-
Notifications
You must be signed in to change notification settings - Fork 6
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
feat(client): log stream appender manager
This PR adds a manager for log stream appenders, `pkg/varlog/x/mlsa.(Manager)`. It provides two methods: - `pkg/varlog/x/mlsa.(Manager).Get`: Get a LogStreamAppender specified by the given topic and log stream. - `pkg/varlog/x/mlsa.(Manager).Any`: Get a writable LogStreamAppender belonging to the given topic.
- Loading branch information
Showing
5 changed files
with
358 additions
and
9 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,129 @@ | ||
| package mlsa | ||
|
|
||
| import ( | ||
| "errors" | ||
|
|
||
| "github.com/puzpuzpuz/xsync/v2" | ||
|
|
||
| "github.com/kakao/varlog/pkg/types" | ||
| "github.com/kakao/varlog/pkg/varlog" | ||
| ) | ||
|
|
||
| type managedLSA struct { | ||
| mgr *Manager | ||
| lsa varlog.LogStreamAppender | ||
| tpid types.TopicID | ||
| lsid types.LogStreamID | ||
| } | ||
|
|
||
| var _ varlog.LogStreamAppender = (*managedLSA)(nil) | ||
|
|
||
| func (m *managedLSA) AppendBatch(dataBatch [][]byte, callback varlog.BatchCallback) error { | ||
| return m.lsa.AppendBatch(dataBatch, callback) | ||
| } | ||
|
|
||
| func (m *managedLSA) Close() { | ||
| m.mgr.mu.Lock() | ||
| appenders, ok := m.mgr.mlsas[m.tpid] | ||
| if ok && appenders[m.lsid] == m { | ||
| delete(appenders, m.lsid) | ||
| } | ||
| m.mgr.mu.Unlock() | ||
|
|
||
| m.lsa.Close() | ||
| } | ||
|
|
||
| // Manager manages a set of LogStreamAppenders. | ||
| // When multiple users attempt to obtain the same LogStreamAppender using the | ||
| // same TopicID and LogStreamID, they may share the same object. Therefore, | ||
| // when one user calls the Close function, another may encounter an ErrClose | ||
| // error. To resolve this issue, users can simply get a new LogStreamAppender | ||
| // by calling the Get function again. | ||
| type Manager struct { | ||
| mlsas map[types.TopicID]map[types.LogStreamID]*managedLSA | ||
| mu *xsync.RBMutex | ||
|
|
||
| vcli varlog.Log | ||
| opts []varlog.LogStreamAppenderOption | ||
| } | ||
|
|
||
| // New returns a new Manager. Generally, users only require one manager. | ||
| func New(vcli varlog.Log, opts ...varlog.LogStreamAppenderOption) *Manager { | ||
| mgr := &Manager{ | ||
| vcli: vcli, | ||
| opts: opts, | ||
| mlsas: make(map[types.TopicID]map[types.LogStreamID]*managedLSA), | ||
| mu: xsync.NewRBMutex(), | ||
| } | ||
| return mgr | ||
| } | ||
|
|
||
| // Get returns a LogStreamAppender specified by the arguments tpid and lsid. It | ||
| // returns an error if it cannot access the given log stream. | ||
| func (mgr *Manager) Get(tpid types.TopicID, lsid types.LogStreamID) (varlog.LogStreamAppender, error) { | ||
| t := mgr.mu.RLock() | ||
| if lsa := mgr.mlsas[tpid][lsid]; lsa != nil { | ||
| mgr.mu.RUnlock(t) | ||
| return lsa, nil | ||
| } | ||
| mgr.mu.RUnlock(t) | ||
|
|
||
| return mgr.getSlow(tpid, lsid) | ||
| } | ||
|
|
||
| func (mgr *Manager) getSlow(tpid types.TopicID, lsid types.LogStreamID) (varlog.LogStreamAppender, error) { | ||
| mgr.mu.Lock() | ||
| defer mgr.mu.Unlock() | ||
|
|
||
| appenders, ok := mgr.mlsas[tpid] | ||
| if !ok { | ||
| appenders = make(map[types.LogStreamID]*managedLSA) | ||
| mgr.mlsas[tpid] = appenders | ||
| } | ||
|
|
||
| mlsa, ok := appenders[lsid] | ||
| if !ok { | ||
| lsa, err := mgr.vcli.NewLogStreamAppender(tpid, lsid, mgr.opts...) | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
| mlsa = &managedLSA{ | ||
| lsa: lsa, | ||
| tpid: tpid, | ||
| lsid: lsid, | ||
| mgr: mgr, | ||
| } | ||
| appenders[lsid] = mlsa | ||
| } | ||
| return mlsa, nil | ||
| } | ||
|
|
||
| // Any returns the LogStreamAppender that is filtered by the argument | ||
| // allowlist. If the allowlist is empty, all log streams in the topic can be | ||
| // chosen. | ||
| // It chooses the writable LogStreamAppender as possible. | ||
| func (mgr *Manager) Any(tpid types.TopicID, allowlist map[types.LogStreamID]struct{}) (varlog.LogStreamAppender, error) { | ||
| var shorter, longer map[types.LogStreamID]struct{} | ||
| candidates := mgr.vcli.AppendableLogStreams(tpid) | ||
| if len(allowlist) == 0 || len(candidates) < len(allowlist) { | ||
| shorter = candidates | ||
| longer = allowlist | ||
| } else { | ||
| shorter = allowlist | ||
| longer = candidates | ||
| } | ||
|
|
||
| for lsid := range shorter { | ||
| if len(longer) > 0 { | ||
| if _, ok := longer[lsid]; !ok { | ||
| continue | ||
| } | ||
| } | ||
|
|
||
| lsa, err := mgr.Get(tpid, lsid) | ||
| if err == nil { | ||
| return lsa, nil | ||
| } | ||
| } | ||
| return nil, errors.New("no appendable log stream") | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.