<Value> SyntaxError(Handle<String> message);
  static Local<Value> TypeError(Handle<String> message);
  static Local<Value> Error(Handle<String> message);
};


// --- C o u n t e r s  C a l l b a c k s

typedef int* (*CounterLookupCallback)(const wchar_t* name);

// --- F a i l e d A c c e s s C h e c k C a l l b a c k ---
typedef void (*FailedAccessCheckCallback)(Local<Object> target,
                                          AccessType type,
                                          Local<Value> data);

// --- G a r b a g e C o l l e c t i o n  C a l l b a c k s

/**
 * Applications can register a callback function which is called
 * before and after a major garbage collection.  Allocations are not
 * allowed in the callback function, you therefore cannot manipulate
 * objects (set or delete properties for example) since it is possible
 * such operations will result in the allocation of objects.
 */
typedef void (*GCCallback)();


//  --- C o n t e x t  G e n e r a t o r

/**
 * Applications must provide a callback function which is called to generate
 * a context if a context was not deserialized from the snapshot.
 */
typedef Persistent<Context> (*ContextGenerator)();


/**
 * Container class for static utility functions.
 */
class EXPORT V8 {
 public:
  /** Set the callback to invoke in case of fatal errors. */
  static void SetFatalErrorHandler(FatalErrorCallback that);

  /**
   * Ignore out-of-memory exceptions.
   *
   * V8 running out of memory is treated as a fatal error by default.
   * This means that the fatal error handler is called and that V8 is
   * terminated.
   *
   * IgnoreOutOfMemoryException can be used to not treat a
   * out-of-memory situation as a fatal error.  This way, the contexts
   * that did not cause the out of memory problem might be able to
   * continue execution.
   */
  static void IgnoreOutOfMemoryException();

  /**
   * Check if V8 is dead and therefore unusable.  This is the case after
   * fatal errors such as out-of-memory situations.
   */
  static bool IsDead();

  /**
   * Adds a message listener.
   *
   * The same message listener can be added more than once and it that
   * case it will be called more than once for each message.
   */
  static bool AddMessageListener(MessageCallback that,
                                 Handle<Value> data = Handle<Value>());

  /**
   * Remove all message listeners from the specified callback function.
   */
  static void RemoveMessageListeners(MessageCallback that);

  /**
   * Sets V8 flags from a string.
   */
  static void SetFlagsFromString(const char* str, int length);

  /**
   * Sets V8 flags from the command line.
   */
  static void SetFlagsFromCommandLine(int* argc,
                                      char** argv,
                                      bool remove_flags);

  /** Get the version string. */
  static const char* GetVersion();

  /**
   * Enables the host application to provide a mechanism for recording
   * statistics counters.
   */
  static void SetCounterFunction(CounterLookupCallback);

  /**
   * Enables the computation of a sliding window of states. The sliding
   * window information is recorded in statistics counters.
   */
  static void EnableSlidingStateWindow();

  /** Callback function for reporting failed access checks.*/
  static void SetFailedAccessCheckCallbackFunction(FailedAccessCheckCallback);

  /**
   * Enables the host application to receive a notification before a
   * major garbage colletion.  Allocations are not allowed in the
   * callback function, you therefore cannot manipulate objects (set
   * or delete properties for example) since it is possible such
   * operations will result in the allocation of objects.
   */
  static void SetGlobalGCPrologueCallback(GCCallback);

  /**
   * Enables the host application to receive a notification after a
   * major garbage collection.  Allocations are not allowed in the
   * callback function, you therefore cannot manipulate objects (set
   * or delete properties for example) since it is possible such
   * operations will result in the allocation of objects.
   */
  static void SetGlobalGCEpilogueCallback(GCCallback);

  /**
   * Allows the host application to group objects together. If one
   * object in the group is alive, all objects in the group are alive.
   * After each garbage collection, object groups are removed. It is
   * intended to be used in the before-garbage-collection callback
   * function for istance to simulate DOM tree connections among JS
   * wrapper objects.
   */
  static void AddObjectToGroup(void* id, Persistent<Object> obj);

  /**
   * Initializes from snapshot if possible. Otherwise, attempts to
   * initialize from scratch.
   */
  static bool Initialize();

  /**
   * Adjusts the amount of registered external memory.  Used to give
   * V8 an indication of the amount of externally allocated memory
   * that is kept alive by JavaScript objects.  V8 uses this to decide
   * when to perform global garbage collections.  Registering
   * externally allocated memory will trigger global garbage
   * collections more often than otherwise in an attempt to garbage
   * collect the JavaScript objects keeping the externally allocated
   * memory alive.
   *
   * \param change_in_bytes the change in externally allocated memory
   *   that is kept alive by JavaScript objects.
   * \returns the adjusted value.
   */
  static int AdjustAmountOfExternalAllocatedMemory(int change_in_bytes);

 private:
  V8();

  static void** GlobalizeReference(void** handle);
  static void DisposeGlobal(void** global_handle);
  static void MakeWeak(void** global_handle, void* data, WeakReferenceCallback);
  static void ClearWeak(void** global_handle);
  static bool IsGlobalNearDeath(void** global_handle);
  static bool IsGlobalWeak(void** global_handle);

  template <class T> friend class Handle;
  template <class T> friend class Local;
  template <class T> friend class Persistent;
  friend class Context;
};


