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// Copyright 2007-2009 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
// When compiling on MinGW stdint.h is available.
#ifdef __MINGW32__
#include <stdint.h>
#else // __MINGW32__
typedef signed char int8_t;
typedef unsigned char uint8_t;
typedef short int16_t; // NOLINT
typedef unsigned short uint16_t; // NOLINT
typedef int int32_t;
typedef unsigned int uint32_t;
typedef __int64 int64_t;
typedef unsigned __int64 uint64_t;
// intptr_t and friends are defined in crtdefs.h through stdio.h.
#endif // __MINGW32__
// 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 V8EXPORT and V8EXPORT_INLINE is that classes which
// have their code inside this header file need 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 V8EXPORT __declspec(dllexport)
#define V8EXPORT_INLINE __declspec(dllexport)
#elif USING_V8_SHARED
#define V8EXPORT __declspec(dllimport)
#define V8EXPORT_INLINE
#else
#define V8EXPORT
#define V8EXPORT_INLINE
#endif // BUILDING_V8_SHARED
#else // _WIN32
#include <stdint.h>
// Setup for Linux shared library export. There is no need to distinguish
// between building or using the V8 shared library, but we should not
// export symbols when we are building a static library.
#if defined(__GNUC__) && (__GNUC__ >= 4) && defined(V8_SHARED)
#define V8EXPORT __attribute__ ((visibility("default")))
#define V8EXPORT_INLINE __attribute__ ((visibility("default")))
#else // defined(__GNUC__) && (__GNUC__ >= 4)
#define V8EXPORT
#define V8EXPORT_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;
namespace internal {
class Arguments;
class Object;
class Top;
}
// --- 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 V8EXPORT_INLINE Handle {
public:
/**
* Creates an empty handle.
*/
inline 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() const { return val_ == 0; }
T* operator->() const { return val_; }
T* operator*() const { return val_; }
/**
* 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) const {
internal::Object** a = reinterpret_cast<internal::Object**>(**this);
internal::Object** b = reinterpret_cast<internal::Object**>(*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) const {
return !operator==(that);
}
template <class S> static inline Handle<T> Cast(Handle<S> that) {
#ifdef V8_ENABLE_CHECKS
// If we're going to perform the type check then we have to check
// that the handle isn't empty before doing the checked cast.
if (that.IsEmpty()) return Handle<T>();
#endif
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 V8EXPORT_INLINE Local : public Handle<T> {
public:
inline 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) {
#ifdef V8_ENABLE_CHECKS
// If we're going to perform the type check then we have to check
// that the handle isn't empty before doing the checked cast.
if (that.IsEmpty()) return Local<T>();
#endif
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.
*/
inline 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 V8EXPORT_INLINE Persistent : public Handle<T> {
public:
/**
* Creates an empty persistent handle that doesn't point to any
* storage cell.
*/
inline 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) {
#ifdef V8_ENABLE_CHECKS
// If we're going to perform the type check then we have to check
// that the handle isn't empty before doing the checked cast.
if (that.IsEmpty()) return Persistent<T>();
#endif
return Persistent<T>(T::Cast(*that));
}
/**
* Creates a new persistent handle for an existing local or
* persistent handle.
*/
inline 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.
*/
inline 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.
*/
inline void MakeWeak(void* parameters, WeakReferenceCallback callback);
/** Clears the weak reference to this object.*/
inline void ClearWeak();
/**
*Checks if the handle holds the only reference to an object.
*/
inline bool IsNearDeath() const;
/**
* Returns true if the handle's reference is weak.
*/
inline bool IsWeak() const;
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 V8EXPORT HandleScope {
public:
HandleScope();
~HandleScope();
/**
* 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 internal::Object** CreateHandle(internal::Object* 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);
// This Data class is accessible internally as HandleScopeData through a
// typedef in the ImplementationUtilities class.
class V8EXPORT Data {
public:
int extensions;
internal::Object** next;
internal::Object** limit;
inline void Initialize() {
extensions = -1;
next = limit = NULL;
}
};
Data previous_;
// Allow for the active closing of HandleScopes which allows to pass a handle
// from the HandleScope being closed to the next top most HandleScope.
bool is_closed_;
internal::Object** RawClose(internal::Object** value);
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 V8EXPORT 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 V8EXPORT 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;
virtual bool HasError() = 0;
};
/**
* The origin, within a file, of a script.
*/
class V8EXPORT 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 V8EXPORT 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.
*
* The script object returned is context independent; when run it
* will use the currently entered context.
*/
static Local<Script> New(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.
*
* The script object returned is context independent; when run it
* will use the currently entered context.
*/
static Local<Script> New(Handle<String> source,
Handle<Value> file_name);
/**
* 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.
*
* The script object returned is bound to the context that was active
* when this function was called. When run it will always use this
* context.
*/
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.
*
* The script object returned is bound to the context that was active
* when this function was called. When run it will always use this
* context.
*/
static Local<Script> Compile(Handle<String> source,
Handle<Value> file_name);
/**
* Runs the script returning the resulting value. If the script is
* context independent (created using ::New) it will be run in the
* currently entered context. If it is context specific (created
* using ::Compile) it will be run in the context in which it was
* compiled.
