v8/include/v8.h

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// Copyright 2007-2008 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
/** \mainpage V8 API Reference Guide
*
* V8 is Google's open source JavaScript engine.
*
* This set of documents provides reference material generated from the
* V8 header file, include/v8.h.
*
* For other documentation see http://code.google.com/apis/v8/
*/
#ifndef V8_H_
#define V8_H_
#include <stdio.h>
#ifdef _WIN32
typedef int int32_t;
typedef unsigned int uint32_t;
typedef unsigned short uint16_t; // NOLINT
typedef long long int64_t; // NOLINT
// Setup for Windows DLL export/import. When building the V8 DLL the
// BUILDING_V8_SHARED needs to be defined. When building a program which uses
// the V8 DLL USING_V8_SHARED needs to be defined. When either building the V8
// static library or building a program which uses the V8 static library neither
// BUILDING_V8_SHARED nor USING_V8_SHARED should be defined.
// The reason for having both EXPORT and EXPORT_INLINE is that classes which
// have their code inside this header file needs to have __declspec(dllexport)
// when building the DLL but cannot have __declspec(dllimport) when building
// a program which uses the DLL.
#if defined(BUILDING_V8_SHARED) && defined(USING_V8_SHARED)
#error both BUILDING_V8_SHARED and USING_V8_SHARED are set - please check the\
build configuration to ensure that at most one of these is set
#endif
#ifdef BUILDING_V8_SHARED
#define EXPORT __declspec(dllexport)
#define EXPORT_INLINE __declspec(dllexport)
#elif USING_V8_SHARED
#define EXPORT __declspec(dllimport)
#define EXPORT_INLINE
#else
#define EXPORT
#define EXPORT_INLINE
#endif // BUILDING_V8_SHARED
#else // _WIN32
#include <stdint.h>
// Setup for Linux shared library export. There is no need to destinguish
// neither between building or using the V8 shared library nor between using
// the shared or static V8 library as there is on Windows. Therefore there is
// no checking of BUILDING_V8_SHARED and USING_V8_SHARED.
#if defined(__GNUC__) && (__GNUC__ >= 4)
#define EXPORT __attribute__ ((visibility("default")))
#define EXPORT_INLINE __attribute__ ((visibility("default")))
#else // defined(__GNUC__) && (__GNUC__ >= 4)
#define EXPORT
#define EXPORT_INLINE
#endif // defined(__GNUC__) && (__GNUC__ >= 4)
#endif // _WIN32
/**
* The v8 JavaScript engine.
*/
namespace v8 {
class Context;
class String;
class Value;
class Utils;
class Number;
class Object;
class Array;
class Int32;
class Uint32;
class External;
class Primitive;
class Boolean;
class Integer;
class Function;
class Date;
class ImplementationUtilities;
class Signature;
template <class T> class Handle;
template <class T> class Local;
template <class T> class Persistent;
class FunctionTemplate;
class ObjectTemplate;
class Data;
// --- W e a k H a n d l e s
/**
* A weak reference callback function.
*
* \param object the weak global object to be reclaimed by the garbage collector
* \param parameter the value passed in when making the weak global object
*/
typedef void (*WeakReferenceCallback)(Persistent<Value> object,
void* parameter);
// --- H a n d l e s ---
#define TYPE_CHECK(T, S) \
while (false) { \
*(static_cast<T**>(0)) = static_cast<S*>(0); \
}
/**
* An object reference managed by the v8 garbage collector.
*
* All objects returned from v8 have to be tracked by the garbage
* collector so that it knows that the objects are still alive. Also,
* because the garbage collector may move objects, it is unsafe to
* point directly to an object. Instead, all objects are stored in
* handles which are known by the garbage collector and updated
* whenever an object moves. Handles should always be passed by value
* (except in cases like out-parameters) and they should never be
* allocated on the heap.
*
* There are two types of handles: local and persistent handles.
* Local handles are light-weight and transient and typically used in
* local operations. They are managed by HandleScopes. Persistent
* handles can be used when storing objects across several independent
* operations and have to be explicitly deallocated when they're no
* longer used.
*
* It is safe to extract the object stored in the handle by
* dereferencing the handle (for instance, to extract the Object* from
* an Handle<Object>); the value will still be governed by a handle
* behind the scenes and the same rules apply to these values as to
* their handles.
*/
template <class T> class EXPORT_INLINE Handle {
public:
/**
* Creates an empty handle.
*/
Handle();
/**
* Creates a new handle for the specified value.
*/
explicit Handle(T* val) : val_(val) { }
/**
* Creates a handle for the contents of the specified handle. This
* constructor allows you to pass handles as arguments by value and
* to assign between handles. However, if you try to assign between
* incompatible handles, for instance from a Handle<String> to a
* Handle<Number> it will cause a compiletime error. Assigning
* between compatible handles, for instance assigning a
* Handle<String> to a variable declared as Handle<Value>, is legal
* because String is a subclass of Value.
*/
template <class S> inline Handle(Handle<S> that)
: val_(reinterpret_cast<T*>(*that)) {
/**
* This check fails when trying to convert between incompatible
* handles. For example, converting from a Handle<String> to a
* Handle<Number>.
*/
TYPE_CHECK(T, S);
}
/**
* Returns true if the handle is empty.
*/
bool IsEmpty() { return val_ == 0; }
T* operator->();
T* operator*();
/**
* Sets the handle to be empty. IsEmpty() will then return true.
*/
void Clear() { this->val_ = 0; }
/**
* Checks whether two handles are the same.
* Returns true if both are empty, or if the objects
* to which they refer are identical.
* The handles' references are not checked.
*/
template <class S> bool operator==(Handle<S> that) {
void** a = reinterpret_cast<void**>(**this);
void** b = reinterpret_cast<void**>(*that);
if (a == 0) return b == 0;
if (b == 0) return false;
return *a == *b;
}
/**
* Checks whether two handles are different.
* Returns true if only one of the handles is empty, or if
* the objects to which they refer are different.
* The handles' references are not checked.
*/
template <class S> bool operator!=(Handle<S> that) {
return !operator==(that);
}
template <class S> static inline Handle<T> Cast(Handle<S> that) {
if (that.IsEmpty()) return Handle<T>();
return Handle<T>(T::Cast(*that));
}
private:
T* val_;
};
/**
* A light-weight stack-allocated object handle. All operations
* that return objects from within v8 return them in local handles. They
* are created within HandleScopes, and all local handles allocated within a
* handle scope are destroyed when the handle scope is destroyed. Hence it
* is not necessary to explicitly deallocate local handles.
*/
template <class T> class EXPORT_INLINE Local : public Handle<T> {
public:
Local();
template <class S> inline Local(Local<S> that)
: Handle<T>(reinterpret_cast<T*>(*that)) {
/**
* This check fails when trying to convert between incompatible
* handles. For example, converting from a Handle<String> to a
* Handle<Number>.
*/
TYPE_CHECK(T, S);
}
template <class S> inline Local(S* that) : Handle<T>(that) { }
template <class S> static inline Local<T> Cast(Local<S> that) {
if (that.IsEmpty()) return Local<T>();
return Local<T>(T::Cast(*that));
}
/** Create a local handle for the content of another handle.
* The referee is kept alive by the local handle even when
* the original handle is destroyed/disposed.
*/
static Local<T> New(Handle<T> that);
};
/**
* An object reference that is independent of any handle scope. Where
* a Local handle only lives as long as the HandleScope in which it was
* allocated, a Persistent handle remains valid until it is explicitly
* disposed.
*
* A persistent handle contains a reference to a storage cell within
* the v8 engine which holds an object value and which is updated by
* the garbage collector whenever the object is moved. A new storage
* cell can be created using Persistent::New and existing handles can
* be disposed using Persistent::Dispose. Since persistent handles
* are passed by value you may have many persistent handle objects
* that point to the same storage cell. For instance, if you pass a
* persistent handle as an argument to a function you will not get two
* different storage cells but rather two references to the same
* storage cell.
*/
template <class T> class EXPORT_INLINE Persistent : public Handle<T> {
public:
/**
* Creates an empty persistent handle that doesn't point to any
* storage cell.
*/
Persistent();
/**
* Creates a persistent handle for the same storage cell as the
* specified handle. This constructor allows you to pass persistent
* handles as arguments by value and to assign between persistent
* handles. However, attempting to assign between incompatible
* persistent handles, for instance from a Persistent<String> to a
* Persistent<Number> will cause a compiletime error. Assigning
* between compatible persistent handles, for instance assigning a
* Persistent<String> to a variable declared as Persistent<Value>,
* is allowed as String is a subclass of Value.
