kvstore

README

KVStore

There are two app's here: the KVStoreApplication and the PersistentKVStoreApplication.

KVStoreApplication

The KVStoreApplication is a simple merkle key-value store. Transactions of the form key=value are stored as key-value pairs in the tree. Transactions without an = sign set the value to the key. The app has no replay protection (other than what the mempool provides).

PersistentKVStoreApplication

The PersistentKVStoreApplication wraps the KVStoreApplication and provides three additional features:

1. persistence of state across app restarts (using Tendermint's ABCI-Handshake mechanism)
2. validator set changes

The state is persisted in leveldb along with the last block committed, and the Handshake allows any necessary blocks to be replayed. Validator set changes are effected using the following transaction format:

"val:pubkey1!power1,pubkey2!power2,pubkey3!power3"

where pubkeyN is a base64-encoded 32-byte ed25519 key and powerN is a new voting power for the validator with pubkeyN (possibly a new one). To remove a validator from the validator set, set power to 0. There is no sybil protection against new validators joining.

Documentation

Index

• Constants
• Variables
• func InitKVStore(ctx context.Context, app *PersistentKVStoreApplication) error
• func MakeValSetChangeTx(pubkey cryptoproto.PublicKey, power int64) []byte
• func RandVal(i int) types.ValidatorUpdate
• func RandVals(cnt int) []types.ValidatorUpdate
• type Application
  • func NewApplication() *Application
  • func (*Application) CheckTx(_ context.Context, req *types.RequestCheckTx) (*types.ResponseCheckTx, error)
  • func (app *Application) Close() error
  • func (app *Application) Commit(_ context.Context) (*types.ResponseCommit, error)
  • func (app *Application) FinalizeBlock(_ context.Context, req *types.RequestFinalizeBlock) (*types.ResponseFinalizeBlock, error)
  • func (app *Application) Info(_ context.Context, req *types.RequestInfo) (*types.ResponseInfo, error)
  • func (app *Application) InitChain(_ context.Context, req *types.RequestInitChain) (*types.ResponseInitChain, error)
  • func (app *Application) PrepareProposal(_ context.Context, req *types.RequestPrepareProposal) (*types.ResponsePrepareProposal, error)
  • func (*Application) ProcessProposal(_ context.Context, req *types.RequestProcessProposal) (*types.ResponseProcessProposal, error)
  • func (app *Application) Query(_ context.Context, reqQuery *types.RequestQuery) (*types.ResponseQuery, error)
  • func (app *Application) Validators() (validators []types.ValidatorUpdate)
• type PersistentKVStoreApplication
  • func NewPersistentKVStoreApplication(logger log.Logger, dbDir string) *PersistentKVStoreApplication
  • func (app *PersistentKVStoreApplication) ApplySnapshotChunk(_ context.Context, req *types.RequestApplySnapshotChunk) (*types.ResponseApplySnapshotChunk, error)
  • func (app *PersistentKVStoreApplication) OfferSnapshot(_ context.Context, req *types.RequestOfferSnapshot) (*types.ResponseOfferSnapshot, error)
• type State

Constants

const PreparePrefix = "prepare"

const (
	ValidatorSetChangePrefix string = "val:"
)

Variables

var (
	ProtocolVersion uint64 = 0x1
)

Functions

func InitKVStore

func InitKVStore(ctx context.Context, app *PersistentKVStoreApplication) error

InitKVStore initializes the kvstore app with some data, which allows tests to pass and is fine as long as you don't make any tx that modify the validator state

func MakeValSetChangeTx

func MakeValSetChangeTx(pubkey cryptoproto.PublicKey, power int64) []byte

func RandVal

func RandVal(i int) types.ValidatorUpdate

RandVal creates one random validator, with a key derived from the input value

func RandVals

func RandVals(cnt int) []types.ValidatorUpdate

RandVals returns a list of cnt validators for initializing the application. Note that the keys are deterministically derived from the index in the array, while the power is random (Change this if not desired)

Types

type Application

type Application struct {
	types.BaseApplication

	RetainBlocks int64 // blocks to retain after commit (via ResponseCommit.RetainHeight)

	// validator set
	ValUpdates []types.ValidatorUpdate
	// contains filtered or unexported fields
}

func NewApplication

func NewApplication() *Application

func (*Application) CheckTx

func (*Application) CheckTx(_ context.Context, req *types.RequestCheckTx) (*types.ResponseCheckTx, error)

func (*Application) Close

func (app *Application) Close() error

func (*Application) Commit

func (app *Application) Commit(_ context.Context) (*types.ResponseCommit, error)

func (*Application) FinalizeBlock

func (app *Application) FinalizeBlock(_ context.Context, req *types.RequestFinalizeBlock) (*types.ResponseFinalizeBlock, error)

func (*Application) Info

func (app *Application) Info(_ context.Context, req *types.RequestInfo) (*types.ResponseInfo, error)

func (*Application) InitChain

func (app *Application) InitChain(_ context.Context, req *types.RequestInitChain) (*types.ResponseInitChain, error)

func (*Application) PrepareProposal

func (app *Application) PrepareProposal(_ context.Context, req *types.RequestPrepareProposal) (*types.ResponsePrepareProposal, error)

func (*Application) ProcessProposal

func (*Application) ProcessProposal(_ context.Context, req *types.RequestProcessProposal) (*types.ResponseProcessProposal, error)

func (*Application) Query

func (app *Application) Query(_ context.Context, reqQuery *types.RequestQuery) (*types.ResponseQuery, error)

Returns an associated value or nil if missing.

func (*Application) Validators

func (app *Application) Validators() (validators []types.ValidatorUpdate)

type PersistentKVStoreApplication

type PersistentKVStoreApplication struct {
	*Application
}

func NewPersistentKVStoreApplication

func NewPersistentKVStoreApplication(logger log.Logger, dbDir string) *PersistentKVStoreApplication

func (*PersistentKVStoreApplication) ApplySnapshotChunk

func (app *PersistentKVStoreApplication) ApplySnapshotChunk(_ context.Context, req *types.RequestApplySnapshotChunk) (*types.ResponseApplySnapshotChunk, error)

func (*PersistentKVStoreApplication) OfferSnapshot

func (app *PersistentKVStoreApplication) OfferSnapshot(_ context.Context, req *types.RequestOfferSnapshot) (*types.ResponseOfferSnapshot, error)

type State

type State struct {
	Size    int64  `json:"size"`
	Height  int64  `json:"height"`
	AppHash []byte `json:"app_hash"`
	// contains filtered or unexported fields
}