*/
Local<Value> Run();
/**
* Returns the script id value.
*/
Local<Value> Id();
/**
* Associate an additional data object with the script. This is mainly used
* with the debugger as this data object is only available through the
* debugger API.
*/
void SetData(Handle<String> data);
};
/**
* An error message.
*/
class V8EXPORT Message {
public:
Local<String> Get() const;
Local<String> GetSourceLine() const;
/**
* Returns the resource name for the script from where the function causing
* the error originates.
*/
Handle<Value> GetScriptResourceName() const;
/**
* Returns the resource data for the script from where the function causing
* the error originates.
*/
Handle<Value> GetScriptData() const;
/**
* Returns the number, 1-based, of the line where the error occurred.
*/
int GetLineNumber() const;
/**
* Returns the index within the script of the first character where
* the error occurred.
*/
int GetStartPosition() const;
/**
* Returns the index within the script of the last character where
* the error occurred.
*/
int GetEndPosition() const;
/**
* Returns the index within the line of the first character where
* the error occurred.
*/
int GetStartColumn() const;
/**
* Returns the index within the line of the last character where
* the error occurred.
*/
int GetEndColumn() const;
// 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 V8EXPORT Value : public Data {
public:
/**
* Returns true if this value is the undefined value. See ECMA-262
* 4.3.10.
*/
bool IsUndefined() const;
/**
* Returns true if this value is the null value. See ECMA-262
* 4.3.11.
*/
bool IsNull() const;
/**
* Returns true if this value is true.
*/
bool IsTrue() const;
/**
* Returns true if this value is false.
*/
bool IsFalse() const;
/**
* Returns true if this value is an instance of the String type.
* See ECMA-262 8.4.
*/
inline bool IsString() const;
/**
* Returns true if this value is a function.
*/
bool IsFunction() const;
/**
* Returns true if this value is an array.
*/
bool IsArray() const;
/**
* Returns true if this value is an object.
*/
bool IsObject() const;
/**
* Returns true if this value is boolean.
*/
bool IsBoolean() const;
/**
* Returns true if this value is a number.
*/
bool IsNumber() const;
/**
* Returns true if this value is external.
*/
bool IsExternal() const;
/**
* Returns true if this value is a 32-bit signed integer.
*/
bool IsInt32() const;
/**
* Returns true if this value is a Date.
*/
bool IsDate() const;
Local<Boolean> ToBoolean() const;
Local<Number> ToNumber() const;
Local<String> ToString() const;
Local<String> ToDetailString() const;
Local<Object> ToObject() const;
Local<Integer> ToInteger() const;
Local<Uint32> ToUint32() const;
Local<Int32> ToInt32() const;
/**
* Attempts to convert a string to an array index.
* Returns an empty handle if the conversion fails.
*/
Local<Uint32> ToArrayIndex() const;
bool BooleanValue() const;
double NumberValue() const;
int64_t IntegerValue() const;
uint32_t Uint32Value() const;
int32_t Int32Value() const;
/** JS == */
bool Equals(Handle<Value> that) const;
bool StrictEquals(Handle<Value> that) const;
private:
inline bool QuickIsString() const;
bool FullIsString() const;
};
/**
* The superclass of primitive values. See ECMA-262 4.3.2.
*/
class V8EXPORT Primitive : public Value { };
/**
* A primitive boolean value (ECMA-262, 4.3.14). Either the true
* or false value.
*/
class V8EXPORT Boolean : public Primitive {
public:
bool Value() const;
static inline Handle<Boolean> New(bool value);
};
/**
* A JavaScript string value (ECMA-262, 4.3.17).
*/
class V8EXPORT String : public Primitive {
public:
/**
* Returns the number of characters in this string.
*/
int Length() const;
/**
* Returns the number of bytes in the UTF-8 encoded
* representation of this string.
*/
int Utf8Length() const;
/**
* 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) const; // UTF-16
int WriteAscii(char* buffer, int start = 0, int length = -1) const; // ASCII
int WriteUtf8(char* buffer, int length = -1) const; // UTF-8
/**
* A zero length string.
*/
static v8::Local<v8::String> Empty();
/**
* Returns true if the string is external
*/
bool IsExternal() const;
/**
* Returns true if the string is both external and ascii
*/
bool IsExternalAscii() const;
class V8EXPORT ExternalStringResourceBase {
public:
virtual ~ExternalStringResourceBase() {}
protected:
ExternalStringResourceBase() {}
private:
// Disallow copying and assigning.
ExternalStringResourceBase(const ExternalStringResourceBase&);
void operator=(const ExternalStringResourceBase&);
};
/**
* 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 V8EXPORT ExternalStringResource
: public ExternalStringResourceBase {
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() {}
};
/**
* 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 V8EXPORT ExternalAsciiStringResource
: public ExternalStringResourceBase {
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() {}
};
/**
* Get the ExternalStringResource for an external string. Returns
* NULL if IsExternal() doesn't return true.
*/
inline ExternalStringResource* GetExternalStringResource() const;
/**
* Get the ExternalAsciiStringResource for an external ascii string.
