// find_and_modify.cpp
/**
* Copyright (C) 2012 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/pch.h"
#include "mongo/db/commands/find_and_modify.h"
#include "mongo/db/clientcursor.h"
#include "mongo/db/commands.h"
#include "mongo/db/dbhelpers.h"
#include "mongo/db/instance.h"
#include "mongo/db/projection.h"
#include "mongo/db/ops/delete.h"
#include "mongo/db/ops/update.h"
#include "mongo/db/ops/update_lifecycle_impl.h"
#include "mongo/db/query/get_runner.h"
#include "mongo/db/operation_context_impl.h"
namespace mongo {
/* Find and Modify an object returning either the old (default) or new value*/
class CmdFindAndModify : public Command {
public:
virtual void help( stringstream &help ) const {
help <<
"{ findAndModify: \"collection\", query: {processed:false}, update: {$set: {processed:true}}, new: true}\n"
"{ findAndModify: \"collection\", query: {processed:false}, remove: true, sort: {priority:-1}}\n"
"Either update or remove is required, all other fields have default values.\n"
"Output is in the \"value\" field\n";
}
CmdFindAndModify() : Command("findAndModify", false, "findandmodify") { }
virtual bool slaveOk() const { return false; }
virtual bool isWriteCommandForConfigServer() const { return true; }
virtual void addRequiredPrivileges(const std::string& dbname,
const BSONObj& cmdObj,
std::vector* out) {
find_and_modify::addPrivilegesRequiredForFindAndModify(this, dbname, cmdObj, out);
}
/* this will eventually replace run, once sort is handled */
bool runNoDirectClient( OperationContext* txn, const string& dbname, BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool) {
verify( cmdObj["sort"].eoo() );
const string ns = dbname + '.' + cmdObj.firstElement().valuestr();
BSONObj query = cmdObj.getObjectField("query");
BSONObj fields = cmdObj.getObjectField("fields");
BSONObj update = cmdObj.getObjectField("update");
bool upsert = cmdObj["upsert"].trueValue();
bool returnNew = cmdObj["new"].trueValue();
bool remove = cmdObj["remove"].trueValue();
if ( remove ) {
if ( upsert ) {
errmsg = "remove and upsert can't co-exist";
return false;
}
if ( returnNew ) {
errmsg = "remove and returnNew can't co-exist";
return false;
}
}
else if ( !cmdObj.hasField("update") ) {
errmsg = "need remove or update";
return false;
}
Lock::DBWrite dbXLock(txn->lockState(), dbname);
Client::Context ctx(ns);
return runNoDirectClient( txn, ns ,
query , fields , update ,
upsert , returnNew , remove ,
result , errmsg );
}
static void _appendHelper(BSONObjBuilder& result,
const BSONObj& doc,
bool found,
const BSONObj& fields,
const MatchExpressionParser::WhereCallback& whereCallback) {
if ( ! found ) {
result.appendNull( "value" );
return;
}
if ( fields.isEmpty() ) {
result.append( "value" , doc );
return;
}
Projection p;
p.init(fields, whereCallback);
result.append( "value" , p.transform( doc ) );
}
static bool runNoDirectClient(OperationContext* txn,
const string& ns,
const BSONObj& queryOriginal,
const BSONObj& fields,
const BSONObj& update,
bool upsert,
bool returnNew,
bool remove ,
BSONObjBuilder& result,
string& errmsg) {
Lock::DBWrite lk(txn->lockState(), ns);
Client::Context cx( ns );
Collection* collection = cx.db()->getCollection( txn, ns );
const WhereCallbackReal whereCallback = WhereCallbackReal(StringData(ns));
BSONObj doc;
bool found = false;
{
CanonicalQuery* cq;
massert(17383, "Could not canonicalize " + queryOriginal.toString(),
CanonicalQuery::canonicalize(ns, queryOriginal, &cq, whereCallback).isOK());
Runner* rawRunner;