*/
template <class S> inline Persistent(Persistent<S> that)
: Handle<T>(reinterpret_cast<T*>(*that)) {
/**
* This check fails when trying to convert between incompatible
* handles. For example, converting from a Handle<String> to a
* Handle<Number>.
*/
TYPE_CHECK(T, S);
}
template <class S> inline Persistent(S* that) : Handle<T>(that) { }
/**
* "Casts" a plain handle which is known to be a persistent handle
* to a persistent handle.
*/
template <class S> explicit inline Persistent(Handle<S> that)
: Handle<T>(*that) { }
template <class S> static inline Persistent<T> Cast(Persistent<S> that) {
if (that.IsEmpty()) return Persistent<T>();
return Persistent<T>(T::Cast(*that));
}
/**
* Creates a new persistent handle for an existing local or
* persistent handle.
*/
static Persistent<T> New(Handle<T> that);
/**
* Releases the storage cell referenced by this persistent handle.
* Does not remove the reference to the cell from any handles.
* This handle's reference, and any any other references to the storage
* cell remain and IsEmpty will still return false.
*/
void Dispose();
/**
* Make the reference to this object weak. When only weak handles
* refer to the object, the garbage collector will perform a
* callback to the given V8::WeakReferenceCallback function, passing
* it the object reference and the given parameters.
*/
void MakeWeak(void* parameters, WeakReferenceCallback callback);
/** Clears the weak reference to this object.*/
void ClearWeak();
/**
*Checks if the handle holds the only reference to an object.
*/
bool IsNearDeath();
/**
* Returns true if the handle's reference is weak.
*/
bool IsWeak();
private:
friend class ImplementationUtilities;
friend class ObjectTemplate;
};
/**
* A stack-allocated class that governs a number of local handles.
* After a handle scope has been created, all local handles will be
* allocated within that handle scope until either the handle scope is
* deleted or another handle scope is created. If there is already a
* handle scope and a new one is created, all allocations will take
* place in the new handle scope until it is deleted. After that,
* new handles will again be allocated in the original handle scope.
*
* After the handle scope of a local handle has been deleted the
* garbage collector will no longer track the object stored in the
* handle and may deallocate it. The behavior of accessing a handle
* for which the handle scope has been deleted is undefined.
*/
class EXPORT HandleScope {
public:
HandleScope() : previous_(current_), is_closed_(false) {
current_.extensions = 0;
}
~HandleScope() {
// TODO(1245391): In a perfect world, there would be a way of not
// having to check for explicitly closed scopes maybe through
// subclassing HandleScope?
if (!is_closed_) RestorePreviousState();
}
/**
* TODO(1245391): Consider introducing a subclass for this.
* Closes the handle scope and returns the value as a handle in the
* previous scope, which is the new current scope after the call.
*/
template <class T> Local<T> Close(Handle<T> value);
/**
* Counts the number of allocated handles.
*/
static int NumberOfHandles();
/**
* Creates a new handle with the given value.
*/
static void** CreateHandle(void* value);
private:
// Make it impossible to create heap-allocated or illegal handle
// scopes by disallowing certain operations.
HandleScope(const HandleScope&);
void operator=(const HandleScope&);
void* operator new(size_t size);
void operator delete(void*, size_t);
class EXPORT Data {
public:
int extensions;
void** next;
void** limit;
inline void Initialize() {
extensions = -1;
next = limit = NULL;
}
};
static Data current_;
const Data previous_;
/**
* Re-establishes the previous scope state. Should be called only
* once, and only for the current scope.
*/
void RestorePreviousState() {
if (current_.extensions > 0) DeleteExtensions();
current_ = previous_;
#ifdef DEBUG
ZapRange(current_.next, current_.limit);
#endif
}
// TODO(1245391): Consider creating a subclass for this.
bool is_closed_;
void** RawClose(void** value);
/** Deallocates any extensions used by the current scope.*/
static void DeleteExtensions();
// Zaps the handles in the half-open interval [start, end).
static void ZapRange(void** start, void** end);
friend class ImplementationUtilities;
};
// --- S p e c i a l o b j e c t s ---
/**
* The superclass of values and API object templates.
*/
class EXPORT Data {
private:
Data();
};
/**
* Pre-compilation data that can be associated with a script. This
* data can be calculated for a script in advance of actually
* compiling it, and can be stored between compilations. When script
* data is given to the compile method compilation will be faster.
*/
class EXPORT ScriptData { // NOLINT
public:
virtual ~ScriptData() { }
static ScriptData* PreCompile(const char* input, int length);
static ScriptData* New(unsigned* data, int length);
virtual int Length() = 0;
virtual unsigned* Data() = 0;
};
/**
* The origin, within a file, of a script.
*/
class EXPORT ScriptOrigin {
public:
ScriptOrigin(Handle<Value> resource_name,
Handle<Integer> resource_line_offset = Handle<Integer>(),
Handle<Integer> resource_column_offset = Handle<Integer>())
: resource_name_(resource_name),
resource_line_offset_(resource_line_offset),
resource_column_offset_(resource_column_offset) { }
inline Handle<Value> ResourceName() const;
inline Handle<Integer> ResourceLineOffset() const;
inline Handle<Integer> ResourceColumnOffset() const;
private:
Handle<Value> resource_name_;
Handle<Integer> resource_line_offset_;
Handle<Integer> resource_column_offset_;
};
/**
* A compiled JavaScript script.
*/
class EXPORT Script {
public:
/**
* Compiles the specified script. The ScriptOrigin* and ScriptData*
* parameters are owned by the caller of Script::Compile. No
* references to these objects are kept after compilation finishes.
*/
static Local<Script> Compile(Handle<String> source,
ScriptOrigin* origin = NULL,
ScriptData* pre_data = NULL);
/**
* Compiles the specified script using the specified file name
* object (typically a string) as the script's origin.
*/
static Local<Script> Compile(Handle<String> source,
Handle<Value> file_name);
/**
* Runs the script returning the resulting value.
*/
Local<Value> Run();
};
/**
* An error message.
*/
class EXPORT Message {
public:
Local<String> Get();
Local<String> GetSourceLine();
Handle<Value> GetScriptResourceName();
/**
* Returns the number, 1-based, of the line where the error occurred.
*/
int GetLineNumber();
/**
* Returns the index within the script of the first character where
* the error occurred.
*/
int GetStartPosition();
/**
* Returns the index within the script of the last character where
* the error occurred.
*/
int GetEndPosition();
/**
* Returns the index within the line of the first character where
* the error occurred.
*/
int GetStartColumn();
/**
* Returns the index within the line of the last character where
* the error occurred.
*/
int GetEndColumn();
// TODO(1245381): Print to a string instead of on a FILE.
static void PrintCurrentStackTrace(FILE* out);
};
// --- V a l u e ---
/**
* The superclass of all JavaScript values and objects.
*/
class EXPORT Value : public Data {
public:
/**
* Returns true if this value is the undefined value. See ECMA-262
* 4.3.10.
*/
bool IsUndefined();
/**
* Returns true if this value is the null value. See ECMA-262
* 4.3.11.
*/
bool IsNull();
/**
* Returns true if this value is true.
*/
bool IsTrue();
/**
* Returns true if this value is false.
*/
bool IsFalse();
/**
* Returns true if this value is an instance of the String type.
* See ECMA-262 8.4.
*/
bool IsString();
/**
* Returns true if this value is a function.
*/
bool IsFunction();
/**
* Returns true if this value is an array.
*/
bool IsArray();
/**
* Returns true if this value is an object.
*/
bool IsObject();
/**
* Returns true if this value is boolean.
*/
bool IsBoolean();
/**
* Returns true if this value is a number.
*/
bool IsNumber();
/**
* Returns true if this value is external.
*/
bool IsExternal();
/**
* Returns true if this value is a 32-bit signed integer.
*/
bool IsInt32();
/**
* Returns true if this value is a Date.
*/
bool IsDate();
Local<Boolean> ToBoolean();
Local<Number> ToNumber();
Local<String> ToString();
Local<String> ToDetailString();
Local<Object> ToObject();
Local<Integer> ToInteger();
Local<Uint32> ToUint32();
Local<Int32> ToInt32();
/**
* Attempts to convert a string to an array index.
* Returns an empty handle if the conversion fails.
*/
Local<Uint32> ToArrayIndex();
bool BooleanValue();
double NumberValue();
int64_t IntegerValue();
uint32_t Uint32Value();
int32_t Int32Value();
/** JS == */
bool Equals(Handle<Value> that);
bool StrictEquals(Handle<Value> that);
};
/**
* The superclass of primitive values. See ECMA-262 4.3.2.
*/
class EXPORT Primitive : public Value { };
/**
* A primitive boolean value (ECMA-262, 4.3.14). Either the true
* or false value.
