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// Copyright 2011 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 "v8stdint.h"
#ifdef _WIN32
// 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.
#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)
#elif USING_V8_SHARED
#define V8EXPORT __declspec(dllimport)
#else
#define V8EXPORT
#endif // BUILDING_V8_SHARED
#else // _WIN32
// 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")))
#else // defined(__GNUC__) && (__GNUC__ >= 4)
#define V8EXPORT
#endif // defined(__GNUC__) && (__GNUC__ >= 4)
#endif // _WIN32
/**
* The v8 JavaScript engine.
*/
namespace v8 {
class Context;
class String;
class StringObject;
class Value;
class Utils;
class Number;
class NumberObject;
class Object;
class Array;
class Int32;
class Uint32;
class External;
class Primitive;
class Boolean;
class BooleanObject;
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;
class AccessorInfo;
class StackTrace;
class StackFrame;
namespace internal {
class Arguments;
class Object;
class Heap;
class HeapObject;
class Isolate;
}
// --- Weak Handles ---
/**
* A weak reference callback function.
*
* This callback should either explicitly invoke Dispose on |object| if
* V8 wrapper is not needed anymore, or 'revive' it by invocation of MakeWeak.
*
* \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);
// --- Handles ---
#define TYPE_CHECK(T, S) \
while (false) { \
*(static_cast<T* volatile*>(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
* a 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 Handle {
public:
/**
* Creates an empty handle.
*/
inline Handle() : val_(0) {}
/**
* Creates a new handle for the specified value.
*/
inline 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 compile-time 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.
*/
inline bool IsEmpty() const { return val_ == 0; }
/**
* Sets the handle to be empty. IsEmpty() will then return true.
*/
inline void Clear() { val_ = 0; }
inline T* operator->() const { return val_; }
inline T* operator*() const { return val_; }
/**
* 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> inline 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> inline 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));
}
template <class S> inline Handle<S> As() {
return Handle<S>::Cast(*this);
}
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 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));
}
template <class S> inline Local<S> As() {
return Local<S>::Cast(*this);
}
/** 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 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 compile-time 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));
}
template <class S> inline Persistent<S> As() {
return Persistent<S>::Cast(*this);
}
/**
* 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 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();
/**
* Marks the reference to this object independent. Garbage collector
* is free to ignore any object groups containing this object.
* Weak callback for an independent handle should not
* assume that it will be preceded by a global GC prologue callback
* or followed by a global GC epilogue callback.
*/
inline void MarkIndependent();
/**
*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;
/**
* Assigns a wrapper class ID to the handle. See RetainedObjectInfo
* interface description in v8-profiler.h for details.
*/
inline void SetWrapperClassId(uint16_t class_id);
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);
// Faster version, uses HeapObject to obtain the current Isolate.
static internal::Object** CreateHandle(internal::HeapObject* 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:
internal::Object** next;
internal::Object** limit;
int level;
inline void Initialize() {
next = limit = NULL;
level = 0;
}
};
void Leave();
internal::Isolate* isolate_;
internal::Object** prev_next_;
internal::Object** prev_limit_;
// 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;
};
// --- Special objects ---
/**
* 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() { }
/**
* Pre-compiles the specified script (context-independent).
*
* \param input Pointer to UTF-8 script source code.
* \param length Length of UTF-8 script source code.
*/
static ScriptData* PreCompile(const char* input, int length);
/**
* Pre-compiles the specified script (context-independent).
*
* NOTE: Pre-compilation using this method cannot happen on another thread
* without using Lockers.
*
* \param source Script source code.
*/
static ScriptData* PreCompile(Handle<String> source);
/**
* Load previous pre-compilation data.
*
* \param data Pointer to data returned by a call to Data() of a previous
* ScriptData. Ownership is not transferred.
* \param length Length of data.
*/
static ScriptData* New(const char* data, int length);
/**
* Returns the length of Data().
*/
virtual int Length() = 0;
/**
* Returns a serialized representation of this ScriptData that can later be
* passed to New(). NOTE: Serialized data is platform-dependent.
*/
virtual const char* Data() = 0;
/**
* Returns true if the source code could not be parsed.
*/
virtual bool HasError() = 0;
};
/**
* The origin, within a file, of a script.
*/
class ScriptOrigin {
public:
inline 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 (context-independent).
*
* \param source Script source code.
* \param origin Script origin, owned by caller, no references are kept
* when New() returns
* \param pre_data Pre-parsing data, as obtained by ScriptData::PreCompile()
* using pre_data speeds compilation if it's done multiple times.
* Owned by caller, no references are kept when New() returns.
* \param script_data Arbitrary data associated with script. Using
* this has same effect as calling SetData(), but allows data to be
* available to compile event handlers.
* \return Compiled script object (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,
Handle<String> script_data = Handle<String>());
/**
* Compiles the specified script using the specified file name
* object (typically a string) as the script's origin.
*
* \param source Script source code.
* \param file_name file name object (typically a string) to be used
* as the script's origin.
* \return Compiled script object (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 (bound to current context).
*
* \param source Script source code.
* \param origin Script origin, owned by caller, no references are kept
* when Compile() returns
* \param pre_data Pre-parsing data, as obtained by ScriptData::PreCompile()
* using pre_data speeds compilation if it's done multiple times.
* Owned by caller, no references are kept when Compile() returns.
* \param script_data Arbitrary data associated with script. Using
* this has same effect as calling SetData(), but makes data available
* earlier (i.e. to compile event handlers).
* \return Compiled script object, 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,
Handle<String> script_data = Handle<String>());
/**
* Compiles the specified script using the specified file name
* object (typically a string) as the script's origin.
*
* \param source Script source code.
* \param file_name File name to use as script's origin
* \param script_data Arbitrary data associated with script. Using
* this has same effect as calling SetData(), but makes data available
* earlier (i.e. to compile event handlers).
* \return Compiled script object, 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,
Handle<String> script_data = Handle<String>());
/**
* 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;
/**
* Exception stack trace. By default stack traces are not captured for
* uncaught exceptions. SetCaptureStackTraceForUncaughtExceptions allows
* to change this option.
*/
Handle<StackTrace> GetStackTrace() 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);
static const int kNoLineNumberInfo = 0;
static const int kNoColumnInfo = 0;
};
/**
* Representation of a JavaScript stack trace. The information collected is a
* snapshot of the execution stack and the information remains valid after
* execution continues.
*/
class V8EXPORT StackTrace {
public:
/**
* Flags that determine what information is placed captured for each
* StackFrame when grabbing the current stack trace.
*/
enum StackTraceOptions {
kLineNumber = 1,
kColumnOffset = 1 << 1 | kLineNumber,
kScriptName = 1 << 2,
kFunctionName = 1 << 3,
kIsEval = 1 << 4,
kIsConstructor = 1 << 5,
kScriptNameOrSourceURL = 1 << 6,
kOverview = kLineNumber | kColumnOffset | kScriptName | kFunctionName,
kDetailed = kOverview | kIsEval | kIsConstructor | kScriptNameOrSourceURL
};
/**
* Returns a StackFrame at a particular index.
*/
Local<StackFrame> GetFrame(uint32_t index) const;
/**
* Returns the number of StackFrames.