massert(17384, "Could not get runner for query " + queryOriginal.toString(),
getRunner(collection, cq, &rawRunner, QueryPlannerParams::DEFAULT).isOK());
auto_ptr runner(rawRunner);
// Set up automatic yielding
const ScopedRunnerRegistration safety(runner.get());
Runner::RunnerState state;
if (Runner::RUNNER_ADVANCED == (state = runner->getNext(&doc, NULL))) {
found = true;
}
}
BSONObj queryModified = queryOriginal;
if ( found && doc["_id"].type() && ! CanonicalQuery::isSimpleIdQuery( queryOriginal ) ) {
// we're going to re-write the query to be more efficient
// we have to be a little careful because of positional operators
// maybe we can pass this all through eventually, but right now isn't an easy way
bool hasPositionalUpdate = false;
{
// if the update has a positional piece ($)
// then we need to pull all query parts in
// so here we check for $
// a little hacky
BSONObjIterator i( update );
while ( i.more() ) {
const BSONElement& elem = i.next();
if ( elem.fieldName()[0] != '$' || elem.type() != Object )
continue;
BSONObjIterator j( elem.Obj() );
while ( j.more() ) {
if ( str::contains( j.next().fieldName(), ".$" ) ) {
hasPositionalUpdate = true;
break;
}
}
}
}
BSONObjBuilder b( queryOriginal.objsize() + 10 );
b.append( doc["_id"] );
bool addedAtomic = false;
BSONObjIterator i( queryOriginal );
while ( i.more() ) {
const BSONElement& elem = i.next();
if ( str::equals( "_id" , elem.fieldName() ) ) {
// we already do _id
continue;
}
if ( ! hasPositionalUpdate ) {
// if there is a dotted field, accept we may need more query parts
continue;
}
if ( ! addedAtomic ) {
b.appendBool( "$atomic" , true );
addedAtomic = true;
}
b.append( elem );
}
queryModified = b.obj();
}
if ( remove ) {
_appendHelper(result, doc, found, fields, whereCallback);
if ( found ) {
deleteObjects(txn, cx.db(), ns, queryModified, true, true);
BSONObjBuilder le( result.subobjStart( "lastErrorObject" ) );
le.appendNumber( "n" , 1 );
le.done();
}
}
else {
// update
if ( ! found && ! upsert ) {
// didn't have it, and am not upserting
_appendHelper(result, doc, found, fields, whereCallback);
}
else {
// we found it or we're updating
if ( ! returnNew ) {
_appendHelper(result, doc, found, fields, whereCallback);
}
const NamespaceString requestNs(ns);
UpdateRequest request(requestNs);
request.setQuery(queryModified);
request.setUpdates(update);
request.setUpsert(upsert);
request.setUpdateOpLog();
// TODO(greg) We need to send if we are ignoring
// the shard version below, but for now no
UpdateLifecycleImpl updateLifecycle(false, requestNs);
request.setLifecycle(&updateLifecycle);
UpdateResult res = mongo::update(txn, cx.db(), request, &cc().curop()->debug());
if ( !collection ) {
// collection created by an upsert
collection = cx.db()->getCollection( ns );
}
LOG(3) << "update result: " << res ;
if ( returnNew ) {
if ( !res.upserted.isEmpty() ) {
BSONElement upsertedElem = res.upserted[kUpsertedFieldName];
LOG(3) << "using new _id to get new doc: "
<< upsertedElem;
queryModified = upsertedElem.wrap("_id");
}
else if ( queryModified["_id"].type() ) {
// we do this so that if the update changes the fields, it still matches
queryModified = queryModified["_id"].wrap();
}
LOG(3) << "using modified query to return the new doc: " << queryModified;
if ( ! Helpers::findOne( collection, queryModified, doc ) ) {
errmsg = str::stream() << "can't find object after modification "
<< " ns: " << ns
<< " queryModified: " << queryModified
<< " queryOriginal: " << queryOriginal;
log() << errmsg << endl;
