NoKV

type BatchSetItem struct {
	Key   []byte
	Value []byte
}

type CacheStatsSnapshot struct {
	BlockL0HitRate float64 `json:"block_l0_hit_rate"`
	BlockL1HitRate float64 `json:"block_l1_hit_rate"`
	IndexHitRate   float64 `json:"index_hit_rate"`
	IteratorReused uint64  `json:"iterator_reused"`
}

type CompactionPolicy string

type CompactionStatsSnapshot struct {
	Backlog              int64   `json:"backlog"`
	MaxScore             float64 `json:"max_score"`
	LastDurationMs       float64 `json:"last_duration_ms"`
	MaxDurationMs        float64 `json:"max_duration_ms"`
	Runs                 uint64  `json:"runs"`
	IngestRuns           int64   `json:"ingest_runs"`
	MergeRuns            int64   `json:"ingest_merge_runs"`
	IngestMs             float64 `json:"ingest_ms"`
	MergeMs              float64 `json:"ingest_merge_ms"`
	IngestTables         int64   `json:"ingest_tables"`
	MergeTables          int64   `json:"ingest_merge_tables"`
	ValueWeight          float64 `json:"value_weight"`
	ValueWeightSuggested float64 `json:"value_weight_suggested,omitempty"`
}

type DB struct {
	sync.RWMutex
	// contains filtered or unexported fields
}

type DBIterator struct {
	// contains filtered or unexported fields
}

type FlushStatsSnapshot struct {
	Pending       int64   `json:"pending"`
	QueueLength   int64   `json:"queue_length"`
	Active        int64   `json:"active"`
	WaitMs        float64 `json:"wait_ms"`
	LastWaitMs    float64 `json:"last_wait_ms"`
	MaxWaitMs     float64 `json:"max_wait_ms"`
	BuildMs       float64 `json:"build_ms"`
	LastBuildMs   float64 `json:"last_build_ms"`
	MaxBuildMs    float64 `json:"max_build_ms"`
	ReleaseMs     float64 `json:"release_ms"`
	LastReleaseMs float64 `json:"last_release_ms"`
	MaxReleaseMs  float64 `json:"max_release_ms"`
	Completed     int64   `json:"completed"`
}

type HotKeyStat struct {
	Key   string `json:"key"`
	Count int32  `json:"count"`
}

type HotStatsSnapshot struct {
	WriteKeys []HotKeyStat   `json:"write_keys,omitempty"`
	WriteRing *hotring.Stats `json:"write_ring,omitempty"`
}

type Item struct {
	// contains filtered or unexported fields
}

type LSMLevelStats struct {
	Level              int     `json:"level"`
	TableCount         int     `json:"tables"`
	SizeBytes          int64   `json:"size_bytes"`
	ValueBytes         int64   `json:"value_bytes"`
	StaleBytes         int64   `json:"stale_bytes"`
	IngestTables       int     `json:"ingest_tables"`
	IngestSizeBytes    int64   `json:"ingest_size_bytes"`
	IngestValueBytes   int64   `json:"ingest_value_bytes"`
	ValueDensity       float64 `json:"value_density"`
	IngestValueDensity float64 `json:"ingest_value_density"`
	IngestRuns         int64   `json:"ingest_runs"`
	IngestMs           float64 `json:"ingest_ms"`
	IngestTablesCount  int64   `json:"ingest_tables_compacted"`
	MergeRuns          int64   `json:"ingest_merge_runs"`
	MergeMs            float64 `json:"ingest_merge_ms"`
	MergeTables        int64   `json:"ingest_merge_tables"`
}

type LSMStatsSnapshot struct {
	Levels            []LSMLevelStats          `json:"levels,omitempty"`
	ValueBytesTotal   int64                    `json:"value_bytes_total"`
	ValueDensityMax   float64                  `json:"value_density_max"`
	ValueDensityAlert bool                     `json:"value_density_alert"`
	RangeFilter       RangeFilterStatsSnapshot `json:"range_filter"`
}

type MVCCStore interface {
	ApplyInternalEntries(entries []*kv.Entry) error
	// GetInternalEntry returns a borrowed internal entry without cloning/copying.
	// entry.Key remains in internal encoding (cf+user_key+ts). Callers must
	// DecrRef exactly once.
	GetInternalEntry(cf kv.ColumnFamily, key []byte, version uint64) (*kv.Entry, error)
	NewInternalIterator(opt *utils.Options) utils.Iterator
}

type MemTableEngine string

type Options struct {
	// FS provides the filesystem implementation used by DB runtime components.
	// Nil defaults to vfs.OSFS.
	FS vfs.FS

