// Moves data from one server to another
// Does the following:
// 1. Lock all necessary clients
// 2. Move Data
// 3. Update router table on servers
// 4. Delete partion from origin
// 5. Unlock
func MovePartition(services *Services, routerTable *shards.RouterTable, partition int, from, to *shards.RouterEntry) error {
err := LockPartition(services, routerTable, partition)
if err != nil {
return err
}
//Unlock partition no matter what
defer UnlockPartition(services, routerTable, partition)
//copy the data
_, err = CopyData(services, routerTable, partition, from, to)
if err != nil {
return err
}
//update the router table.
parts := make([]int, 0)
for _, p := range from.Partitions {
if p != partition {
parts = append(parts, p)
}
}
from.Partitions = parts
to.Partitions = append(to.Partitions, partition)
routerTable, err = routerTable.AddEntries(from, to)
routerTable, ok := RouterTableUpdate(services, routerTable, len(routerTable.Entries))
if !ok {
services.Logger.Printf("Uh oh, Didnt update any router tables")
}
//Delete the data on the from server.
err = DeletePartition(services, from, partition)
if err != nil {
return err
}
return nil
}
