/**
* Copyright (C) 2013 10gen 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/db/ops/modifier_object_replace.h"
#include "mongo/base/error_codes.h"
#include "mongo/bson/mutable/document.h"
#include "mongo/db/ops/log_builder.h"
#include "mongo/util/mongoutils/str.h"
namespace mongo {
namespace {
// TODO: Egregiously stolen from jsobjmanipulator.h and instance.cpp to break a link
// dependency cycle. We should sort this out, but we don't need to do it right now.
void fixupTimestamps( const BSONObj& obj ) {
BSONObjIterator i(obj);
for(int j = 0; i.moreWithEOO() && j < 2; ++j) {
BSONElement e = i.next();
if (e.eoo())
break;
if (e.type() == Timestamp) {
// performance note, this locks a mutex:
unsigned long long ×tamp =
*(reinterpret_cast(
const_cast(e.value())));
if (timestamp == 0) {
mutex::scoped_lock lk(OpTime::m);
timestamp = OpTime::now(lk).asDate();
}
break;
}
}
}
}
struct ModifierObjectReplace::PreparedState {
PreparedState(mutablebson::Document* targetDoc)
: doc(*targetDoc)
, noOp(false) {
}
// Document that is going to be changed
mutablebson::Document& doc;
// This is a no op
bool noOp;
};
ModifierObjectReplace::ModifierObjectReplace() : _val() {
}
ModifierObjectReplace::~ModifierObjectReplace() {
}
Status ModifierObjectReplace::init(const BSONElement& modExpr, const Options& opts) {
if (modExpr.type() != Object) {
return Status(ErrorCodes::BadValue, mongoutils::str::stream() <<
"object replace expects full object but type was " << modExpr.type());
}
if (opts.enforceOkForStorage && !modExpr.embeddedObject().okForStorageAsRoot()) {
return Status(ErrorCodes::BadValue, "not okForStorage: "
" the document has invalid fields");
}
BSONObjIterator it(modExpr.embeddedObject());
while (it.more()) {
BSONElement elem = it.next();
if (*elem.fieldName() == '$') {
return Status(ErrorCodes::BadValue, "can't mix modifiers and non-modifiers");
}
}
// We make a copy of the object here because the update driver does not guarantees, in
// the case of object replacement, that the modExpr is going to outlive this mod.
_val = modExpr.embeddedObject().getOwned();
fixupTimestamps(_val);
return Status::OK();
}
Status ModifierObjectReplace::prepare(mutablebson::Element root,
const StringData& matchedField,
ExecInfo* execInfo) {
_preparedState.reset(new PreparedState(&root.getDocument()));
// objectSize checked by binaryEqual (optimization)
BSONObj objOld = root.getDocument().getObject();
if (objOld.binaryEqual(_val)) {
_preparedState->noOp = true;
execInfo->noOp = true;
}
return Status::OK();
}
Status ModifierObjectReplace::apply() const {
dassert(!_preparedState->noOp);
// Remove the contents of the provided doc.
mutablebson::Document& doc = _preparedState->doc;
mutablebson::Element current = doc.root().leftChild();
mutablebson::Element srcIdElement = doc.end();
while (current.ok()) {
mutablebson::Element toRemove = current;
current = current.rightSibling();
// Skip _id field element -- it should not change
if (toRemove.getFieldName() == "_id") {
srcIdElement = toRemove;
continue;
}
Status status = toRemove.remove();
if (!status.isOK()) {
return status;
}
}
// Insert the provided contents instead.
BSONElement dstIdElement;
BSONObjIterator it(_val);
while (it.more()) {
BSONElement elem = it.next();
if (elem.fieldNameStringData() == "_id") {
dstIdElement = elem;
// Do not duplicate _id field
if (srcIdElement.ok()) {
continue;
}
}
Status status = doc.root().appendElement(elem);
if (!status.isOK()) {
return status;
}
}
// Error if the _id changed
if (srcIdElement.ok() && !dstIdElement.eoo() &&
(srcIdElement.compareWithBSONElement(dstIdElement) != 0)) {
return Status(ErrorCodes::CannotMutateObject, "The _id field cannot be changed");
}
return Status::OK();
}
Status ModifierObjectReplace::log(LogBuilder* logBuilder) const {
mutablebson::Document& doc = logBuilder->getDocument();
mutablebson::Element replacementObject = doc.end();
Status status = logBuilder->getReplacementObject(&replacementObject);
if (status.isOK()) {
BSONObjIterator it(_val);
while (status.isOK() && it.more())
status = replacementObject.appendElement(it.next());
}
return status;
}
} // namespace mongo