// DumpIntent dumps the specified database's collection.
func (dump *MongoDump) DumpIntent(intent *intents.Intent) error {
session, err := dump.sessionProvider.GetSession()
if err != nil {
return err
}
defer session.Close()
// in mgo, setting prefetch = 1.0 causes the driver to make requests for
// more results as soon as results are returned. This effectively
// duplicates the behavior of an exhaust cursor.
session.SetPrefetch(1.0)
err = intent.BSONFile.Open()
if err != nil {
return err
}
defer intent.BSONFile.Close()
var findQuery *mgo.Query
switch {
case len(dump.query) > 0:
findQuery = session.DB(intent.DB).C(intent.C).Find(dump.query)
case dump.InputOptions.TableScan:
// ---forceTablesScan runs the query without snapshot enabled
findQuery = session.DB(intent.DB).C(intent.C).Find(nil)
default:
findQuery = session.DB(intent.DB).C(intent.C).Find(nil).Snapshot()
}
var dumpCount int64
if dump.OutputOptions.Out == "-" {
log.Logvf(log.Always, "writing %v to stdout", intent.Namespace())
dumpCount, err = dump.dumpQueryToWriter(findQuery, intent)
if err == nil {
// on success, print the document count
log.Logvf(log.Always, "dumped %v %v", dumpCount, docPlural(dumpCount))
}
return err
}
// set where the intent will be written to
if dump.OutputOptions.Archive != "" {
if dump.OutputOptions.Archive == "-" {
intent.Location = "archive on stdout"
} else {
intent.Location = fmt.Sprintf("archive '%v'", dump.OutputOptions.Archive)
}
}
if !dump.OutputOptions.Repair {
log.Logvf(log.Always, "writing %v to %v", intent.Namespace(), intent.Location)
if dumpCount, err = dump.dumpQueryToWriter(findQuery, intent); err != nil {
return err
}
} else {
// handle repairs as a special case, since we cannot count them
log.Logvf(log.Always, "writing repair of %v to %v", intent.Namespace(), intent.Location)
repairIter := session.DB(intent.DB).C(intent.C).Repair()
repairCounter := progress.NewCounter(1) // this counter is ignored
if err := dump.dumpIterToWriter(repairIter, intent.BSONFile, repairCounter); err != nil {
return fmt.Errorf("repair error: %v", err)
}
_, repairCount := repairCounter.Progress()
log.Logvf(log.Always, "\trepair cursor found %v %v in %v",
repairCount, docPlural(repairCount), intent.Namespace())
}
log.Logvf(log.Always, "done dumping %v (%v %v)", intent.Namespace(), dumpCount, docPlural(dumpCount))
return nil
}