*/
int GetFrameCount() const;
/**
* Returns StackTrace as a v8::Array that contains StackFrame objects.
*/
Local<Array> AsArray();
/**
* Grab a snapshot of the current JavaScript execution stack.
*
* \param frame_limit The maximum number of stack frames we want to capture.
* \param options Enumerates the set of things we will capture for each
* StackFrame.
*/
static Local<StackTrace> CurrentStackTrace(
int frame_limit,
StackTraceOptions options = kOverview);
};
/**
* A single JavaScript stack frame.
*/
class V8EXPORT StackFrame {
public:
/**
* Returns the number, 1-based, of the line for the associate function call.
* This method will return Message::kNoLineNumberInfo if it is unable to
* retrieve the line number, or if kLineNumber was not passed as an option
* when capturing the StackTrace.
*/
int GetLineNumber() const;
/**
* Returns the 1-based column offset on the line for the associated function
* call.
* This method will return Message::kNoColumnInfo if it is unable to retrieve
* the column number, or if kColumnOffset was not passed as an option when
* capturing the StackTrace.
*/
int GetColumn() const;
/**
* Returns the name of the resource that contains the script for the
* function for this StackFrame.
*/
Local<String> GetScriptName() const;
/**
* Returns the name of the resource that contains the script for the
* function for this StackFrame or sourceURL value if the script name
* is undefined and its source ends with //@ sourceURL=... string.
*/
Local<String> GetScriptNameOrSourceURL() const;
/**
* Returns the name of the function associated with this stack frame.
*/
Local<String> GetFunctionName() const;
/**
* Returns whether or not the associated function is compiled via a call to
* eval().
*/
bool IsEval() const;
/**
* Returns whether or not the associated function is called as a
* constructor via "new".
*/
bool IsConstructor() const;
};
// --- Value ---
/**
* The superclass of all JavaScript values and objects.
*/
class Value : public Data {
public:
/**
* Returns true if this value is the undefined value. See ECMA-262
* 4.3.10.
*/
V8EXPORT bool IsUndefined() const;
/**
* Returns true if this value is the null value. See ECMA-262
* 4.3.11.
*/
V8EXPORT bool IsNull() const;
/**
* Returns true if this value is true.
*/
V8EXPORT bool IsTrue() const;
/**
* Returns true if this value is false.
*/
V8EXPORT 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.
*/
V8EXPORT bool IsFunction() const;
/**
* Returns true if this value is an array.
*/
V8EXPORT bool IsArray() const;
/**
* Returns true if this value is an object.
*/
V8EXPORT bool IsObject() const;
/**
* Returns true if this value is boolean.
*/
V8EXPORT bool IsBoolean() const;
/**
* Returns true if this value is a number.
*/
V8EXPORT bool IsNumber() const;
/**
* Returns true if this value is external.
*/
V8EXPORT bool IsExternal() const;
/**
* Returns true if this value is a 32-bit signed integer.
*/
V8EXPORT bool IsInt32() const;
/**
* Returns true if this value is a 32-bit unsigned integer.
*/
V8EXPORT bool IsUint32() const;
/**
* Returns true if this value is a Date.
*/
V8EXPORT bool IsDate() const;
/**
* Returns true if this value is a Boolean object.
*/
V8EXPORT bool IsBooleanObject() const;
/**
* Returns true if this value is a Number object.
*/
V8EXPORT bool IsNumberObject() const;
/**
* Returns true if this value is a String object.
*/
V8EXPORT bool IsStringObject() const;
/**
* Returns true if this value is a NativeError.
*/
V8EXPORT bool IsNativeError() const;
/**
* Returns true if this value is a RegExp.
*/
V8EXPORT bool IsRegExp() const;
V8EXPORT Local<Boolean> ToBoolean() const;
V8EXPORT Local<Number> ToNumber() const;
V8EXPORT Local<String> ToString() const;
V8EXPORT Local<String> ToDetailString() const;
V8EXPORT Local<Object> ToObject() const;
V8EXPORT Local<Integer> ToInteger() const;
V8EXPORT Local<Uint32> ToUint32() const;
V8EXPORT Local<Int32> ToInt32() const;
/**
* Attempts to convert a string to an array index.
* Returns an empty handle if the conversion fails.
*/
V8EXPORT Local<Uint32> ToArrayIndex() const;
V8EXPORT bool BooleanValue() const;
V8EXPORT double NumberValue() const;
V8EXPORT int64_t IntegerValue() const;
V8EXPORT uint32_t Uint32Value() const;
V8EXPORT int32_t Int32Value() const;
/** JS == */
V8EXPORT bool Equals(Handle<Value> that) const;
V8EXPORT bool StrictEquals(Handle<Value> that) const;
private:
inline bool QuickIsString() const;
V8EXPORT bool FullIsString() const;
};
/**
* The superclass of primitive values. See ECMA-262 4.3.2.
*/
class Primitive : public Value { };
/**
* A primitive boolean value (ECMA-262, 4.3.14). Either the true
* or false value.
*/
class Boolean : public Primitive {
public:
V8EXPORT bool Value() const;
static inline Handle<Boolean> New(bool value);
};
/**
* A JavaScript string value (ECMA-262, 4.3.17).
*/
class String : public Primitive {
public:
/**
* Returns the number of characters in this string.
*/
V8EXPORT int Length() const;
/**
* Returns the number of bytes in the UTF-8 encoded
* representation of this string.
*/
V8EXPORT 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.
*
* WriteUtf8 will not write partial UTF-8 sequences, preferring to stop
* before the end of 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 characters to copy from the string. For
* WriteUtf8 the number of bytes in the buffer.
* \param nchars_ref The number of characters written, can be NULL.
* \param options Various options that might affect performance of this or
* subsequent operations.
* \return The number of characters copied to the buffer excluding the null
* terminator. For WriteUtf8: The number of bytes copied to the buffer
* including the null terminator (if written).
*/
enum WriteOptions {
NO_OPTIONS = 0,
HINT_MANY_WRITES_EXPECTED = 1,
NO_NULL_TERMINATION = 2
};
// 16-bit character codes.
V8EXPORT int Write(uint16_t* buffer,
int start = 0,
int length = -1,
int options = NO_OPTIONS) const;
// ASCII characters.
V8EXPORT int WriteAscii(char* buffer,
int start = 0,
int length = -1,
int options = NO_OPTIONS) const;
// UTF-8 encoded characters.
V8EXPORT int WriteUtf8(char* buffer,
int length = -1,
int* nchars_ref = NULL,
int options = NO_OPTIONS) const;
/**
* A zero length string.
*/
V8EXPORT static v8::Local<v8::String> Empty();
/**
* Returns true if the string is external
*/
V8EXPORT bool IsExternal() const;
/**
* Returns true if the string is both external and ASCII
*/
V8EXPORT bool IsExternalAscii() const;
class V8EXPORT ExternalStringResourceBase { // NOLINT
public:
virtual ~ExternalStringResourceBase() {}
protected:
ExternalStringResourceBase() {}
/**
* Internally V8 will call this Dispose method when the external string
* resource is no longer needed. The default implementation will use the
* delete operator. This method can be overridden in subclasses to
* control how allocated external string resources are disposed.
