/**
* Copyright (C) 2017 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see .
*
* 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 GNU Affero General 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.
*/
#include "mongo/platform/basic.h"
#include "mongo/db/update/update_internal_node.h"
namespace mongo {
namespace {
std::string toArrayFilterIdentifier(const std::string& fieldName) {
return "$[" + fieldName + "]";
}
}
// static
std::map> UpdateInternalNode::createUpdateNodeMapByMerging(
const std::map>& leftMap,
const std::map>& rightMap,
FieldRef* pathTaken,
bool wrapFieldNameAsArrayFilterIdentifier) {
std::map> mergedMap;
// Get the union of the field names we know about among the leftMap and rightMap.
stdx::unordered_set allFields;
for (const auto& child : leftMap) {
allFields.insert(child.first);
}
for (const auto& child : rightMap) {
allFields.insert(child.first);
}
// Create an entry in mergedMap for all the fields we found.
for (const std::string& fieldName : allFields) {
auto leftChildIt = leftMap.find(fieldName);
auto rightChildIt = rightMap.find(fieldName);
UpdateNode* leftChildPtr =
(leftChildIt != leftMap.end()) ? leftChildIt->second.get() : nullptr;
UpdateNode* rightChildPtr =
(rightChildIt != rightMap.end()) ? rightChildIt->second.get() : nullptr;
invariant(leftChildPtr || rightChildPtr);
mergedMap.insert(
std::make_pair(fieldName,
copyOrMergeAsNecessary(leftChildPtr,
rightChildPtr,
pathTaken,
fieldName,
wrapFieldNameAsArrayFilterIdentifier)));
}
return mergedMap;
}
// static
std::unique_ptr UpdateInternalNode::copyOrMergeAsNecessary(
UpdateNode* leftNode,
UpdateNode* rightNode,
FieldRef* pathTaken,
const std::string& nextField,
bool wrapFieldNameAsArrayFilterIdentifier) {
if (!leftNode && !rightNode) {
return nullptr;
} else if (!leftNode) {
return rightNode->clone();
} else if (!rightNode) {
return leftNode->clone();
} else {
FieldRefTempAppend tempAppend(
*pathTaken,
wrapFieldNameAsArrayFilterIdentifier ? toArrayFilterIdentifier(nextField) : nextField);
return UpdateNode::createUpdateNodeByMerging(*leftNode, *rightNode, pathTaken);
}
}
} // namespace mongo