* Returns NULL if IsExternalAscii() doesn't return true.
*/
ExternalAsciiStringResource* GetExternalAsciiStringResource() const;
static inline 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 string by concatenating the left and the right strings
* passed in as parameters.
*/
static Local<String> Concat(Handle<String> left, Handle<String>right);
/**
* 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);
/**
* Associate an external string resource with this string by transforming it
* in place so that existing references to this string in the JavaScript heap
* will use the external string resource. The external string resource's
* character contents needs to be equivalent to this string.
* Returns true if the string has been changed to be an external string.
* The string is not modified if the operation fails.
*/
bool MakeExternal(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);
/**
* Associate an external string resource with this string by transforming it
* in place so that existing references to this string in the JavaScript heap
* will use the external string resource. The external string resource's
* character contents needs to be equivalent to this string.
* Returns true if the string has been changed to be an external string.
* The string is not modified if the operation fails.
*/
bool MakeExternal(ExternalAsciiStringResource* resource);
/**
* Returns true if this string can be made external.
*/
bool CanMakeExternal();
/** 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. If conversion to a string fails
* (eg. due to an exception in the toString() method of the object)
* then the length() method returns 0 and the * operator returns
* NULL.
*/
class V8EXPORT Utf8Value {
public:
explicit Utf8Value(Handle<v8::Value> obj);
~Utf8Value();
char* operator*() { return str_; }
const char* operator*() const { return str_; }
int length() const { 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.
* If conversion to a string fails (eg. due to an exception in the toString()
* method of the object) then the length() method returns 0 and the * operator
* returns NULL.
*/
class V8EXPORT AsciiValue {
public:
explicit AsciiValue(Handle<v8::Value> obj);
~AsciiValue();
char* operator*() { return str_; }
const char* operator*() const { return str_; }
int length() const { 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.
* If conversion to a string fails (eg. due to an exception in the toString()
* method of the object) then the length() method returns 0 and the * operator
* returns NULL.
*/
class V8EXPORT Value {
public:
explicit Value(Handle<v8::Value> obj);
~Value();
uint16_t* operator*() { return str_; }
const uint16_t* operator*() const { return str_; }
int length() const { return length_; }
private:
uint16_t* str_;
int length_;
// Disallow copying and assigning.
Value(const Value&);
void operator=(const Value&);
};
private:
void VerifyExternalStringResource(ExternalStringResource* val) const;
static void CheckCast(v8::Value* obj);
};
/**
* A JavaScript number value (ECMA-262, 4.3.20)
*/
class V8EXPORT Number : public Primitive {
public:
double Value() const;
static Local<Number> New(double value);
static inline Number* Cast(v8::Value* obj);
private:
Number();
static void CheckCast(v8::Value* obj);
};
/**
* A JavaScript value representing a signed integer.
*/
class V8EXPORT Integer : public Number {
public:
static Local<Integer> New(int32_t value);
static Local<Integer> NewFromUnsigned(uint32_t value);
int64_t Value() const;
static inline Integer* Cast(v8::Value* obj);
private:
Integer();
static void CheckCast(v8::Value* obj);
};
/**
* A JavaScript value representing a 32-bit signed integer.
*/
class V8EXPORT Int32 : public Integer {
public:
int32_t Value() const;
private:
Int32();
};
/**
* A JavaScript value representing a 32-bit unsigned integer.
*/
class V8EXPORT Uint32 : public Integer {
public:
uint32_t Value() const;
private:
Uint32();
};
/**
* An instance of the built-in Date constructor (ECMA-262, 15.9).
*/
class V8EXPORT 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() const;
static inline Date* Cast(v8::Value* obj);
private:
static void CheckCast(v8::Value* obj);
};
enum PropertyAttribute {
None = 0,
ReadOnly = 1 << 0,
DontEnum = 1 << 1,
DontDelete = 1 << 2
};
enum ExternalArrayType {
kExternalByteArray = 1,
kExternalUnsignedByteArray,
kExternalShortArray,
kExternalUnsignedShortArray,
kExternalIntArray,
kExternalUnsignedIntArray,
kExternalFloatArray
};
/**
* A JavaScript object (ECMA-262, 4.3.3)
*/
class V8EXPORT Object : public Value {
public:
bool Set(Handle<Value> key,
Handle<Value> value,
PropertyAttribute attribs = None);
// Sets a local property on this object bypassing interceptors and
// overriding accessors or read-only properties.
//
// Note that if the object has an interceptor the property will be set
// locally, but since the interceptor takes precedence the local property
// will only be returned if the interceptor doesn't return a value.
//
// Note also that this only works for named properties.
bool ForceSet(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);
// Delete a property on this object bypassing interceptors and
// ignoring dont-delete attributes.
bool ForceDelete(Handle<Value> 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();
/**
* Set the prototype object. This does not skip objects marked to
* be skipped by __proto__ and it does not consult the security
* handler.
*/
bool SetPrototype(Handle<Value> prototype);
/**
* Finds an instance of the given function template in the prototype
* chain.