*/
virtual void Dispose() { delete this; }
private:
// Disallow copying and assigning.
ExternalStringResourceBase(const ExternalStringResourceBase&);
void operator=(const ExternalStringResourceBase&);
friend class v8::internal::Heap;
};
/**
* 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 Latin-1 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.
*/
V8EXPORT const 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.
*/
V8EXPORT static Local<String> New(const char* data, int length = -1);
/** Allocates a new string from 16-bit character codes.*/
V8EXPORT static Local<String> New(const uint16_t* data, int length = -1);
/** Creates a symbol. Returns one if it exists already.*/
V8EXPORT 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.
*/
V8EXPORT static Local<String> Concat(Handle<String> left,
Handle<String> right);
/**
* Creates a new external string using the data defined in the given
* resource. When the external string is no longer live on V8's heap the
* resource will be disposed by calling its Dispose method. The caller of
* this function should not otherwise delete or modify the resource. Neither
* should the underlying buffer be deallocated or modified except through the
* destructor of the external string resource.
*/
V8EXPORT 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 need 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. See NewExternal for
* information on the lifetime of the resource.
*/
V8EXPORT bool MakeExternal(ExternalStringResource* resource);
/**
* Creates a new external string using the ASCII data defined in the given
* resource. When the external string is no longer live on V8's heap the
* resource will be disposed by calling its Dispose method. The caller of
* this function should not otherwise delete or modify the resource. Neither
* should the underlying buffer be deallocated or modified except through the
* destructor of the external string resource.
*/
V8EXPORT 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 need 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. See NewExternal for
* information on the lifetime of the resource.
*/
V8EXPORT bool MakeExternal(ExternalAsciiStringResource* resource);
/**
* Returns true if this string can be made external.
*/
V8EXPORT bool CanMakeExternal();
/** Creates an undetectable string from the supplied ASCII or UTF-8 data.*/
V8EXPORT static Local<String> NewUndetectable(const char* data,
int length = -1);
/** Creates an undetectable string from the supplied 16-bit character codes.*/
V8EXPORT static Local<String> NewUndetectable(const uint16_t* data,
int length = -1);
/**
* Converts an object to a UTF-8-encoded character array. Useful if
* you want to print the object. If conversion to a string fails
* (e.g. 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:
V8EXPORT void VerifyExternalStringResource(ExternalStringResource* val) const;
V8EXPORT static void CheckCast(v8::Value* obj);
};
/**
* A JavaScript number value (ECMA-262, 4.3.20)
*/
class Number : public Primitive {
public:
V8EXPORT double Value() const;
V8EXPORT static Local<Number> New(double value);
static inline Number* Cast(v8::Value* obj);
private:
V8EXPORT Number();
V8EXPORT static void CheckCast(v8::Value* obj);
};
/**
* A JavaScript value representing a signed integer.
*/
class Integer : public Number {
public:
V8EXPORT static Local<Integer> New(int32_t value);
V8EXPORT static Local<Integer> NewFromUnsigned(uint32_t value);
V8EXPORT int64_t Value() const;
static inline Integer* Cast(v8::Value* obj);
private:
V8EXPORT Integer();
V8EXPORT static void CheckCast(v8::Value* obj);
};
/**
* A JavaScript value representing a 32-bit signed integer.
*/
class Int32 : public Integer {
public:
V8EXPORT int32_t Value() const;
private:
V8EXPORT Int32();
};
/**
* A JavaScript value representing a 32-bit unsigned integer.
*/
class Uint32 : public Integer {
public:
V8EXPORT uint32_t Value() const;
private:
V8EXPORT Uint32();
};
enum PropertyAttribute {
None = 0,
ReadOnly = 1 << 0,
DontEnum = 1 << 1,
DontDelete = 1 << 2
};
enum ExternalArrayType {
kExternalByteArray = 1,
kExternalUnsignedByteArray,
kExternalShortArray,
kExternalUnsignedShortArray,
kExternalIntArray,
kExternalUnsignedIntArray,
kExternalFloatArray,
kExternalDoubleArray,
kExternalPixelArray
};
/**
* Accessor[Getter|Setter] are used as callback functions when
* setting|getting a particular property. See Object and ObjectTemplate's
* method SetAccessor.
*/
typedef Handle<Value> (*AccessorGetter)(Local<String> property,
const AccessorInfo& info);
typedef void (*AccessorSetter)(Local<String> property,
Local<Value> value,
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
};
/**
* A JavaScript object (ECMA-262, 4.3.3)
*/
class Object : public Value {
public:
V8EXPORT bool Set(Handle<Value> key,
Handle<Value> value,
PropertyAttribute attribs = None);
V8EXPORT bool Set(uint32_t index,
Handle<Value> value);
// 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.
V8EXPORT bool ForceSet(Handle<Value> key,
Handle<Value> value,
PropertyAttribute attribs = None);
V8EXPORT Local<Value> Get(Handle<Value> key);
V8EXPORT Local<Value> Get(uint32_t index);
/**
* Gets the property attributes of a property which can be None or
* any combination of ReadOnly, DontEnum and DontDelete. Returns
* None when the property doesn't exist.
*/
V8EXPORT PropertyAttribute GetPropertyAttributes(Handle<Value> key);
// TODO(1245389): Replace the type-specific versions of these
// functions with generic ones that accept a Handle<Value> key.
V8EXPORT bool Has(Handle<String> key);
V8EXPORT bool Delete(Handle<String> key);
// Delete a property on this object bypassing interceptors and
// ignoring dont-delete attributes.
V8EXPORT bool ForceDelete(Handle<Value> key);
V8EXPORT bool Has(uint32_t index);
V8EXPORT bool Delete(uint32_t index);
V8EXPORT bool SetAccessor(Handle<String> name,
AccessorGetter getter,
AccessorSetter setter = 0,
Handle<Value> data = Handle<Value>(),
AccessControl settings = DEFAULT,
PropertyAttribute attribute = None);
/**
* 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.
*/
V8EXPORT Local<Array> GetPropertyNames();
/**
* This function has the same functionality as GetPropertyNames but
* the returned array doesn't contain the names of properties from
* prototype objects.
*/
V8EXPORT Local<Array> GetOwnPropertyNames();
/**
* Get the prototype object. This does not skip objects marked to
* be skipped by __proto__ and it does not consult the security
* handler.
*/
V8EXPORT 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.
*/
V8EXPORT bool SetPrototype(Handle<Value> prototype);
/**
* Finds an instance of the given function template in the prototype
* chain.
*/
V8EXPORT 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.
*/
V8EXPORT Local<String> ObjectProtoToString();
/**
* Returns the name of the function invoked as a constructor for this object.
*/
V8EXPORT Local<String> GetConstructorName();
/** Gets the number of internal fields for this Object. */
V8EXPORT int InternalFieldCount();
/** Gets the value in an internal field. */
inline Local<Value> GetInternalField(int index);
/** Sets the value in an internal field. */
V8EXPORT 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. */
V8EXPORT void SetPointerInInternalField(int index, void* value);
// Testers for local properties.
