SERVER-10026 index intersection hashed and sorted

1 files changed, 45 insertions, 0 deletions

diff --git a/src/mongo/db/exec/and_common-inl.h b/src/mongo/db/exec/and_common-inl.h
new file mode 100644
index 00000000000..364936e92e9
--- /dev/null
+++ b/src/mongo/db/exec/and_common-inl.h
@@ -0,0 +1,45 @@
+/**
+ *    Copyright (C) 2013 10gen Inc.
+ *
+ *    This program is free software: you can redistribute it and/or  modify
+ *    it under the terms of the GNU Affero General Public License, version 3,
+ *    as published by the Free Software Foundation.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU Affero General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Affero General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+namespace mongo {
+
+    class AndCommon {
+    public:
+        /**
+         * If src has any data dest doesn't, add that data to dest.
+         */
+        static void mergeFrom(WorkingSetMember* dest, WorkingSetMember* src) {
+            verify(dest->hasLoc());
+            verify(src->hasLoc());
+            verify(dest->loc == src->loc);
+
+            // This is N^2 but N is probably pretty small.  Easy enough to revisit.
+            // Merge key data.
+            for (size_t i = 0; i < src->keyData.size(); ++i) {
+                bool found = false;
+                for (size_t j = 0; j < dest->keyData.size(); ++j) {
+                    if (dest->keyData[j].indexKeyPattern == src->keyData[i].indexKeyPattern) {
+                        found = true;
+                        break;
+                    }
+                }
+                if (!found) { dest->keyData.push_back(src->keyData[i]); }
+            }
+        }
+    };
+
+}  // namespace mongo
+