tmindex

type IdxRecord struct {
	Ts  int64
	Val uint32
}

type Item struct {
	// IndexId contains the index file identifier. 0 means not assigned yet
	IndexId uint64
	// Pos identifies the root block number
	Pos int
}

type RecordsInfo struct {
	Id    chunk.Id
	MinTs int64
	MaxTs int64
}

type TsIndexer interface {
	// OnWrite notifies the indexer about new data added. It will create the new time
	// index for the chunk, if it doesn't exist yet. The function returns error if the
	// operation is unsuccessful. It must return ErrTmIndexCorrupted if the index should
	// be rebuilt. This case caller can RebuildIndex() to fix the index.
	OnWrite(src string, firstRec, lastRec uint32, rInfo RecordsInfo) error

	// LastChunkRecordsInfo returns information about last chunk, or an error
	// if it is not found (errors2.NotFound)
	LastChunkRecordsInfo(src string) (res RecordsInfo, err error)

	// GetRecordsInfo returns records info by chunk Id, or an error if the chunk is
	// not found (errors2.NotFound)
	GetRecordsInfo(src string, cid chunk.Id) (res RecordsInfo, err error)

	// Count returns number of records in the time index or it returns error if
	// the index is corrupted (ErrTmIndexCorrupted), or it doesn't exist (errors2.NotFound)
	Count(src string, cid chunk.Id) (int, error)

	// ReadData allows to read all points and return them. The function returns
	// err == errors2.NotFound if either src or the cid is not found. It returns
	// ErrTmIndexCorrupted if the index exists, but it is corrupted
	ReadData(src string, cid chunk.Id) ([]IdxRecord, error)

	// GetPosForGreaterOrEqualTime returns the position in the chunk which records'
	// timestamps are greater or equal to ts starting from the position. Could return
	// the following errors:
	// NotFound - there is no such partition or the chunk Id
	// ErrTmIndexCorrupted - there is a timestamp in the index, but it is corrupted, must be rebuilt, but
	// 				starting from 0, most probably will get some records
	// ErrOutOfRange - all known timestamps are less than ts e.g. maxTime < ts
	GetPosForGreaterOrEqualTime(src string, cid chunk.Id, ts int64) (uint32, error)

	// GetPosForLessTime returns the position in the chunk which records' timestamps are
	// less than ts starting from the position. Could return the following errors:
	// NotFound - there is no such partition or the chunk Id
	// ErrTmIndexCorrupted - there is a timestamp in the index, but it is corrupted, must be rebuilt, but
	// 				starting from tail, most probably will get some records
	// ErrOutOfRange - all known timestamps are greater than ts e.g. minTime > ts
	GetPosForLessTime(src string, cid chunk.Id, ts int64) (uint32, error)

	// SyncChunks expects the list of known chunks in cks. It updates internal chunks information and
	// returns the updated info as a slice of RecordsInfo. The function will remove all
	// chunks and its indexes that are not in the cks. It will remove the source information
	// completely if len(cks) == 0.
	SyncChunks(ctx context.Context, src string, cks chunk.Chunks) []RecordsInfo

	// Rebuild Index allows to re-build time index for the chunk provided. It
	// runs the procedure for building the time index if it is marked as corrupted.
	RebuildIndex(ctx context.Context, src string, ck chunk.Chunk, force bool)

	// VisitSources allows to iterate over the collection of known sources and pass them to the vistior.
	// if the visitor returns false, the function will stop the iteration and get complete the iteration
	VisitSources(visitor func(src string) bool)
}

type TsIndexerConfig struct {
	// Dir is where the data will be persisted
	Dir string
}