Files
tendermint/rpc/client/interface.go
Anton Kaliaev fb8b00f1d8 lite2: light client with weak subjectivity (#3989)
Refs #1771

ADR: https://github.com/tendermint/tendermint/blob/master/docs/architecture/adr-044-lite-client-with-weak-subjectivity.md

## Commits:

* add Verifier and VerifyCommitTrusting

* add two more checks

make trustLevel an option

* float32 for trustLevel

* check newHeader time

* started writing lite Client

* unify Verify methods

* ensure h2.Header.bfttime < h1.Header.bfttime + tp

* move trust checks into Verify function

* add more comments

* more docs

* started writing tests

* unbonding period failures

* tests are green

* export ErrNewHeaderTooFarIntoFuture

* make golangci happy

* test for non-adjusted headers

* more precision

* providers and stores

* VerifyHeader and VerifyHeaderAtHeight funcs

* fix compile errors

* remove lastVerifiedHeight, persist new trusted header

* sequential verification

* remove TrustedStore option

* started writing tests for light client

* cover basic cases for linear verification

* bisection tests PASS

* rename BisectingVerification to SkippingVerification

* refactor the code

* add TrustedHeader method

* consolidate sequential verification tests

* consolidate skipping verification tests

* rename trustedVals to trustedNextVals

* start writing docs

* ValidateTrustLevel func and ErrOldHeaderExpired error

* AutoClient and example tests

* fix errors

* update doc

* remove ErrNewHeaderTooFarIntoFuture

This check is unnecessary given existing a) ErrOldHeaderExpired b)
h2.Time > now checks.

* return an error if we're at more recent height

* add comments

* add LastSignedHeaderHeight method to Store

I think it's fine if Store tracks last height

* copy over proxy from old lite package

* make TrustedHeader return latest if height=0

* modify LastSignedHeaderHeight to return an error if no headers exist

* copy over proxy impl

* refactor proxy and start http lite client

* Tx and BlockchainInfo methods

* Block method

* commit method

* code compiles again

* lite client compiles

* extract updateLiteClientIfNeededTo func

* move final parts

* add placeholder for tests

* force usage of lite http client in proxy

* comment out query tests for now

* explicitly mention tp: trusting period

* verify nextVals in VerifyHeader

* refactor bisection

* move the NextValidatorsHash check into updateTrustedHeaderAndVals

+ update the comment

* add ConsensusParams method to RPC client

* add ConsensusParams to rpc/mock/client

* change trustLevel type to a new cmn.Fraction type

+ update SkippingVerification comment

* stress out trustLevel is only used for non-adjusted headers

* fixes after Fede's review

Co-authored-by: Federico Kunze <31522760+fedekunze@users.noreply.github.com>

* compare newHeader with a header from an alternative provider

* save pivot header

Refs https://github.com/tendermint/tendermint/pull/3989#discussion_r349122824

* check header can still be trusted in TrustedHeader

Refs https://github.com/tendermint/tendermint/pull/3989#discussion_r349101424

* lite: update Validators and Block endpoints

- Block no longer contains BlockMeta
- Validators now accept two additional params: page and perPage