	ValueThreshold int64
	WorkDir        string
	MemTableSize   int64
	MemTableEngine MemTableEngine
	SSTableMaxSz   int64
	// MaxBatchCount bounds the number of entries grouped into one internal
	// write batch. NewDefaultOptions exposes a concrete default; zero is only
	// interpreted as a legacy unset value during normalization.
	MaxBatchCount int64
	// MaxBatchSize bounds the size in bytes of one internal write batch.
	// NewDefaultOptions exposes a concrete default; zero is only interpreted as
	// a legacy unset value during normalization.
	MaxBatchSize       int64
	ValueLogFileSize   int
	ValueLogMaxEntries uint32
	// ValueLogBucketCount controls how many hash buckets the value log uses.
	// Values <= 1 disable bucketization.
	ValueLogBucketCount     int
	ValueSeparationPolicies []*kv.ValueSeparationPolicy

	// ValueLogGCInterval specifies how frequently to trigger a check for value
	// log garbage collection. Zero or negative values disable automatic GC.
	ValueLogGCInterval time.Duration
	// ValueLogGCDiscardRatio is the discard ratio for a value log file to be
	// considered for garbage collection. It must be in the range (0.0, 1.0).
	ValueLogGCDiscardRatio float64
	// ValueLogGCParallelism controls how many value-log GC tasks can run in
	// parallel. Values <= 0 auto-tune based on compaction workers.
	ValueLogGCParallelism int
	// ValueLogGCReduceScore lowers GC parallelism when compaction max score meets
	// or exceeds this threshold. Values <= 0 use defaults.
	ValueLogGCReduceScore float64
	// ValueLogGCSkipScore skips GC when compaction max score meets or exceeds this
	// threshold. Values <= 0 use defaults.
	ValueLogGCSkipScore float64
	// ValueLogGCReduceBacklog lowers GC parallelism when compaction backlog meets
	// or exceeds this threshold. Values <= 0 use defaults.
	ValueLogGCReduceBacklog int
	// ValueLogGCSkipBacklog skips GC when compaction backlog meets or exceeds this
	// threshold. Values <= 0 use defaults.
	ValueLogGCSkipBacklog int

	// Value log GC sampling parameters. Ratios <= 0 fall back to defaults.
	ValueLogGCSampleSizeRatio  float64
	ValueLogGCSampleCountRatio float64
	ValueLogGCSampleFromHead   bool

	// ValueLogVerbose enables verbose logging across value-log operations.
	ValueLogVerbose bool

	// WriteBatchMaxCount bounds how many requests the commit worker coalesces in
	// one pass. NewDefaultOptions exposes a concrete default; zero is only
	// interpreted as a legacy unset value during normalization.
	WriteBatchMaxCount int
	// WriteBatchMaxSize bounds the byte size the commit worker coalesces in one
	// pass. NewDefaultOptions exposes a concrete default; zero is only
	// interpreted as a legacy unset value during normalization.
	WriteBatchMaxSize int64