*/
class EXPORT Boolean : public Primitive {
public:
bool Value();
static inline Handle<Boolean> New(bool value);
};
/**
* A JavaScript string value (ECMA-262, 4.3.17).
*/
class EXPORT String : public Primitive {
public:
/**
* Returns the number of characters in this string.
*/
int Length();
/**
* Returns the number of bytes in the UTF-8 encoded
* representation of this string.
*/
int Utf8Length();
/**
* Write the contents of the string to an external buffer.
* If no arguments are given, expects the buffer to be large
* enough to hold the entire string and NULL terminator. Copies
* the contents of the string and the NULL terminator into the
* buffer.
*
* Copies up to length characters into the output buffer.
* Only null-terminates if there is enough space in the buffer.
*
* \param buffer The buffer into which the string will be copied.
* \param start The starting position within the string at which
* copying begins.
* \param length The number of bytes to copy from the string.
* \return The number of characters copied to the buffer
* excluding the NULL terminator.
*/
int Write(uint16_t* buffer, int start = 0, int length = -1); // UTF-16
int WriteAscii(char* buffer, int start = 0, int length = -1); // ASCII
int WriteUtf8(char* buffer, int length = -1); // UTF-8
/**
* Returns true if the string is external
*/
bool IsExternal();
/**
* Returns true if the string is both external and ascii
*/
bool IsExternalAscii();
/**
* An ExternalStringResource is a wrapper around a two-byte string
* buffer that resides outside V8's heap. Implement an
* ExternalStringResource to manage the life cycle of the underlying
* buffer. Note that the string data must be immutable.
*/
class EXPORT ExternalStringResource { // NOLINT
public:
/**
* Override the destructor to manage the life cycle of the underlying
* buffer.
*/
virtual ~ExternalStringResource() {}
/** The string data from the underlying buffer.*/
virtual const uint16_t* data() const = 0;
/** The length of the string. That is, the number of two-byte characters.*/
virtual size_t length() const = 0;
protected:
ExternalStringResource() {}
private:
// Disallow copying and assigning.
ExternalStringResource(const ExternalStringResource&);
void operator=(const ExternalStringResource&);
};
/**
* An ExternalAsciiStringResource is a wrapper around an ascii
* string buffer that resides outside V8's heap. Implement an
* ExternalAsciiStringResource to manage the life cycle of the
* underlying buffer. Note that the string data must be immutable
* and that the data must be strict 7-bit ASCII, not Latin1 or
* UTF-8, which would require special treatment internally in the
* engine and, in the case of UTF-8, do not allow efficient indexing.
* Use String::New or convert to 16 bit data for non-ASCII.
*/
class EXPORT ExternalAsciiStringResource { // NOLINT
public:
/**
* Override the destructor to manage the life cycle of the underlying
* buffer.
*/
virtual ~ExternalAsciiStringResource() {}
/** The string data from the underlying buffer.*/
virtual const char* data() const = 0;
/** The number of ascii characters in the string.*/
virtual size_t length() const = 0;
protected:
ExternalAsciiStringResource() {}
private:
// Disallow copying and assigning.
ExternalAsciiStringResource(const ExternalAsciiStringResource&);
void operator=(const ExternalAsciiStringResource&);
};
/**
* Get the ExternalStringResource for an external string. Only
* valid if IsExternal() returns true.
*/
ExternalStringResource* GetExternalStringResource();
/**
* Get the ExternalAsciiStringResource for an external ascii string.
* Only valid if IsExternalAscii() returns true.
*/
ExternalAsciiStringResource* GetExternalAsciiStringResource();
static String* Cast(v8::Value* obj);
/**
* Allocates a new string from either utf-8 encoded or ascii data.
* The second parameter 'length' gives the buffer length.
* If the data is utf-8 encoded, the caller must
* be careful to supply the length parameter.
* If it is not given, the function calls
* 'strlen' to determine the buffer length, it might be
* wrong if 'data' contains a null character.
*/
static Local<String> New(const char* data, int length = -1);
/** Allocates a new string from utf16 data.*/
static Local<String> New(const uint16_t* data, int length = -1);
/** Creates a symbol. Returns one if it exists already.*/
static Local<String> NewSymbol(const char* data, int length = -1);
/**
* Creates a new external string using the data defined in the given
* resource. The resource is deleted when the external string is no
* longer live on V8's heap. The caller of this function should not
* delete or modify the resource. Neither should the underlying buffer be
* deallocated or modified except through the destructor of the
* external string resource.
*/
static Local<String> NewExternal(ExternalStringResource* resource);
/**
* Creates a new external string using the ascii data defined in the given
* resource. The resource is deleted when the external string is no
* longer live on V8's heap. The caller of this function should not
* delete or modify the resource. Neither should the underlying buffer be
* deallocated or modified except through the destructor of the
* external string resource.
*/
static Local<String> NewExternal(ExternalAsciiStringResource* resource);
/** Creates an undetectable string from the supplied ascii or utf-8 data.*/
static Local<String> NewUndetectable(const char* data, int length = -1);
/** Creates an undetectable string from the supplied utf-16 data.*/
static Local<String> NewUndetectable(const uint16_t* data, int length = -1);
/**
* Converts an object to a utf8-encoded character array. Useful if
* you want to print the object.
*/
class EXPORT Utf8Value {
public:
explicit Utf8Value(Handle<v8::Value> obj);
~Utf8Value();
char* operator*() { return str_; }
int length() { return length_; }
private:
char* str_;
int length_;
// Disallow copying and assigning.
Utf8Value(const Utf8Value&);
void operator=(const Utf8Value&);
};
/**
* Converts an object to an ascii string.
* Useful if you want to print the object.
*/
class EXPORT AsciiValue {
public:
explicit AsciiValue(Handle<v8::Value> obj);
~AsciiValue();
char* operator*() { return str_; }
int length() { return length_; }
private:
char* str_;
int length_;
// Disallow copying and assigning.
AsciiValue(const AsciiValue&);
void operator=(const AsciiValue&);
};
/**
* Converts an object to a two-byte string.
*/
class EXPORT Value {
public:
explicit Value(Handle<v8::Value> obj);
~Value();
uint16_t* operator*() { return str_; }
int length() { return length_; }
private:
uint16_t* str_;
int length_;
// Disallow copying and assigning.
Value(const Value&);
void operator=(const Value&);
};
};
/**
* A JavaScript number value (ECMA-262, 4.3.20)
*/
class EXPORT Number : public Primitive {
public:
double Value();
static Local<Number> New(double value);
static Number* Cast(v8::Value* obj);
private:
Number();
};
/**
* A JavaScript value representing a signed integer.
*/
class EXPORT Integer : public Number {
public:
static Local<Integer> New(int32_t value);
int64_t Value();
static Integer* Cast(v8::Value* obj);
private:
Integer();
};
/**
* A JavaScript value representing a 32-bit signed integer.
*/
class EXPORT Int32 : public Integer {
public:
int32_t Value();
private:
Int32();
};
/**
* A JavaScript value representing a 32-bit unsigned integer.
*/
class EXPORT Uint32 : public Integer {
public:
uint32_t Value();
private:
Uint32();
};
/**
* An instance of the built-in Date constructor (ECMA-262, 15.9).
*/
class EXPORT Date : public Value {
public:
static Local<Value> New(double time);
/**
* A specialization of Value::NumberValue that is more efficient
* because we know the structure of this object.
*/
double NumberValue();
static Date* Cast(v8::Value* obj);
};
enum PropertyAttribute {
None = 0,
ReadOnly = 1 << 0,
DontEnum = 1 << 1,
DontDelete = 1 << 2
};
/**
* A JavaScript object (ECMA-262, 4.3.3)
*/
class EXPORT Object : public Value {
public:
bool Set(Handle<Value> key,
Handle<Value> value,
PropertyAttribute attribs = None);
Local<Value> Get(Handle<Value> key);
// TODO(1245389): Replace the type-specific versions of these
// functions with generic ones that accept a Handle<Value> key.
bool Has(Handle<String> key);
bool Delete(Handle<String> key);
bool Has(uint32_t index);
bool Delete(uint32_t index);
/**
* Returns an array containing the names of the enumerable properties
* of this object, including properties from prototype objects. The
* array returned by this method contains the same values as would
* be enumerated by a for-in statement over this object.
*/
Local<Array> GetPropertyNames();
/**
* Get the prototype object. This does not skip objects marked to
* be skipped by __proto__ and it does not consult the security
* handler.
*/
Local<Value> GetPrototype();
/**
* Call builtin Object.prototype.toString on this object.
* This is different from Value::ToString() that may call
* user-defined toString function. This one does not.
