本文整理汇总了C++中namespacedetails::IndexIterator::pos方法的典型用法代码示例。如果您正苦于以下问题：C++ IndexIterator::pos方法的具体用法？C++ IndexIterator::pos怎么用？C++ IndexIterator::pos使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类namespacedetails::IndexIterator的用法示例。
在下文中一共展示了IndexIterator::pos方法的3个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: run
bool run(const string& dbname, BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool fromRepl ) {
Timer t;
string ns = dbname + '.' + cmdObj.firstElement().valuestr();
string key = cmdObj["key"].valuestrsafe();
BSONObj keyPattern = BSON( key << 1 );
BSONObj query = getQuery( cmdObj );
int bufSize = BSONObjMaxUserSize - 4096;
BufBuilder bb( bufSize );
char * start = bb.buf();
BSONArrayBuilder arr( bb );
BSONElementSet values;
long long nscanned = 0; // locations looked at
long long nscannedObjects = 0; // full objects looked at
long long n = 0; // matches
MatchDetails md;
NamespaceDetails * d = nsdetails( ns );
if ( ! d ) {
result.appendArray( "values" , BSONObj() );
result.append( "stats" , BSON( "n" << 0 << "nscanned" << 0 << "nscannedObjects" << 0 ) );
return true;
}
shared_ptr<Cursor> cursor;
if ( ! query.isEmpty() ) {
cursor = getOptimizedCursor( ns.c_str(), query, BSONObj() );
}
else {
// query is empty, so lets see if we can find an index
// with the key so we don't have to hit the raw data
NamespaceDetails::IndexIterator ii = d->ii();
while ( ii.more() ) {
IndexDetails& idx = ii.next();
if ( d->isMultikey( ii.pos() - 1 ) )
continue;
if ( idx.inKeyPattern( key ) ) {
cursor = getBestGuessCursor( ns.c_str(), BSONObj(), idx.keyPattern() );
if( cursor.get() ) break;
}
}
if ( ! cursor.get() )
cursor = getOptimizedCursor(ns.c_str() , query , BSONObj() );
}
verify( cursor );
string cursorName = cursor->toString();
auto_ptr<ClientCursor> cc (new ClientCursor(QueryOption_NoCursorTimeout, cursor, ns));
// map from indexed field to offset in key object
map<string, int> indexedFields;
if (!cursor->modifiedKeys()) {
// store index information so we can decide if we can
// get something out of the index key rather than full object
int x = 0;
BSONObjIterator i( cursor->indexKeyPattern() );
while ( i.more() ) {
BSONElement e = i.next();
if ( e.isNumber() ) {
// only want basic index fields, not "2d" etc
indexedFields[e.fieldName()] = x;
}
x++;
}
}
while ( cursor->ok() ) {
nscanned++;
bool loadedRecord = false;
if ( cursor->currentMatches( &md ) && !cursor->getsetdup( cursor->currLoc() ) ) {
n++;
BSONObj holder;
BSONElementSet temp;
// Try to get the record from the key fields.
loadedRecord = !getFieldsDotted(indexedFields, cursor, key, temp, holder);
for ( BSONElementSet::iterator i=temp.begin(); i!=temp.end(); ++i ) {
BSONElement e = *i;
if ( values.count( e ) )
continue;
int now = bb.len();
uassert(10044, "distinct too big, 16mb cap", ( now + e.size() + 1024 ) < bufSize );
//.........这里部分代码省略.........
示例2: init
void QueryPlanSet::init() {
DEBUGQO( "QueryPlanSet::init " << ns << "\t" << _originalQuery );
_plans.clear();
_mayRecordPlan = true;
_usingPrerecordedPlan = false;
const char *ns = _frsp->ns();
NamespaceDetails *d = nsdetails( ns );
if ( !d || !_frsp->matchPossible() ) {
// Table scan plan, when no matches are possible
_plans.push_back( QueryPlanPtr( new QueryPlan( d, -1, *_frsp, *_originalFrsp, _originalQuery, _order ) ) );
return;
}
BSONElement hint = _hint.firstElement();
if ( !hint.eoo() ) {
_mayRecordPlan = false;
IndexDetails *id = parseHint( hint, d );
if ( id ) {
addHint( *id );
}
else {
massert( 10366 , "natural order cannot be specified with $min/$max", _min.isEmpty() && _max.isEmpty() );
// Table scan plan
_plans.push_back( QueryPlanPtr( new QueryPlan( d, -1, *_frsp, *_originalFrsp, _originalQuery, _order ) ) );
}
return;
}
if ( !_min.isEmpty() || !_max.isEmpty() ) {
string errmsg;
BSONObj keyPattern;
IndexDetails *idx = indexDetailsForRange( ns, errmsg, _min, _max, keyPattern );
massert( 10367 , errmsg, idx );
_plans.push_back( QueryPlanPtr( new QueryPlan( d, d->idxNo(*idx), *_frsp, *_originalFrsp, _originalQuery, _order, _min, _max ) ) );
return;
}
if ( isSimpleIdQuery( _originalQuery ) ) {
int idx = d->findIdIndex();
if ( idx >= 0 ) {
_usingPrerecordedPlan = true;
_mayRecordPlan = false;
