From a23f4a3138dce2f71ca3f3f4529b64366e1cfce5 Mon Sep 17 00:00:00 2001
From: Aaron <aaron@10gen.com>
Date: Thu, 14 May 2009 11:30:13 -0400
Subject: [PATCH] don't do de duping for capped collections

---
 db/clientcursor.h        |  2 +-
 db/cursor.h              |  3 +++
 db/query.cpp             | 22 ++++++++++++----------
 jstests/disk/norepeat.js | 13 +++++++++++++
 4 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/db/clientcursor.h b/db/clientcursor.h
index 0e8d3f10c21..99eda2c0e6b 100644
--- a/db/clientcursor.h
+++ b/db/clientcursor.h
@@ -151,7 +151,7 @@ namespace mongo {
         
         void mayUpgradeStorage() {
             stringstream ss;
-            ss << cursorid;
+            ss << ns << "." << cursorid;
             ids_->mayUpgradeStorage( ss.str() );
         }
     };
diff --git a/db/cursor.h b/db/cursor.h
index 78cb389f509..68214cd251d 100644
--- a/db/cursor.h
+++ b/db/cursor.h
@@ -103,6 +103,7 @@ namespace mongo {
         virtual BSONObj prettyStartKey() const { return BSONObj(); }
         virtual BSONObj prettyEndKey() const { return BSONObj(); }
 
+        virtual bool capped() const { return false; }
     };
 
     class AdvanceStrategy {
@@ -197,6 +198,7 @@ namespace mongo {
             return "ForwardCappedCursor";
         }
         virtual DiskLoc next( const DiskLoc &prev ) const;
+        virtual bool capped() const { return true; }
     private:
         NamespaceDetails *nsd;
     };
@@ -208,6 +210,7 @@ namespace mongo {
             return "ReverseCappedCursor";
         }
         virtual DiskLoc next( const DiskLoc &prev ) const;
+        virtual bool capped() const { return true; }
     private:
         NamespaceDetails *nsd;
     };
diff --git a/db/query.cpp b/db/query.cpp
index 0bccc0d244f..1547bd64c8d 100644
--- a/db/query.cpp
+++ b/db/query.cpp
@@ -822,16 +822,18 @@ namespace mongo {
                     }
                     else {
                         BSONObj js = c->current();
-                        BSONElement idRef = js.getField( "_id" );
-                        if ( !idRef.eoo() ) {
-                            BSONObjBuilder idBuilder;
-                            idBuilder.append( idRef );
-                            BSONObj id = idBuilder.obj();
-                            if ( cc->ids_->get( id ) ) {
-                                c->advance();
-                                continue;
+                        if ( cc->ids_.get() ) {
+                            BSONElement idRef = js.getField( "_id" );
+                            if ( !idRef.eoo() ) {
+                                BSONObjBuilder idBuilder;
+                                idBuilder.append( idRef );
+                                BSONObj id = idBuilder.obj();
+                                if ( cc->ids_->get( id ) ) {
+                                    c->advance();
+                                    continue;
+                                }
+                                cc->ids_->put( id ); 
                             }
-                            cc->ids_->put( id ); 
                         }
                         bool ok = fillQueryResultFromObj(b, cc->filter.get(), js);
                         if ( ok ) {
@@ -1043,7 +1045,7 @@ namespace mongo {
             
             bool mayCreateCursor1 = wantMore_ && ntoreturn_ != 1 && useCursors;
             
-            if ( ( mayCreateCursor1 || mayCreateCursor2() ) && !ids_.get() ) {
+            if ( !ids_.get() && !c_->capped() && ( mayCreateCursor1 || mayCreateCursor2() ) ) {
                 ids_.reset( new IdSet() );
             }
             
diff --git a/jstests/disk/norepeat.js b/jstests/disk/norepeat.js
index be64106d7be..b636c3eaa91 100644
--- a/jstests/disk/norepeat.js
+++ b/jstests/disk/norepeat.js
@@ -43,4 +43,17 @@ assert.throws( function() { c.next() }, [], "unexpected: object found" );
 
 m.getDB( "local" ).getCollectionNames().forEach( function( x ) { assert( !x.match( /^temp/ ), "temp collection found" ); } );
 
+t.drop();
+m.getDB( baseName ).createCollection( baseName, { capped:true, size:100000, autoIdIndex:false } );
+t = m.getDB( baseName ).getCollection( baseName );
+t.insert( {_id:"a"} );
+t.insert( {_id:"a"} );
+t.insert( {_id:"a"} );
+
+c = t.find().limit( 2 );
+assert.eq( "a", c.next()._id );
+assert.eq( "a", c.next()._id );
+assert.eq( "a", c.next()._id );
+assert( !c.hasNext() );
+
 assert( t.validate().valid );