react-native/ReactCommon/jschelpers/Value.cpp

273 lines
9.0 KiB
C++

// Copyright 2004-present Facebook. All Rights Reserved.
#include <folly/json.h>
#include "Value.h"
#include "JSCHelpers.h"
#include "JavaScriptCore.h"
// See the comment under Value::fromDynamic()
#if !defined(__APPLE__) && defined(WITH_FB_JSC_TUNING)
#define USE_FAST_FOLLY_DYNAMIC_CONVERSION 1
#else
#define USE_FAST_FOLLY_DYNAMIC_CONVERSION 0
#endif
namespace facebook {
namespace react {
Value::Value(JSContextRef context, JSValueRef value) :
m_context(context),
m_value(value)
{
}
Value::Value(JSContextRef context, JSStringRef str) :
m_context(context),
m_value(JSC_JSValueMakeString(context, str))
{
}
Value::Value(Value&& other) :
m_context(other.m_context),
m_value(other.m_value)
{
other.m_value = nullptr;
}
JSContextRef Value::context() const {
return m_context;
}
std::string Value::toJSONString(unsigned indent) const {
JSValueRef exn;
auto stringToAdopt = JSC_JSValueCreateJSONString(m_context, m_value, indent, &exn);
if (stringToAdopt == nullptr) {
std::string exceptionText = Value(m_context, exn).toString().str();
throwJSExecutionException("Exception creating JSON string: %s", exceptionText.c_str());
}
return String::adopt(m_context, stringToAdopt).str();
}
/* static */
Value Value::fromJSON(JSContextRef ctx, const String& json) {
auto result = JSC_JSValueMakeFromJSONString(ctx, json);
if (!result) {
throwJSExecutionException("Failed to create String from JSON: %s", json.str().c_str());
}
return Value(ctx, result);
}
JSValueRef Value::fromDynamic(JSContextRef ctx, const folly::dynamic& value) {
// JavaScriptCore's iOS APIs have their own version of this direct conversion.
// In addition, using this requires exposing some of JSC's private APIs,
// so it's limited to non-apple platforms and to builds that use the custom JSC.
// Otherwise, we use the old way of converting through JSON.
#if USE_FAST_FOLLY_DYNAMIC_CONVERSION
// Defer GC during the creation of the JSValue, as we don't want
// intermediate objects to be collected.
// We could use JSValueProtect(), but it will make the process much slower.
JSDeferredGCRef deferGC = JSDeferGarbageCollection(ctx);
// Set a global lock for the whole process,
// instead of re-acquiring the lock for each operation.
JSLock(ctx);
JSValueRef jsVal = Value::fromDynamicInner(ctx, value);
JSUnlock(ctx);
JSResumeGarbageCollection(ctx, deferGC);
return jsVal;
#else
auto json = folly::toJson(value);
return fromJSON(ctx, String(ctx, json.c_str()));
#endif
}
JSValueRef Value::fromDynamicInner(JSContextRef ctx, const folly::dynamic& obj) {
switch (obj.type()) {
// For primitive types (and strings), just create and return an equivalent JSValue
case folly::dynamic::Type::NULLT:
return JSC_JSValueMakeNull(ctx);
case folly::dynamic::Type::BOOL:
return JSC_JSValueMakeBoolean(ctx, obj.getBool());
case folly::dynamic::Type::DOUBLE:
return JSC_JSValueMakeNumber(ctx, obj.getDouble());
case folly::dynamic::Type::INT64:
return JSC_JSValueMakeNumber(ctx, obj.asDouble());
case folly::dynamic::Type::STRING:
return JSC_JSValueMakeString(ctx, String(ctx, obj.getString().c_str()));
case folly::dynamic::Type::ARRAY: {
// Collect JSValue for every element in the array
JSValueRef vals[obj.size()];
for (size_t i = 0; i < obj.size(); ++i) {
vals[i] = fromDynamicInner(ctx, obj[i]);
}
// Create a JSArray with the values
JSValueRef arr = JSC_JSObjectMakeArray(ctx, obj.size(), vals, nullptr);
return arr;
}
case folly::dynamic::Type::OBJECT: {
// Create an empty object
JSObjectRef jsObj = JSC_JSObjectMake(ctx, nullptr, nullptr);
// Create a JSValue for each of the object's children and set them in the object
for (auto it = obj.items().begin(); it != obj.items().end(); ++it) {
JSC_JSObjectSetProperty(
ctx,
jsObj,
String(ctx, it->first.asString().c_str()),
fromDynamicInner(ctx, it->second),
kJSPropertyAttributeNone,
nullptr);
}
return jsObj;
}
default:
// Assert not reached
LOG(FATAL) << "Trying to convert a folly object of unsupported type.";
return JSC_JSValueMakeNull(ctx);
}
}
Object Value::asObject() {
JSValueRef exn;
JSObjectRef jsObj = JSC_JSValueToObject(context(), m_value, &exn);
if (!jsObj) {
std::string exceptionText = Value(m_context, exn).toString().str();
throwJSExecutionException("Failed to convert to object: %s", exceptionText.c_str());
}
Object ret = Object(context(), jsObj);
m_value = nullptr;
return ret;
}
