1 files changed, 110 insertions, 0 deletions
diff --git a/src/mongo/db/commands/count.h b/src/mongo/db/commands/count.h
new file mode 100644
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+++ b/src/mongo/db/commands/count.h
@@ -0,0 +1,110 @@
+/**
+ *    Copyright (C) 2014 MongoDB 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/>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the GNU Affero General Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#pragma once
+
+#include "mongo/db/catalog/collection.h"
+#include "mongo/db/commands.h"
+#include "mongo/db/jsobj.h"
+#include "mongo/db/repl/repl_settings.h"
+
+namespace mongo {
+
+    class OperationContext;
+
+    /**
+     * 'ns' is the namespace we're counting on.
+     *
+     * { count: "collectionname"[, query: <query>] }
+     *
+     * @return -1 on ns does not exist error and other errors, 0 on other errors, otherwise the
+     * match count.
+     */
+    long long runCount(OperationContext* txn,
+                       const std::string& ns,
+                       const BSONObj& cmd,
+                       std::string& err,
+                       int& errCode);
+
+    /* select count(*) */
+    class CmdCount : public Command {
+    public:
+        virtual bool isWriteCommandForConfigServer() const { return false; }
+        CmdCount() : Command("count") { }
+        virtual bool slaveOk() const {
+            // ok on --slave setups
+            return repl::replSettings.slave == repl::SimpleSlave;
+        }
+        virtual bool slaveOverrideOk() const { return true; }
+        virtual bool maintenanceOk() const { return false; }
+        virtual bool adminOnly() const { return false; }
+        virtual void help( stringstream& help ) const { help << "count objects in collection"; }
+        virtual void addRequiredPrivileges(const std::string& dbname,
+                                           const BSONObj& cmdObj,
+                                           std::vector<Privilege>* out) {
+            ActionSet actions;
+            actions.addAction(ActionType::find);
+            out->push_back(Privilege(parseResourcePattern(dbname, cmdObj), actions));
+        }
+
+        virtual Status explain(OperationContext* txn,
+                               const std::string& dbname,
+                               const BSONObj& cmdObj,
+                               Explain::Verbosity verbosity,
+                               BSONObjBuilder* out) const;
+
+        virtual bool run(OperationContext* txn,
+                         const string& dbname,
+                         BSONObj& cmdObj,
+                         int, string& errmsg,
+                         BSONObjBuilder& result, bool);
+
+    private:
+        /**
+         * Converts the command object 'cmdObj' for a count into a PlanExecutor capable
+         * of running the count and a CanonicalQuery.
+         *
+         * If successful, returns the executor through 'execOut' and the canonicalized
+         * query through 'queryOut'. The caller must delete both 'queryOut' and 'execOut'.
+         *
+         * On failure, returns a non-OK status, and the caller should not delete either
+         * 'queryOut' or 'execOut'.
+         *
+         * TODO: the regular run() command for count should call this instead of getting
+         * a runner.
+         */
+        Status parseCountToExecutor(const BSONObj& cmdObj,
+                                    const std::string& dbname,
+                                    const std::string& ns,
+                                    Collection* collection,
+                                    CanonicalQuery** queryOut,
+                                    PlanExecutor** execOut) const;
+
+    };
+
+}  // namespace mongo