*/
Local<String> ObjectProtoToString();
/** Gets the number of internal fields for this Object. */
int InternalFieldCount();
/** Gets the value in an internal field. */
Local<Value> GetInternalField(int index);
/** Sets the value in an internal field. */
void SetInternalField(int index, Handle<Value> value);
// Testers for local properties.
bool HasRealNamedProperty(Handle<String> key);
bool HasRealIndexedProperty(uint32_t index);
bool HasRealNamedCallbackProperty(Handle<String> key);
/**
* If result.IsEmpty() no real property was located in the prototype chain.
* This means interceptors in the prototype chain are not called.
*/
Handle<Value> GetRealNamedPropertyInPrototypeChain(Handle<String> key);
/** Tests for a named lookup interceptor.*/
bool HasNamedLookupInterceptor();
/** Tests for an index lookup interceptor.*/
bool HasIndexedLookupInterceptor();
Split window support from V8. Here is a description of the background and design of split window in Chrome and V8: https://docs.google.com/a/google.com/Doc?id=chhjkpg_47fwddxbfr This change list splits the window object into two parts: 1) an inner window object used as the global object of contexts; 2) an outer window object exposed to JavaScript and accessible by the name 'window'. Firefox did it awhile ago, here are some discussions: https://wiki.mozilla.org/Gecko:SplitWindow. One additional benefit of splitting window in Chrome is that accessing global variables don't need security checks anymore, it can improve applications that use many global variables. V8 support of split window: There are a small number of changes on V8 api to support split window: Security context is removed from V8, so does related API functions; A global object can be detached from its context and reused by a new context; Access checks on an object template can be turned on/off by default; An object can turn on its access checks later; V8 has a new object type, ApiGlobalObject, which is the outer window object type. The existing JSGlobalObject becomes the inner window object type. Security checks are moved from JSGlobalObject to ApiGlobalObject. ApiGlobalObject is the one exposed to JavaScript, it is accessible through Context::Global(). ApiGlobalObject's prototype is set to JSGlobalObject so that property lookups are forwarded to JSGlobalObject. ApiGlobalObject forwards all other property access requests to JSGlobalObject, such as SetProperty, DeleteProperty, etc. Security token is moved to a global context, and ApiGlobalObject has a reference to its global context. JSGlobalObject has a reference to its global context as well. When accessing properties on a global object in JavaScript, the domain security check is performed by comparing the security token of the lexical context (Top::global_context()) to the token of global object's context. The check is only needed when the receiver is a window object, such as 'window.document'. Accessing global variables, such as 'var foo = 3; foo' does not need checks because the receiver is the inner window object. When an outer window is detached from its global context (when a frame navigates away from a page), it is completely detached from the inner window. A new context is created for the new page, and the outer global object is reused. At this point, the access check on the DOMWindow wrapper of the old context is turned on. The code in old context is still able to access DOMWindow properties, but it has to go through domain security checks. It is debatable on how to implement the outer window object. Currently each property access function has to check if the receiver is ApiGlobalObject type. This approach might be error-prone that one may forget to check the receiver when adding new functions. It is unlikely a performance issue because accessing global variables are more common than 'window.foo' style coding. I am still working on the ARM port, and I'd like to hear comments and suggestions on the best way to support it in V8. Review URL: http://codereview.chromium.org/7366 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@540 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2008-10-21 19:07:58 +00:00
/**
* Turns on access check on the object if the object is an instance of
* a template that has access check callbacks. If an object has no
* access check info, the object cannot be accessed by anyone.
*/
Split window support from V8. Here is a description of the background and design of split window in Chrome and V8: https://docs.google.com/a/google.com/Doc?id=chhjkpg_47fwddxbfr This change list splits the window object into two parts: 1) an inner window object used as the global object of contexts; 2) an outer window object exposed to JavaScript and accessible by the name 'window'. Firefox did it awhile ago, here are some discussions: https://wiki.mozilla.org/Gecko:SplitWindow. One additional benefit of splitting window in Chrome is that accessing global variables don't need security checks anymore, it can improve applications that use many global variables. V8 support of split window: There are a small number of changes on V8 api to support split window: Security context is removed from V8, so does related API functions; A global object can be detached from its context and reused by a new context; Access checks on an object template can be turned on/off by default; An object can turn on its access checks later; V8 has a new object type, ApiGlobalObject, which is the outer window object type. The existing JSGlobalObject becomes the inner window object type. Security checks are moved from JSGlobalObject to ApiGlobalObject. ApiGlobalObject is the one exposed to JavaScript, it is accessible through Context::Global(). ApiGlobalObject's prototype is set to JSGlobalObject so that property lookups are forwarded to JSGlobalObject. ApiGlobalObject forwards all other property access requests to JSGlobalObject, such as SetProperty, DeleteProperty, etc. Security token is moved to a global context, and ApiGlobalObject has a reference to its global context. JSGlobalObject has a reference to its global context as well. When accessing properties on a global object in JavaScript, the domain security check is performed by comparing the security token of the lexical context (Top::global_context()) to the token of global object's context. The check is only needed when the receiver is a window object, such as 'window.document'. Accessing global variables, such as 'var foo = 3; foo' does not need checks because the receiver is the inner window object. When an outer window is detached from its global context (when a frame navigates away from a page), it is completely detached from the inner window. A new context is created for the new page, and the outer global object is reused. At this point, the access check on the DOMWindow wrapper of the old context is turned on. The code in old context is still able to access DOMWindow properties, but it has to go through domain security checks. It is debatable on how to implement the outer window object. Currently each property access function has to check if the receiver is ApiGlobalObject type. This approach might be error-prone that one may forget to check the receiver when adding new functions. It is unlikely a performance issue because accessing global variables are more common than 'window.foo' style coding. I am still working on the ARM port, and I'd like to hear comments and suggestions on the best way to support it in V8. Review URL: http://codereview.chromium.org/7366 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@540 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2008-10-21 19:07:58 +00:00
void TurnOnAccessCheck();
static Local<Object> New();
static Object* Cast(Value* obj);
private:
Object();
};
/**
* An instance of the built-in array constructor (ECMA-262, 15.4.2).
*/
class EXPORT Array : public Object {
public:
uint32_t Length();
static Local<Array> New(int length = 0);
static Array* Cast(Value* obj);
private:
Array();
};
/**
* A JavaScript function object (ECMA-262, 15.3).
*/
class EXPORT Function : public Object {
public:
Local<Object> NewInstance();
Local<Object> NewInstance(int argc, Handle<Value> argv[]);
Local<Value> Call(Handle<Object> recv, int argc, Handle<Value> argv[]);
void SetName(Handle<String> name);
Handle<Value> GetName();
static Function* Cast(Value* obj);
private:
Function();
};
/**
* A JavaScript value that wraps a c++ void*. This type of value is
* mainly used to associate c++ data structures with JavaScript
* objects.
*/
class EXPORT External : public Value {
public:
static Local<External> New(void* value);
static External* Cast(Value* obj);
void* Value();
private:
External();
};
// --- T e m p l a t e s ---
/**
* The superclass of object and function templates.
*/
class EXPORT Template : public Data {
public:
/** Adds a property to each instance created by this template.*/
void Set(Handle<String> name, Handle<Data> value,
PropertyAttribute attributes = None);
inline void Set(const char* name, Handle<Data> value);
private:
Template();
friend class ObjectTemplate;
friend class FunctionTemplate;
};
/**
* The argument information given to function call callbacks. This
* class provides access to information about the context of the call,
* including the receiver, the number and values of arguments, and
* the holder of the function.
*/
class EXPORT Arguments {
public:
inline int Length() const;
inline Local<Value> operator[](int i) const;
inline Local<Function> Callee() const;
inline Local<Object> This() const;
inline Local<Object> Holder() const;
inline bool IsConstructCall() const;
inline Local<Value> Data() const;
private:
Arguments();
friend class ImplementationUtilities;
inline Arguments(Local<Value> data,
Local<Object> holder,
Local<Function> callee,
bool is_construct_call,
void** values, int length);
Local<Value> data_;
Local<Object> holder_;
Local<Function> callee_;
bool is_construct_call_;
void** values_;
int length_;
};
/**
* The information passed to an accessor callback about the context
* of the property access.
*/
class EXPORT AccessorInfo {
public:
inline AccessorInfo(Local<Object> self,
Local<Value> data,
Local<Object> holder)
: self_(self), data_(data), holder_(holder) { }
inline Local<Value> Data() const;
inline Local<Object> This() const;
inline Local<Object> Holder() const;
private:
Local<Object> self_;
Local<Value> data_;
Local<Object> holder_;
};
typedef Handle<Value> (*InvocationCallback)(const Arguments& args);
typedef int (*LookupCallback)(Local<Object> self, Local<String> name);
/**
* Accessor[Getter|Setter] are used as callback functions when
* setting|getting a particular property. See objectTemplate::SetAccessor.
