Documentation
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Overview ¶
Package sqlite is the persistent result store (SPEC §9.4, §13): the run and window summaries and the run errors of the monitoring sessions, in an SQLite database that survives a restart of gotwampd.
The Store keeps a store.Memory in front of the database: Publish feeds it and the watchers as before, and queues the results to keep for one writer goroutine, so that a slow disk never holds up a run. Recent, Packets, Sessions and Watch answer from memory, which Open fills with the latest results of each session; Range reads the database, so that it reaches back as far as the retention. Per-packet records stay in memory only.
The database uses the WAL journal. Its schema carries a version, upgraded on Open; results older than the retention are deleted every hour.
Index ¶
- Constants
- Variables
- type Config
- type DefinitionCodec
- type Stats
- type Store
- func (s *Store) Close() error
- func (s *Store) Delete(session string)
- func (s *Store) Packets(session string) []store.PacketSample
- func (s *Store) Publish(e store.Event)
- func (s *Store) Range(session string, from, to time.Time) []store.Event
- func (s *Store) Recent(session string, n int) []store.Event
- func (s *Store) Sessions() []string
- func (s *Store) Stats() Stats
- func (s *Store) Watch(opts store.WatchOptions) *store.Watcher
Constants ¶
const ( // DefaultRetention is how long results are kept. // //declscope:ignore overexported // the default of store.sqlite.retention, for internal/config, which impl-stats wires next DefaultRetention = 30 * 24 * time.Hour )
Defaults of Config.
Variables ¶
var ( // ErrCorrupt means the file is not a gotwamp database or failed its // integrity check; Config.ResetCorrupt moves it aside instead. ErrCorrupt = errors.New("result database is corrupt") // ErrNewerSchema means the database was written by a newer gotwampd. ErrNewerSchema = errors.New("result database has a newer schema") )
Errors of Open.
Functions ¶
This section is empty.
Types ¶
type Config ¶
type Config struct {
// Path is the database file (store.sqlite.path). Required.
Path string
// Retention is how long results are kept (store.sqlite.retention);
// zero means 30 days, negative keeps them for ever.
Retention time.Duration
// MaxSize is the size of the database and its WAL above which every
// sweep logs a warning; zero never warns.
MaxSize int64
// History and MaxPackets size the memory in front of the database, as
// for store.NewMemory: Recent returns at most History results per
// session.
History, MaxPackets int
// Buffer is how many results may wait for the writer; more are dropped
// and counted. Zero means 4096.
Buffer int
// Definitions keeps the session definitions; see DefinitionCodec.
Definitions DefinitionCodec
// ResetCorrupt moves a corrupt database aside (to Path plus
// ".corrupt-" and the time) and starts an empty one, rather than fail.
ResetCorrupt bool
// Logger receives the warnings; nil discards them.
Logger *slog.Logger
// Now returns the current time, for the retention; nil means time.Now.
Now func() time.Time
// Sweep is how often expired results are deleted; zero means an hour.
Sweep time.Duration
}
Config configures a Store. Zero values take the defaults.
type DefinitionCodec ¶
type DefinitionCodec struct {
Encode func(def any) ([]byte, error)
Decode func(b []byte) (any, error)
}
DefinitionCodec turns store.SessionInfo.Definition, which the store does not know, into octets and back. gotwampd passes one for its session definitions; without it the definitions are not kept and come back nil.
type Stats ¶
type Stats struct {
// Written counts results committed to the database.
Written uint64
// Dropped counts results not written because the writer was behind by
// Config.Buffer, or the store was closed.
Dropped uint64
// Failed counts results the database refused.
Failed uint64
}
Stats are the counters of a Store.
type Store ¶
type Store struct {
// contains filtered or unexported fields
}
Store is the SQLite result store. It implements store.Store; its methods are safe for concurrent use. Close it to flush and release the database.
func Open ¶
Open opens the database at cfg.Path, creating it, upgrading its schema and deleting what the retention expired, and loads the latest results of each session into memory. A corrupt file is an error wrapping ErrCorrupt, or with cfg.ResetCorrupt is moved aside for an empty database.
func (*Store) Close ¶
Close writes what is queued and closes the database. Results published afterwards are dropped. It may be called more than once.
func (*Store) Delete ¶
Delete implements store.Store: the session's results go from memory at once and from the database in order with the writes queued before.
func (*Store) Packets ¶
func (s *Store) Packets(session string) []store.PacketSample
Packets implements store.Store from memory.
func (*Store) Publish ¶
Publish implements store.ResultSink: the memory and the watchers get e at once, and the summaries and run errors of named sessions are queued for the database. When the writer is Config.Buffer results behind, e is not written and is counted in Stats.Dropped. The Summary and Error of e must not be modified afterwards.
func (*Store) Range ¶
Range implements store.Store from the database, after the writer has caught up: it reaches back as far as the retention, beyond History.
Source Files