/**
 * An external exception handler.
 */
class EXPORT TryCatch {
 public:

  /**
   * Creates a new try/catch block and registers it with v8.
   */
  TryCatch();

  /**
   * Unregisters and deletes this try/catch block.
   */
  ~TryCatch();

  /**
   * Returns true if an exception has been caught by this try/catch block.
   */
  bool HasCaught();

  /**
   * Returns the exception caught by this try/catch block.  If no exception has
   * been caught an empty handle is returned.
   *
   * The returned handle is valid until this TryCatch block has been destroyed.
   */
  Local<Value> Exception();

  /**
   * Returns the message associated with this exception.  If there is
   * no message associated an empty handle is returned.
   *
   * The returned handle is valid until this TryCatch block has been
   * destroyed.
   */
  Local<v8::Message> Message();

  /**
   * Clears any exceptions that may have been caught by this try/catch block.
   * After this method has been called, HasCaught() will return false.
   *
   * It is not necessary to clear a try/catch block before using it again; if
   * another exception is thrown the previously caught exception will just be
   * overwritten.  However, it is often a good idea since it makes it easier
   * to determine which operation threw a given exception.
   */
  void Reset();

  /**
   * Set verbosity of the external exception handler.
   *
   * By default, exceptions that are caught by an external exception
   * handler are not reported.  Call SetVerbose with true on an
   * external exception handler to have exceptions caught by the
   * handler reported as if they were not caught.
   */
  void SetVerbose(bool value);

  /**
   * Set whether or not this TryCatch should capture a Message object
   * which holds source information about where the exception
   * occurred.  True by default.
   */
  void SetCaptureMessage(bool value);

 public:
  TryCatch* next_;
  void* exception_;
  void* message_;
  bool is_verbose_;
  bool capture_message_;
};


// --- C o n t e x t ---


/**
 * Ignore
 */
class EXPORT ExtensionConfiguration {
 public:
  ExtensionConfiguration(int name_count, const char* names[])
      : name_count_(name_count), names_(names) { }
 private:
  friend class ImplementationUtilities;
  int name_count_;
  const char** names_;
};


/**
 * A sandboxed execution context with its own set of built-in objects
 * and functions.
 */
class EXPORT Context {
 public:
  Local<Object> Global();

  /** Creates a new context. */
  static Persistent<Context> New(
      ExtensionConfiguration* extensions = 0,
      Handle<ObjectTemplate> global_template = Handle<ObjectTemplate>(),
      Handle<Value> global_object = Handle<Value>());

  /** Returns the last entered context. */
  static Local<Context> GetEntered();

  /** Returns the context that is on the top of the stack. */
  static Local<Context> GetCurrent();

  /** Returns the security context that is currently used. */
  static Local<Context> GetCurrentSecurityContext();

  /**
   * Sets the security token for the context.  To access an object in
   * another context, the security tokens must match.
   */
  void SetSecurityToken(Handle<Value> token);

  /** Returns the security token of this context.*/
  Handle<Value> GetSecurityToken();

  /**
   * Enter this context.  After entering a context, all code compiled
   * and run is compiled and run in this context.  If another context
   * is already entered, this old context is saved so it can be
   * restored when the new context is exited.
   */
  void Enter();

  /**
   * Exit this context.  Exiting the current context restores the
   * context that was in place when entering the current context.
   */
  void Exit();

  /** Returns true if the context has experienced an out of memory situation. */
  bool HasOutOfMemoryException();

  /** Returns true if V8 has a current context. */
  static bool InContext();

  /** Returns true if V8 has a current security context. */
  static bool InSecurityContext();

  /**
   * Stack-allocated class which sets the execution context for all
   * operations executed within a local scope.
   */
  class EXPORT Scope {
   public:
    inline Scope(Handle<Context> context) : context_(context) {
      context_->Enter();
    }
    inline ~Scope() { context_->Exit(); }
   private:
    Handle<Context> context_;
  };

 private:
  friend class Value;
  friend class Script;
  friend class Object;
  friend class Function;
};


/**
 * Multiple threads in V8 are allowed, but only one thread at a time
 * is allowed to use V8.  The definition of 'using V8' includes
 * accessing handles or holding onto object pointers obtained from V8
 * handles.  It is up to the user of V8 to ensure (perhaps with
 * locking) that this constraint is not violated.
 *
 * If you wish to start using V8 in a thread you can