*/
typedef Handle<Value> (*AccessorGetter)(Local<String> property,
const AccessorInfo& info);
typedef void (*AccessorSetter)(Local<String> property,
Local<Value> value,
const AccessorInfo& info);
/**
* NamedProperty[Getter|Setter] are used as interceptors on object.
* See ObjectTemplate::SetNamedPropertyHandler.
*/
typedef Handle<Value> (*NamedPropertyGetter)(Local<String> property,
const AccessorInfo& info);
/**
* Returns the value if the setter intercepts the request.
* Otherwise, returns an empty handle.
*/
typedef Handle<Value> (*NamedPropertySetter)(Local<String> property,
Local<Value> value,
const AccessorInfo& info);
/**
* Returns a non-empty handle if the interceptor intercepts the request.
* The result is true if the property exists and false otherwise.
*/
typedef Handle<Boolean> (*NamedPropertyQuery)(Local<String> property,
const AccessorInfo& info);
/**
* Returns a non-empty handle if the deleter intercepts the request.
* The return value is true if the property could be deleted and false
* otherwise.
*/
typedef Handle<Boolean> (*NamedPropertyDeleter)(Local<String> property,
const AccessorInfo& info);
/**
* Returns an array containing the names of the properties the named
* property getter intercepts.
*/
typedef Handle<Array> (*NamedPropertyEnumerator)(const AccessorInfo& info);
/**
* Returns the value of the property if the getter intercepts the
* request. Otherwise, returns an empty handle.
*/
typedef Handle<Value> (*IndexedPropertyGetter)(uint32_t index,
const AccessorInfo& info);
/**
* Returns the value if the setter intercepts the request.
* Otherwise, returns an empty handle.
*/
typedef Handle<Value> (*IndexedPropertySetter)(uint32_t index,
Local<Value> value,
const AccessorInfo& info);
/**
* Returns a non-empty handle if the interceptor intercepts the request.
* The result is true if the property exists and false otherwise.
*/
typedef Handle<Boolean> (*IndexedPropertyQuery)(uint32_t index,
const AccessorInfo& info);
/**
* Returns a non-empty handle if the deleter intercepts the request.
* The return value is true if the property could be deleted and false
* otherwise.
*/
typedef Handle<Boolean> (*IndexedPropertyDeleter)(uint32_t index,
const AccessorInfo& info);
/**
* Returns an array containing the indices of the properties the
* indexed property getter intercepts.
*/
typedef Handle<Array> (*IndexedPropertyEnumerator)(const AccessorInfo& info);
/**
* Access control specifications.
*
* Some accessors should be accessible across contexts. These
* accessors have an explicit access control parameter which specifies
* the kind of cross-context access that should be allowed.
*
* Additionally, for security, accessors can prohibit overwriting by
* accessors defined in JavaScript. For objects that have such
* accessors either locally or in their prototype chain it is not
* possible to overwrite the accessor by using __defineGetter__ or
* __defineSetter__ from JavaScript code.
*/
enum AccessControl {
DEFAULT = 0,
ALL_CAN_READ = 1,
ALL_CAN_WRITE = 1 << 1,
PROHIBITS_OVERWRITING = 1 << 2
};
/**
* Access type specification.
*/
enum AccessType {
ACCESS_GET,
ACCESS_SET,
ACCESS_HAS,
ACCESS_DELETE,
ACCESS_KEYS
};
/**
* Returns true if cross-context access should be allowed to the named
* property with the given key on the global object.
*/
typedef bool (*NamedSecurityCallback)(Local<Object> global,
Local<Value> key,
AccessType type,
Local<Value> data);
/**
* Returns true if cross-context access should be allowed to the indexed
* property with the given index on the global object.
*/
typedef bool (*IndexedSecurityCallback)(Local<Object> global,
uint32_t index,
AccessType type,
Local<Value> data);
/**
* A FunctionTemplate is used to create functions at runtime. There
* can only be one function created from a FunctionTemplate in a
* context.
*
* A FunctionTemplate can have properties, these properties are added to the
* function object when it is created.
*
* A FunctionTemplate has a corresponding instance template which is
* used to create object instances when the function is used as a
* constructor. Properties added to the instance template are added to
* each object instance.
*
* A FunctionTemplate can have a prototype template. The prototype template
* is used to create the prototype object of the function.
*
* The following example shows how to use a FunctionTemplate:
*
* \code
* v8::Local<v8::FunctionTemplate> t = v8::FunctionTemplate::New();
* t->Set("func_property", v8::Number::New(1));
*
* v8::Local<v8::Template> proto_t = t->PrototypeTemplate();
* proto_t->Set("proto_method", v8::FunctionTemplate::New(InvokeCallback));
* proto_t->Set("proto_const", v8::Number::New(2));
*
* v8::Local<v8::ObjectTemplate> instance_t = t->InstanceTemplate();
* instance_t->SetAccessor("instance_accessor", InstanceAccessorCallback);
* instance_t->SetNamedPropertyHandler(PropertyHandlerCallback, ...);
* instance_t->Set("instance_property", Number::New(3));
*
* v8::Local<v8::Function> function = t->GetFunction();
* v8::Local<v8::Object> instance = function->NewInstance();
* \endcode
*
* Let's use "function" as the JS variable name of the function object
* and "instance" for the instance object created above. The function
* and the instance will have the following properties:
*
* \code
* func_property in function == true;
* function.func_property == 1;
*
* function.prototype.proto_method() invokes 'InvokeCallback'
* function.prototype.proto_const == 2;
*
* instance instanceof function == true;
* instance.instance_accessor calls 'InstanceAccessorCallback'
* instance.instance_property == 3;
* \endcode
*
* A FunctionTemplate can inherit from another one by calling the
* FunctionTemplate::Inherit method. The following graph illustrates
* the semantics of inheritance:
*
* \code
* FunctionTemplate Parent -> Parent() . prototype -> { }
* ^ ^
* | Inherit(Parent) | .__proto__
* | |
* FunctionTemplate Child -> Child() . prototype -> { }
* \endcode
*
* A FunctionTemplate 'Child' inherits from 'Parent', the prototype
* object of the Child() function has __proto__ pointing to the
* Parent() function's prototype object. An instance of the Child
* function has all properties on Parent's instance templates.
*
* Let Parent be the FunctionTemplate initialized in the previous
* section and create a Child FunctionTemplate by:
*
* \code
* Local<FunctionTemplate> parent = t;
* Local<FunctionTemplate> child = FunctionTemplate::New();
* child->Inherit(parent);
*
* Local<Function> child_function = child->GetFunction();
* Local<Object> child_instance = child_function->NewInstance();
* \endcode
*
* The Child function and Child instance will have the following
* properties:
*
* \code
* child_func.prototype.__proto__ == function.prototype;
* child_instance.instance_accessor calls 'InstanceAccessorCallback'
* child_instance.instance_property == 3;
* \endcode
*/
class EXPORT FunctionTemplate : public Template {
public:
/** Creates a function template.*/
static Local<FunctionTemplate> New(
InvocationCallback callback = 0,
Handle<Value> data = Handle<Value>(),
Handle<Signature> signature = Handle<Signature>());
/** Returns the unique function instance in the current execution context.*/
Local<Function> GetFunction();
/**
* Set the call-handler callback for a FunctionTemplate. This
* callback is called whenever the function created from this
* FunctionTemplate is called.
*/
void SetCallHandler(InvocationCallback callback,
Handle<Value> data = Handle<Value>());
/** Get the InstanceTemplate. */
Local<ObjectTemplate> InstanceTemplate();
/** Causes the function template to inherit from a parent function template.*/
void Inherit(Handle<FunctionTemplate> parent);
/**
* A PrototypeTemplate is the template used to create the prototype object
* of the function created by this template.
*/
Local<ObjectTemplate> PrototypeTemplate();
/**
* Set the class name of the FunctionTemplate. This is used for
* printing objects created with the function created from the
* FunctionTemplate as its constructor.
*/
void SetClassName(Handle<String> name);
/**
* Determines whether the __proto__ accessor ignores instances of
* the function template. If instances of the function template are
* ignored, __proto__ skips all instances and instead returns the
* next object in the prototype chain.
*
* Call with a value of true to make the __proto__ accessor ignore
* instances of the function template. Call with a value of false
* to make the __proto__ accessor not ignore instances of the
* function template. By default, instances of a function template
* are not ignored.
*/
void SetHiddenPrototype(bool value);
/**
* Returns true if the given object is an instance of this function
* template.