V8EXPORT bool HasOwnProperty(Handle<String> key);
V8EXPORT bool HasRealNamedProperty(Handle<String> key);
V8EXPORT bool HasRealIndexedProperty(uint32_t index);
V8EXPORT 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.
*/
V8EXPORT 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.
*/
V8EXPORT Local<Value> GetRealNamedProperty(Handle<String> key);
/** Tests for a named lookup interceptor.*/
V8EXPORT bool HasNamedLookupInterceptor();
/** Tests for an index lookup interceptor.*/
V8EXPORT 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.
*/
V8EXPORT void TurnOnAccessCheck();
/**
* Returns the identity hash for this object. The current implementation
* 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.
*/
V8EXPORT 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::".
*/
V8EXPORT bool SetHiddenValue(Handle<String> key, Handle<Value> value);
V8EXPORT Local<Value> GetHiddenValue(Handle<String> key);
V8EXPORT 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.
*/
V8EXPORT bool IsDirty();
/**
* Clone this object with a fast but shallow copy. Values will point
* to the same values as the original object.
*/
V8EXPORT Local<Object> Clone();
/**
* Returns the context in which the object was created.
*/
V8EXPORT Local<Context> CreationContext();
/**
* 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.
*/
V8EXPORT void SetIndexedPropertiesToPixelData(uint8_t* data, int length);
V8EXPORT bool HasIndexedPropertiesInPixelData();
V8EXPORT uint8_t* GetIndexedPropertiesPixelData();
V8EXPORT int GetIndexedPropertiesPixelDataLength();
/**
* 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.
*/
V8EXPORT void SetIndexedPropertiesToExternalArrayData(
void* data,
ExternalArrayType array_type,
int number_of_elements);
V8EXPORT bool HasIndexedPropertiesInExternalArrayData();
V8EXPORT void* GetIndexedPropertiesExternalArrayData();
V8EXPORT ExternalArrayType GetIndexedPropertiesExternalArrayDataType();
V8EXPORT int GetIndexedPropertiesExternalArrayDataLength();
/**
* Checks whether a callback is set by the
* ObjectTemplate::SetCallAsFunctionHandler method.
* When an Object is callable this method returns true.
*/
V8EXPORT bool IsCallable();
/**
* Call an Object as a function if a callback is set by the
* ObjectTemplate::SetCallAsFunctionHandler method.
*/
V8EXPORT Local<Value> CallAsFunction(Handle<Object> recv,
int argc,
Handle<Value> argv[]);
/**
* Call an Object as a constructor if a callback is set by the
* ObjectTemplate::SetCallAsFunctionHandler method.
* Note: This method behaves like the Function::NewInstance method.
*/
V8EXPORT Local<Value> CallAsConstructor(int argc,
Handle<Value> argv[]);
V8EXPORT static Local<Object> New();
static inline Object* Cast(Value* obj);
private:
V8EXPORT Object();
V8EXPORT static void CheckCast(Value* obj);
V8EXPORT Local<Value> CheckedGetInternalField(int index);
V8EXPORT 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 Array : public Object {
public:
V8EXPORT uint32_t Length() const;
/**
* Clones an element at index |index|. Returns an empty
* handle if cloning fails (for any reason).
*/
V8EXPORT Local<Object> CloneElementAt(uint32_t index);
/**
* Creates a JavaScript array with the given length. If the length
* is negative the returned array will have length 0.
*/
V8EXPORT static Local<Array> New(int length = 0);
static inline Array* Cast(Value* obj);
private:
V8EXPORT Array();
V8EXPORT static void CheckCast(Value* obj);
};
/**
* A JavaScript function object (ECMA-262, 15.3).
*/
class Function : public Object {
public:
V8EXPORT Local<Object> NewInstance() const;
V8EXPORT Local<Object> NewInstance(int argc, Handle<Value> argv[]) const;
V8EXPORT Local<Value> Call(Handle<Object> recv,
int argc,
Handle<Value> argv[]);
V8EXPORT void SetName(Handle<String> name);
V8EXPORT Handle<Value> GetName() const;
/**
* Name inferred from variable or property assignment of this function.
* Used to facilitate debugging and profiling of JavaScript code written
* in an OO style, where many functions are anonymous but are assigned
* to object properties.
*/
V8EXPORT Handle<Value> GetInferredName() const;
/**
* Returns zero based line number of function body and
* kLineOffsetNotFound if no information available.
*/
V8EXPORT int GetScriptLineNumber() const;
/**
* Returns zero based column number of function body and
* kLineOffsetNotFound if no information available.
*/
V8EXPORT int GetScriptColumnNumber() const;
V8EXPORT Handle<Value> GetScriptId() const;
V8EXPORT ScriptOrigin GetScriptOrigin() const;
static inline Function* Cast(Value* obj);
V8EXPORT static const int kLineOffsetNotFound;
private:
V8EXPORT Function();
V8EXPORT static void CheckCast(Value* obj);
};
/**
* An instance of the built-in Date constructor (ECMA-262, 15.9).
*/
class Date : public Object {
public:
V8EXPORT static Local<Value> New(double time);
/**
* A specialization of Value::NumberValue that is more efficient
* because we know the structure of this object.
*/
V8EXPORT double NumberValue() const;
static inline Date* Cast(v8::Value* obj);
/**
* Notification that the embedder has changed the time zone,
* daylight savings time, or other date / time configuration
* parameters. V8 keeps a cache of various values used for
* date / time computation. This notification will reset
* those cached values for the current context so that date /
* time configuration changes would be reflected in the Date
* object.
*
* This API should not be called more than needed as it will
* negatively impact the performance of date operations.
*/
V8EXPORT static void DateTimeConfigurationChangeNotification();
private:
V8EXPORT static void CheckCast(v8::Value* obj);
};
/**
* A Number object (ECMA-262, 4.3.21).
*/
class NumberObject : public Object {
public:
V8EXPORT static Local<Value> New(double value);
/**
* Returns the Number held by the object.
*/
V8EXPORT double NumberValue() const;
static inline NumberObject* Cast(v8::Value* obj);
private:
V8EXPORT static void CheckCast(v8::Value* obj);
};
/**
* A Boolean object (ECMA-262, 4.3.15).
*/
class BooleanObject : public Object {
public:
V8EXPORT static Local<Value> New(bool value);
/**
* Returns the Boolean held by the object.
*/
V8EXPORT bool BooleanValue() const;
static inline BooleanObject* Cast(v8::Value* obj);
private:
V8EXPORT static void CheckCast(v8::Value* obj);
};
/**
* A String object (ECMA-262, 4.3.18).
*/
class StringObject : public Object {
public:
V8EXPORT static Local<Value> New(Handle<String> value);
/**
* Returns the String held by the object.
*/
V8EXPORT Local<String> StringValue() const;
static inline StringObject* Cast(v8::Value* obj);
private:
V8EXPORT static void CheckCast(v8::Value* obj);
};
/**
* An instance of the built-in RegExp constructor (ECMA-262, 15.10).
*/
class RegExp : public Object {
public:
/**
* Regular expression flag bits. They can be or'ed to enable a set
* of flags.
