SERVER-12213: IndexAccessMethod::initializeAsEmpty is way to start new index

5 files changed, 32 insertions, 10 deletions

diff --git a/src/mongo/db/index/btree_based_access_method.cpp b/src/mongo/db/index/btree_based_access_method.cpp
index 8af96bbadbf..a15729a1339 100644
--- a/src/mongo/db/index/btree_based_access_method.cpp
+++ b/src/mongo/db/index/btree_based_access_method.cpp
@@ -159,6 +159,26 @@ namespace mongo {
         }
     }
 
+    Status BtreeBasedAccessMethod::initializeAsEmpty() {
+        if ( !_btreeState->head().isNull() )
+            return Status( ErrorCodes::InternalError, "index already initialized" );
+
+        DiskLoc newHead;
+        if ( 0 == _descriptor->version() ) {
+            newHead = BtreeBucket<V0>::addBucket( _btreeState );
+        }
+        else if ( 1 == _descriptor->version() ) {
+            newHead = BtreeBucket<V1>::addBucket( _btreeState );
+        }
+        else {
+            return Status( ErrorCodes::InternalError, "invalid index number" );
+        }
+        _btreeState->setHead( newHead );
+
+        return Status::OK();
+    }
+
+
     Status BtreeBasedAccessMethod::touch(const BSONObj& obj) {
         BSONObjSet keys;
         getKeys(obj, &keys);
diff --git a/src/mongo/db/index/btree_based_access_method.h b/src/mongo/db/index/btree_based_access_method.h
index 320c1de8944..f541d302f60 100644
--- a/src/mongo/db/index/btree_based_access_method.h
+++ b/src/mongo/db/index/btree_based_access_method.h
@@ -75,6 +75,8 @@ namespace mongo {
 
         virtual Status newCursor(IndexCursor **out) const = 0;
 
+        virtual Status initializeAsEmpty();
+
         virtual Status touch(const BSONObj& obj);
 
         virtual Status validate(int64_t* numKeys);
diff --git a/src/mongo/db/index/btree_based_builder.cpp b/src/mongo/db/index/btree_based_builder.cpp
index 1a321f43b4e..c2e452fcc7d 100644
--- a/src/mongo/db/index/btree_based_builder.cpp
+++ b/src/mongo/db/index/btree_based_builder.cpp
@@ -136,14 +136,6 @@ namespace mongo {
         }
     }
 
-    DiskLoc BtreeBasedBuilder::makeEmptyIndex(IndexCatalogEntry* idx) {
-        if (0 == idx->descriptor()->version()) {
-            return BtreeBucket<V0>::addBucket(idx);
-        } else {
-            return BtreeBucket<V1>::addBucket(idx);
-        }
-    }
-
     ExternalSortComparison* BtreeBasedBuilder::getComparison(int version,
                                                              const BSONObj& keyPattern) {
         if (0 == version) {
diff --git a/src/mongo/db/index/btree_based_builder.h b/src/mongo/db/index/btree_based_builder.h
index d9515c3f6de..967c17bb2b5 100644
--- a/src/mongo/db/index/btree_based_builder.h
+++ b/src/mongo/db/index/btree_based_builder.h
@@ -62,8 +62,6 @@ namespace mongo {
                                        IndexCatalogEntry* descriptor,
                                        bool mayInterrupt);
 
-        static DiskLoc makeEmptyIndex(IndexCatalogEntry* idx);
-
         static ExternalSortComparison* getComparison(int version,
                                                      const BSONObj& keyPattern);
 
diff --git a/src/mongo/db/index/index_access_method.h b/src/mongo/db/index/index_access_method.h
index 303b09d9ed2..a04e54610ab 100644
--- a/src/mongo/db/index/index_access_method.h
+++ b/src/mongo/db/index/index_access_method.h
@@ -110,6 +110,16 @@ namespace mongo {
          */
         virtual Status newCursor(IndexCursor **out) const = 0;
 
+        // ------ index level operations ------
+
+
+        /**
+         * initializes this index
+         * only called once for the lifetime of the index
+         * if called multiple times, is an error
+         */
+        virtual Status initializeAsEmpty() = 0;
+
         /**
          * Try to page-in the pages that contain the keys generated from 'obj'.
          * This can be used to speed up future accesses to an index by trying to ensure the