*/
bool HasInstance(Handle<Value> object);
private:
FunctionTemplate();
void AddInstancePropertyAccessor(Handle<String> name,
AccessorGetter getter,
AccessorSetter setter,
Handle<Value> data,
AccessControl settings,
PropertyAttribute attributes);
void SetNamedInstancePropertyHandler(NamedPropertyGetter getter,
NamedPropertySetter setter,
NamedPropertyQuery query,
NamedPropertyDeleter remover,
NamedPropertyEnumerator enumerator,
Handle<Value> data);
void SetIndexedInstancePropertyHandler(IndexedPropertyGetter getter,
IndexedPropertySetter setter,
IndexedPropertyQuery query,
IndexedPropertyDeleter remover,
IndexedPropertyEnumerator enumerator,
Handle<Value> data);
void SetInstanceCallAsFunctionHandler(InvocationCallback callback,
Handle<Value> data);
friend class Context;
friend class ObjectTemplate;
};
/**
* An ObjectTemplate is used to create objects at runtime.
*
* Properties added to an ObjectTemplate are added to each object
* created from the ObjectTemplate.
*/
class EXPORT ObjectTemplate : public Template {
public:
/** Creates an ObjectTemplate. */
static Local<ObjectTemplate> New();
/** Creates a new instance of this template.*/
Local<Object> NewInstance();
/**
* Sets an accessor on the object template.
*
* Whenever the property with the given name is accessed on objects
* created from this ObjectTemplate the getter and setter callbacks
* are called instead of getting and setting the property directly
* on the JavaScript object.
*
* \param name The name of the property for which an accessor is added.
* \param getter The callback to invoke when getting the property.
* \param setter The callback to invoke when setting the property.
* \param data A piece of data that will be passed to the getter and setter
* callbacks whenever they are invoked.
* \param settings Access control settings for the accessor. This is a bit
* field consisting of one of more of
* DEFAULT = 0, ALL_CAN_READ = 1, or ALL_CAN_WRITE = 2.
* The default is to not allow cross-context access.
* ALL_CAN_READ means that all cross-context reads are allowed.
* ALL_CAN_WRITE means that all cross-context writes are allowed.
* The combination ALL_CAN_READ | ALL_CAN_WRITE can be used to allow all
* cross-context access.
* \param attribute The attributes of the property for which an accessor
* is added.
*/
void SetAccessor(Handle<String> name,
AccessorGetter getter,
AccessorSetter setter = 0,
Handle<Value> data = Handle<Value>(),
AccessControl settings = DEFAULT,
PropertyAttribute attribute = None);
/**
* Sets a named property handler on the object template.
*
* Whenever a named property is accessed on objects created from
* this object template, the provided callback is invoked instead of
* accessing the property directly on the JavaScript object.
*
* \param getter The callback to invoke when getting a property.
* \param setter The callback to invoke when setting a property.
* \param query The callback to invoke to check is an object has a property.
* \param deleter The callback to invoke when deleting a property.
* \param enumerator The callback to invoke to enumerate all the named
* properties of an object.
* \param data A piece of data that will be passed to the callbacks
* whenever they are invoked.
*/
void SetNamedPropertyHandler(NamedPropertyGetter getter,
NamedPropertySetter setter = 0,
NamedPropertyQuery query = 0,
NamedPropertyDeleter deleter = 0,
NamedPropertyEnumerator enumerator = 0,
Handle<Value> data = Handle<Value>());
/**
* Sets an indexed property handler on the object template.
*
* Whenever an indexed property is accessed on objects created from
* this object template, the provided callback is invoked instead of
* accessing the property directly on the JavaScript object.
*
* \param getter The callback to invoke when getting a property.
* \param setter The callback to invoke when setting a property.
* \param query The callback to invoke to check is an object has a property.
* \param deleter The callback to invoke when deleting a property.
* \param enumerator The callback to invoke to enumerate all the indexed
* properties of an object.
* \param data A piece of data that will be passed to the callbacks
* whenever they are invoked.
*/
void SetIndexedPropertyHandler(IndexedPropertyGetter getter,
IndexedPropertySetter setter = 0,
IndexedPropertyQuery query = 0,
IndexedPropertyDeleter deleter = 0,
IndexedPropertyEnumerator enumerator = 0,
Handle<Value> data = Handle<Value>());
/**
* Sets the callback to be used when calling instances created from
* this template as a function. If no callback is set, instances
* behave like normal JavaScript objects that cannot be called as a
* function.
*/
void SetCallAsFunctionHandler(InvocationCallback callback,
Handle<Value> data = Handle<Value>());
/**
* Mark object instances of the template as undetectable.
*
* In many ways, undetectable objects behave as though they are not
* there. They behave like 'undefined' in conditionals and when
* printed. However, properties can be accessed and called as on
* normal objects.
*/
void MarkAsUndetectable();
/**
* Sets access check callbacks on the object template.
*
* When accessing properties on instances of this object template,
* the access check callback will be called to determine whether or
* not to allow cross-context access to the properties.
Split window support from V8. Here is a description of the background and design of split window in Chrome and V8: https://docs.google.com/a/google.com/Doc?id=chhjkpg_47fwddxbfr This change list splits the window object into two parts: 1) an inner window object used as the global object of contexts; 2) an outer window object exposed to JavaScript and accessible by the name 'window'. Firefox did it awhile ago, here are some discussions: https://wiki.mozilla.org/Gecko:SplitWindow. One additional benefit of splitting window in Chrome is that accessing global variables don't need security checks anymore, it can improve applications that use many global variables. V8 support of split window: There are a small number of changes on V8 api to support split window: Security context is removed from V8, so does related API functions; A global object can be detached from its context and reused by a new context; Access checks on an object template can be turned on/off by default; An object can turn on its access checks later; V8 has a new object type, ApiGlobalObject, which is the outer window object type. The existing JSGlobalObject becomes the inner window object type. Security checks are moved from JSGlobalObject to ApiGlobalObject. ApiGlobalObject is the one exposed to JavaScript, it is accessible through Context::Global(). ApiGlobalObject's prototype is set to JSGlobalObject so that property lookups are forwarded to JSGlobalObject. ApiGlobalObject forwards all other property access requests to JSGlobalObject, such as SetProperty, DeleteProperty, etc. Security token is moved to a global context, and ApiGlobalObject has a reference to its global context. JSGlobalObject has a reference to its global context as well. When accessing properties on a global object in JavaScript, the domain security check is performed by comparing the security token of the lexical context (Top::global_context()) to the token of global object's context. The check is only needed when the receiver is a window object, such as 'window.document'. Accessing global variables, such as 'var foo = 3; foo' does not need checks because the receiver is the inner window object. When an outer window is detached from its global context (when a frame navigates away from a page), it is completely detached from the inner window. A new context is created for the new page, and the outer global object is reused. At this point, the access check on the DOMWindow wrapper of the old context is turned on. The code in old context is still able to access DOMWindow properties, but it has to go through domain security checks. It is debatable on how to implement the outer window object. Currently each property access function has to check if the receiver is ApiGlobalObject type. This approach might be error-prone that one may forget to check the receiver when adding new functions. It is unlikely a performance issue because accessing global variables are more common than 'window.foo' style coding. I am still working on the ARM port, and I'd like to hear comments and suggestions on the best way to support it in V8. Review URL: http://codereview.chromium.org/7366 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@540 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2008-10-21 19:07:58 +00:00
* The last parameter specifies whether access checks are turned
* on by default on instances. If access checks are off by default,
* they can be turned on on individual instances by calling
* Object::TurnOnAccessCheck().