*/
Local<Object> FindInstanceInPrototypeChain(Handle<FunctionTemplate> tmpl);
/**
* 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. */
inline Local<Value> GetInternalField(int index);
/** Sets the value in an internal field. */
void SetInternalField(int index, Handle<Value> value);
/** Gets a native pointer from an internal field. */
inline void* GetPointerFromInternalField(int index);
/** Sets a native pointer in an internal field. */
void SetPointerInInternalField(int index, void* 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.
*/
Local<Value> GetRealNamedPropertyInPrototypeChain(Handle<String> key);
/**
* If result.IsEmpty() no real property was located on the object or
* in the prototype chain.
* This means interceptors in the prototype chain are not called.
*/
Local<Value> GetRealNamedProperty(Handle<String> key);
/** Tests for a named lookup interceptor.*/
bool HasNamedLookupInterceptor();
/** Tests for an index lookup interceptor.*/
bool HasIndexedLookupInterceptor();
/**
* 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.
*/
void TurnOnAccessCheck();
/**
* Returns the identity hash for this object. The current implemenation uses
* a hidden property on the object to store the identity hash.
*
* The return value will never be 0. Also, it is not guaranteed to be
* unique.
*/
int GetIdentityHash();
/**
* Access hidden properties on JavaScript objects. These properties are
* hidden from the executing JavaScript and only accessible through the V8
* C++ API. Hidden properties introduced by V8 internally (for example the
* identity hash) are prefixed with "v8::".
*/
bool SetHiddenValue(Handle<String> key, Handle<Value> value);
Local<Value> GetHiddenValue(Handle<String> key);
bool DeleteHiddenValue(Handle<String> key);
/**
* Returns true if this is an instance of an api function (one
* created from a function created from a function template) and has
* been modified since it was created. Note that this method is
* conservative and may return true for objects that haven't actually
* been modified.
*/
bool IsDirty();
/**
* Clone this object with a fast but shallow copy. Values will point
* to the same values as the original object.
*/
Local<Object> Clone();
/**
* Set the backing store of the indexed properties to be managed by the
* embedding layer. Access to the indexed properties will follow the rules
* spelled out in CanvasPixelArray.
* Note: The embedding program still owns the data and needs to ensure that
* the backing store is preserved while V8 has a reference.
*/
void SetIndexedPropertiesToPixelData(uint8_t* data, int length);
/**
* Set the backing store of the indexed properties to be managed by the
* embedding layer. Access to the indexed properties will follow the rules
* spelled out for the CanvasArray subtypes in the WebGL specification.
* Note: The embedding program still owns the data and needs to ensure that
* the backing store is preserved while V8 has a reference.
*/
void SetIndexedPropertiesToExternalArrayData(void* data,
ExternalArrayType array_type,
int number_of_elements);
static Local<Object> New();
static inline Object* Cast(Value* obj);
private:
Object();
static void CheckCast(Value* obj);
Local<Value> CheckedGetInternalField(int index);
void* SlowGetPointerFromInternalField(int index);
/**
* If quick access to the internal field is possible this method
* returns the value. Otherwise an empty handle is returned.
*/
inline Local<Value> UncheckedGetInternalField(int index);
};
/**
* An instance of the built-in array constructor (ECMA-262, 15.4.2).
*/
class V8EXPORT Array : public Object {
public:
uint32_t Length() const;
/**
* Clones an element at index |index|. Returns an empty
* handle if cloning fails (for any reason).
*/
Local<Object> CloneElementAt(uint32_t index);
static Local<Array> New(int length = 0);
static inline Array* Cast(Value* obj);
private:
Array();
static void CheckCast(Value* obj);
};
/**
* A JavaScript function object (ECMA-262, 15.3).
*/
class V8EXPORT Function : public Object {
public:
Local<Object> NewInstance() const;
Local<Object> NewInstance(int argc, Handle<Value> argv[]) const;
Local<Value> Call(Handle<Object> recv, int argc, Handle<Value> argv[]);
void SetName(Handle<String> name);
Handle<Value> GetName() const;
static inline Function* Cast(Value* obj);
private:
Function();
static void CheckCast(Value* obj);
};
/**
* A JavaScript value that wraps a C++ void*. This type of value is
* mainly used to associate C++ data structures with JavaScript
* objects.
*
* The Wrap function V8 will return the most optimal Value object wrapping the
* C++ void*. The type of the value is not guaranteed to be an External object
* and no assumptions about its type should be made. To access the wrapped
* value Unwrap should be used, all other operations on that object will lead
* to unpredictable results.
*/
class V8EXPORT External : public Value {
public:
static Local<Value> Wrap(void* data);
static inline void* Unwrap(Handle<Value> obj);
static Local<External> New(void* value);
static inline External* Cast(Value* obj);
void* Value() const;
private:
External();
static void CheckCast(v8::Value* obj);
static inline void* QuickUnwrap(Handle<v8::Value> obj);
static void* FullUnwrap(Handle<v8::Value> obj);
};
// --- T e m p l a t e s ---
/**
* The superclass of object and function templates.
