SERVER-28621 Parse BSON update expression into an UpdateNode tree

1 files changed, 203 insertions, 0 deletions

diff --git a/src/mongo/db/update/update_driver.h b/src/mongo/db/update/update_driver.h
new file mode 100644
index 00000000000..6152e22cefb
--- /dev/null
+++ b/src/mongo/db/update/update_driver.h
@@ -0,0 +1,203 @@
+/**
+ *    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/>.
+ *
+ *    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 <string>
+#include <vector>
+
+#include "mongo/base/owned_pointer_vector.h"
+#include "mongo/base/status.h"
+#include "mongo/bson/mutable/document.h"
+#include "mongo/db/field_ref_set.h"
+#include "mongo/db/jsobj.h"
+#include "mongo/db/ops/modifier_interface.h"
+#include "mongo/db/query/canonical_query.h"
+#include "mongo/db/update/modifier_table.h"
+#include "mongo/db/update_index_data.h"
+
+namespace mongo {
+
+class CollatorInterface;
+class OperationContext;
+
+class UpdateDriver {
+public:
+    struct Options;
+    UpdateDriver(const Options& opts);
+
+    ~UpdateDriver();
+
+    /**
+     * Returns OK and fills in '_mods' if 'updateExpr' is correct. Otherwise returns an
+     * error status with a corresponding description.
+     */
+    Status parse(const BSONObj& updateExpr, const bool multi = false);
+
+    /**
+     * Fills in document with any fields in the query which are valid.
+     *
+     * Valid fields include equality matches like "a":1, or "a.b":false
+     *
+     * Each valid field will be expanded (from dot notation) and conflicts will be
+     * checked for all fields added to the underlying document.
+     *
+     * Returns Status::OK() if the document can be used. If there are any error or
+     * conflicts along the way then those errors will be returned.
+     */
+    Status populateDocumentWithQueryFields(OperationContext* opCtx,
+                                           const BSONObj& query,
+                                           const std::vector<FieldRef*>* immutablePaths,
+                                           mutablebson::Document& doc) const;
+
+    Status populateDocumentWithQueryFields(const CanonicalQuery& query,
+                                           const std::vector<FieldRef*>* immutablePaths,
+                                           mutablebson::Document& doc) const;
+
+    /**
+     * return a BSONObj with the _id field of the doc passed in, or the doc itself.
+     * If no _id and multi, error.
+     */
+    BSONObj makeOplogEntryQuery(const BSONObj& doc, bool multi) const;
+
+    /**
+     * Returns OK and executes '_mods' over 'doc', generating 'newObj'. If any mod is
+     * positional, use 'matchedField' (index of the array item matched). If doc allows
+     * mods to be applied in place and no index updating is involved, then the mods may
+     * be applied "in place" over 'doc'.
+     *
+     * If the driver's '_logOp' mode is turned on, and if 'logOpRec' is not NULL, fills in
+     * the latter with the oplog entry corresponding to the update. If '_mods' can't be
+     * applied, returns an error status with a corresponding description.
+     *
+     * If a non-NULL updatedField vector* is supplied,
+     * then all updated fields will be added to it.
+     */
+    Status update(StringData matchedField,
+                  mutablebson::Document* doc,
+                  BSONObj* logOpRec = NULL,
+                  FieldRefSet* updatedFields = NULL,
+                  bool* docWasModified = NULL);
+
+    //
+    // Accessors
+    //
+
+    size_t numMods() const;
+
+    bool isDocReplacement() const;
+
+    bool modsAffectIndices() const;
+    void refreshIndexKeys(const UpdateIndexData* indexedFields);
+
+    bool logOp() const;
+    void setLogOp(bool logOp);
+
+    ModifierInterface::Options modOptions() const;
+    void setModOptions(ModifierInterface::Options modOpts);
+
+    ModifierInterface::ExecInfo::UpdateContext context() const;
+    void setContext(ModifierInterface::ExecInfo::UpdateContext context);
+
+    mutablebson::Document& getDocument() {
+        return _objDoc;
+    }
+
+    const mutablebson::Document& getDocument() const {
+        return _objDoc;
+    }
+
+    bool needMatchDetails() const {
+        return _positional;
+    }
+
+    /**
+     * Set the collator which will be used by all of the UpdateDriver's underlying modifiers.
+     *
+     * 'collator' must outlive the UpdateDriver.
+     */
+    void setCollator(const CollatorInterface* collator);
+
+private:
+    /** Resets the state of the class associated with mods (not the error state) */
+    void clear();
+
+    /** Create the modifier and add it to the back of the modifiers vector */
+    inline Status addAndParse(const modifiertable::ModifierType type, const BSONElement& elem);
+
+    //
+    // immutable properties after parsing
+    //
+
+    // Is there a list of $mod's on '_mods' or is it just full object replacement?
+    bool _replacementMode;
+
+    // Collection of update mod instances. Owned here.
+    std::vector<ModifierInterface*> _mods;
+
+    // What are the list of fields in the collection over which the update is going to be
+    // applied that participate in indices?
+    //
+    // NOTE: Owned by the collection's info cache!.
+    const UpdateIndexData* _indexedFields;
+
+    //
+    // mutable properties after parsing
+    //
+
+    // Should this driver generate an oplog record when it applies the update?
+    bool _logOp;
+
+    // The options to initiate the mods with
+    ModifierInterface::Options _modOptions;
+
+    // Are any of the fields mentioned in the mods participating in any index? Is set anew
+    // at each call to update.
+    bool _affectIndices;
+
+    // Do any of the mods require positional match details when calling 'prepare'?
+    bool _positional;
+
+    // Is this update going to be an upsert?
+    ModifierInterface::ExecInfo::UpdateContext _context;
+
+    // The document used to represent or store the object being updated.
+    mutablebson::Document _objDoc;
+
+    // The document used to build the oplog entry for the update.
+    mutablebson::Document _logDoc;
+};
+
+struct UpdateDriver::Options {
+    bool logOp;
+    ModifierInterface::Options modOptions;
+
+    Options() : logOp(false), modOptions() {}
+};
+
+}  // namespace mongo