*/
void SetAccessCheckCallbacks(NamedSecurityCallback named_handler,
IndexedSecurityCallback indexed_handler,
Split window support from V8. Here is a description of the background and design of split window in Chrome and V8: https://docs.google.com/a/google.com/Doc?id=chhjkpg_47fwddxbfr This change list splits the window object into two parts: 1) an inner window object used as the global object of contexts; 2) an outer window object exposed to JavaScript and accessible by the name 'window'. Firefox did it awhile ago, here are some discussions: https://wiki.mozilla.org/Gecko:SplitWindow. One additional benefit of splitting window in Chrome is that accessing global variables don't need security checks anymore, it can improve applications that use many global variables. V8 support of split window: There are a small number of changes on V8 api to support split window: Security context is removed from V8, so does related API functions; A global object can be detached from its context and reused by a new context; Access checks on an object template can be turned on/off by default; An object can turn on its access checks later; V8 has a new object type, ApiGlobalObject, which is the outer window object type. The existing JSGlobalObject becomes the inner window object type. Security checks are moved from JSGlobalObject to ApiGlobalObject. ApiGlobalObject is the one exposed to JavaScript, it is accessible through Context::Global(). ApiGlobalObject's prototype is set to JSGlobalObject so that property lookups are forwarded to JSGlobalObject. ApiGlobalObject forwards all other property access requests to JSGlobalObject, such as SetProperty, DeleteProperty, etc. Security token is moved to a global context, and ApiGlobalObject has a reference to its global context. JSGlobalObject has a reference to its global context as well. When accessing properties on a global object in JavaScript, the domain security check is performed by comparing the security token of the lexical context (Top::global_context()) to the token of global object's context. The check is only needed when the receiver is a window object, such as 'window.document'. Accessing global variables, such as 'var foo = 3; foo' does not need checks because the receiver is the inner window object. When an outer window is detached from its global context (when a frame navigates away from a page), it is completely detached from the inner window. A new context is created for the new page, and the outer global object is reused. At this point, the access check on the DOMWindow wrapper of the old context is turned on. The code in old context is still able to access DOMWindow properties, but it has to go through domain security checks. It is debatable on how to implement the outer window object. Currently each property access function has to check if the receiver is ApiGlobalObject type. This approach might be error-prone that one may forget to check the receiver when adding new functions. It is unlikely a performance issue because accessing global variables are more common than 'window.foo' style coding. I am still working on the ARM port, and I'd like to hear comments and suggestions on the best way to support it in V8. Review URL: http://codereview.chromium.org/7366 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@540 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2008-10-21 19:07:58 +00:00
Handle<Value> data = Handle<Value>(),
bool turned_on_by_default = true);
/**
* Gets the number of internal fields for objects generated from
* this template.
*/
int InternalFieldCount();
/**
* Sets the number of internal fields for objects generated from
* this template.
*/
void SetInternalFieldCount(int value);
private:
ObjectTemplate();
static Local<ObjectTemplate> New(Handle<FunctionTemplate> constructor);
friend class FunctionTemplate;
};
/**
* A Signature specifies which receivers and arguments a function can
* legally be called with.
*/
class EXPORT Signature : public Data {
public:
static Local<Signature> New(Handle<FunctionTemplate> receiver =
Handle<FunctionTemplate>(),
int argc = 0,
Handle<FunctionTemplate> argv[] = 0);
private:
Signature();
};
/**
* A utility for determining the type of objects based on the template
* they were constructed from.
*/
class EXPORT TypeSwitch : public Data {
public:
static Local<TypeSwitch> New(Handle<FunctionTemplate> type);
static Local<TypeSwitch> New(int argc, Handle<FunctionTemplate> types[]);
int match(Handle<Value> value);
private:
TypeSwitch();
};
// --- E x t e n s i o n s ---
/**
* Ignore
*/
class EXPORT Extension { // NOLINT
public:
Extension(const char* name,
const char* source = 0,
int dep_count = 0,
const char** deps = 0);
virtual ~Extension() { }
virtual v8::Handle<v8::FunctionTemplate>
GetNativeFunction(v8::Handle<v8::String> name) {
return v8::Handle<v8::FunctionTemplate>();
}
const char* name() { return name_; }
const char* source() { return source_; }
int dependency_count() { return dep_count_; }
const char** dependencies() { return deps_; }
void set_auto_enable(bool value) { auto_enable_ = value; }
bool auto_enable() { return auto_enable_; }
private:
const char* name_;
const char* source_;
int dep_count_;
const char** deps_;
bool auto_enable_;
// Disallow copying and assigning.
Extension(const Extension&);
void operator=(const Extension&);
};
void EXPORT RegisterExtension(Extension* extension);
/**
* 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() const { return max_young_space_size_; }
void set_max_young_space_size(int value) { max_young_space_size_ = value; }
int max_old_space_size() const { return max_old_space_size_; }
void set_max_old_space_size(int value) { max_old_space_size_ = value; }
uint32_t* stack_limit() const { 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() const;
/**
* 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() const;
/**
* 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() const;
/**
* 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_;
void* js_handler_;
};
// --- 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:
Split window support from V8. Here is a description of the background and design of split window in Chrome and V8: https://docs.google.com/a/google.com/Doc?id=chhjkpg_47fwddxbfr This change list splits the window object into two parts: 1) an inner window object used as the global object of contexts; 2) an outer window object exposed to JavaScript and accessible by the name 'window'. Firefox did it awhile ago, here are some discussions: https://wiki.mozilla.org/Gecko:SplitWindow. One additional benefit of splitting window in Chrome is that accessing global variables don't need security checks anymore, it can improve applications that use many global variables. V8 support of split window: There are a small number of changes on V8 api to support split window: Security context is removed from V8, so does related API functions; A global object can be detached from its context and reused by a new context; Access checks on an object template can be turned on/off by default; An object can turn on its access checks later; V8 has a new object type, ApiGlobalObject, which is the outer window object type. The existing JSGlobalObject becomes the inner window object type. Security checks are moved from JSGlobalObject to ApiGlobalObject. ApiGlobalObject is the one exposed to JavaScript, it is accessible through Context::Global(). ApiGlobalObject's prototype is set to JSGlobalObject so that property lookups are forwarded to JSGlobalObject. ApiGlobalObject forwards all other property access requests to JSGlobalObject, such as SetProperty, DeleteProperty, etc. Security token is moved to a global context, and ApiGlobalObject has a reference to its global context. JSGlobalObject has a reference to its global context as well. When accessing properties on a global object in JavaScript, the domain security check is performed by comparing the security token of the lexical context (Top::global_context()) to the token of global object's context. The check is only needed when the receiver is a window object, such as 'window.document'. Accessing global variables, such as 'var foo = 3; foo' does not need checks because the receiver is the inner window object. When an outer window is detached from its global context (when a frame navigates away from a page), it is completely detached from the inner window. A new context is created for the new page, and the outer global object is reused. At this point, the access check on the DOMWindow wrapper of the old context is turned on. The code in old context is still able to access DOMWindow properties, but it has to go through domain security checks. It is debatable on how to implement the outer window object. Currently each property access function has to check if the receiver is ApiGlobalObject type. This approach might be error-prone that one may forget to check the receiver when adding new functions. It is unlikely a performance issue because accessing global variables are more common than 'window.foo' style coding. I am still working on the ARM port, and I'd like to hear comments and suggestions on the best way to support it in V8. Review URL: http://codereview.chromium.org/7366 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@540 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2008-10-21 19:07:58 +00:00
/** Returns the global object of the context. */
Local<Object> Global();
Split window support from V8. Here is a description of the background and design of split window in Chrome and V8: https://docs.google.com/a/google.com/Doc?id=chhjkpg_47fwddxbfr This change list splits the window object into two parts: 1) an inner window object used as the global object of contexts; 2) an outer window object exposed to JavaScript and accessible by the name 'window'. Firefox did it awhile ago, here are some discussions: https://wiki.mozilla.org/Gecko:SplitWindow. One additional benefit of splitting window in Chrome is that accessing global variables don't need security checks anymore, it can improve applications that use many global variables. V8 support of split window: There are a small number of changes on V8 api to support split window: Security context is removed from V8, so does related API functions; A global object can be detached from its context and reused by a new context; Access checks on an object template can be turned on/off by default; An object can turn on its access checks later; V8 has a new object type, ApiGlobalObject, which is the outer window object type. The existing JSGlobalObject becomes the inner window object type. Security checks are moved from JSGlobalObject to ApiGlobalObject. ApiGlobalObject is the one exposed to JavaScript, it is accessible through Context::Global(). ApiGlobalObject's prototype is set to JSGlobalObject so that property lookups are forwarded to JSGlobalObject. ApiGlobalObject forwards all other property access requests to JSGlobalObject, such as SetProperty, DeleteProperty, etc. Security token is moved to a global context, and ApiGlobalObject has a reference to its global context. JSGlobalObject has a reference to its global context as well. When accessing properties on a global object in JavaScript, the domain security check is performed by comparing the security token of the lexical context (Top::global_context()) to the token of global object's context. The check is only needed when the receiver is a window object, such as 'window.document'. Accessing global variables, such as 'var foo = 3; foo' does not need checks because the receiver is the inner window object. When an outer window is detached from its global context (when a frame navigates away from a page), it is completely detached from the inner window. A new context is created for the new page, and the outer global object is reused. At this point, the access check on the DOMWindow wrapper of the old context is turned on. The code in old context is still able to access DOMWindow properties, but it has to go through domain security checks. It is debatable on how to implement the outer window object. Currently each property access function has to check if the receiver is ApiGlobalObject type. This approach might be error-prone that one may forget to check the receiver when adding new functions. It is unlikely a performance issue because accessing global variables are more common than 'window.foo' style coding. I am still working on the ARM port, and I'd like to hear comments and suggestions on the best way to support it in V8. Review URL: http://codereview.chromium.org/7366 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@540 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2008-10-21 19:07:58 +00:00
/**
* Detaches the global object from its context before
* the global object can be reused to create a new context.