*/
class V8EXPORT 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 V8EXPORT 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 V8EXPORT AccessorInfo {
public:
inline AccessorInfo(internal::Object** args)
: args_(args) { }
inline Local<Value> Data() const;
inline Local<Object> This() const;
inline Local<Object> Holder() const;
private:
internal::Object** args_;
};
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 host object.
*/
typedef bool (*NamedSecurityCallback)(Local<Object> host,
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 host object.
*/
typedef bool (*IndexedSecurityCallback)(Local<Object> host,
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. The lifetime of the created function is equal to the
* lifetime of the context. So in case the embedder needs to create
* temporary functions that can be collected using Scripts is
* preferred.
*
* 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 V8EXPORT 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 V8EXPORT 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.
* 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,
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 V8EXPORT 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 V8EXPORT 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 V8EXPORT 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 V8EXPORT RegisterExtension(Extension* extension);
/**
* Ignore
*/
class V8EXPORT DeclareExtension {
public:
inline DeclareExtension(Extension* extension) {
RegisterExtension(extension);
}
};
// --- S t a t i c s ---
Handle<Primitive> V8EXPORT Undefined();
Handle<Primitive> V8EXPORT Null();
Handle<Boolean> V8EXPORT True();
Handle<Boolean> V8EXPORT False();
/**
* A set of constraints that specifies the limits of the runtime's memory use.
* You must set the heap size before initializing the VM - the size cannot be
* adjusted after the VM is initialized.
*
* If you are using threads then you should hold the V8::Locker lock while
* setting the stack limit and you must set a non-default stack limit separately
* for each thread.
*/
class V8EXPORT 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_; }
// Sets an address beyond which the VM's stack may not grow.
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> V8EXPORT ThrowException(Handle<Value> exception);
/**
* Create new error objects by calling the corresponding error object
* constructor with the message.
*/
class V8EXPORT 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 char* name);
typedef void* (*CreateHistogramCallback)(const char* name,
int min,
int max,
size_t buckets);
typedef void (*AddHistogramSampleCallback)(void* histogram, int sample);
// --- 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)();
/**
* Profiler modules.
*
* In V8, profiler consists of several modules: CPU profiler, and different
* kinds of heap profiling. Each can be turned on / off independently.
* When PROFILER_MODULE_HEAP_SNAPSHOT flag is passed to ResumeProfilerEx,
* modules are enabled only temporarily for making a snapshot of the heap.
*/
enum ProfilerModules {
PROFILER_MODULE_NONE = 0,
PROFILER_MODULE_CPU = 1,
PROFILER_MODULE_HEAP_STATS = 1 << 1,
PROFILER_MODULE_JS_CONSTRUCTORS = 1 << 2,
PROFILER_MODULE_HEAP_SNAPSHOT = 1 << 16
};
/**
* Collection of V8 heap information.
*
* Instances of this class can be passed to v8::V8::HeapStatistics to
* get heap statistics from V8.
*/
class V8EXPORT HeapStatistics {
public:
HeapStatistics();
size_t total_heap_size() { return total_heap_size_; }
size_t used_heap_size() { return used_heap_size_; }
private:
void set_total_heap_size(size_t size) { total_heap_size_ = size; }
void set_used_heap_size(size_t size) { used_heap_size_ = size; }
size_t total_heap_size_;
size_t used_heap_size_;
friend class V8;
};
/**
* Container class for static utility functions.
*/
class V8EXPORT 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 host application to provide a mechanism for recording
* histograms. The CreateHistogram function returns a
* histogram which will later be passed to the AddHistogramSample
* function.
*/
static void SetCreateHistogramFunction(CreateHistogramCallback);
static void SetAddHistogramSampleFunction(AddHistogramSampleCallback);
/**
* 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 instance to simulate DOM tree connections among JS
* wrapper objects.
*/
static void AddObjectGroup(Persistent<Value>* objects, size_t length);
/**
* Initializes from snapshot if possible. Otherwise, attempts to
* initialize from scratch. This function is called implicitly if
* you use the API without calling it first.
*/
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);
/**
* Suspends recording of tick samples in the profiler.
* When the V8 profiling mode is enabled (usually via command line
* switches) this function suspends recording of tick samples.
* Profiling ticks are discarded until ResumeProfiler() is called.
*
* See also the --prof and --prof_auto command line switches to
* enable V8 profiling.
*/
static void PauseProfiler();
/**
* Resumes recording of tick samples in the profiler.
* See also PauseProfiler().
*/
static void ResumeProfiler();
/**
* Return whether profiler is currently paused.
*/
static bool IsProfilerPaused();
/**
* Resumes specified profiler modules.
* "ResumeProfiler" is equivalent to "ResumeProfilerEx(PROFILER_MODULE_CPU)".
* See ProfilerModules enum.
*
* \param flags Flags specifying profiler modules.
*/
static void ResumeProfilerEx(int flags);
/**
* Pauses specified profiler modules.
* "PauseProfiler" is equivalent to "PauseProfilerEx(PROFILER_MODULE_CPU)".
* See ProfilerModules enum.
*
* \param flags Flags specifying profiler modules.
*/
static void PauseProfilerEx(int flags);
/**
* Returns active (resumed) profiler modules.
* See ProfilerModules enum.
*
* \returns active profiler modules.
