shard versioning checkpoint

s/cursors.cpp

@@ -48,6 +48,8 @@ namespace mongo {
         }
 
         ScopedDbConnection conn( server );
+        checkShardVersion( conn.conn() , _ns );
+
         log(5) << "ShardedCursor::query  server:" << server << " ns:" << _ns << " query:" << q << " num:" << num << " _fields:" << _fields << " options: " << _options << endl;
         auto_ptr<DBClientCursor> cursor = conn->query( _ns.c_str() , q , num , 0 , ( _fields.isEmpty() ? 0 : &_fields ) , _options );
         conn.done();

s/shard.cpp

@@ -190,7 +190,7 @@ namespace mongo {
         }
         return added;
     }
-
+    
     void ShardManager::save(){
         for ( vector<Shard*>::const_iterator i=_shards.begin(); i!=_shards.end(); i++ ){
             Shard* s = *i;
@@ -200,6 +200,24 @@ namespace mongo {
         }
     }
 
+    ServerShardVersion ShardManager::getVersion( const string& server ) const{
+        // TODO: cache or something?
+        
+        ServerShardVersion max = 0;
+        cout << "getVersion for: " << server << endl;
+        for ( vector<Shard*>::const_iterator i=_shards.begin(); i!=_shards.end(); i++ ){
+            Shard* s = *i;
+            cout << "\t" << s->getServer() << endl;
+            if ( s->getServer() != server )
+                continue;
+            
+            if ( s->_lastmod > max )
+                max = s->_lastmod;
+        }        
+
+        return max;
+    }
+
     string ShardManager::toString() const {
         stringstream ss;
         ss << "ShardManager: " << _ns << " key:" << _key.toString() << "\n";

s/shard.h

@@ -35,6 +35,8 @@ namespace mongo {
     class ShardManager;
     class ShardObjUnitTest;
 
+    typedef unsigned long long ServerShardVersion;
+
     /**
        config.shard
        { ns : "alleyinsider.fs.chunks" , min : {} , max : {} , server : "localhost:30001" }
@@ -88,7 +90,7 @@ namespace mongo {
         BSONObj _min;
         BSONObj _max;
         string _server;
-        unsigned long long _lastmod;
+        ServerShardVersion _lastmod;
 
         bool _modified;
         
@@ -129,7 +131,8 @@ namespace mongo {
 
         string toString() const;
         operator string() const { return toString(); }
-        
+
+        ServerShardVersion getVersion( const string& server ) const;
     private:
         DBConfig * _config;
         string _ns;

s/strategy.cpp

@@ -4,6 +4,7 @@
 #include "request.h"
 #include "../client/connpool.h"
 #include "../db/commands.h"
+#include "shard.h"
 
 namespace mongo {
 
@@ -25,6 +26,8 @@ namespace mongo {
             ScopedDbConnection dbcon( server );
             DBClientBase &_c = dbcon.conn();
             
+            checkShardVersion( _c , r.getns() );
+
             // TODO: This will not work with Paired connections.  Fix. 
             DBClientConnection&c = dynamic_cast<DBClientConnection&>(_c);
             Message response;
@@ -47,4 +50,22 @@ namespace mongo {
         dbcon.done();
     }
 
+    void checkShardVersion( DBClientBase& conn , const string& ns ){
+        // TODO: cache, optimize, etc...
+        
+        DBConfig * conf = grid.getDBConfig( ns );
+        if ( ! conf )
+            return;
+        
+        if ( ! conf->sharded( ns ) )
+            return;
+        
+        ServerShardVersion version = conf->getShardManager( ns )->getVersion( conn.getServerAddress() );
+        cout << "got version: " << version << " for : " << ns << endl;
+        
+        
+        // grid->getVersion( conn.server() , ns );
+        // check
+    }
+
 }

s/strategy.h

@@ -19,6 +19,8 @@ namespace mongo {
         void insert( string server , const char * ns , const BSONObj& obj );
         
     };
+
+    void checkShardVersion( DBClientBase & conn , const string& ns );
     
     extern Strategy * SINGLE;
     extern Strategy * SHARDED;