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v8
V8 is Google’s open source high-performance JavaScript and WebAssembly engine, written in C++.
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#include <v8-context.h>
Classes | |
class | BackupIncumbentScope |
class | DeepFreezeDelegate |
class | Scope |
Public Types | |
enum | EmbedderDataFields { kDebugIdIndex = 0 } |
using | AbortScriptExecutionCallback |
Private Member Functions | |
internal::ValueHelper::InternalRepresentationType | GetDataFromSnapshotOnce (size_t index) |
Local< Value > | SlowGetEmbedderData (int index) |
void * | SlowGetAlignedPointerFromEmbedderData (int index) |
Static Private Member Functions | |
static void | CheckCast (Data *obj) |
Friends | |
class | Value |
class | Script |
class | Object |
class | Function |
A sandboxed execution context with its own set of built-in objects and functions.
Definition at line 48 of file v8-context.h.
If callback is set, abort any attempt to execute JavaScript in this context, call the specified callback, and throw an exception. To unset abort, pass nullptr as callback.
Definition at line 363 of file v8-context.h.
The field at kDebugIdIndex used to be reserved for the inspector. It now serves no purpose.
Enumerator | |
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kDebugIdIndex |
Definition at line 271 of file v8-context.h.
void v8::Context::AllowCodeGenerationFromStrings | ( | bool | allow | ) |
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::ModifyCodeGenerationFromStringsCallback 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.
Definition at line 7235 of file api.cc.
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Maybe< void > v8::Context::DeepFreeze | ( | DeepFreezeDelegate * | delegate = nullptr | ) |
Attempts to recursively freeze all objects reachable from this context. Some objects (generators, iterators, non-const closures) can not be frozen and will cause this method to throw an error. An optional delegate can be provided to help freeze embedder-specific objects.
Freezing occurs in two steps:
Definition at line 7159 of file api.cc.
void v8::Context::DetachGlobal | ( | ) |
void v8::Context::Enter | ( | ) |
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.
Definition at line 818 of file api.cc.
void v8::Context::Exit | ( | ) |
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Create a new context from a (non-default) context snapshot. There is no way to provide a global object template since we do not create a new global object from template, but we can reuse a global object.
isolate | See v8::Context::New(). |
context_snapshot_index | The index of the context snapshot to deserialize from. Use v8::Context::New() for the default snapshot. |
internal_fields_deserializer | An optional callback used to deserialize fields set by v8::Object::SetAlignedPointerInInternalField() in wrapper objects from the default context snapshot. It does not need to be configured if there are no wrapper objects with no internal pointer fields in the default context snapshot or if no startup snapshot is configured when the isolate is created. |
extensions | See v8::Context::New(). |
global_object | See v8::Context::New(). |
internal_fields_deserializer | Similar to internal_fields_deserializer in v8::Context::New() but applies to the context specified by the context_snapshot_index. |
microtask_queue | See v8::Context::New(). |
context_data_deserializer | Similar to context_data_deserializer in v8::Context::New() but applies to the context specified by the context_snapshot_index. |
api_wrapper_deserializer | Similar to api_wrapper_deserializer in v8::Context::New() but applies to the context specified by the context_snapshot_index. |
Definition at line 6794 of file api.cc.
void * v8::Context::GetAlignedPointerFromEmbedderData | ( | int | index | ) |
void * v8::Context::GetAlignedPointerFromEmbedderData | ( | Isolate * | isolate, |
int | index ) |
Gets a 2-byte-aligned native pointer from the embedder data with the given index, which must have been set by a previous call to SetAlignedPointerInEmbedderData with the same index. Note that index 0 currently has a special meaning for Chrome's debugger.
Definition at line 462 of file v8-context.h.
V8_INLINE MaybeLocal< T > v8::Context::GetDataFromSnapshotOnce | ( | size_t | index | ) |
Return data that was previously attached to the context snapshot via SnapshotCreator, and removes the reference to it. Repeated call with the same index returns an empty MaybeLocal.