*/
static int GetActiveProfilerModules();
/**
* If logging is performed into a memory buffer (via --logfile=*), allows to
* retrieve previously written messages. This can be used for retrieving
* profiler log data in the application. This function is thread-safe.
*
* Caller provides a destination buffer that must exist during GetLogLines
* call. Only whole log lines are copied into the buffer.
*
* \param from_pos specified a point in a buffer to read from, 0 is the
* beginning of a buffer. It is assumed that caller updates its current
* position using returned size value from the previous call.
* \param dest_buf destination buffer for log data.
* \param max_size size of the destination buffer.
* \returns actual size of log data copied into buffer.
*/
static int GetLogLines(int from_pos, char* dest_buf, int max_size);
/**
* Retrieve the V8 thread id of the calling thread.
*
* The thread id for a thread should only be retrieved after the V8
* lock has been acquired with a Locker object with that thread.
*/
static int GetCurrentThreadId();
/**
* Forcefully terminate execution of a JavaScript thread. This can
* be used to terminate long-running scripts.
*
* TerminateExecution should only be called when then V8 lock has
* been acquired with a Locker object. Therefore, in order to be
* able to terminate long-running threads, preemption must be
* enabled to allow the user of TerminateExecution to acquire the
* lock.
*
* The termination is achieved by throwing an exception that is
* uncatchable by JavaScript exception handlers. Termination
* exceptions act as if they were caught by a C++ TryCatch exception
* handlers. If forceful termination is used, any C++ TryCatch
* exception handler that catches an exception should check if that
* exception is a termination exception and immediately return if
* that is the case. Returning immediately in that case will
* continue the propagation of the termination exception if needed.
*
* The thread id passed to TerminateExecution must have been
* obtained by calling GetCurrentThreadId on the thread in question.
*
* \param thread_id The thread id of the thread to terminate.
*/
static void TerminateExecution(int thread_id);
/**
* Forcefully terminate the current thread of JavaScript execution.
*
* This method can be used by any thread even if that thread has not
* acquired the V8 lock with a Locker object.
*/
static void TerminateExecution();
/**
* Releases any resources used by v8 and stops any utility threads
* that may be running. Note that disposing v8 is permanent, it
* cannot be reinitialized.
*
* It should generally not be necessary to dispose v8 before exiting
* a process, this should happen automatically. It is only necessary
* to use if the process needs the resources taken up by v8.
*/
static bool Dispose();
/**
* Get statistics about the heap memory usage.
*/
static void GetHeapStatistics(HeapStatistics* heap_statistics);
/**
* Optional notification that the embedder is idle.
* V8 uses the notification to reduce memory footprint.
* This call can be used repeatedly if the embedder remains idle.
* Returns true if the embedder should stop calling IdleNotification
* until real work has been done. This indicates that V8 has done
* as much cleanup as it will be able to do.
*/
static bool IdleNotification();
/**
* Optional notification that the system is running low on memory.
* V8 uses these notifications to attempt to free memory.
*/
static void LowMemoryNotification();
private:
V8();
static internal::Object** GlobalizeReference(internal::Object** handle);
static void DisposeGlobal(internal::Object** global_handle);
static void MakeWeak(internal::Object** global_handle,
void* data,
WeakReferenceCallback);
static void ClearWeak(internal::Object** global_handle);
static bool IsGlobalNearDeath(internal::Object** global_handle);
static bool IsGlobalWeak(internal::Object** 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 V8EXPORT 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;
/**
* For certain types of exceptions, it makes no sense to continue
* execution.
*
* Currently, the only type of exception that can be caught by a
* TryCatch handler and for which it does not make sense to continue
* is termination exception. Such exceptions are thrown when the
* TerminateExecution methods are called to terminate a long-running
* script.
*
* If CanContinue returns false, the correct action is to perform
* any C++ cleanup needed and then return.
*/
bool CanContinue() const;
/**
* Throws the exception caught by this TryCatch in a way that avoids
* it being caught again by this same TryCatch. As with ThrowException
* it is illegal to execute any JavaScript operations after calling
* ReThrow; the caller must return immediately to where the exception
* is caught.
*/
Handle<Value> ReThrow();
/**
* 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 .stack property of the thrown object. If no .stack
* property is present an empty handle is returned.
*/
Local<Value> StackTrace() 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);
private:
void* next_;
void* exception_;
void* message_;
bool is_verbose_ : 1;
bool can_continue_ : 1;
bool capture_message_ : 1;
bool rethrow_ : 1;
friend class v8::internal::Top;
};
// --- C o n t e x t ---
/**
* Ignore
*/
class V8EXPORT 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 V8EXPORT Context {
public:
/** Returns the global object of the context. */
Local<Object> Global();
/**
* 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();
/**
* Returns the context of the calling JavaScript code. That is the
* context of the top-most JavaScript frame. If there are no
* JavaScript frames an empty handle is returned.
*/
static Local<Context> GetCalling();
/**
* Sets the security token for the context. To access an object in
* another context, the security tokens must match.
*/
void SetSecurityToken(Handle<Value> token);
/** 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();
/**
* Associate an additional data object with the context. This is mainly used
* with the debugger to provide additional information on the context through
* the debugger API.