*/
enum Flags {
kNone = 0,
kGlobal = 1,
kIgnoreCase = 2,
kMultiline = 4
};
/**
* Creates a regular expression from the given pattern string and
* the flags bit field. May throw a JavaScript exception as
* described in ECMA-262, 15.10.4.1.
*
* For example,
* RegExp::New(v8::String::New("foo"),
* static_cast<RegExp::Flags>(kGlobal | kMultiline))
* is equivalent to evaluating "/foo/gm".
*/
V8EXPORT static Local<RegExp> New(Handle<String> pattern,
Flags flags);
/**
* Returns the value of the source property: a string representing
* the regular expression.
*/
V8EXPORT Local<String> GetSource() const;
/**
* Returns the flags bit field.
*/
V8EXPORT Flags GetFlags() const;
static inline RegExp* Cast(v8::Value* obj);
private:
V8EXPORT static void CheckCast(v8::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 External : public Value {
public:
V8EXPORT static Local<Value> Wrap(void* data);
static inline void* Unwrap(Handle<Value> obj);
V8EXPORT static Local<External> New(void* value);
static inline External* Cast(Value* obj);
V8EXPORT void* Value() const;
private:
V8EXPORT External();
V8EXPORT static void CheckCast(v8::Value* obj);
static inline void* QuickUnwrap(Handle<v8::Value> obj);
V8EXPORT static void* FullUnwrap(Handle<v8::Value> obj);
};
// --- Templates ---
/**
* 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 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:
static const int kDataIndex = 0;
static const int kCalleeIndex = -1;
static const int kHolderIndex = -2;
friend class ImplementationUtilities;
inline Arguments(internal::Object** implicit_args,
internal::Object** values,
int length,
bool is_construct_call);
internal::Object** implicit_args_;
internal::Object** values_;
int length_;
bool is_construct_call_;
};
/**
* 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);
/**
* 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 an integer encoding property attributes (like v8::None,
* v8::DontEnum, etc.)
*/
typedef Handle<Integer> (*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 an integer encoding property attributes.
*/
typedef Handle<Integer> (*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 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);
/**
* Sets the ReadOnly flag in the attributes of the 'prototype' property
* of functions created from this FunctionTemplate to true.
*/
void ReadOnlyPrototype();
/**
* 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 if a property is present,
* and if present, get its attributes.
* \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 if 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();
};
// --- Extensions ---
class V8EXPORT ExternalAsciiStringResourceImpl
: public String::ExternalAsciiStringResource {
public:
ExternalAsciiStringResourceImpl() : data_(0), length_(0) {}
ExternalAsciiStringResourceImpl(const char* data, size_t length)
: data_(data), length_(length) {}
const char* data() const { return data_; }
size_t length() const { return length_; }
private:
const char* data_;
size_t length_;
};
/**
* Ignore
*/
class V8EXPORT Extension { // NOLINT
public:
// Note that the strings passed into this constructor must live as long
// as the Extension itself.
Extension(const char* name,
const char* source = 0,
int dep_count = 0,
const char** deps = 0,
int source_length = -1);
virtual ~Extension() { }
virtual v8::Handle<v8::FunctionTemplate>
GetNativeFunction(v8::Handle<v8::String> name) {
return v8::Handle<v8::FunctionTemplate>();
}
const char* name() const { return name_; }
size_t source_length() const { return source_length_; }
const String::ExternalAsciiStringResource* source() const {
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_;
size_t source_length_; // expected to initialize before source_
ExternalAsciiStringResourceImpl 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);
}
};
// --- Statics ---
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; }
int max_executable_size() { return max_executable_size_; }
void set_max_executable_size(int value) { max_executable_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_;
int max_executable_size_;
uint32_t* stack_limit_;
};
bool V8EXPORT SetResourceConstraints(ResourceConstraints* constraints);
// --- Exceptions ---
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);
};
// --- Counters Callbacks ---
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);
// --- Memory Allocation Callback ---
enum ObjectSpace {
kObjectSpaceNewSpace = 1 << 0,
kObjectSpaceOldPointerSpace = 1 << 1,
kObjectSpaceOldDataSpace = 1 << 2,
kObjectSpaceCodeSpace = 1 << 3,
kObjectSpaceMapSpace = 1 << 4,
kObjectSpaceLoSpace = 1 << 5,
kObjectSpaceAll = kObjectSpaceNewSpace | kObjectSpaceOldPointerSpace |
kObjectSpaceOldDataSpace | kObjectSpaceCodeSpace | kObjectSpaceMapSpace |
kObjectSpaceLoSpace
};
enum AllocationAction {
kAllocationActionAllocate = 1 << 0,
kAllocationActionFree = 1 << 1,
kAllocationActionAll = kAllocationActionAllocate | kAllocationActionFree
};
typedef void (*MemoryAllocationCallback)(ObjectSpace space,
AllocationAction action,
int size);
// --- Leave Script Callback ---
typedef void (*CallCompletedCallback)();
// --- Failed Access Check Callback ---
typedef void (*FailedAccessCheckCallback)(Local<Object> target,
AccessType type,
Local<Value> data);
// --- AllowCodeGenerationFromStrings callbacks ---
/**
* Callback to check if code generation from strings is allowed. See
* Context::AllowCodeGenerationFromStrings.
*/
typedef bool (*AllowCodeGenerationFromStringsCallback)(Local<Context> context);
// --- Garbage Collection Callbacks ---
/**
* Applications can register callback functions which will be called
* before and after a garbage collection. Allocations are not
* allowed in the callback functions, you therefore cannot manipulate
* objects (set or delete properties for example) since it is possible
* such operations will result in the allocation of objects.
*/
enum GCType {
kGCTypeScavenge = 1 << 0,
kGCTypeMarkSweepCompact = 1 << 1,
kGCTypeAll = kGCTypeScavenge | kGCTypeMarkSweepCompact
};
enum GCCallbackFlags {
kNoGCCallbackFlags = 0,
kGCCallbackFlagCompacted = 1 << 0
};
typedef void (*GCPrologueCallback)(GCType type, GCCallbackFlags flags);
typedef void (*GCEpilogueCallback)(GCType type, GCCallbackFlags flags);
typedef void (*GCCallback)();
/**
* 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 total_heap_size_executable() { return total_heap_size_executable_; }
size_t used_heap_size() { return used_heap_size_; }
size_t heap_size_limit() { return heap_size_limit_; }
private:
void set_total_heap_size(size_t size) { total_heap_size_ = size; }
void set_total_heap_size_executable(size_t size) {
total_heap_size_executable_ = size;
}
void set_used_heap_size(size_t size) { used_heap_size_ = size; }
void set_heap_size_limit(size_t size) { heap_size_limit_ = size; }
size_t total_heap_size_;
size_t total_heap_size_executable_;
size_t used_heap_size_;
size_t heap_size_limit_;
friend class V8;
};
class RetainedObjectInfo;
/**
* Isolate represents an isolated instance of the V8 engine. V8
* isolates have completely separate states. Objects from one isolate
* must not be used in other isolates. When V8 is initialized a
* default isolate is implicitly created and entered. The embedder
* can create additional isolates and use them in parallel in multiple
* threads. An isolate can be entered by at most one thread at any
* given time. The Locker/Unlocker API must be used to synchronize.