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MaybeLocal< T > v8::Context::GetDataFromSnapshotOnce | ( | size_t | index | ) |
Gets the embedder data with the given index, which must have been set by a previous call to SetEmbedderData with the same index.
Definition at line 438 of file v8-context.h.
Local< v8::Object > v8::Context::GetExtrasBindingObject | ( | ) |
Gets the binding object used by V8 extras. Extra natives get a reference to this object and can use it to "export" functionality by adding properties. Extra natives can also "import" functionality by accessing properties added by the embedder using the V8 API.
Definition at line 7228 of file api.cc.
v8::Isolate * v8::Context::GetIsolate | ( | ) |
v8::MicrotaskQueue * v8::Context::GetMicrotaskQueue | ( | ) |
uint32_t v8::Context::GetNumberOfEmbedderDataFields | ( | ) |
v8::Local< v8::Object > v8::Context::Global | ( | ) |
Returns the global proxy object.
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.
Definition at line 7208 of file api.cc.
bool v8::Context::IsCodeGenerationFromStringsAllowed | ( | ) | const |
Returns true if code generation from strings is allowed for the context. For more details see AllowCodeGenerationFromStrings(bool) documentation.
Definition at line 7243 of file api.cc.
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static |
Creates a new context and returns a handle to the newly allocated context.
isolate | The isolate in which to create the context. |
extensions | An optional extension configuration containing the extensions to be installed in the newly created context. |
global_template | An optional object template from which the global object for the newly created context will be created. |
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. |
internal_fields_deserializer | An optional callback used to deserialize fields set by v8::Object::SetAlignedPointerInInternalField() in wrapper objects from the default context snapshot. It should match the SerializeInternalFieldsCallback() used by v8::SnapshotCreator::SetDefaultContext() when the default context snapshot is created. It does not need to be configured if the default context snapshot contains no wrapper objects with pointer internal fields, or if no custom startup snapshot is configured in the v8::CreateParams used to create the isolate. |
microtask_queue | An optional microtask queue used to manage the microtasks created in this context. If not set the per-isolate default microtask queue would be used. |
context_data_deserializer | An optional callback used to deserialize embedder data set by v8::Context::SetAlignedPointerInEmbedderData() in the default context from the default context snapshot. It does not need to be configured if the default context snapshot contains no pointer embedder data, or if no custom startup snapshot is configured in the v8::CreateParams used to create the isolate. |
api_wrapper_deserializer | An optional callback used to deserialize API wrapper objects that was initially set with v8::Object::Wrap() and then serialized using SerializeAPIWrapperCallback. |
Definition at line 6778 of file api.cc.
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Returns an global object that isn't backed by an actual context.
The global template needs to have access checks with handlers installed. If an existing global object is passed in, the global object is detached from its context.
Note that this is different from a detached context where all accesses to the global proxy will fail. Instead, the access check handlers are invoked.
It is also not possible to detach an object returned by this method. Instead, the access check handlers need to return nothing to achieve the same effect.
It is possible, however, to create a new context from the global object returned by this method.
Definition at line 6816 of file api.cc.
void v8::Context::SetAbortScriptExecution | ( | Context::AbortScriptExecutionCallback | callback | ) |
void v8::Context::SetAlignedPointerInEmbedderData | ( | int | index, |
void * | value ) |
void v8::Context::SetMicrotaskQueue | ( | v8::MicrotaskQueue * | queue | ) |
void v8::Context::SetPromiseHooks | ( | Local< Function > | init_hook, |
Local< Function > | before_hook, | ||
Local< Function > | after_hook, | ||
Local< Function > | resolve_hook ) |
Set or clear hooks to be invoked for promise lifecycle operations. To clear a hook, set it to an empty v8::Function. Each function will receive the observed promise as the first argument. If a chaining operation is used on a promise, the init will additionally receive the parent promise as the second argument.
Definition at line 7274 of file api.cc.
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void v8::Context::UseDefaultSecurityToken | ( | ) |
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Definition at line 426 of file v8-context.h.
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friend |
Definition at line 425 of file v8-context.h.
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Definition at line 424 of file v8-context.h.
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Definition at line 423 of file v8-context.h.