return false;
}
_appendHelper(result, doc, true, fields, whereCallback);
}
BSONObjBuilder le( result.subobjStart( "lastErrorObject" ) );
le.appendBool( "updatedExisting" , res.existing );
le.appendNumber( "n" , res.numMatched );
if ( !res.upserted.isEmpty() ) {
le.append( res.upserted[kUpsertedFieldName] );
}
le.done();
}
}
return true;
}
virtual bool run(OperationContext* txn, const string& dbname, BSONObj& cmdObj, int x, string& errmsg, BSONObjBuilder& result, bool y) {
DBDirectClient db(txn);
if (cmdObj["sort"].eoo()) {
return runNoDirectClient(txn, dbname, cmdObj, x, errmsg, result, y);
}
const string ns = dbname + '.' + cmdObj.firstElement().valuestr();
BSONObj origQuery = cmdObj.getObjectField("query"); // defaults to {}
Query q (origQuery);
BSONElement sort = cmdObj["sort"];
if (!sort.eoo())
q.sort(sort.embeddedObjectUserCheck());
bool upsert = cmdObj["upsert"].trueValue();
BSONObj fieldsHolder (cmdObj.getObjectField("fields"));
const BSONObj* fields = (fieldsHolder.isEmpty() ? NULL : &fieldsHolder);
Projection projection;
if (fields) {
projection.init(fieldsHolder, WhereCallbackReal(StringData(dbname)));
if (!projection.includeID()) {
fields = NULL; // do projection in post-processing
}
}
Lock::DBWrite dbXLock(txn->lockState(), dbname);
Client::Context ctx(ns);
BSONObj out = db.findOne(ns, q, fields);
if (out.isEmpty()) {
if (!upsert) {
result.appendNull("value");
return true;
}
BSONElement update = cmdObj["update"];
uassert(13329, "upsert mode requires update field", !update.eoo());
uassert(13330, "upsert mode requires query field", !origQuery.isEmpty());
db.update(ns, origQuery, update.embeddedObjectUserCheck(), true);
BSONObj gle = db.getLastErrorDetailed(dbname);
result.append("lastErrorObject", gle);
if (gle["err"].type() == String) {
errmsg = gle["err"].String();
return false;
}
if (!cmdObj["new"].trueValue()) {
result.appendNull("value");
return true;
}
BSONObjBuilder bob;
BSONElement _id = gle[kUpsertedFieldName];
if (!_id.eoo())
bob.appendAs(_id, "_id");
else
bob.appendAs(origQuery["_id"], "_id");
out = db.findOne(ns, bob.done(), fields);
}
else {
if (cmdObj["remove"].trueValue()) {
uassert(12515, "can't remove and update", cmdObj["update"].eoo());
db.remove(ns, QUERY("_id" << out["_id"]), 1);
BSONObj gle = db.getLastErrorDetailed(dbname);
result.append("lastErrorObject", gle);
if (gle["err"].type() == String) {
errmsg = gle["err"].String();
return false;
}
}
else { // update
BSONElement queryId = origQuery["_id"];
if (queryId.eoo() || getGtLtOp(queryId) != BSONObj::Equality) {
// need to include original query for $ positional operator
BSONObjBuilder b;
b.append(out["_id"]);
BSONObjIterator it(origQuery);
while (it.more()) {
BSONElement e = it.next();
if (strcmp(e.fieldName(), "_id"))
b.append(e);
}
q = Query(b.obj());
}
if (q.isComplex()) // update doesn't work with complex queries
q = Query(q.getFilter().getOwned());
BSONElement update = cmdObj["update"];
uassert(12516, "must specify remove or update", !update.eoo());
db.update(ns, q, update.embeddedObjectUserCheck());
BSONObj gle = db.getLastErrorDetailed(dbname);
result.append("lastErrorObject", gle);
if (gle["err"].type() == String) {
errmsg = gle["err"].String();
return false;
}
if (cmdObj["new"].trueValue())
out = db.findOne(ns, QUERY("_id" << out["_id"]), fields);
}
}
if (!fieldsHolder.isEmpty() && !fields){
// we need to run projection but haven't yet
out = projection.transform(out);
}
result.append("value", out);
return true;
}
} cmdFindAndModify;
}