*/
void SetData(Handle<String> data);
Local<Value> GetData();
/**
* Stack-allocated class which sets the execution context for all
* operations executed within a local scope.
*/
class V8EXPORT 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 V8EXPORT Unlocker {
public:
Unlocker();
~Unlocker();
};
class V8EXPORT 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();
/**
* Returns whether v8::Locker is being used by this V8 instance.
*/
static bool IsActive() { return active_; }
private:
bool has_lock_;
bool top_level_;
static bool active_;
// 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 ---
namespace internal {
// Tag information for HeapObject.
const int kHeapObjectTag = 1;
const int kHeapObjectTagSize = 2;
const intptr_t kHeapObjectTagMask = (1 << kHeapObjectTagSize) - 1;
// Tag information for Smi.
const int kSmiTag = 0;
const int kSmiTagSize = 1;
const intptr_t kSmiTagMask = (1 << kSmiTagSize) - 1;
template <size_t ptr_size> struct SmiConstants;
// Smi constants for 32-bit systems.
template <> struct SmiConstants<4> {
static const int kSmiShiftSize = 0;
static const int kSmiValueSize = 31;
static inline int SmiToInt(internal::Object* value) {
int shift_bits = kSmiTagSize + kSmiShiftSize;
// Throw away top 32 bits and shift down (requires >> to be sign extending).
return static_cast<int>(reinterpret_cast<intptr_t>(value)) >> shift_bits;
}
};
// Smi constants for 64-bit systems.
template <> struct SmiConstants<8> {
static const int kSmiShiftSize = 31;
static const int kSmiValueSize = 32;
static inline int SmiToInt(internal::Object* value) {
int shift_bits = kSmiTagSize + kSmiShiftSize;
// Shift down and throw away top 32 bits.
return static_cast<int>(reinterpret_cast<intptr_t>(value) >> shift_bits);
}
};
const int kSmiShiftSize = SmiConstants<sizeof(void*)>::kSmiShiftSize;
const int kSmiValueSize = SmiConstants<sizeof(void*)>::kSmiValueSize;
template <size_t ptr_size> struct InternalConstants;
// Internal constants for 32-bit systems.
template <> struct InternalConstants<4> {
static const int kStringResourceOffset = 3 * sizeof(void*);
};
// Internal constants for 64-bit systems.
template <> struct InternalConstants<8> {
static const int kStringResourceOffset = 2 * sizeof(void*);
};
/**
* This class exports constants and functionality from within v8 that
* is necessary to implement inline functions in the v8 api. Don't
* depend on functions and constants defined here.
*/
class Internals {
public:
// These values match non-compiler-dependent values defined within
// the implementation of v8.
static const int kHeapObjectMapOffset = 0;
static const int kMapInstanceTypeOffset = sizeof(void*) + sizeof(int);
static const int kStringResourceOffset =
InternalConstants<sizeof(void*)>::kStringResourceOffset;
static const int kProxyProxyOffset = sizeof(void*);
static const int kJSObjectHeaderSize = 3 * sizeof(void*);
static const int kFullStringRepresentationMask = 0x07;
static const int kExternalTwoByteRepresentationTag = 0x03;
// These constants are compiler dependent so their values must be
// defined within the implementation.
V8EXPORT static int kJSObjectType;
V8EXPORT static int kFirstNonstringType;
V8EXPORT static int kProxyType;
static inline bool HasHeapObjectTag(internal::Object* value) {
return ((reinterpret_cast<intptr_t>(value) & kHeapObjectTagMask) ==
kHeapObjectTag);
}
static inline bool HasSmiTag(internal::Object* value) {
return ((reinterpret_cast<intptr_t>(value) & kSmiTagMask) == kSmiTag);
}
static inline int SmiValue(internal::Object* value) {
return SmiConstants<sizeof(void*)>::SmiToInt(value);
}
static inline int GetInstanceType(internal::Object* obj) {
typedef internal::Object O;
O* map = ReadField<O*>(obj, kHeapObjectMapOffset);
return ReadField<uint8_t>(map, kMapInstanceTypeOffset);
}
static inline void* GetExternalPointer(internal::Object* obj) {
if (HasSmiTag(obj)) {
return obj;
} else if (GetInstanceType(obj) == kProxyType) {
return ReadField<void*>(obj, kProxyProxyOffset);
} else {
return NULL;
}
}
static inline bool IsExternalTwoByteString(int instance_type) {
int representation = (instance_type & kFullStringRepresentationMask);
return representation == kExternalTwoByteRepresentationTag;
}
template <typename T>
static inline T ReadField(Object* ptr, int offset) {
uint8_t* addr = reinterpret_cast<uint8_t*>(ptr) + offset - kHeapObjectTag;
return *reinterpret_cast<T*>(addr);
}
};
}
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>();
internal::Object** p = reinterpret_cast<internal::Object**>(*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>();
internal::Object** p = reinterpret_cast<internal::Object**>(*that);
return Persistent<T>(reinterpret_cast<T*>(V8::GlobalizeReference(p)));
}
template <class T>
bool Persistent<T>::IsNearDeath() const {
if (this->IsEmpty()) return false;
return V8::IsGlobalNearDeath(reinterpret_cast<internal::Object**>(**this));