*/
class V8EXPORT Isolate {
public:
/**
* Stack-allocated class which sets the isolate for all operations
* executed within a local scope.
*/
class V8EXPORT Scope {
public:
explicit Scope(Isolate* isolate) : isolate_(isolate) {
isolate->Enter();
}
~Scope() { isolate_->Exit(); }
private:
Isolate* const isolate_;
// Prevent copying of Scope objects.
Scope(const Scope&);
Scope& operator=(const Scope&);
};
/**
* Creates a new isolate. Does not change the currently entered
* isolate.
*
* When an isolate is no longer used its resources should be freed
* by calling Dispose(). Using the delete operator is not allowed.
*/
static Isolate* New();
/**
* Returns the entered isolate for the current thread or NULL in
* case there is no current isolate.
*/
static Isolate* GetCurrent();
/**
* Methods below this point require holding a lock (using Locker) in
* a multi-threaded environment.
*/
/**
* Sets this isolate as the entered one for the current thread.
* Saves the previously entered one (if any), so that it can be
* restored when exiting. Re-entering an isolate is allowed.
*/
void Enter();
/**
* Exits this isolate by restoring the previously entered one in the
* current thread. The isolate may still stay the same, if it was
* entered more than once.
*
* Requires: this == Isolate::GetCurrent().
*/
void Exit();
/**
* Disposes the isolate. The isolate must not be entered by any
* thread to be disposable.
*/
void Dispose();
/**
* Associate embedder-specific data with the isolate
*/
void SetData(void* data);
/**
* Retrive embedder-specific data from the isolate.
* Returns NULL if SetData has never been called.
*/
void* GetData();
private:
Isolate();
Isolate(const Isolate&);
~Isolate();
Isolate& operator=(const Isolate&);
void* operator new(size_t size);
void operator delete(void*, size_t);
};
class StartupData {
public:
enum CompressionAlgorithm {
kUncompressed,
kBZip2
};
const char* data;
int compressed_size;
int raw_size;
};
/**
* A helper class for driving V8 startup data decompression. It is based on
* "CompressedStartupData" API functions from the V8 class. It isn't mandatory
* for an embedder to use this class, instead, API functions can be used
* directly.
*
* For an example of the class usage, see the "shell.cc" sample application.
*/
class V8EXPORT StartupDataDecompressor { // NOLINT
public:
StartupDataDecompressor();
virtual ~StartupDataDecompressor();
int Decompress();
protected:
virtual int DecompressData(char* raw_data,
int* raw_data_size,
const char* compressed_data,
int compressed_data_size) = 0;
private:
char** raw_data;
};
/**
* EntropySource is used as a callback function when v8 needs a source
* of entropy.
*/
typedef bool (*EntropySource)(unsigned char* buffer, size_t length);
/**
* Interface for iterating though all external resources in the heap.
*/
class V8EXPORT ExternalResourceVisitor { // NOLINT
public:
virtual ~ExternalResourceVisitor() {}
virtual void VisitExternalString(Handle<String> string) {}
};
/**
* 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);
/**
* Set the callback to invoke to check if code generation from
* strings should be allowed.
*/
static void SetAllowCodeGenerationFromStringsCallback(
AllowCodeGenerationFromStringsCallback 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 an
* 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();
/**
* The following 4 functions are to be used when V8 is built with
* the 'compress_startup_data' flag enabled. In this case, the
* embedder must decompress startup data prior to initializing V8.
*
* This is how interaction with V8 should look like:
* int compressed_data_count = v8::V8::GetCompressedStartupDataCount();
* v8::StartupData* compressed_data =
* new v8::StartupData[compressed_data_count];
* v8::V8::GetCompressedStartupData(compressed_data);
* ... decompress data (compressed_data can be updated in-place) ...
* v8::V8::SetDecompressedStartupData(compressed_data);
* ... now V8 can be initialized
* ... make sure the decompressed data stays valid until V8 shutdown
*
* A helper class StartupDataDecompressor is provided. It implements
* the protocol of the interaction described above, and can be used in
* most cases instead of calling these API functions directly.
*/
static StartupData::CompressionAlgorithm GetCompressedStartupDataAlgorithm();
static int GetCompressedStartupDataCount();
static void GetCompressedStartupData(StartupData* compressed_data);
static void SetDecompressedStartupData(StartupData* decompressed_data);
/**
* Adds a message listener.
*
* The same message listener can be added more than once and in 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);
/**
* Tells V8 to capture current stack trace when uncaught exception occurs
* and report it to the message listeners. The option is off by default.
*/
static void SetCaptureStackTraceForUncaughtExceptions(
bool capture,
int frame_limit = 10,
StackTrace::StackTraceOptions options = StackTrace::kOverview);
/**
* 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
* 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. It is possible
* to specify the GCType filter for your callback. But it is not possible to
* register the same callback function two times with different
* GCType filters.
*/
static void AddGCPrologueCallback(
GCPrologueCallback callback, GCType gc_type_filter = kGCTypeAll);
/**
* This function removes callback which was installed by
* AddGCPrologueCallback function.
*/
static void RemoveGCPrologueCallback(GCPrologueCallback callback);
/**
* The function is deprecated. Please use AddGCPrologueCallback instead.
* Enables the host application to receive a notification before a
* 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 SetGlobalGCPrologueCallback(GCCallback);
/**
* Enables the host application to receive a notification after a
* 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. It is possible
* to specify the GCType filter for your callback. But it is not possible to
* register the same callback function two times with different
* GCType filters.
*/
static void AddGCEpilogueCallback(
GCEpilogueCallback callback, GCType gc_type_filter = kGCTypeAll);
/**
* This function removes callback which was installed by
* AddGCEpilogueCallback function.
*/
static void RemoveGCEpilogueCallback(GCEpilogueCallback callback);
/**
* The function is deprecated. Please use AddGCEpilogueCallback instead.
* 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);
/**
* Enables the host application to provide a mechanism to be notified
* and perform custom logging when V8 Allocates Executable Memory.
*/
static void AddMemoryAllocationCallback(MemoryAllocationCallback callback,
ObjectSpace space,
AllocationAction action);
/**
* Removes callback that was installed by AddMemoryAllocationCallback.
*/
static void RemoveMemoryAllocationCallback(MemoryAllocationCallback callback);
/**
* Adds a callback to notify the host application when a script finished
* running. If a script re-enters the runtime during executing, the
* CallCompletedCallback is only invoked when the outer-most script
* execution ends. Executing scripts inside the callback do not trigger
* further callbacks.
*/
static void AddCallCompletedCallback(CallCompletedCallback callback);
/**
* Removes callback that was installed by AddCallCompletedCallback.
*/
static void RemoveCallCompletedCallback(CallCompletedCallback callback);
/**
* 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.
* See v8-profiler.h for RetainedObjectInfo interface description.
*/
static void AddObjectGroup(Persistent<Value>* objects,
size_t length,
RetainedObjectInfo* info = NULL);
/**
* Allows the host application to declare implicit references between
* the objects: if |parent| is alive, all |children| are alive too.
