func (kv *consulKV) Snapshot(prefix string) (kvdb.Kvdb, uint64, error) {
// Create a new bootstrap key : lowest index
r := rand.New(rand.NewSource(time.Now().UnixNano())).Int63()
bootStrapKeyLow := bootstrap + strconv.FormatInt(r, 10) +
strconv.FormatInt(time.Now().UnixNano(), 10)
val, _ := common.ToBytes(time.Now().UnixNano())
kvPair, err := kv.Put(bootStrapKeyLow, val, 0)
if err != nil {
return nil, 0, fmt.Errorf("Failed to create snap bootstrap key %v, "+
"err: %v", bootStrapKeyLow, err)
}
lowestKvdbIndex := kvPair.ModifiedIndex
options := &api.QueryOptions{
AllowStale: false,
RequireConsistent: true,
}
listKey := kv.domain + prefix
listKey = stripConsecutiveForwardslash(listKey)
pairs, _, err := kv.client.KV().List(listKey, options)
if err != nil {
return nil, 0, err
}
kvPairs := kv.pairToKvs("enumerate", pairs, nil)
snapDb, err := mem.New(
kv.domain,
nil,
map[string]string{mem.KvSnap: "true"},
kv.FatalCb,
)
if err != nil {
return nil, 0, err
}
for _, kvPair := range kvPairs {
_, err := snapDb.SnapPut(kvPair)
if err != nil {
return nil, 0, fmt.Errorf("Failed creating snap: %v", err)
}
}
// Create bootrap key : highest index
bootStrapKeyHigh := bootstrap + strconv.FormatInt(r, 10) +
strconv.FormatInt(time.Now().UnixNano(), 10)
val, _ = common.ToBytes(time.Now().UnixNano())
kvPair, err = kv.Put(bootStrapKeyHigh, val, 0)
if err != nil {
return nil, 0, fmt.Errorf("Failed to create snap bootstrap key %v, "+
"err: %v", bootStrapKeyHigh, err)
}
highestKvdbIndex := kvPair.ModifiedIndex
// In consul Delete does not increment kvdb index.
// Hence the put (bootstrap) key and delete both return the same index
if lowestKvdbIndex+1 != highestKvdbIndex {
// create a watch to get all changes
// between lowestKvdbIndex and highestKvdbIndex
done := make(chan error)
mutex := &sync.Mutex{}
cb := func(
prefix string,
opaque interface{},
kvp *kvdb.KVPair,
err error,
) error {
var watchErr error
var sendErr error
var m *sync.Mutex
ok := false
if err != nil {
if err == kvdb.ErrWatchStopped {
return nil
}
watchErr = err
sendErr = err
goto errordone
}
if kvp == nil {
watchErr = fmt.Errorf("kvp is nil")
sendErr = watchErr
goto errordone
}
m, ok = opaque.(*sync.Mutex)
if !ok {
watchErr = fmt.Errorf("Failed to get mutex")
sendErr = watchErr
goto errordone
}
m.Lock()
defer m.Unlock()
if kvp.ModifiedIndex > highestKvdbIndex {
// done applying changes, just return
watchErr = fmt.Errorf("done")
sendErr = nil
goto errordone
} else if kvp.ModifiedIndex == highestKvdbIndex {
// last update that we needed. Put it inside snap db
// and return
_, err = snapDb.SnapPut(kvp)
if err != nil {
watchErr = fmt.Errorf("Failed to apply update to snap: %v", err)
sendErr = watchErr
} else {
watchErr = fmt.Errorf("done")
sendErr = nil
}
goto errordone
} else {
_, err = snapDb.SnapPut(kvp)
if err != nil {
watchErr = fmt.Errorf("Failed to apply update to snap: %v", err)
sendErr = watchErr
goto errordone
}
}
return nil
errordone:
done <- sendErr
return watchErr
}
if err := kv.WatchTree("", lowestKvdbIndex, mutex,
cb); err != nil {
return nil, 0, fmt.Errorf("Failed to start watch: %v", err)