}
template <class T>
bool Persistent<T>::IsWeak() const {
if (this->IsEmpty()) return false;
return V8::IsGlobalWeak(reinterpret_cast<internal::Object**>(**this));
}
template <class T>
void Persistent<T>::Dispose() {
if (this->IsEmpty()) return;
V8::DisposeGlobal(reinterpret_cast<internal::Object**>(**this));
}
template <class T>
Persistent<T>::Persistent() : Handle<T>() { }
template <class T>
void Persistent<T>::MakeWeak(void* parameters, WeakReferenceCallback callback) {
V8::MakeWeak(reinterpret_cast<internal::Object**>(**this),
parameters,
callback);
}
template <class T>
void Persistent<T>::ClearWeak() {
V8::ClearWeak(reinterpret_cast<internal::Object**>(**this));
}
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_;
}
template <class T>
Local<T> HandleScope::Close(Handle<T> value) {
internal::Object** before = reinterpret_cast<internal::Object**>(*value);
internal::Object** after = RawClose(before);
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);
}
Local<Value> Object::GetInternalField(int index) {
#ifndef V8_ENABLE_CHECKS
Local<Value> quick_result = UncheckedGetInternalField(index);
if (!quick_result.IsEmpty()) return quick_result;
#endif
return CheckedGetInternalField(index);
}
Local<Value> Object::UncheckedGetInternalField(int index) {
typedef internal::Object O;
typedef internal::Internals I;
O* obj = *reinterpret_cast<O**>(this);
if (I::GetInstanceType(obj) == I::kJSObjectType) {
// If the object is a plain JSObject, which is the common case,
// we know where to find the internal fields and can return the
// value directly.
int offset = I::kJSObjectHeaderSize + (sizeof(void*) * index);
O* value = I::ReadField<O*>(obj, offset);
O** result = HandleScope::CreateHandle(value);
return Local<Value>(reinterpret_cast<Value*>(result));
} else {
return Local<Value>();
}
}
void* External::Unwrap(Handle<v8::Value> obj) {
#ifdef V8_ENABLE_CHECKS
return FullUnwrap(obj);
#else
return QuickUnwrap(obj);
#endif
}
void* External::QuickUnwrap(Handle<v8::Value> wrapper) {
typedef internal::Object O;
O* obj = *reinterpret_cast<O**>(const_cast<v8::Value*>(*wrapper));
return internal::Internals::GetExternalPointer(obj);
}
void* Object::GetPointerFromInternalField(int index) {
typedef internal::Object O;
typedef internal::Internals I;
O* obj = *reinterpret_cast<O**>(this);
if (I::GetInstanceType(obj) == I::kJSObjectType) {
// If the object is a plain JSObject, which is the common case,
// we know where to find the internal fields and can return the
// value directly.
int offset = I::kJSObjectHeaderSize + (sizeof(void*) * index);
O* value = I::ReadField<O*>(obj, offset);
return I::GetExternalPointer(value);
}
return SlowGetPointerFromInternalField(index);
}
String* String::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<String*>(value);
}
String::ExternalStringResource* String::GetExternalStringResource() const {
typedef internal::Object O;
typedef internal::Internals I;
O* obj = *reinterpret_cast<O**>(const_cast<String*>(this));
String::ExternalStringResource* result;
if (I::IsExternalTwoByteString(I::GetInstanceType(obj))) {
void* value = I::ReadField<void*>(obj, I::kStringResourceOffset);
result = reinterpret_cast<String::ExternalStringResource*>(value);
} else {
result = NULL;
}
#ifdef V8_ENABLE_CHECKS
VerifyExternalStringResource(result);
#endif
return result;
}
bool Value::IsString() const {
#ifdef V8_ENABLE_CHECKS
return FullIsString();
#else
return QuickIsString();
#endif
}
bool Value::QuickIsString() const {
typedef internal::Object O;
typedef internal::Internals I;
O* obj = *reinterpret_cast<O**>(const_cast<Value*>(this));
if (!I::HasHeapObjectTag(obj)) return false;
return (I::GetInstanceType(obj) < I::kFirstNonstringType);
}
Number* Number::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Number*>(value);
}
Integer* Integer::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Integer*>(value);
}
Date* Date::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Date*>(value);
}
Object* Object::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Object*>(value);
}
Array* Array::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Array*>(value);
}
Function* Function::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<Function*>(value);
}
External* External::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<External*>(value);
}
Local<Value> AccessorInfo::Data() const {
return Local<Value>(reinterpret_cast<Value*>(&args_[-3]));
}
Local<Object> AccessorInfo::This() const {
return Local<Object>(reinterpret_cast<Object*>(&args_[0]));
}
Local<Object> AccessorInfo::Holder() const {
return Local<Object>(reinterpret_cast<Object*>(&args_[-1]));
}
/**
* \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 V8EXPORT
#undef V8EXPORT_INLINE
#undef TYPE_CHECK
#endif // V8_H_
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