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// dbhelpers.cpp
/**
* Copyright (C) 2008 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 <http://www.gnu.org/licenses/>.
*/
#include "stdafx.h"
#include "db.h"
#include "dbhelpers.h"
#include "query.h"
#include "json.h"
namespace mongo {
void Helpers::ensureIndex(const char *ns, BSONObj keyPattern, const char *name) {
NamespaceDetails *d = nsdetails(ns);
if( d == 0 )
return;
for( int i = 0; i < d->nIndexes; i++ ) {
if( d->indexes[i].keyPattern().woCompare(keyPattern) == 0 )
return;
}
if( d->nIndexes >= MaxIndexes ) {
problem() << "Helper::ensureIndex fails, MaxIndexes exceeded " << ns << '\n';
return;
}
string system_indexes = database->name + ".system.indexes";
BSONObjBuilder b;
b.append("name", name);
b.append("ns", ns);
b.append("key", keyPattern);
BSONObj o = b.done();
theDataFileMgr.insert(system_indexes.c_str(), o.objdata(), o.objsize());
}
/* fetch a single object from collection ns that matches query
set your db context first
*/
bool Helpers::findOne(const char *ns, BSONObj query, BSONObj& result, bool requireIndex) {
auto_ptr<Cursor> c = getIndexCursor(ns, query, emptyObj);
if ( c.get() == 0 ) {
massert("index missing on server's findOne invocation", !requireIndex);
c = DataFileMgr::findAll(ns);
}
if( !c->ok() )
return false;
JSMatcher matcher(query, c->indexKeyPattern());
do {
BSONObj js = c->current();
if( matcher.matches(js) ) {
result = js;
return true;
}
c->advance();
} while( c->ok() );
return false;
}
int test2_dbh() {
dblock lk;
DBContext c("dwight.foo");
BSONObj q = fromjson("{\"x\":9}");
BSONObj result;
{
BSONObj kp = fromjson("{\"x\":1}");
Helpers::ensureIndex("dwight.foo", kp, "x_1");
}
cout << Helpers::findOne("dwight.foo", q, result, true) << endl;
cout << result.toString() << endl;
return 0;
}
/* Get the first object from a collection. Generally only useful if the collection
only ever has a single object -- which is a "singleton collection.
Returns: true if object exists.
*/
bool Helpers::getSingleton(const char *ns, BSONObj& result) {
DBContext context(ns);
auto_ptr<Cursor> c = DataFileMgr::findAll(ns);
if ( !c->ok() )
return false;
result = c->current();
return true;
}
void Helpers::putSingleton(const char *ns, BSONObj obj) {
DBContext context(ns);
stringstream ss;
updateObjects(ns, obj, /*pattern=*/emptyObj, /*upsert=*/true, ss);
}
void Helpers::emptyCollection(const char *ns) {
DBContext context(ns);
deleteObjects(ns, emptyObj, false);
}
} // namespace mongo
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