// ResolveKeyspaceWildcard will resolve keyspace wildcards.
// - If the param is not a wildcard, it will just be returned (if the keyspace
// doesn't exist, it is still returned).
// - If the param is a wildcard, it will get all keyspaces and returns
// the ones which match the wildcard (which may be an empty list).
func ResolveKeyspaceWildcard(server WildcardBackend, param string) ([]string, error) {
if !fileutil.HasWildcard(param) {
return []string{param}, nil
}
result := make([]string, 0)
keyspaces, err := server.GetKeyspaces()
if err != nil {
return nil, fmt.Errorf("failed to read keyspaces from topo: %v", err)
}
for _, k := range keyspaces {
matched, err := path.Match(param, k)
if err != nil {
return nil, fmt.Errorf("invalid pattern %v: %v", param, err)
}
if matched {
result = append(result, k)
}
}
return result, nil
}
func resolveRecursive(zconn Conn, parts []string, toplevel bool) ([]string, error) {
for i, part := range parts {
if fileutil.HasWildcard(part) {
var children []string
if i == 2 {
children = ZkKnownCells(false)
} else {
zkParentPath := strings.Join(parts[:i], "/")
var err error
children, _, err = zconn.Children(zkParentPath)
if err != nil {
// we asked for something like
// /zk/cell/aaa/* and
// /zk/cell/aaa doesn't exist
// -> return empty list, no error
// (note we check both a regular zk
// error and the error the test
// produces)
if zookeeper.IsError(err, zookeeper.ZNONODE) {
return nil, nil
}
// otherwise we return the error
return nil, err
}
}
sort.Strings(children)
results := make([][]string, len(children))
wg := &sync.WaitGroup{}
mu := &sync.Mutex{}
var firstError error
for j, child := range children {
matched, err := path.Match(part, child)
if err != nil {
return nil, err
}
if matched {
// we have a match!
wg.Add(1)
newParts := make([]string, len(parts))
copy(newParts, parts)
newParts[i] = child
go func(j int) {
defer wg.Done()
subResult, err := resolveRecursive(zconn, newParts, false)
if err != nil {
mu.Lock()
if firstError != nil {
log.Infof("Multiple error: %v", err)
} else {
firstError = err
}
mu.Unlock()
} else {
results[j] = subResult
}
}(j)
}
}
wg.Wait()
if firstError != nil {
return nil, firstError
}
result := make([]string, 0, 32)
for j := 0; j < len(children); j++ {
subResult := results[j]
if subResult != nil {
result = append(result, subResult...)
}
}
// we found a part that is a wildcard, we
// added the children already, we're done
return result, nil
}
}
// no part contains a wildcard, add the path if it exists, and done
path := strings.Join(parts, "/")
if toplevel {
// for whatever the user typed at the toplevel, we don't
// check it exists or not, we just return it
return []string{path}, nil
}
// this is an expanded path, we need to check if it exists
stat, err := zconn.Exists(path)
if err != nil {
return nil, err
}
if stat != nil {
return []string{path}, nil
}
return nil, nil
}
// ResolveShardWildcard will resolve shard wildcards. Both keyspace and shard
// names can use wildcard. Errors talking to the topology server are returned.
// ErrNoNode is ignored if it's the result of resolving a wildcard. Examples:
// - */* returns all keyspace/shard pairs, or empty list if none.
// - user/* returns all shards in user keyspace (or error if user keyspace
// doesn't exist)
// - us*/* returns all shards in all keyspaces that start with 'us'. If no such
// keyspace exists, list is empty (it is not an error).
func ResolveShardWildcard(server WildcardBackend, param string) ([]KeyspaceShard, error) {
parts := strings.Split(param, "/")
if len(parts) != 2 {
return nil, fmt.Errorf("invalid shard path: %v", param)
}
result := make([]KeyspaceShard, 0, 1)
// get all the matched keyspaces first, remember if it was a wildcard
keyspaceHasWildcards := fileutil.HasWildcard(parts[0])
matchedKeyspaces, err := ResolveKeyspaceWildcard(server, parts[0])
if err != nil {
return nil, err
}
// for each matched keyspace, get the shards
for _, matchedKeyspace := range matchedKeyspaces {
shard := parts[1]
if fileutil.HasWildcard(shard) {
// get all the shards for the keyspace
shardNames, err := server.GetShardNames(matchedKeyspace)
switch err {
case nil:
// got all the shards, we can keep going
case ErrNoNode:
// keyspace doesn't exist
if keyspaceHasWildcards {
// that's the */* case when a keyspace has no shards
continue
}
return nil, fmt.Errorf("keyspace %v doesn't exist", matchedKeyspace)
default:
return nil, fmt.Errorf("cannot read keyspace shards for %v: %v", matchedKeyspace, err)
}
for _, s := range shardNames {
matched, err := path.Match(shard, s)
if err != nil {
return nil, fmt.Errorf("Invalid pattern %v: %v", shard, err)
}
if matched {
result = append(result, KeyspaceShard{matchedKeyspace, s})
}
}
} else {
// if the shard name contains a '-', we assume it's the
// name for a ranged based shard, so we lower case it.
if strings.Contains(shard, "-") {
shard = strings.ToLower(shard)
}
if keyspaceHasWildcards {
// keyspace was a wildcard, shard is not, just try it
_, err := server.GetShard(matchedKeyspace, shard)
switch err {
case nil:
// shard exists, add it
result = append(result, KeyspaceShard{matchedKeyspace, shard})
case ErrNoNode:
// no shard, ignore
default:
// other error
return nil, fmt.Errorf("Cannot read shard %v/%v: %v", matchedKeyspace, shard, err)
}
} else {
// keyspace and shards are not wildcards, just add the value
result = append(result, KeyspaceShard{matchedKeyspace, shard})
}
}
}
return result, nil
}