	DetectConflicts bool
	HotRingEnabled  bool
	HotRingBits     uint8
	HotRingTopK     int
	// HotRingRotationInterval enables dual-ring rotation for hotness tracking.
	// Zero disables rotation.
	HotRingRotationInterval time.Duration
	// HotRingNodeCap caps the number of tracked keys per ring. Zero disables the cap.
	HotRingNodeCap uint64
	// HotRingNodeSampleBits controls stable sampling once the cap is reached.
	// A value of 0 enforces a strict cap; larger values sample 1/2^N keys.
	HotRingNodeSampleBits uint8
	// HotRingDecayInterval controls how often HotRing halves its global counters.
	// Zero disables periodic decay.
	HotRingDecayInterval time.Duration
	// HotRingDecayShift determines how aggressively counters decay (count >>= shift).
	HotRingDecayShift uint32
	// HotRingWindowSlots controls the number of sliding-window buckets tracked per key.
	// Zero disables the sliding window.
	HotRingWindowSlots int
	// HotRingWindowSlotDuration sets the duration of each sliding-window bucket.
	HotRingWindowSlotDuration time.Duration
	SyncWrites                bool
	// SyncPipeline enables a dedicated sync worker goroutine that decouples
	// WAL fsync from the commit pipeline. When false (the default), the commit
	// worker performs fsync inline. Only effective when SyncWrites is true.
	SyncPipeline bool
	ManifestSync bool
	// ManifestRewriteThreshold triggers a manifest rewrite when the active
	// MANIFEST file grows beyond this size (bytes). Values <= 0 disable rewrites.
	ManifestRewriteThreshold int64
	// WriteHotKeyLimit caps how many consecutive writes a single key can issue
	// before the DB returns utils.ErrHotKeyWriteThrottle. Zero disables write-path
	// throttling.
	WriteHotKeyLimit int32
	// WriteBatchWait adds an optional coalescing delay when the commit queue is
	// momentarily empty, letting small bursts share one WAL fsync/apply pass.
	// Zero disables the delay.
	WriteBatchWait time.Duration
	// WriteThrottleMinRate is the target write admission rate in bytes/sec when
	// slowdown pressure approaches the stop threshold. NewDefaultOptions
	// exposes a concrete default; zero is only interpreted as a legacy unset
	// value during normalization.
	WriteThrottleMinRate int64
	// WriteThrottleMaxRate is the target write admission rate in bytes/sec when
	// slowdown first becomes active. NewDefaultOptions exposes a concrete
	// default; zero is only interpreted as a legacy unset value during
	// normalization.
	WriteThrottleMaxRate int64

	// BlockCacheBytes bounds the in-memory budget for cached L0/L1 data blocks.
	// Deeper levels continue to rely on the OS page cache.
	BlockCacheBytes int64
	// IndexCacheBytes bounds the in-memory budget for decoded SSTable indexes.
	IndexCacheBytes int64

	// RaftLagWarnSegments determines how many WAL segments a follower can lag
	// behind the active segment before stats surfaces a warning. Zero disables
	// the alert.
	RaftLagWarnSegments int64

	// EnableWALWatchdog enables the background WAL backlog watchdog which
	// surfaces typed-record warnings and optionally runs automated segment GC.
	EnableWALWatchdog bool
	// WALBufferSize controls the size of the in-memory write buffer used by
	// the WAL manager. Larger buffers reduce syscall frequency at the cost of
	// memory. NewDefaultOptions exposes a concrete default; zero is only
	// interpreted as a legacy unset value during normalization.
	WALBufferSize int
	// WALAutoGCInterval controls how frequently the watchdog evaluates WAL
	// backlog for automated garbage collection.
	WALAutoGCInterval time.Duration
	// WALAutoGCMinRemovable is the minimum number of removable WAL segments
	// required before an automated GC pass will run.
	WALAutoGCMinRemovable int
	// WALAutoGCMaxBatch bounds how many WAL segments are removed during a single
	// automated GC pass.
	WALAutoGCMaxBatch int
	// WALTypedRecordWarnRatio triggers a typed-record warning when raft records
	// constitute at least this fraction of WAL writes. Zero disables ratio-based
	// warnings.
	WALTypedRecordWarnRatio float64
	// WALTypedRecordWarnSegments triggers a typed-record warning when the number
	// of WAL segments containing raft records exceeds this threshold. Zero
	// disables segment-count warnings.
	WALTypedRecordWarnSegments int64
	// RaftPointerSnapshot returns store-local raft WAL checkpoints used by WAL
	// watchdogs, GC policy, and diagnostics. It must return a detached snapshot.
	// Nil disables raft-specific backlog accounting.
	RaftPointerSnapshot func() map[uint64]raftmeta.RaftLogPointer

