add with-skipped-blocks and with-reorgs flags

Author: sduchesneau

CHANGELOG.md

@@ -1,5 +1,10 @@
 # CHANGELOG
 
+## 1.7.2
+
+- Added `--with-skipped-blocks` flag to control behavior of skipping blocks that are multiples of 13.
+- Added `--with-reorgs` flag to control behavior of producing 2 block reorg sequences every 17 blocks.
+
 ## 1.7.1
 
 - Fixed `--log-level` not being picked up correctly.

README.md

@@ -50,12 +50,14 @@ To enable firehose instrumentation:
 Firehose logger statement will be printed as blocks are executed/produced. This mode is meant to be run
 using by a Firehose `reader-node`, see https://github.com/streamingfast/firehose-acme.
 
-### Block Skipping and Forks
+### Block Skipping and Forks(reorgs)
 
 The dummy chain skips a block that are divisible by 13 so for example we are at block #25 (abc) the next produced block will be #27 (def) and #26 will never be produced.
 
 THe dummy chain also generates forks at regular interval, every 17 blocks. The generated fork sequence is of 1 block if the current block is odd otherwise if it's even, a 2 blocks fork sequence will be generated.
 
+These two features can be disabled with flags `--with-skipped-blocks=false` and `--with-reorgs=false`.
+
 ## Tracer
 
 This project showcase a "fake" blockchain's node codebase. For developers looking into integrating a native Firehose integration, we suggest to integrate in blockchain's client code directly by some form of tracing plugin that is able to receive all the important callback's while transactions are execution integrating as deeply as wanted.

cmd/dummy-blockchain/app/app.go

@@ -27,6 +27,8 @@ type Flags struct {
 	BlockSizeInBytes  int
 	ServerAddr        string
 	WithSignal        bool
+	WithSkippedBlocks bool
+	WithReorgs        bool
 	Tracer            string
 	StopHeight        uint64
 
@@ -78,6 +80,8 @@ func initFlags(root *cobra.Command) error {
 	flags.StringVar(&cliOpts.ServerAddr, "server-addr", "0.0.0.0:8080", "Server address")
 	flags.StringVar(&cliOpts.Tracer, "tracer", "", "The tracer to use, either <empty>, none or firehose")
 	flags.BoolVar(&cliOpts.WithSignal, "with-signal", false, "whether we produce BlockCommitmentLevel signals on top of blocks")
+	flags.BoolVar(&cliOpts.WithSkippedBlocks, "with-skipped-blocks", true, "whether skip a block number every 13 slots")
+	flags.BoolVar(&cliOpts.WithReorgs, "with-reorgs", true, "whether we produce reorgs every 17 slots")
 
 	return nil
 }
@@ -168,6 +172,8 @@ func makeStartComand() *cobra.Command {
 				cliOpts.ServerAddr,
 				blockTracer,
 				cliOpts.WithSignal,
+				cliOpts.WithSkippedBlocks,
+				cliOpts.WithReorgs,
 			)
 
 			if err := node.Initialize(); err != nil {

core/engine.go

@@ -22,9 +22,11 @@ type Engine struct {
 	signalChan        chan *types.Signal
 	prevBlock         *types.Block
 	finalBlock        *types.Block
+	withSkippedBlocks bool
+	withReorgs        bool
 }
 
-func NewEngine(genesisHash string, genesisHeight uint64, genesisTime time.Time, genesisBlockBurst uint64, stopHeight uint64, rate int, blockSizeInBytes int) Engine {
+func NewEngine(genesisHash string, genesisHeight uint64, genesisTime time.Time, genesisBlockBurst uint64, stopHeight uint64, rate int, blockSizeInBytes int, withSkippedBlocks bool, withReorgs bool) Engine {
 	blockRate := time.Minute / time.Duration(rate)
 
 	return Engine{
@@ -37,6 +39,8 @@ func NewEngine(genesisHash string, genesisHeight uint64, genesisTime time.Time,
 		blockSizeInBytes:  blockSizeInBytes,
 		blockChan:         make(chan *types.Block),
 		signalChan:        make(chan *types.Signal),
+		withSkippedBlocks: withSkippedBlocks,
+		withReorgs:        withReorgs,
 	}
 }
 
@@ -136,12 +140,12 @@ func (e *Engine) createBlocks() (out []*types.Block) {
 	}
 
 	heightToProduce := e.prevBlock.Header.Height + 1
-	if heightToProduce%13 == 0 {
+	if e.withSkippedBlocks && heightToProduce%13 == 0 {
 		heightToProduce += 1
 		logrus.Info(fmt.Sprintf("skipping block #%d that is a multiple of 13, producing %d instead", heightToProduce-1, heightToProduce))
 	}
 
-	if heightToProduce%17 == 0 {
+	if e.withReorgs && heightToProduce%17 == 0 {
 		if heightToProduce%2 == 0 {
 			logrus.Info("producing 2 block fork sequence")
 			firstFork := e.newBlock(heightToProduce, ptr(uint64(1)), e.prevBlock)

core/node.go

@@ -31,11 +31,13 @@ func NewNode(
 	serverAddr string,
 	tracer tracer.Tracer,
 	withSignal bool,
+	withSkippedBlocks bool,
+	withReorgs bool,
 ) *Node {
 	store := NewStore(storeDir, genesisHash, genesisHeight, genesisTime)
 
 	return &Node{
-		engine:     NewEngine(genesisHash, genesisHeight, genesisTime, genesisBlockBurst, stopHeight, blockRate, blockSizeInBytes),
+		engine:     NewEngine(genesisHash, genesisHeight, genesisTime, genesisBlockBurst, stopHeight, blockRate, blockSizeInBytes, withSkippedBlocks, withReorgs),
 		store:      store,
 		server:     NewServer(store, serverAddr),
 		tracer:     tracer,