// PurgeMissing removes from collections any state that refers to transaction
// documents that for whatever reason have been lost from the system (removed
// by accident or lost in a hard crash, for example).
//
// This method should very rarely be needed, if at all, and should never be
// used during the normal operation of an application. Its purpose is to put
// a system that has seen unavoidable corruption back in a working state.
func (r *Runner) PurgeMissing(collections ...string) error {
type M map[string]interface{}
type S []interface{}
type TDoc struct {
Id interface{} "_id"
TxnQueue []string "txn-queue"
}
found := make(map[bson.ObjectId]bool)
sort.Strings(collections)
for _, collection := range collections {
c := r.tc.Database.C(collection)
iter := c.Find(nil).Select(bson.M{"_id": 1, "txn-queue": 1}).Iter()
var tdoc TDoc
for iter.Next(&tdoc) {
for _, txnToken := range tdoc.TxnQueue {
txnId := bson.ObjectIdHex(txnToken[:24])
if found[txnId] {
continue
}
if r.tc.FindId(txnId).One(nil) == nil {
found[txnId] = true
continue
}
logf("WARNING: purging from document %s/%v the missing transaction id %s", collection, tdoc.Id, txnId)
err := c.UpdateId(tdoc.Id, M{"$pull": M{"txn-queue": M{"$regex": "^" + txnId.Hex() + "_*"}}})
if err != nil {
return fmt.Errorf("error purging missing transaction %s: %v", txnId.Hex(), err)
}
}
}
if err := iter.Close(); err != nil {
return fmt.Errorf("transaction queue iteration error for %s: %v", collection, err)
}
}
type StashTDoc struct {
Id docKey "_id"
TxnQueue []string "txn-queue"
}
iter := r.sc.Find(nil).Select(bson.M{"_id": 1, "txn-queue": 1}).Iter()
var stdoc StashTDoc
for iter.Next(&stdoc) {
for _, txnToken := range stdoc.TxnQueue {
txnId := bson.ObjectIdHex(txnToken[:24])
if found[txnId] {
continue
}
if r.tc.FindId(txnId).One(nil) == nil {
found[txnId] = true
continue
}
logf("WARNING: purging from stash document %s/%v the missing transaction id %s", stdoc.Id.C, stdoc.Id.Id, txnId)
err := r.sc.UpdateId(stdoc.Id, M{"$pull": M{"txn-queue": M{"$regex": "^" + txnId.Hex() + "_*"}}})
if err != nil {
return fmt.Errorf("error purging missing transaction %s: %v", txnId.Hex(), err)
}
}
}
if err := iter.Close(); err != nil {
return fmt.Errorf("transaction stash iteration error: %v", err)
}
return nil
}
func (tt token) id() bson.ObjectId { return bson.ObjectIdHex(string(tt[:24])) }