* After each garbage collection, all implicit references
* are removed. It is intended to be used in the before-garbage-collection
* callback function.
*/
static void AddImplicitReferences(Persistent<Object> parent,
Persistent<Value>* children,
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();
/**
* Allows the host application to provide a callback which can be used
* as a source of entropy for random number generators.
*/
static void SetEntropySource(EntropySource source);
/**
* 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();
/**
* 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
* handler. 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
* in the given isolate. If no isolate is provided, the default
* isolate is used.
*
* This method can be used by any thread even if that thread has not
* acquired the V8 lock with a Locker object.
*
* \param isolate The isolate in which to terminate the current JS execution.
*/
static void TerminateExecution(Isolate* isolate = NULL);
/**
* Is V8 terminating JavaScript execution.
*
* Returns true if JavaScript execution is currently terminating
* because of a call to TerminateExecution. In that case there are
* still JavaScript frames on the stack and the termination
* exception is still active.
*
* \param isolate The isolate in which to check.
*/
static bool IsExecutionTerminating(Isolate* isolate = NULL);
/**
* 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);
/**
* Iterates through all external resources referenced from current isolate
* heap. This method is not expected to be used except for debugging purposes
* and may be quite slow.
*/
static void VisitExternalResources(ExternalResourceVisitor* visitor);
/**
* 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.
*
* The hint argument specifies the amount of work to be done in the function
* on scale from 1 to 1000. There is no guarantee that the actual work will
* match the hint.
*/
static bool IdleNotification(int hint = 1000);
/**
* Optional notification that the system is running low on memory.
* V8 uses these notifications to attempt to free memory.
*/
static void LowMemoryNotification();
/**
* Optional notification that a context has been disposed. V8 uses
* these notifications to guide the GC heuristic. Returns the number
* of context disposals - including this one - since the last time
* V8 had a chance to clean up.
*/
static int ContextDisposedNotification();
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 void MarkIndependent(internal::Object** global_handle);
static bool IsGlobalNearDeath(internal::Object** global_handle);
static bool IsGlobalWeak(internal::Object** global_handle);
static void SetWrapperClassId(internal::Object** global_handle,
uint16_t class_id);
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:
v8::internal::Isolate* isolate_;
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::Isolate;
};
// --- Context ---
/**
* 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 proxy object or global object itself for
* detached contexts.
*
* Global proxy object is a thin wrapper whose prototype points to
* actual context's global object with the properties like Object, etc.
* This is done that way for security reasons (for more details see
* https://wiki.mozilla.org/Gecko:SplitWindow).
*
* Please note that changes to global proxy object prototype most probably
* would break VM---v8 expects only global object as a prototype of
* global proxy object.
*
* If DetachGlobal() has been invoked, Global() would return actual global
* object until global is reattached with ReattachGlobal().
*/
Local<Object> Global();
/**
* Detaches the global object from its context before
* the global object can be reused to create a new context.
*/
void DetachGlobal();
/**
* Reattaches a global object to a context. This can be used to
* restore the connection between a global object and a context
* after DetachGlobal has been called.
*
* \param global_object The global object to reattach to the
* context. For this to work, the global object must be the global
* object that was associated with this context before a call to
* DetachGlobal.
*/
void ReattachGlobal(Handle<Object> global_object);
/** Creates a new context.
*
* Returns a persistent handle to the newly allocated context. This
* persistent handle has to be disposed when the context is no
* longer used so the context can be garbage collected.
*
* \param extensions An optional extension configuration containing
* the extensions to be installed in the newly created context.
*
* \param global_template An optional object template from which the
* global object for the newly created context will be created.
*
* \param global_object An optional global object to be reused for
* the newly created context. This global object must have been
* created by a previous call to Context::New with the same global
* template. The state of the global object will be completely reset
* and only object identify will remain.
*/
static Persistent<Context> New(
ExtensionConfiguration* extensions = NULL,
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();
/**
* Control whether code generation from strings is allowed. Calling
* this method with false will disable 'eval' and the 'Function'
* constructor for code running in this context. If 'eval' or the
* 'Function' constructor are used an exception will be thrown.
*
* If code generation from strings is not allowed the
* V8::AllowCodeGenerationFromStrings callback will be invoked if
* set before blocking the call to 'eval' or the 'Function'
* constructor. If that callback returns true, the call will be
* allowed, otherwise an exception will be thrown. If no callback is
* set an exception will be thrown.
*/
void AllowCodeGenerationFromStrings(bool allow);
/**
* Returns true if code generation from strings is allowed for the context.
* For more details see AllowCodeGenerationFromStrings(bool) documentation.
*/
bool IsCodeGenerationFromStringsAllowed();
/**
* Stack-allocated class which sets the execution context for all
* operations executed within a local scope.
*/
class Scope {
public:
explicit 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 any given V8 isolate. See Isolate class
* comments. The definition of 'using V8 isolate' includes
* accessing handles or holding onto object pointers obtained
* from V8 handles while in the particular V8 isolate. It is up
* to the user of V8 to ensure (perhaps with locking) that this
* constraint is not violated. In addition to any other synchronization
* mechanism that may be used, the v8::Locker and v8::Unlocker classes
* must be used to signal thead switches to V8.
*
* v8::Locker is a scoped lock object. While it's
* active (i.e. between its construction and destruction) the current thread is
* allowed to use the locked isolate. V8 guarantees that an isolate can be
* locked by at most one thread at any time. In other words, the scope of a
* v8::Locker is a critical section.
*
* Sample usage:
* \code
* ...
* {
* v8::Locker locker(isolate);
* v8::Isolate::Scope isolate_scope(isolate);
* ...
* // Code using V8 and isolate goes here.
* ...
* } // Destructor called here
* \endcode
*
* If you wish to stop using V8 in a thread A you can do this either
* by destroying the v8::Locker object as above or by constructing a
* v8::Unlocker object:
*
* \code
* {
* isolate->Exit();
* v8::Unlocker unlocker(isolate);
* ...
* // Code not using V8 goes here while V8 can run in another thread.
* ...
* } // Destructor called here.
* isolate->Enter();
* \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(isolate);
* Isolate::Scope isolate_scope(isolate);
* // V8 locked.
* {
* v8::Locker another_locker(isolate);
* // V8 still locked (2 levels).
* {
* isolate->Exit();
* v8::Unlocker unlocker(isolate);
* // V8 not locked.
* }
* isolate->Enter();
* // V8 locked again (2 levels).
* }
* // V8 still locked (1 level).
* }
* // V8 Now no longer locked.
* \endcode
*
*
*/
class V8EXPORT Unlocker {
public:
/**
* Initialize Unlocker for a given Isolate. NULL means default isolate.
*/
explicit Unlocker(Isolate* isolate = NULL);
~Unlocker();
private:
internal::Isolate* isolate_;
};
class V8EXPORT Locker {
public:
/**
* Initialize Locker for a given Isolate. NULL means default isolate.
*/
explicit Locker(Isolate* isolate = NULL);
~Locker();
/**
* Start preemption.
*
* When preemption is started, a timer is fired every n milliseconds
* 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 for a given isolate, or default isolate
* if NULL is given, is locked by the current thread.