* make linter happy
2019-11-25 19:07:40 +04:00

123 lines
4.5 KiB
Go

package client
/*
The client package provides a general purpose interface (Client) for connecting
to a tendermint node, as well as higher-level functionality.
The main implementation for production code is client.HTTP, which
connects via http to the jsonrpc interface of the tendermint node.
For connecting to a node running in the same process (eg. when
compiling the abci app in the same process), you can use the client.Local
implementation.
For mocking out server responses during testing to see behavior for
arbitrary return values, use the mock package.
In addition to the Client interface, which should be used externally
for maximum flexibility and testability, and two implementations,
this package also provides helper functions that work on any Client
implementation.
*/
import (
"context"
cmn "github.com/tendermint/tendermint/libs/common"
ctypes "github.com/tendermint/tendermint/rpc/core/types"
"github.com/tendermint/tendermint/types"
)
// Client wraps most important rpc calls a client would make if you want to
// listen for events, test if it also implements events.EventSwitch.
type Client interface {
cmn.Service
ABCIClient
EventsClient
HistoryClient
NetworkClient
SignClient
StatusClient
EvidenceClient
MempoolClient
}
// ABCIClient groups together the functionality that principally affects the
// ABCI app.
//
// In many cases this will be all we want, so we can accept an interface which
// is easier to mock.
type ABCIClient interface {
// Reading from abci app
ABCIInfo() (*ctypes.ResultABCIInfo, error)
ABCIQuery(path string, data cmn.HexBytes) (*ctypes.ResultABCIQuery, error)
ABCIQueryWithOptions(path string, data cmn.HexBytes,
opts ABCIQueryOptions) (*ctypes.ResultABCIQuery, error)
// Writing to abci app
BroadcastTxCommit(tx types.Tx) (*ctypes.ResultBroadcastTxCommit, error)
BroadcastTxAsync(tx types.Tx) (*ctypes.ResultBroadcastTx, error)
BroadcastTxSync(tx types.Tx) (*ctypes.ResultBroadcastTx, error)
}
// SignClient groups together the functionality needed to get valid signatures
// and prove anything about the chain.
type SignClient interface {
Block(height *int64) (*ctypes.ResultBlock, error)
BlockResults(height *int64) (*ctypes.ResultBlockResults, error)
Commit(height *int64) (*ctypes.ResultCommit, error)
Validators(height *int64, page, perPage int) (*ctypes.ResultValidators, error)
Tx(hash []byte, prove bool) (*ctypes.ResultTx, error)
TxSearch(query string, prove bool, page, perPage int) (*ctypes.ResultTxSearch, error)
}
// HistoryClient provides access to data from genesis to now in large chunks.
type HistoryClient interface {
Genesis() (*ctypes.ResultGenesis, error)
BlockchainInfo(minHeight, maxHeight int64) (*ctypes.ResultBlockchainInfo, error)
}
// StatusClient provides access to general chain info.
type StatusClient interface {
Status() (*ctypes.ResultStatus, error)
}
// NetworkClient is general info about the network state. May not be needed
// usually.
type NetworkClient interface {
NetInfo() (*ctypes.ResultNetInfo, error)
DumpConsensusState() (*ctypes.ResultDumpConsensusState, error)
ConsensusState() (*ctypes.ResultConsensusState, error)
ConsensusParams(height *int64) (*ctypes.ResultConsensusParams, error)
Health() (*ctypes.ResultHealth, error)
}
// EventsClient is reactive, you can subscribe to any message, given the proper
// string. see tendermint/types/events.go
type EventsClient interface {
// Subscribe subscribes given subscriber to query. Returns a channel with
// cap=1 onto which events are published. An error is returned if it fails to
// subscribe. outCapacity can be used optionally to set capacity for the
// channel. Channel is never closed to prevent accidental reads.
//
// ctx cannot be used to unsubscribe. To unsubscribe, use either Unsubscribe
// or UnsubscribeAll.
Subscribe(ctx context.Context, subscriber, query string, outCapacity ...int) (out <-chan ctypes.ResultEvent, err error)
// Unsubscribe unsubscribes given subscriber from query.
Unsubscribe(ctx context.Context, subscriber, query string) error
// UnsubscribeAll unsubscribes given subscriber from all the queries.
UnsubscribeAll(ctx context.Context, subscriber string) error
}
// MempoolClient shows us data about current mempool state.
type MempoolClient interface {
UnconfirmedTxs(limit int) (*ctypes.ResultUnconfirmedTxs, error)
NumUnconfirmedTxs() (*ctypes.ResultUnconfirmedTxs, error)
}
// EvidenceClient is used for submitting an evidence of the malicious
// behaviour.
type EvidenceClient interface {
BroadcastEvidence(ev types.Evidence) (*ctypes.ResultBroadcastEvidence, error)
}