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-rw-r--r--src/mongo/db/commands/distinct.cpp235
1 files changed, 120 insertions, 115 deletions
diff --git a/src/mongo/db/commands/distinct.cpp b/src/mongo/db/commands/distinct.cpp
index ceae947fc52..2c281140c63 100644
--- a/src/mongo/db/commands/distinct.cpp
+++ b/src/mongo/db/commands/distinct.cpp
@@ -47,137 +47,142 @@
namespace mongo {
- using std::unique_ptr;
- using std::string;
- using std::stringstream;
-
- class DistinctCommand : public Command {
- public:
- DistinctCommand() : Command("distinct") {}
-
- virtual bool slaveOk() const { return false; }
- virtual bool slaveOverrideOk() const { return true; }
- virtual bool isWriteCommandForConfigServer() const { return false; }
-
- virtual void addRequiredPrivileges(const std::string& dbname,
- const BSONObj& cmdObj,
- std::vector<Privilege>* out) {
- ActionSet actions;
- actions.addAction(ActionType::find);
- out->push_back(Privilege(parseResourcePattern(dbname, cmdObj), actions));
+using std::unique_ptr;
+using std::string;
+using std::stringstream;
+
+class DistinctCommand : public Command {
+public:
+ DistinctCommand() : Command("distinct") {}
+
+ virtual bool slaveOk() const {
+ return false;
+ }
+ virtual bool slaveOverrideOk() const {
+ return true;
+ }
+ virtual bool isWriteCommandForConfigServer() const {
+ return false;
+ }
+
+ virtual void addRequiredPrivileges(const std::string& dbname,
+ const BSONObj& cmdObj,
+ std::vector<Privilege>* out) {
+ ActionSet actions;
+ actions.addAction(ActionType::find);
+ out->push_back(Privilege(parseResourcePattern(dbname, cmdObj), actions));
+ }
+
+ virtual void help(stringstream& help) const {
+ help << "{ distinct : 'collection name' , key : 'a.b' , query : {} }";
+ }
+
+ bool run(OperationContext* txn,
+ const string& dbname,
+ BSONObj& cmdObj,
+ int,
+ string& errmsg,
+ BSONObjBuilder& result) {
+ Timer t;
+
+ // ensure that the key is a string
+ uassert(18510,
+ mongoutils::str::stream() << "The first argument to the distinct command "
+ << "must be a string but was a "
+ << typeName(cmdObj["key"].type()),
+ cmdObj["key"].type() == mongo::String);
+
+ // ensure that the where clause is a document
+ if (cmdObj["query"].isNull() == false && cmdObj["query"].eoo() == false) {
+ uassert(18511,
+ mongoutils::str::stream() << "The query for the distinct command must be a "
+ << "document but was a "
+ << typeName(cmdObj["query"].type()),
+ cmdObj["query"].type() == mongo::Object);
}
- virtual void help( stringstream &help ) const {
- help << "{ distinct : 'collection name' , key : 'a.b' , query : {} }";
- }
+ string key = cmdObj["key"].valuestrsafe();
+ BSONObj keyPattern = BSON(key << 1);
- bool run(OperationContext* txn,
- const string& dbname,
- BSONObj& cmdObj,
- int,
- string& errmsg,
- BSONObjBuilder& result) {
-
- Timer t;
-
- // ensure that the key is a string
- uassert(18510,
- mongoutils::str::stream() << "The first argument to the distinct command " <<
- "must be a string but was a " << typeName(cmdObj["key"].type()),
- cmdObj["key"].type() == mongo::String);
-
- // ensure that the where clause is a document
- if( cmdObj["query"].isNull() == false && cmdObj["query"].eoo() == false ){
- uassert(18511,
- mongoutils::str::stream() << "The query for the distinct command must be a " <<
- "document but was a " << typeName(cmdObj["query"].type()),
- cmdObj["query"].type() == mongo::Object);
- }
+ BSONObj query = getQuery(cmdObj);
- string key = cmdObj["key"].valuestrsafe();
- BSONObj keyPattern = BSON( key << 1 );
+ int bufSize = BSONObjMaxUserSize - 4096;
+ BufBuilder bb(bufSize);
+ char* start = bb.buf();
- BSONObj query = getQuery( cmdObj );
+ BSONArrayBuilder arr(bb);
+ BSONElementSet values;
- int bufSize = BSONObjMaxUserSize - 4096;
- BufBuilder bb( bufSize );
- char * start = bb.buf();
+ const string ns = parseNs(dbname, cmdObj);
+ AutoGetCollectionForRead ctx(txn, ns);
- BSONArrayBuilder arr( bb );
- BSONElementSet values;
+ Collection* collection = ctx.getCollection();
+ if (!collection) {
+ result.appendArray("values", BSONObj());
+ result.append("stats", BSON("n" << 0 << "nscanned" << 0 << "nscannedObjects" << 0));
+ return true;
+ }
- const string ns = parseNs(dbname, cmdObj);
- AutoGetCollectionForRead ctx(txn, ns);
+ PlanExecutor* rawExec;
+ Status status =
+ getExecutorDistinct(txn, collection, query, key, PlanExecutor::YIELD_AUTO, &rawExec);
+ if (!status.isOK()) {
+ uasserted(17216,
+ mongoutils::str::stream() << "Can't get executor for query " << query << ": "
+ << status.toString());
+ return 0;
+ }
- Collection* collection = ctx.getCollection();
- if (!collection) {
- result.appendArray( "values" , BSONObj() );
- result.append("stats", BSON("n" << 0 <<
- "nscanned" << 0 <<
- "nscannedObjects" << 0));
- return true;
- }
+ unique_ptr<PlanExecutor> exec(rawExec);
+
+ BSONObj obj;
+ PlanExecutor::ExecState state;
+ while (PlanExecutor::ADVANCED == (state = exec->getNext(&obj, NULL))) {
+ // Distinct expands arrays.