_plans.push_back( QueryPlanPtr( new QueryPlan( d , idx , *_frsp , *_originalFrsp , _originalQuery, _order ) ) );
return;
}
}
if ( _originalQuery.isEmpty() && _order.isEmpty() ) {
_plans.push_back( QueryPlanPtr( new QueryPlan( d, -1, *_frsp, *_originalFrsp, _originalQuery, _order ) ) );
return;
}
DEBUGQO( "\t special : " << _frsp->getSpecial() );
if ( _frsp->getSpecial().size() ) {
_special = _frsp->getSpecial();
NamespaceDetails::IndexIterator i = d->ii();
while( i.more() ) {
int j = i.pos();
IndexDetails& ii = i.next();
const IndexSpec& spec = ii.getSpec();
if ( spec.getTypeName() == _special && spec.suitability( _originalQuery , _order ) ) {
_usingPrerecordedPlan = true;
_mayRecordPlan = false;
_plans.push_back( QueryPlanPtr( new QueryPlan( d , j , *_frsp , *_originalFrsp , _originalQuery, _order ,
BSONObj() , BSONObj() , _special ) ) );
return;
}
}
uassert( 13038 , (string)"can't find special index: " + _special + " for: " + _originalQuery.toString() , 0 );
}
if ( _honorRecordedPlan ) {
pair< BSONObj, long long > best = QueryUtilIndexed::bestIndexForPatterns( *_frsp, _order );
BSONObj bestIndex = best.first;
long long oldNScanned = best.second;
if ( !bestIndex.isEmpty() ) {
QueryPlanPtr p;
_oldNScanned = oldNScanned;
if ( !strcmp( bestIndex.firstElement().fieldName(), "$natural" ) ) {
// Table scan plan
p.reset( new QueryPlan( d, -1, *_frsp, *_originalFrsp, _originalQuery, _order ) );
}
NamespaceDetails::IndexIterator i = d->ii();
while( i.more() ) {
int j = i.pos();
IndexDetails& ii = i.next();
if( ii.keyPattern().woCompare(bestIndex) == 0 ) {
p.reset( new QueryPlan( d, j, *_frsp, *_originalFrsp, _originalQuery, _order ) );
}
}
massert( 10368 , "Unable to locate previously recorded index", p.get() );
if ( !( _bestGuessOnly && p->scanAndOrderRequired() ) ) {
_usingPrerecordedPlan = true;
_mayRecordPlan = false;
_plans.push_back( p );
return;
}
//.........这里部分代码省略.........
示例3: run
bool run(const string& dbname, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool fromRepl ) {
Timer t;
string ns = dbname + '.' + cmdObj.firstElement().valuestr();
string key = cmdObj["key"].valuestrsafe();
BSONObj keyPattern = BSON( key << 1 );
BSONObj query = getQuery( cmdObj );
int bufSize = BSONObjMaxUserSize - 4096;
BufBuilder bb( bufSize );
char * start = bb.buf();
BSONArrayBuilder arr( bb );
BSONElementSet values;
long long nscanned = 0; // locations looked at
long long nscannedObjects = 0; // full objects looked at
long long n = 0; // matches
MatchDetails md;
NamespaceDetails * d = nsdetails( ns.c_str() );
if ( ! d ) {
result.appendArray( "values" , BSONObj() );
result.append( "stats" , BSON( "n" << 0 << "nscanned" << 0 << "nscannedObjects" << 0 ) );
return true;
}
shared_ptr<Cursor> cursor;
if ( ! query.isEmpty() ) {
cursor = NamespaceDetailsTransient::getCursor(ns.c_str() , query , BSONObj() );
}
else {
// query is empty, so lets see if we can find an index
// with the key so we don't have to hit the raw data
NamespaceDetails::IndexIterator ii = d->ii();
while ( ii.more() ) {
IndexDetails& idx = ii.next();
if ( d->isMultikey( ii.pos() - 1 ) )
continue;
if ( idx.inKeyPattern( key ) ) {
cursor = bestGuessCursor( ns.c_str() , BSONObj() , idx.keyPattern() );
if( cursor.get() ) break;
}
}
if ( ! cursor.get() )
cursor = NamespaceDetailsTransient::getCursor(ns.c_str() , query , BSONObj() );
}
assert( cursor );
string cursorName = cursor->toString();
auto_ptr<ClientCursor> cc (new ClientCursor(QueryOption_NoCursorTimeout, cursor, ns));
while ( cursor->ok() ) {
nscanned++;
bool loadedObject = false;
if ( ( !cursor->matcher() || cursor->matcher()->matchesCurrent( cursor.get() , &md ) ) &&
!cursor->getsetdup( cursor->currLoc() ) ) {
n++;
BSONElementSet temp;
loadedObject = ! cc->getFieldsDotted( key , temp );
for ( BSONElementSet::iterator i=temp.begin(); i!=temp.end(); ++i ) {
BSONElement e = *i;
if ( values.count( e ) )
continue;
int now = bb.len();
uassert(10044, "distinct too big, 16mb cap", ( now + e.size() + 1024 ) < bufSize );
arr.append( e );
BSONElement x( start + now );
values.insert( x );
}
}
if ( loadedObject || md._loadedObject )
nscannedObjects++;
cursor->advance();
if (!cc->yieldSometimes( ClientCursor::MaybeCovered )) {
cc.release();
break;
}
RARELY killCurrentOp.checkForInterrupt();
//.........这里部分代码省略.........