func comparePartitions(a, b partition.Partition) int {
// Highest timestamp first
return int(b.MinTimestamp() - a.MinTimestamp())
}
// loadPartitions reads a slice of partition file names
// and updates the internal partition state.
func (db *DB) loadPartitions(names []string) error {
// Slice of partition IDs
partitions := []int{}
isWAL := map[int]bool{}
for _, name := range names {
partitionNum := -1
wal := false
if strings.HasSuffix(name, ".wal") {
_, err := fmt.Sscanf(name, "%d.wal", &partitionNum)
if err != nil {
return err
}
wal = true
}
if strings.HasSuffix(name, ".part") {
_, err := fmt.Sscanf(name, "%d.part", &partitionNum)
if err != nil {
return err
}
}
if partitionNum < 0 {
return errors.New(fmt.Sprintf("catena: invalid partition %s", name))
}
if seenWAL, seen := isWAL[partitionNum]; seen {
if (seenWAL && !wal) || (!seenWAL && wal) {
// We have both a .wal and a .part, so
// we'll get rid of the .part and recompact.
wal = true
err := os.Remove(filepath.Join(db.baseDir, fmt.Sprintf("%d.part", partitionNum)))
if err != nil {
return err
}
}
}
isWAL[partitionNum] = wal
}
for partitionNum := range isWAL {
partitions = append(partitions, partitionNum)
}
// Sort the partitions in increasing order.
sort.Ints(partitions)
for _, part := range partitions {
if int64(part) > db.lastPartitionID {
db.lastPartitionID = int64(part)
}
var p partition.Partition
var err error
var filename string
if isWAL[part] {
filename = filepath.Join(db.baseDir,
fmt.Sprintf("%d.wal", part))
w, err := wal.OpenFileWAL(filename)
if err != nil {
return err
}
p, err = memory.RecoverMemoryPartition(w)
if err != nil {
return err
}
} else {
filename = filepath.Join(db.baseDir,
fmt.Sprintf("%d.part", part))
p, err = disk.OpenDiskPartition(filename)
if err != nil {
return err
}
}
// No need for locks here.
if db.partitionList.Size() == 1 {
db.minTimestamp = p.MinTimestamp()
db.maxTimestamp = p.MaxTimestamp()
}
if db.minTimestamp > p.MinTimestamp() {
db.minTimestamp = p.MinTimestamp()
}
if db.maxTimestamp < p.MaxTimestamp() {
db.maxTimestamp = p.MaxTimestamp()
}
db.partitionList.Insert(p)
}
return nil
}