+ //
+ // If our query is covered, each value of the key should be in the index key and
+ // available to us without this. If a collection scan is providing the data, we may
+ // have to expand an array.
+ BSONElementSet elts;
+ obj.getFieldsDotted(key, elts);
+
+ for (BSONElementSet::iterator it = elts.begin(); it != elts.end(); ++it) {
+ BSONElement elt = *it;
+ if (values.count(elt)) {
+ continue;
+ }
+ int currentBufPos = bb.len();
- PlanExecutor* rawExec;
- Status status = getExecutorDistinct(txn,
- collection,
- query,
- key,
- PlanExecutor::YIELD_AUTO,
- &rawExec);
- if (!status.isOK()) {
- uasserted(17216, mongoutils::str::stream() << "Can't get executor for query "
- << query << ": " << status.toString());
- return 0;
- }
+ uassert(17217,
+ "distinct too big, 16mb cap",
+ (currentBufPos + elt.size() + 1024) < bufSize);
- unique_ptr<PlanExecutor> exec(rawExec);
-
- BSONObj obj;
- PlanExecutor::ExecState state;
- while (PlanExecutor::ADVANCED == (state = exec->getNext(&obj, NULL))) {
- // Distinct expands arrays.
- //
- // If our query is covered, each value of the key should be in the index key and
- // available to us without this. If a collection scan is providing the data, we may
- // have to expand an array.
- BSONElementSet elts;
- obj.getFieldsDotted(key, elts);
-
- for (BSONElementSet::iterator it = elts.begin(); it != elts.end(); ++it) {
- BSONElement elt = *it;
- if (values.count(elt)) { continue; }
- int currentBufPos = bb.len();
-
- uassert(17217, "distinct too big, 16mb cap",
- (currentBufPos + elt.size() + 1024) < bufSize);
-
- arr.append(elt);
- BSONElement x(start + currentBufPos);
- values.insert(x);
- }
+ arr.append(elt);
+ BSONElement x(start + currentBufPos);
+ values.insert(x);
}
+ }
- // Get summary information about the plan.
- PlanSummaryStats stats;
- Explain::getSummaryStats(exec.get(), &stats);
-
- verify( start == bb.buf() );
+ // Get summary information about the plan.
+ PlanSummaryStats stats;
+ Explain::getSummaryStats(exec.get(), &stats);
- result.appendArray( "values" , arr.done() );
+ verify(start == bb.buf());
- {
- BSONObjBuilder b;
- b.appendNumber( "n" , stats.nReturned );
- b.appendNumber( "nscanned" , stats.totalKeysExamined );
- b.appendNumber( "nscannedObjects" , stats.totalDocsExamined );
- b.appendNumber( "timems" , t.millis() );
- b.append( "planSummary" , Explain::getPlanSummary(exec.get()) );
- result.append( "stats" , b.obj() );
- }
+ result.appendArray("values", arr.done());
- return true;
+ {
+ BSONObjBuilder b;
+ b.appendNumber("n", stats.nReturned);
+ b.appendNumber("nscanned", stats.totalKeysExamined);
+ b.appendNumber("nscannedObjects", stats.totalDocsExamined);
+ b.appendNumber("timems", t.millis());
+ b.append("planSummary", Explain::getPlanSummary(exec.get()));
+ result.append("stats", b.obj());
}
- } distinctCmd;
+
+ return true;
+ }
+} distinctCmd;
} // namespace mongo
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