tindex

type InMemConfig struct {
	// DoNotSave flag indicates that the data should not be persisted. Used for testing.
	DoNotSave bool

	// WorkingDir contains path to the folder for persisting the index data
	WorkingDir string
}

type Service interface {
	// GetOrCreateJournal returns the journal name for the unique Tags combination. It will try
	// to create the new journal Id if it is not found in the index. If the result
	// is returned with no error, the JournalName MUST be released using the Release method later
	GetOrCreateJournal(tags string) (string, tag.Set, error)

	// GetJournal returns the journal name for the unique Tags combination. If the result
	// is returned with no error, the JournalName MUST be released using the Release method later
	GetJournal(tags string) (string, tag.Set, error)

	// GetJournalTags returns the journal Tags combination by its name. If the result
	// is returned with no error, and the lock == true, the journal src MUST be released
	// using the Release method later. If lock == false either an error happens or not
	// the source must not be released.
	// The function returns NotFound if the source is not found
	GetJournalTags(src string, lock bool) (tag.Set, error)

	// Visit walks over the tags-sources that corresponds to the srcCond. VF_SKIP_IF_LOCKED allows to skip the source if it
	// is locked. If VF_SKIP_IF_LOCKED is not set, the Visit will wait until the source become available or removed.
	// VF_DO_NOT_RELEASE will not release the partition automatically, but it is the client responsibility to release
	// the partition later
	Visit(srcCond *lql.Source, v VisitorF, visitFlags int) error

	// LockExclusively changes the acquired source jn (via GetOrCreateJournal or Visit) to exclusive lock.
	// If it returns true, the partition will not be returned in Visit and GetOrCreateJournal will be blocked unitl
	// it is released. The partition must be un-locked the exclusivelies, it was not deleted.
	LockExclusively(jn string) bool

	// UnlockExclusively removes the exclusive lock from the partition. If the lock is not acquired, will panic
	UnlockExclusively(jn string)

	// Release allows to release the journal name which could be acquired by GetOrCreateJournal
	Release(jn string)

	// Delete allows to delete a partition. It must be exclusively locked before the call. If the partition
	// was deleted, the consequireve Release() call will not have any effect. If the Delete returns any
	// error, the partition must be unlocked and released if it was acquired before
	Delete(jn string) error
}

type VisitorF func(tags tag.Set, jrnl string) bool