Value Value::makeError(JSContextRef ctx, const char *error)
{
JSValueRef exn;
JSValueRef args[] = { Value(ctx, String(ctx, error)) };
JSObjectRef errorObj = JSC_JSObjectMakeError(ctx, 1, args, &exn);
if (!errorObj) {
std::string exceptionText = Value(ctx, exn).toString().str();
throwJSExecutionException("%s", exceptionText.c_str());
}
return Value(ctx, errorObj);
}
Object::operator Value() const {
return Value(m_context, m_obj);
}
Value Object::callAsFunction(std::initializer_list<JSValueRef> args) const {
return callAsFunction(nullptr, args.size(), args.begin());
}
Value Object::callAsFunction(const Object& thisObj, std::initializer_list<JSValueRef> args) const {
return callAsFunction((JSObjectRef)thisObj, args.size(), args.begin());
}
Value Object::callAsFunction(int nArgs, const JSValueRef args[]) const {
return callAsFunction(nullptr, nArgs, args);
}
Value Object::callAsFunction(const Object& thisObj, int nArgs, const JSValueRef args[]) const {
return callAsFunction(static_cast<JSObjectRef>(thisObj), nArgs, args);
}
Value Object::callAsFunction(JSObjectRef thisObj, int nArgs, const JSValueRef args[]) const {
JSValueRef exn;
JSValueRef result = JSC_JSObjectCallAsFunction(m_context, m_obj, thisObj, nArgs, args, &exn);
if (!result) {
std::string exceptionText = Value(m_context, exn).toString().str();
throwJSExecutionException("Exception calling object as function: %s", exceptionText.c_str());
}
return Value(m_context, result);
}
Object Object::callAsConstructor(std::initializer_list<JSValueRef> args) const {
JSValueRef exn;
JSObjectRef result = JSC_JSObjectCallAsConstructor(m_context, m_obj, args.size(), args.begin(), &exn);
if (!result) {
std::string exceptionText = Value(m_context, exn).toString().str();
throwJSExecutionException("Exception calling object as constructor: %s", exceptionText.c_str());
}
return Object(m_context, result);
}
Value Object::getProperty(const String& propName) const {
JSValueRef exn;
JSValueRef property = JSC_JSObjectGetProperty(m_context, m_obj, propName, &exn);
if (!property) {
std::string exceptionText = Value(m_context, exn).toString().str();
throwJSExecutionException("Failed to get property: %s", exceptionText.c_str());
}
return Value(m_context, property);
}
Value Object::getPropertyAtIndex(unsigned index) const {
JSValueRef exn;
JSValueRef property = JSC_JSObjectGetPropertyAtIndex(m_context, m_obj, index, &exn);
if (!property) {
std::string exceptionText = Value(m_context, exn).toString().str();
throwJSExecutionException("Failed to get property at index %u: %s", index, exceptionText.c_str());
}
return Value(m_context, property);
}
Value Object::getProperty(const char *propName) const {
return getProperty(String(m_context, propName));
}
void Object::setProperty(const String& propName, const Value& value) const {
JSValueRef exn = NULL;
JSC_JSObjectSetProperty(m_context, m_obj, propName, value, kJSPropertyAttributeNone, &exn);
if (exn) {
std::string exceptionText = Value(m_context, exn).toString().str();
throwJSExecutionException("Failed to set property: %s", exceptionText.c_str());
}
}
void Object::setProperty(const char *propName, const Value& value) const {
setProperty(String(m_context, propName), value);
}
std::vector<String> Object::getPropertyNames() const {
auto namesRef = JSC_JSObjectCopyPropertyNames(m_context, m_obj);
size_t count = JSC_JSPropertyNameArrayGetCount(m_context, namesRef);
std::vector<String> names;
names.reserve(count);
for (size_t i = 0; i < count; i++) {
names.emplace_back(String::ref(m_context,
JSC_JSPropertyNameArrayGetNameAtIndex(m_context, namesRef, i)));
}
JSC_JSPropertyNameArrayRelease(m_context, namesRef);
return names;
}
std::unordered_map<std::string, std::string> Object::toJSONMap() const {
std::unordered_map<std::string, std::string> map;
auto namesRef = JSC_JSObjectCopyPropertyNames(m_context, m_obj);
size_t count = JSC_JSPropertyNameArrayGetCount(m_context, namesRef);
for (size_t i = 0; i < count; i++) {
auto key = String::ref(m_context,
JSC_JSPropertyNameArrayGetNameAtIndex(m_context, namesRef, i));
map.emplace(key.str(), getProperty(key).toJSONString());
}
JSC_JSPropertyNameArrayRelease(m_context, namesRef);
return map;
}
/* static */
Object Object::create(JSContextRef ctx) {
JSObjectRef newObj = JSC_JSObjectMake(
ctx,
NULL, // create instance of default object class
NULL); // no private data
return Object(ctx, newObj);
}
} }