*/
static bool IsLocked(Isolate* isolate = NULL);
/**
* Returns whether v8::Locker is being used by this V8 instance.
*/
static bool IsActive();
private:
bool has_lock_;
bool top_level_;
internal::Isolate* isolate_;
static bool active_;
// Disallow copying and assigning.
Locker(const Locker&);
void operator=(const Locker&);
};
/**
* An interface for exporting data from V8, using "push" model.
*/
class V8EXPORT OutputStream { // NOLINT
public:
enum OutputEncoding {
kAscii = 0 // 7-bit ASCII.
};
enum WriteResult {
kContinue = 0,
kAbort = 1
};
virtual ~OutputStream() {}
/** Notify about the end of stream. */
virtual void EndOfStream() = 0;
/** Get preferred output chunk size. Called only once. */
virtual int GetChunkSize() { return 1024; }
/** Get preferred output encoding. Called only once. */
virtual OutputEncoding GetOutputEncoding() { return kAscii; }
/**
* Writes the next chunk of snapshot data into the stream. Writing
* can be stopped by returning kAbort as function result. EndOfStream
* will not be called in case writing was aborted.
*/
virtual WriteResult WriteAsciiChunk(char* data, int size) = 0;
};
/**
* An interface for reporting progress and controlling long-running
* activities.
*/
class V8EXPORT ActivityControl { // NOLINT
public:
enum ControlOption {
kContinue = 0,
kAbort = 1
};
virtual ~ActivityControl() {}
/**
* Notify about current progress. The activity can be stopped by
* returning kAbort as the callback result.
*/
virtual ControlOption ReportProgressValue(int done, int total) = 0;
};
// --- Implementation ---
namespace internal {
const int kApiPointerSize = sizeof(void*); // NOLINT
const int kApiIntSize = sizeof(int); // NOLINT
// 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 SmiTagging;
// Smi constants for 32-bit systems.
template <> struct SmiTagging<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;
}
// For 32-bit systems any 2 bytes aligned pointer can be encoded as smi
// with a plain reinterpret_cast.
static const uintptr_t kEncodablePointerMask = 0x1;
static const int kPointerToSmiShift = 0;
};
// Smi constants for 64-bit systems.
template <> struct SmiTagging<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);
}
// To maximize the range of pointers that can be encoded
// in the available 32 bits, we require them to be 8 bytes aligned.
// This gives 2 ^ (32 + 3) = 32G address space covered.
// It might be not enough to cover stack allocated objects on some platforms.
static const int kPointerAlignment = 3;
static const uintptr_t kEncodablePointerMask =
~(uintptr_t(0xffffffff) << kPointerAlignment);
static const int kPointerToSmiShift =
kSmiTagSize + kSmiShiftSize - kPointerAlignment;
};
typedef SmiTagging<kApiPointerSize> PlatformSmiTagging;
const int kSmiShiftSize = PlatformSmiTagging::kSmiShiftSize;
const int kSmiValueSize = PlatformSmiTagging::kSmiValueSize;
const uintptr_t kEncodablePointerMask =
PlatformSmiTagging::kEncodablePointerMask;
const int kPointerToSmiShift = PlatformSmiTagging::kPointerToSmiShift;
template <size_t ptr_size> struct InternalConstants;
// Internal constants for 32-bit systems.
template <> struct InternalConstants<4> {
static const int kStringResourceOffset = 3 * kApiPointerSize;
};
// Internal constants for 64-bit systems.
template <> struct InternalConstants<8> {
static const int kStringResourceOffset = 3 * kApiPointerSize;
};
/**
* 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 = 1 * kApiPointerSize + kApiIntSize;
static const int kStringResourceOffset =
InternalConstants<kApiPointerSize>::kStringResourceOffset;
static const int kForeignAddressOffset = kApiPointerSize;
static const int kJSObjectHeaderSize = 3 * kApiPointerSize;
static const int kFullStringRepresentationMask = 0x07;
static const int kExternalTwoByteRepresentationTag = 0x02;
static const int kJSObjectType = 0xa8;
static const int kFirstNonstringType = 0x80;
static const int kForeignType = 0x85;
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 PlatformSmiTagging::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* GetExternalPointerFromSmi(internal::Object* value) {
const uintptr_t address = reinterpret_cast<uintptr_t>(value);
return reinterpret_cast<void*>(address >> kPointerToSmiShift);
}
static inline void* GetExternalPointer(internal::Object* obj) {
if (HasSmiTag(obj)) {
return GetExternalPointerFromSmi(obj);
} else if (GetInstanceType(obj) == kForeignType) {
return ReadField<void*>(obj, kForeignAddressOffset);
} 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);
}
static inline bool CanCastToHeapObject(void* o) { return false; }
static inline bool CanCastToHeapObject(Context* o) { return true; }
static inline bool CanCastToHeapObject(String* o) { return true; }
static inline bool CanCastToHeapObject(Object* o) { return true; }
static inline bool CanCastToHeapObject(Message* o) { return true; }
static inline bool CanCastToHeapObject(StackTrace* o) { return true; }
static inline bool CanCastToHeapObject(StackFrame* o) { return true; }
};
} // namespace internal
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>();
T* that_ptr = *that;
internal::Object** p = reinterpret_cast<internal::Object**>(that_ptr);
if (internal::Internals::CanCastToHeapObject(that_ptr)) {
return Local<T>(reinterpret_cast<T*>(HandleScope::CreateHandle(
reinterpret_cast<internal::HeapObject*>(*p))));
}
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));
}
template <class T>
void Persistent<T>::MarkIndependent() {
V8::MarkIndependent(reinterpret_cast<internal::Object**>(**this));
}
template <class T>
void Persistent<T>::SetWrapperClassId(uint16_t class_id) {
V8::SetWrapperClassId(reinterpret_cast<internal::Object**>(**this), class_id);
}
Arguments::Arguments(internal::Object** implicit_args,
internal::Object** values, int length,
bool is_construct_call)
: implicit_args_(implicit_args),
values_(values),
length_(length),
is_construct_call_(is_construct_call) { }
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 Local<Function>(reinterpret_cast<Function*>(
&implicit_args_[kCalleeIndex]));
}
Local<Object> Arguments::This() const {
return Local<Object>(reinterpret_cast<Object*>(values_ + 1));
}
Local<Object> Arguments::Holder() const {
return Local<Object>(reinterpret_cast<Object*>(
&implicit_args_[kHolderIndex]));
}
Local<Value> Arguments::Data() const {
return Local<Value>(reinterpret_cast<Value*>(&implicit_args_[kDataIndex]));
}
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 + (internal::kApiPointerSize * 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 + (internal::kApiPointerSize * 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);
}
StringObject* StringObject::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<StringObject*>(value);
}
NumberObject* NumberObject::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<NumberObject*>(value);
}
BooleanObject* BooleanObject::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<BooleanObject*>(value);
}
RegExp* RegExp::Cast(v8::Value* value) {
#ifdef V8_ENABLE_CHECKS
CheckCast(value);
#endif
return static_cast<RegExp*>(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_[-2]));
}
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 TYPE_CHECK
#endif // V8_H_