*/
void DetachGlobal();
/** 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();
/**
* Sets the security token for the context. To access an object in
* another context, the security tokens must match.
*/
void SetSecurityToken(Handle<Value> token);
Split window support from V8. Here is a description of the background and design of split window in Chrome and V8: https://docs.google.com/a/google.com/Doc?id=chhjkpg_47fwddxbfr This change list splits the window object into two parts: 1) an inner window object used as the global object of contexts; 2) an outer window object exposed to JavaScript and accessible by the name 'window'. Firefox did it awhile ago, here are some discussions: https://wiki.mozilla.org/Gecko:SplitWindow. One additional benefit of splitting window in Chrome is that accessing global variables don't need security checks anymore, it can improve applications that use many global variables. V8 support of split window: There are a small number of changes on V8 api to support split window: Security context is removed from V8, so does related API functions; A global object can be detached from its context and reused by a new context; Access checks on an object template can be turned on/off by default; An object can turn on its access checks later; V8 has a new object type, ApiGlobalObject, which is the outer window object type. The existing JSGlobalObject becomes the inner window object type. Security checks are moved from JSGlobalObject to ApiGlobalObject. ApiGlobalObject is the one exposed to JavaScript, it is accessible through Context::Global(). ApiGlobalObject's prototype is set to JSGlobalObject so that property lookups are forwarded to JSGlobalObject. ApiGlobalObject forwards all other property access requests to JSGlobalObject, such as SetProperty, DeleteProperty, etc. Security token is moved to a global context, and ApiGlobalObject has a reference to its global context. JSGlobalObject has a reference to its global context as well. When accessing properties on a global object in JavaScript, the domain security check is performed by comparing the security token of the lexical context (Top::global_context()) to the token of global object's context. The check is only needed when the receiver is a window object, such as 'window.document'. Accessing global variables, such as 'var foo = 3; foo' does not need checks because the receiver is the inner window object. When an outer window is detached from its global context (when a frame navigates away from a page), it is completely detached from the inner window. A new context is created for the new page, and the outer global object is reused. At this point, the access check on the DOMWindow wrapper of the old context is turned on. The code in old context is still able to access DOMWindow properties, but it has to go through domain security checks. It is debatable on how to implement the outer window object. Currently each property access function has to check if the receiver is ApiGlobalObject type. This approach might be error-prone that one may forget to check the receiver when adding new functions. It is unlikely a performance issue because accessing global variables are more common than 'window.foo' style coding. I am still working on the ARM port, and I'd like to hear comments and suggestions on the best way to support it in V8. Review URL: http://codereview.chromium.org/7366 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@540 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2008-10-21 19:07:58 +00:00
/** Restores the security token to the default value. */
void UseDefaultSecurityToken();
/** 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();
/**
* 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 do this by constructing
* a v8::Locker object. After the code using V8 has completed for the
* current thread you can call the destructor. This can be combined
* with C++ scope-based construction as follows:
*
* \code
* ...
* {
* v8::Locker locker;
* ...
* // Code using V8 goes here.
* ...
* } // Destructor called here
* \endcode
*
* If you wish to stop using V8 in a thread A you can do this by either
* by destroying the v8::Locker object as above or by constructing a
* v8::Unlocker object:
*
* \code
* {
* v8::Unlocker unlocker;
* ...
* // Code not using V8 goes here while V8 can run in another thread.
* ...
* } // Destructor called here.
* \endcode
*
* The Unlocker object is intended for use in a long-running callback
* from V8, where you want to release the V8 lock for other threads to
* use.
*
* The v8::Locker is a recursive lock. That is, you can lock more than
* once in a given thread. This can be useful if you have code that can
* be called either from code that holds the lock or from code that does
* not. The Unlocker is not recursive so you can not have several
* Unlockers on the stack at once, and you can not use an Unlocker in a
* thread that is not inside a Locker's scope.
*
* An unlocker will unlock several lockers if it has to and reinstate
* the correct depth of locking on its destruction. eg.:
*
* \code
* // V8 not locked.
* {
* v8::Locker locker;
* // V8 locked.
* {
* v8::Locker another_locker;
* // V8 still locked (2 levels).
* {
* v8::Unlocker unlocker;
* // V8 not locked.
* }
* // V8 locked again (2 levels).
* }
* // V8 still locked (1 level).
* }
* // V8 Now no longer locked.
* \endcode
*/
class EXPORT Unlocker {
public:
Unlocker();
~Unlocker();
};
class EXPORT Locker {
public:
Locker();
~Locker();
/**
* Start preemption.
*
* When preemption is started, a timer is fired every n milli seconds
* that will switch between multiple threads that are in contention
* for the V8 lock.
*/
static void StartPreemption(int every_n_ms);
/**
* Stop preemption.
*/
static void StopPreemption();
/**
* Returns whether or not the locker is locked by the current thread.
*/
static bool IsLocked();
private:
bool has_lock_;
bool top_level_;
// Disallow copying and assigning.
Locker(const Locker&);
void operator=(const Locker&);
};
// --- I m p l e m e n t a t i o n ---
template <class T>
Handle<T>::Handle() : val_(0) { }
template <class T>
Local<T>::Local() : Handle<T>() { }
template <class T>
Local<T> Local<T>::New(Handle<T> that) {
if (that.IsEmpty()) return Local<T>();
void** p = reinterpret_cast<void**>(*that);
return Local<T>(reinterpret_cast<T*>(HandleScope::CreateHandle(*p)));
}
template <class T>
Persistent<T> Persistent<T>::New(Handle<T> that) {
if (that.IsEmpty()) return Persistent<T>();
void** p = reinterpret_cast<void**>(*that);
return Persistent<T>(reinterpret_cast<T*>(V8::GlobalizeReference(p)));
}
template <class T>
bool Persistent<T>::IsNearDeath() {
if (this->IsEmpty()) return false;
return V8::IsGlobalNearDeath(reinterpret_cast<void**>(**this));
}
template <class T>
bool Persistent<T>::IsWeak() {
if (this->IsEmpty()) return false;
return V8::IsGlobalWeak(reinterpret_cast<void**>(**this));
}
template <class T>
void Persistent<T>::Dispose() {
if (this->IsEmpty()) return;
V8::DisposeGlobal(reinterpret_cast<void**>(**this));
}
template <class T>
Persistent<T>::Persistent() : Handle<T>() { }
template <class T>
void Persistent<T>::MakeWeak(void* parameters, WeakReferenceCallback callback) {
V8::MakeWeak(reinterpret_cast<void**>(**this), parameters, callback);
}
template <class T>
void Persistent<T>::ClearWeak() {
V8::ClearWeak(reinterpret_cast<void**>(**this));
}
template <class T>
T* Handle<T>::operator->() {
return val_;
}
template <class T>
T* Handle<T>::operator*() {
return val_;
}
Local<Value> Arguments::operator[](int i) const {
if (i < 0 || length_ <= i) return Local<Value>(*Undefined());
return Local<Value>(reinterpret_cast<Value*>(values_ - i));
}
Local<Function> Arguments::Callee() const {
return callee_;
}
Local<Object> Arguments::This() const {
return Local<Object>(reinterpret_cast<Object*>(values_ + 1));
}
Local<Object> Arguments::Holder() const {
return holder_;
}
Local<Value> Arguments::Data() const {
return data_;
}
bool Arguments::IsConstructCall() const {
return is_construct_call_;
}
int Arguments::Length() const {
return length_;
}
Local<Value> AccessorInfo::Data() const {
return data_;
}
Local<Object> AccessorInfo::This() const {
return self_;
}
Local<Object> AccessorInfo::Holder() const {
return holder_;
}
template <class T>
Local<T> HandleScope::Close(Handle<T> value) {
void** after = RawClose(reinterpret_cast<void**>(*value));
return Local<T>(reinterpret_cast<T*>(after));
}
Handle<Value> ScriptOrigin::ResourceName() const {
return resource_name_;
}
Handle<Integer> ScriptOrigin::ResourceLineOffset() const {
return resource_line_offset_;
}
Handle<Integer> ScriptOrigin::ResourceColumnOffset() const {
return resource_column_offset_;
}
Handle<Boolean> Boolean::New(bool value) {
return value ? True() : False();
}
void Template::Set(const char* name, v8::Handle<Data> value) {
Set(v8::String::New(name), value);
}
/**
* \example shell.cc
* A simple shell that takes a list of expressions on the
* command-line and executes them.
*/
/**
* \example process.cc
*/
} // namespace v8
#undef EXPORT
#undef EXPORT_INLINE
#undef TYPE_CHECK
#endif // V8_H_