}
err = <-done
if err != nil {
return nil, 0, err
}
}
_, err = kv.Delete(bootStrapKeyLow)
if err != nil {
return nil, 0, fmt.Errorf("Failed to delete snap bootstrap key: %v, "+
"err: %v", bootStrapKeyLow, err)
}
_, err = kv.Delete(bootStrapKeyHigh)
if err != nil {
return nil, 0, fmt.Errorf("Failed to delete snap bootstrap key: %v, "+
"err: %v", bootStrapKeyHigh, err)
}
return snapDb, highestKvdbIndex, nil
}
func (kv *etcdKV) Snapshot(prefix string) (kvdb.Kvdb, uint64, error) {
// Create a new bootstrap key
r := rand.New(rand.NewSource(time.Now().UnixNano())).Int63()
bootStrapKey := ec.Bootstrap + strconv.FormatInt(r, 10) +
strconv.FormatInt(time.Now().UnixNano(), 10)
kvPair, err := kv.Put(bootStrapKey, time.Now().UnixNano(), 0)
if err != nil {
return nil, 0, fmt.Errorf("Failed to create snap bootstrap key %v, "+
"err: %v", bootStrapKey, err)
}
lowestKvdbIndex := kvPair.ModifiedIndex
kvPairs, err := kv.Enumerate(prefix)
if err != nil {
return nil, 0, fmt.Errorf("Failed to enumerate %v: err: %v", prefix,
err)
}
snapDb, err := mem.New(
kv.domain,
nil,
map[string]string{mem.KvSnap: "true"},
kv.FatalCb,
)
if err != nil {
return nil, 0, fmt.Errorf("Failed to create in-mem kv store: %v", err)
}
for i := 0; i < len(kvPairs); i++ {
kvPair := kvPairs[i]
if len(kvPair.Value) > 0 {
// Only create a leaf node
_, err := snapDb.SnapPut(kvPair)
if err != nil {
return nil, 0, fmt.Errorf("Failed creating snap: %v", err)
}
} else {
newKvPairs, err := kv.Enumerate(kvPair.Key)
if err != nil {
return nil, 0, fmt.Errorf("Failed to get child keys: %v", err)
}
if len(newKvPairs) > 0 {
kvPairs = append(kvPairs, newKvPairs...)
}
}
}
kvPair, err = kv.Delete(bootStrapKey)
if err != nil {
return nil, 0, fmt.Errorf("Failed to delete snap bootstrap key: %v, "+
"err: %v", bootStrapKey, err)
}
highestKvdbIndex := kvPair.ModifiedIndex
if lowestKvdbIndex+1 != highestKvdbIndex {
// create a watch to get all changes
// between lowestKvdbIndex and highestKvdbIndex
done := make(chan error)
mutex := &sync.Mutex{}
cb := func(
prefix string,
opaque interface{},
kvp *kvdb.KVPair,
err error,
) error {
var watchErr error
var sendErr error
var m *sync.Mutex
ok := false
if err != nil {
if err == kvdb.ErrWatchStopped {
return nil
}
watchErr = err
sendErr = err
goto errordone
}
if kvp == nil {
watchErr = fmt.Errorf("kvp is nil")
sendErr = watchErr
goto errordone
}
m, ok = opaque.(*sync.Mutex)
if !ok {
watchErr = fmt.Errorf("Failed to get mutex")
sendErr = watchErr
goto errordone
}
m.Lock()
defer m.Unlock()
if kvp.ModifiedIndex >= highestKvdbIndex {
// Done applying changes.
watchErr = fmt.Errorf("done")
sendErr = nil
goto errordone
}
_, err = snapDb.SnapPut(kvp)
if err != nil {
watchErr = fmt.Errorf("Failed to apply update to snap: %v", err)
sendErr = watchErr
goto errordone
}
return nil
errordone:
done <- sendErr
return watchErr
}
if err := kv.WatchTree("", lowestKvdbIndex, mutex,
cb); err != nil {
return nil, 0, fmt.Errorf("Failed to start watch: %v", err)
}
err = <-done
if err != nil {
return nil, 0, err
}
}
return snapDb, highestKvdbIndex, nil
}