complete

Documentation

Index

• Constants
• type Ledger
  • func NewLedger(wal wal.LedgerWAL, capacity int, metrics module.LedgerMetrics, ...) (*Ledger, error)
  • func (l *Ledger) Checkpointer() (*wal.Checkpointer, error)
  • func (l *Ledger) Done() <-chan struct{}
  • func (l *Ledger) DumpTrieAsJSON(state ledger.State, writer io.Writer) error
  • func (l *Ledger) ExportCheckpointAt(state ledger.State, migrations []ledger.Migration, reporters []ledger.Reporter, ...) (ledger.State, error)
  • func (l *Ledger) ForestSize() int
  • func (l *Ledger) Get(query *ledger.Query) (values []ledger.Value, err error)
  • func (l *Ledger) InitialState() ledger.State
  • func (l *Ledger) MemSize() (int64, error)
  • func (l *Ledger) MostRecentTouchedState() (ledger.State, error)
  • func (l *Ledger) Prove(query *ledger.Query) (proof ledger.Proof, err error)
  • func (l *Ledger) Ready() <-chan struct{}
  • func (l *Ledger) Set(update *ledger.Update) (newState ledger.State, err error)

Constants

const DefaultCacheSize = 1000

const DefaultPathFinderVersion = 1

Types

type Ledger

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

Ledger (complete) is a fast memory-efficient fork-aware thread-safe trie-based key/value storage. Ledger holds an array of registers (key-value pairs) and keeps tracks of changes over a limited time. Each register is referenced by an ID (key) and holds a value (byte slice). Ledger provides atomic batched updates and read (with or without proofs) operation given a list of keys. Every update to the Ledger creates a new state which captures the state of the storage. Under the hood, it uses binary Merkle tries to generate inclusion and non-inclusion proofs. Ledger is fork-aware which means any update can be applied at any previous state which forms a tree of tries (forest). The forest is in memory but all changes (e.g. register updates) are captured inside write-ahead-logs for crash recovery reasons. In order to limit the memory usage and maintain the performance storage only keeps a limited number of tries and purge the old ones (LRU-based); in other words, Ledger is not designed to be used for archival usage but make it possible for other software components to reconstruct very old tries using write-ahead logs.

func NewLedger

func NewLedger(
	wal wal.LedgerWAL,
	capacity int,
	metrics module.LedgerMetrics,
	log zerolog.Logger,
	pathFinderVer uint8) (*Ledger, error)

NewLedger creates a new in-memory trie-backed ledger storage with persistence.

func (*Ledger) Checkpointer

func (l *Ledger) Checkpointer() (*wal.Checkpointer, error)

Checkpointer returns a checkpointer instance

func (*Ledger) Done

func (l *Ledger) Done() <-chan struct{}

Done implements interface module.ReadyDoneAware it closes all the open write-ahead log files.

func (*Ledger) DumpTrieAsJSON

func (l *Ledger) DumpTrieAsJSON(state ledger.State, writer io.Writer) error

DumpTrieAsJSON export trie at specific state as JSONL (each line is JSON encoding of a payload)

func (*Ledger) ExportCheckpointAt

func (l *Ledger) ExportCheckpointAt(state ledger.State,
	migrations []ledger.Migration,
	reporters []ledger.Reporter,
	targetPathFinderVersion uint8,
	outputDir, outputFile string) (ledger.State, error)

ExportCheckpointAt exports a checkpoint at specific state commitment after applying migrations and returns the new state (after migration) and any errors

func (*Ledger) ForestSize

func (l *Ledger) ForestSize() int

ForestSize returns the number of tries stored in the forest

func (*Ledger) Get

func (l *Ledger) Get(query *ledger.Query) (values []ledger.Value, err error)

Get read the values of the given keys at the given state it returns the values in the same order as given registerIDs and errors (if any)

func (*Ledger) InitialState

func (l *Ledger) InitialState() ledger.State

InitialState returns the state of an empty ledger

func (*Ledger) MemSize

func (l *Ledger) MemSize() (int64, error)

MemSize return the amount of memory used by ledger TODO implement an approximate MemSize method

func (*Ledger) MostRecentTouchedState

func (l *Ledger) MostRecentTouchedState() (ledger.State, error)

MostRecentTouchedState returns a state which is most recently touched.

func (*Ledger) Prove

func (l *Ledger) Prove(query *ledger.Query) (proof ledger.Proof, err error)

Prove provides proofs for a ledger query and errors (if any).

Proves are generally _not_ provided in the register order of the query. In the current implementation, proofs are sorted in a deterministic order specified by the forest and mtrie implementation.

func (*Ledger) Ready

func (l *Ledger) Ready() <-chan struct{}

Ready implements interface module.ReadyDoneAware it starts the EventLoop's internal processing loop.

func (*Ledger) Set

func (l *Ledger) Set(update *ledger.Update) (newState ledger.State, err error)

Set updates the ledger given an update it returns the state after update and errors (if any)