	// DiscardStatsFlushThreshold controls how many discard-stat updates must be
	// accumulated before they are flushed back into the LSM. Zero keeps the
	// default threshold.
	DiscardStatsFlushThreshold int

	// NumCompactors controls how many background compaction workers are spawned.
	// Zero uses an auto value derived from the host CPU count.
	NumCompactors int
	// CompactionPolicy selects how compaction priorities are arranged.
	// Supported values: leveled, tiered, hybrid.
	CompactionPolicy CompactionPolicy
	// NumLevelZeroTables controls when write throttling kicks in and feeds into
	// the compaction priority calculation. NewDefaultOptions populates a concrete
	// default; normalizeInPlace only backfills zero-valued legacy configs.
	NumLevelZeroTables int
	// L0SlowdownWritesTrigger starts write pacing when L0 table count reaches
	// this threshold. Defaults are populated up front; zero is only interpreted
	// as a legacy unset value during normalization.
	L0SlowdownWritesTrigger int
	// L0StopWritesTrigger blocks writes when L0 table count reaches this
	// threshold. Defaults are populated up front; zero is only interpreted as a
	// legacy unset value during normalization.
	L0StopWritesTrigger int
	// L0ResumeWritesTrigger clears throttling only when L0 table count drops to
	// this threshold or lower. Defaults are populated up front; zero is only
	// interpreted as a legacy unset value during normalization.
	L0ResumeWritesTrigger int
	// CompactionSlowdownTrigger starts write pacing when max compaction score
	// reaches this value. Defaults are populated up front; zero is only
	// interpreted as a legacy unset value during normalization.
	CompactionSlowdownTrigger float64
	// CompactionStopTrigger blocks writes when max compaction score reaches this
	// value. Defaults are populated up front; zero is only interpreted as a
	// legacy unset value during normalization.
	CompactionStopTrigger float64
	// CompactionResumeTrigger clears throttling only when max compaction score
	// drops to this value or lower. Defaults are populated up front; zero is only
	// interpreted as a legacy unset value during normalization.
	CompactionResumeTrigger float64
	// IngestCompactBatchSize decides how many L0 tables to promote into the
	// ingest buffer per compaction cycle. NewDefaultOptions populates a concrete
	// default; normalizeInPlace only backfills zero-valued legacy configs.
	IngestCompactBatchSize int
	// IngestBacklogMergeScore triggers an ingest-merge task when the ingest
	// backlog score exceeds this threshold. Defaults are populated up front; zero
	// is only interpreted as a legacy unset value during normalization.
	IngestBacklogMergeScore float64

	// CompactionValueWeight adjusts how aggressively the scheduler prioritises
	// levels whose entries reference large value log payloads. Higher values
	// make the compaction picker favour levels with high ValuePtr density.
	CompactionValueWeight float64

	// CompactionValueAlertThreshold triggers stats alerts when a level's
	// value-density (value bytes / total bytes) exceeds this ratio.
	CompactionValueAlertThreshold float64

	// IngestShardParallelism caps how many ingest shards can be compacted in a
	// single ingest-only pass. A value <= 0 falls back to 1 (sequential).
	IngestShardParallelism int
}

type RaftLog interface {
	Open(groupID uint64, meta *raftmeta.Store) (engine.PeerStorage, error)
}

type RaftStatsSnapshot struct {
	GroupCount       int    `json:"group_count"`
	LaggingGroups    int    `json:"lagging_groups"`
	MinLogSegment    uint32 `json:"min_log_segment"`
	MaxLogSegment    uint32 `json:"max_log_segment"`
	MaxLagSegments   int64  `json:"max_lag_segments"`
	LagWarnThreshold int64  `json:"lag_warn_threshold"`
	LagWarning       bool   `json:"lag_warning"`
}

