make forcing a split work better SERVER-2419 180?

1 files changed, 46 insertions, 33 deletions

diff --git a/s/d_split.cpp b/s/d_split.cpp
index a2e92f9be3e..0896803d1f7 100644
--- a/s/d_split.cpp
+++ b/s/d_split.cpp
@@ -373,47 +373,60 @@ namespace mongo {
                 // split on the following key.
                 set<BSONObj> tooFrequentKeys;
                 splitKeys.push_back( c->currKey().getOwned() );
-                while ( cc->ok() ) {
-                    currCount++;
-                    BSONObj currKey = c->currKey();
-                    
-                    DEV assert( currKey.woCompare( max ) <= 0 );
-                    
-                    if ( currCount > keyCount ) {
-                        // Do not use this split key if it is the same used in the previous split point.
-                        if ( currKey.woCompare( splitKeys.back() ) == 0 ) {
-                            tooFrequentKeys.insert( currKey.getOwned() );
+                while ( 1 ) {
+                    while ( cc->ok() ) {
+                        currCount++;
+                        BSONObj currKey = c->currKey();
+                        
+                        DEV assert( currKey.woCompare( max ) <= 0 );
+                        
+                        if ( currCount > keyCount ) {
+                            // Do not use this split key if it is the same used in the previous split point.
+                            if ( currKey.woCompare( splitKeys.back() ) == 0 ) {
+                                tooFrequentKeys.insert( currKey.getOwned() );
+                                
+                            }
+                            else {
+                                splitKeys.push_back( currKey.getOwned() );
+                                currCount = 0;
+                                numChunks++;
+                                
+                                LOG(4) << "picked a split key: " << bc->prettyKey( currKey ) << endl;
+                            }
                             
                         }
-                        else {
-                            splitKeys.push_back( currKey.getOwned() );
-                            currCount = 0;
-                            numChunks++;
-                            
-                            LOG(4) << "picked a split key: " << bc->prettyKey( currKey ) << endl;
+                        
+                        cc->advance();
+                        
+                        // Stop if we have enough split points.
+                        if ( maxSplitPoints && ( numChunks >= maxSplitPoints ) ) {
+                            log() << "max number of requested split points reached (" << numChunks
+                                  << ") before the end of chunk " << ns << " " << min << " -->> " << max
+                                  << endl;
+                            break;
                         }
                         
+                        if ( ! cc->yieldSometimes() ) {
+                            // we were near and and got pushed to the end
+                            // i think returning the splits we've already found is fine
+                            
+                            // don't use the btree cursor pointer to acces keys beyond this point but ok
+                            // to use it for format the keys we've got already
+                            
+                            break;
+                        }
                     }
-
-                    cc->advance();
                     
-                    // Stop if we have enough split points.
-                    if ( maxSplitPoints && ( numChunks >= maxSplitPoints ) ) {
-                        log() << "max number of requested split points reached (" << numChunks
-                              << ") before the end of chunk " << ns << " " << min << " -->> " << max
-                              << endl;
+                    if ( splitKeys.size() > 1 || ! force )
                         break;
-                    }
                     
-                    if ( ! cc->yieldSometimes() ) {
-                        // we were near and and got pushed to the end
-                        // i think returning the splits we've already found is fine
-                        
-                        // don't use the btree cursor pointer to acces keys beyond this point but ok
-                        // to use it for format the keys we've got already
-                        
-                        break;
-                    }
+                    force = false;
+                    keyCount = currCount / 2;
+                    currCount = 0;
+                    log() << "splitVector doing another cycle because of force, keyCount now: " << keyCount << endl;
+                    
+                    c.reset( new BtreeCursor( d , d->idxNo(*idx) , *idx , min , max , false , 1 ) );
+                    cc.reset( new ClientCursor( QueryOption_NoCursorTimeout , c , ns ) );
                 }
                 
                 //