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 two 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(app *PersistentKVStoreApplication)
• func MakeValSetChangeTx(pubkey types.PubKey, power int64) []byte
• func RandVal(i int) types.ValidatorUpdate
• func RandVals(cnt int) []types.ValidatorUpdate
• type Application
  • func NewApplication() *Application
  • func (app *Application) CheckTx(req types.RequestCheckTx) types.ResponseCheckTx
  • func (app *Application) Commit() types.ResponseCommit
  • func (app *Application) DeliverTx(req types.RequestDeliverTx) types.ResponseDeliverTx
  • func (app *Application) Info(req types.RequestInfo) (resInfo types.ResponseInfo)
  • func (app *Application) Query(reqQuery types.RequestQuery) (resQuery types.ResponseQuery)
• type PersistentKVStoreApplication
  • func NewPersistentKVStoreApplication(dbDir string) *PersistentKVStoreApplication
  • func (app *PersistentKVStoreApplication) BeginBlock(req types.RequestBeginBlock) types.ResponseBeginBlock
  • func (app *PersistentKVStoreApplication) CheckTx(req types.RequestCheckTx) types.ResponseCheckTx
  • func (app *PersistentKVStoreApplication) Commit() types.ResponseCommit
  • func (app *PersistentKVStoreApplication) DeliverTx(req types.RequestDeliverTx) types.ResponseDeliverTx
  • func (app *PersistentKVStoreApplication) EndBlock(req types.RequestEndBlock) types.ResponseEndBlock
  • func (app *PersistentKVStoreApplication) Info(req types.RequestInfo) types.ResponseInfo
  • func (app *PersistentKVStoreApplication) InitChain(req types.RequestInitChain) types.ResponseInitChain
  • func (app *PersistentKVStoreApplication) Query(reqQuery types.RequestQuery) (resQuery types.ResponseQuery)
  • func (app *PersistentKVStoreApplication) SetLogger(l log.Logger)
  • func (app *PersistentKVStoreApplication) SetOption(req types.RequestSetOption) types.ResponseSetOption
  • func (app *PersistentKVStoreApplication) Validators() (validators []types.ValidatorUpdate)
• type State

Constants

const (
	ValidatorSetChangePrefix string = "val:"
)

Variables

var (
	ProtocolVersion version.Protocol = 0x1
)

Functions

func InitKVStore

func InitKVStore(app *PersistentKVStoreApplication)

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 types.PubKey, 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)
	// contains filtered or unexported fields
}

func NewApplication

func NewApplication() *Application

func (*Application) CheckTx

func (app *Application) CheckTx(req types.RequestCheckTx) types.ResponseCheckTx

func (*Application) Commit

func (app *Application) Commit() types.ResponseCommit

func (*Application) DeliverTx

func (app *Application) DeliverTx(req types.RequestDeliverTx) types.ResponseDeliverTx

tx is either "key=value" or just arbitrary bytes

func (*Application) Info

func (app *Application) Info(req types.RequestInfo) (resInfo types.ResponseInfo)

func (*Application) Query

func (app *Application) Query(reqQuery types.RequestQuery) (resQuery types.ResponseQuery)

Returns an associated value or nil if missing.

type PersistentKVStoreApplication

type PersistentKVStoreApplication struct {

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

func NewPersistentKVStoreApplication

func NewPersistentKVStoreApplication(dbDir string) *PersistentKVStoreApplication

func (*PersistentKVStoreApplication) BeginBlock

func (app *PersistentKVStoreApplication) BeginBlock(req types.RequestBeginBlock) types.ResponseBeginBlock

Track the block hash and header information

func (*PersistentKVStoreApplication) CheckTx

func (app *PersistentKVStoreApplication) CheckTx(req types.RequestCheckTx) types.ResponseCheckTx

func (*PersistentKVStoreApplication) Commit

func (app *PersistentKVStoreApplication) Commit() types.ResponseCommit

Commit will panic if InitChain was not called

func (*PersistentKVStoreApplication) DeliverTx

func (app *PersistentKVStoreApplication) DeliverTx(req types.RequestDeliverTx) types.ResponseDeliverTx

tx is either "val:pubkey!power" or "key=value" or just arbitrary bytes

func (*PersistentKVStoreApplication) EndBlock

func (app *PersistentKVStoreApplication) EndBlock(req types.RequestEndBlock) types.ResponseEndBlock

Update the validator set

func (*PersistentKVStoreApplication) Info

func (app *PersistentKVStoreApplication) Info(req types.RequestInfo) types.ResponseInfo

func (*PersistentKVStoreApplication) InitChain

func (app *PersistentKVStoreApplication) InitChain(req types.RequestInitChain) types.ResponseInitChain

Save the validators in the merkle tree

func (*PersistentKVStoreApplication) Query

func (app *PersistentKVStoreApplication) Query(reqQuery types.RequestQuery) (resQuery types.ResponseQuery)

When path=/val and data={validator address}, returns the validator update (types.ValidatorUpdate) varint encoded. For any other path, returns an associated value or nil if missing.

func (*PersistentKVStoreApplication) SetLogger

func (app *PersistentKVStoreApplication) SetLogger(l log.Logger)

func (*PersistentKVStoreApplication) SetOption

func (app *PersistentKVStoreApplication) SetOption(req types.RequestSetOption) types.ResponseSetOption

func (*PersistentKVStoreApplication) Validators

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

type State

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