1 files changed, 153 insertions, 0 deletions
diff --git a/db/commands/find_and_modify.cpp b/db/commands/find_and_modify.cpp
new file mode 100644
index 0000000..0cf766f
--- /dev/null
+++ b/db/commands/find_and_modify.cpp
@@ -0,0 +1,153 @@
+// find_and_modify.cpp
+
+/**
+*
+*    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/>.
+*/
+
+#include "pch.h"
+#include "../commands.h"
+#include "../instance.h"
+#include "../clientcursor.h"
+
+namespace mongo {
+
+    /* Find and Modify an object returning either the old (default) or new value*/
+    class CmdFindAndModify : public Command {
+    public:
+        virtual void help( stringstream &help ) const {
+            help <<
+                 "{ findAndModify: \"collection\", query: {processed:false}, update: {$set: {processed:true}}, new: true}\n"
+                 "{ findAndModify: \"collection\", query: {processed:false}, remove: true, sort: {priority:-1}}\n"
+                 "Either update or remove is required, all other fields have default values.\n"
+                 "Output is in the \"value\" field\n";
+        }
+
+        CmdFindAndModify() : Command("findAndModify", false, "findandmodify") { }
+        virtual bool logTheOp() { return false; } // the modifications will be logged directly
+        virtual bool slaveOk() const { return false; }
+        virtual LockType locktype() const { return WRITE; }
+        virtual bool run(const string& dbname, BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool) {
+            static DBDirectClient db;
+
+            string ns = dbname + '.' + cmdObj.firstElement().valuestr();
+
+            BSONObj origQuery = cmdObj.getObjectField("query"); // defaults to {}
+            Query q (origQuery);
+            BSONElement sort = cmdObj["sort"];
+            if (!sort.eoo())
+                q.sort(sort.embeddedObjectUserCheck());
+
+            bool upsert = cmdObj["upsert"].trueValue();
+
+            BSONObj fieldsHolder (cmdObj.getObjectField("fields"));
+            const BSONObj* fields = (fieldsHolder.isEmpty() ? NULL : &fieldsHolder);
+
+            Projection projection;
+            if (fields) {
+                projection.init(fieldsHolder);
+                if (!projection.includeID())
+                    fields = NULL; // do projection in post-processing
+            }
+
+            BSONObj out = db.findOne(ns, q, fields);
+            if (out.isEmpty()) {
+                if (!upsert) {
+                    result.appendNull("value");
+                    return true;
+                }
+
+                BSONElement update = cmdObj["update"];
+                uassert(13329, "upsert mode requires update field", !update.eoo());
+                uassert(13330, "upsert mode requires query field", !origQuery.isEmpty());
+                db.update(ns, origQuery, update.embeddedObjectUserCheck(), true);
+
+                BSONObj gle = db.getLastErrorDetailed();
+                result.append("lastErrorObject", gle);
+                if (gle["err"].type() == String) {
+                    errmsg = gle["err"].String();
+                    return false;
+                }
+
+                if (cmdObj["new"].trueValue()) {
+                    BSONElement _id = gle["upserted"];
+                    if (_id.eoo())
+                        _id = origQuery["_id"];
+
+                    out = db.findOne(ns, QUERY("_id" << _id), fields);
+                }
+
+            }
+            else {
+
+                if (cmdObj["remove"].trueValue()) {
+                    uassert(12515, "can't remove and update", cmdObj["update"].eoo());
+                    db.remove(ns, QUERY("_id" << out["_id"]), 1);
+
+                    BSONObj gle = db.getLastErrorDetailed();
+                    result.append("lastErrorObject", gle);
+                    if (gle["err"].type() == String) {
+                        errmsg = gle["err"].String();
+                        return false;
+                    }
+
+                }
+                else {   // update
+
+                    BSONElement queryId = origQuery["_id"];
+                    if (queryId.eoo() || getGtLtOp(queryId) != BSONObj::Equality) {
+                        // need to include original query for $ positional operator
+
+                        BSONObjBuilder b;
+                        b.append(out["_id"]);
+                        BSONObjIterator it(origQuery);
+                        while (it.more()) {
+                            BSONElement e = it.next();
+                            if (strcmp(e.fieldName(), "_id"))
+                                b.append(e);
+                        }
+                        q = Query(b.obj());
+                    }
+
+                    if (q.isComplex()) // update doesn't work with complex queries
+                        q = Query(q.getFilter().getOwned());
+
+                    BSONElement update = cmdObj["update"];
+                    uassert(12516, "must specify remove or update", !update.eoo());
+                    db.update(ns, q, update.embeddedObjectUserCheck());
+
+                    BSONObj gle = db.getLastErrorDetailed();
+                    result.append("lastErrorObject", gle);
+                    if (gle["err"].type() == String) {
+                        errmsg = gle["err"].String();
+                        return false;
+                    }
+
+                    if (cmdObj["new"].trueValue())
+                        out = db.findOne(ns, QUERY("_id" << out["_id"]), fields);
+                }
+            }
+
+            if (!fieldsHolder.isEmpty() && !fields){
+                // we need to run projection but haven't yet
+                out = projection.transform(out);
+            }
+
+            result.append("value", out);
+
+            return true;
+        }
+    } cmdFindAndModify;
+
+
+}