move code into ShardKeyPattern::moveToFront() and add unit tests. SERVER-1540

1 files changed, 2 insertions, 58 deletions

diff --git a/s/strategy_shard.cpp b/s/strategy_shard.cpp
index f269e9c4bdb..9124d28ddc4 100644
--- a/s/strategy_shard.cpp
+++ b/s/strategy_shard.cpp
@@ -146,65 +146,9 @@ namespace mongo {
                     
                 }
 
-                {
-                    // Move Shard Key to front of object
-                    // Current implementation only works on top-level keys
-                    const ShardKeyPattern& sk = manager->getShardKey();
-
-                    vector<const char*> keysToMove;
-                    keysToMove.push_back("_id");
-                    BSONForEach(e, sk.key()){
-                        if (strchr(e.fieldName(), '.') == NULL)
-                            keysToMove.push_back(e.fieldName());
-                    }
-
-                    if (keysToMove.size() > 1){
-                        BufBuilder buf (o.objsize());
-                        buf.appendNum(o.objsize());
-
-                        vector<pair<const char*, size_t> > copies;
-                        pair<const char*, size_t> toCopy (NULL, 0);
-
-                        BSONForEach(e, o){
-                            bool moveToFront = false;
-                            for (vector<const char*>::const_iterator it(keysToMove.begin()), end(keysToMove.end()); it!=end; ++it){
-                                if (strcmp(e.fieldName(), *it) == 0){
-                                    moveToFront = true;
-                                    break;
-                                }
-                            }
-
-                            if (moveToFront){
-                                buf.appendBuf(e.fieldName()-1, e.size());
-                                if (toCopy.first){
-                                    copies.push_back(toCopy);
-                                    toCopy.first = NULL;
-                                }
-                            } else {
-                                if (!toCopy.first){
-                                    toCopy.first = e.fieldName()-1;
-                                    toCopy.second = e.size();
-                                } else {
-                                    toCopy.second += e.size();
-                                }
-                            }
-                        }
-
-                        for (vector<pair<const char*, size_t> >::const_iterator it(copies.begin()), end(copies.end()); it!=end; ++it){
-                            buf.appendBuf(it->first, it->second);
-                        }
+                // Many operations benefit from having the shard key early in the object
+                o = manager->getShardKey().moveToFront(o);
 
-                        if (toCopy.first){
-                            buf.appendBuf(toCopy.first, toCopy.second);
-                        }
-
-                        buf.appendChar('\0');
-
-                        o = BSONObj(buf.buf(), true);
-                        buf.decouple();
-                    } 
-                }
-                
                 bool gotThrough = false;
                 for ( int i=0; i<10; i++ ){
                     try {