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/**
* Copyright (C) 2019-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include "mongo/base/string_data.h"
#include "mongo/db/client.h"
#include "mongo/db/exec/document_value/value.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/query/query_knobs_gen.h"
#include "mongo/scripting/engine.h"
namespace mongo {
class OperationContext;
/*
* This class provides a more sensible interface with JavaScript Scope objects. It helps with
* boilerplate related to calling JS functions from C++ code, and extracting BSON objects from the
* JS engine.
*/
class JsExecution {
public:
/**
* Create or get a pointer to a JsExecution instance, capable of invoking Javascript functions
* and reading the return value. If `loadStoredProcedures` is true, this will load all stored
* procedures from database unless 'disableLoadStored' is set on the global ScriptEngine. The
* JsExecution* returned is owned by 'opCtx'.
*/
static JsExecution* get(OperationContext* opCtx,
const BSONObj& scope,
StringData database,
bool loadStoredProcedures,
boost::optional<int> jsHeapLimitMB);
/**
* Construct with a thread-local scope and initialize with the given scope variables.
*/
JsExecution(OperationContext* opCtx,
const BSONObj& scopeVars,
boost::optional<int> jsHeapLimitMB = boost::none)
: _scope(getGlobalScriptEngine()->newScopeForCurrentThread(jsHeapLimitMB)) {
_scopeVars = scopeVars.getOwned();
_scope->init(&_scopeVars);
_fnCallTimeoutMillis = internalQueryJavaScriptFnTimeoutMillis.load();
_scope->registerOperation(opCtx);
}
~JsExecution() {
_scope->unregisterOperation();
};
/**
* Invokes the javascript function given by 'func' with the arguments 'params' and input object
* 'thisObj'.
*
* This method assumes that the desired function to execute does not return a value.
*/
void callFunctionWithoutReturn(ScriptingFunction func,
const BSONObj& params,
const BSONObj& thisObj);
/**
* Invokes the javascript function given by 'func' with the arguments 'params' and input object
* 'thisObj'.
*
* Returns the value returned by the function.
*/
Value callFunction(ScriptingFunction func, const BSONObj& params, const BSONObj& thisObj);
/**
* Creates a function in the owned Scope* if it hasn't been created yet.
*/
ScriptingFunction createFunction(std::string funcCode) {
return _scope->createFunction(funcCode.c_str());
};
/**
* Injects the given function 'emitFn' as a native JS function named 'emit', callable from
* user-defined functions.
*/
void injectEmitIfNecessary(NativeFunction emitFn, void* data) {
if (!_emitCreated) {
_scope->injectNative("emit", emitFn, data);
_emitCreated = true;
}
}
Scope* getScope() {
return _scope.get();
}
private:
BSONObj _scopeVars;
std::unique_ptr<Scope> _scope;
bool _emitCreated = false;
bool _storedProceduresLoaded = false;
int _fnCallTimeoutMillis;
Value doCallFunction(ScriptingFunction func,
const BSONObj& params,
const BSONObj& thisObj,
bool noReturnVal);
};
} // namespace mongo
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