/**
* 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/object_replace_node.h"
#include "mongo/base/data_view.h"
#include "mongo/db/bson/dotted_path_support.h"
#include "mongo/db/logical_clock.h"
#include "mongo/db/logical_time.h"
#include "mongo/db/service_context.h"
#include "mongo/db/update/storage_validation.h"
namespace mongo {
namespace {
constexpr StringData kIdFieldName = "_id"_sd;
} // namespace
ObjectReplaceNode::ObjectReplaceNode(BSONObj val)
: UpdateNode(Type::Replacement), _val(val.getOwned()), _containsId(false) {
// Replace all zero-valued timestamps with the current time and check for the existence of _id.
for (auto&& elem : _val) {
// Do not change the _id field.
if (elem.fieldNameStringData() == kIdFieldName) {
_containsId = true;
continue;
}
if (elem.type() == BSONType::bsonTimestamp) {
auto timestampView = DataView(const_cast(elem.value()));
// We don't need to do an endian-safe read here, because 0 is 0 either way.
unsigned long long timestamp = timestampView.read();
if (timestamp == 0) {
ServiceContext* service = getGlobalServiceContext();
auto ts = LogicalClock::get(service)->reserveTicks(1).asTimestamp();
timestampView.write(tagLittleEndian(ts.asULL()));
}
}
}
}
UpdateNode::ApplyResult ObjectReplaceNode::apply(ApplyParams applyParams) const {
invariant(applyParams.pathToCreate->empty());
invariant(applyParams.pathTaken->empty());
auto original = applyParams.element.getDocument().getObject();
// Check for noop.
if (original.binaryEqual(_val)) {
return ApplyResult::noopResult();
}
// Remove the contents of the provided document.
auto current = applyParams.element.leftChild();
while (current.ok()) {
// Keep the _id if the replacement document does not have one.
if (!_containsId && current.getFieldName() == kIdFieldName) {
current = current.rightSibling();
continue;
}
auto toRemove = current;
current = current.rightSibling();
invariantOK(toRemove.remove());
}
// Insert the provided contents instead.
for (auto&& elem : _val) {
invariantOK(applyParams.element.appendElement(elem));
}
// Validate for storage.
if (applyParams.validateForStorage) {
storage_validation::storageValid(applyParams.element.getDocument());
}
// Check immutable paths.
for (auto path = applyParams.immutablePaths.begin(); path != applyParams.immutablePaths.end();
++path) {
// Find the updated field in the updated document.
auto newElem = applyParams.element;
for (size_t i = 0; i < (*path)->numParts(); ++i) {
newElem = newElem[(*path)->getPart(i)];
if (!newElem.ok()) {
break;
}
uassert(ErrorCodes::NotSingleValueField,
str::stream()
<< "After applying the update to the document, the (immutable) field '"
<< (*path)->dottedField()
<< "' was found to be an array or array descendant.",
newElem.getType() != BSONType::Array);
}
auto oldElem = dotted_path_support::extractElementAtPath(original, (*path)->dottedField());
uassert(ErrorCodes::ImmutableField,
str::stream() << "After applying the update, the '" << (*path)->dottedField()
<< "' (required and immutable) field was "
"found to have been removed --"
<< original,
newElem.ok() || !oldElem.ok());
if (newElem.ok() && oldElem.ok()) {
uassert(ErrorCodes::ImmutableField,
str::stream() << "After applying the update, the (immutable) field '"
<< (*path)->dottedField()
<< "' was found to have been altered to "
<< newElem.toString(),
newElem.compareWithBSONElement(oldElem, nullptr, false) == 0);
}
}
if (applyParams.logBuilder) {
auto replacementObject = applyParams.logBuilder->getDocument().end();
invariantOK(applyParams.logBuilder->getReplacementObject(&replacementObject));
for (auto current = applyParams.element.leftChild(); current.ok();
current = current.rightSibling()) {
invariantOK(replacementObject.appendElement(current.getValue()));
}
}
return ApplyResult();
}
} // namespace mongo