type RangeFilterStatsSnapshot struct {
	PointCandidates   uint64 `json:"point_candidates"`
	PointPruned       uint64 `json:"point_pruned"`
	BoundedCandidates uint64 `json:"bounded_candidates"`
	BoundedPruned     uint64 `json:"bounded_pruned"`
	Fallbacks         uint64 `json:"fallbacks"`
}

type RegionStatsSnapshot struct {
	Total     int64 `json:"total"`
	New       int64 `json:"new"`
	Running   int64 `json:"running"`
	Removing  int64 `json:"removing"`
	Tombstone int64 `json:"tombstone"`
	Other     int64 `json:"other"`
}

type Stats struct {
	// contains filtered or unexported fields
}

type StatsSnapshot struct {
	Entries    int64                             `json:"entries"`
	Flush      FlushStatsSnapshot                `json:"flush"`
	Compaction CompactionStatsSnapshot           `json:"compaction"`
	ValueLog   ValueLogStatsSnapshot             `json:"value_log"`
	WAL        WALStatsSnapshot                  `json:"wal"`
	Raft       RaftStatsSnapshot                 `json:"raft"`
	Write      WriteStatsSnapshot                `json:"write"`
	Region     RegionStatsSnapshot               `json:"region"`
	Hot        HotStatsSnapshot                  `json:"hot"`
	Cache      CacheStatsSnapshot                `json:"cache"`
	LSM        LSMStatsSnapshot                  `json:"lsm"`
	Transport  transportpkg.GRPCTransportMetrics `json:"transport"`
	Redis      metrics.RedisSnapshot             `json:"redis"`
}

type ValueLogStatsSnapshot struct {
	Segments       int                        `json:"segments"`
	PendingDeletes int                        `json:"pending_deletes"`
	DiscardQueue   int                        `json:"discard_queue"`
	Heads          map[uint32]kv.ValuePtr     `json:"heads,omitempty"`
	GC             metrics.ValueLogGCSnapshot `json:"gc"`
}

type WALStatsSnapshot struct {
	ActiveSegment           int64             `json:"active_segment"`
	SegmentCount            int64             `json:"segment_count"`
	ActiveSize              int64             `json:"active_size"`
	SegmentsRemoved         uint64            `json:"segments_removed"`
	RecordCounts            wal.RecordMetrics `json:"record_counts"`
	SegmentsWithRaftRecords int               `json:"segments_with_raft_records"`
	RemovableRaftSegments   int               `json:"removable_raft_segments"`
	TypedRecordRatio        float64           `json:"typed_record_ratio"`
	TypedRecordWarning      bool              `json:"typed_record_warning"`
	TypedRecordReason       string            `json:"typed_record_reason,omitempty"`
	AutoGCRuns              uint64            `json:"auto_gc_runs"`
	AutoGCRemoved           uint64            `json:"auto_gc_removed"`
	AutoGCLastUnix          int64             `json:"auto_gc_last_unix"`
}

type WriteStatsSnapshot struct {
	QueueDepth       int64   `json:"queue_depth"`
	QueueEntries     int64   `json:"queue_entries"`
	QueueBytes       int64   `json:"queue_bytes"`
	AvgBatchEntries  float64 `json:"avg_batch_entries"`
	AvgBatchBytes    float64 `json:"avg_batch_bytes"`
	AvgRequestWaitMs float64 `json:"avg_request_wait_ms"`
	AvgValueLogMs    float64 `json:"avg_vlog_ms"`
	AvgApplyMs       float64 `json:"avg_apply_ms"`
	AvgSyncMs        float64 `json:"avg_sync_ms"`
	AvgSyncBatch     float64 `json:"avg_sync_batch"`
	SyncCount        int64   `json:"sync_count"`
	BatchesTotal     int64   `json:"batches_total"`
	ThrottleActive   bool    `json:"throttle_active"`
	SlowdownActive   bool    `json:"slowdown_active"`
	ThrottleMode     string  `json:"throttle_mode"`
	ThrottlePressure uint32  `json:"throttle_pressure_permille"`
	ThrottleRate     uint64  `json:"throttle_rate_bytes_per_sec"`
	HotKeyLimited    uint64  `json:"hot_key_limited"`
}