Add forking detection to TBC

api/tbcapi/README.md

@@ -38,7 +38,7 @@ This document provides details on the RPC protocol and available commands for th
       * [📥 Response](#-response-1)
         * [Payload](#payload-3)
         * [Example Response](#example-response-1)
-  * [👉 Best Block Headers](#-best-block-headers)
+  * [👉 Best Block Header](#-best-block-header)
     * [🗂 Raw Data](#-raw-data-1)
       * [📤 Request](#-request-2)
         * [Example Request](#example-request-2)
@@ -330,16 +330,16 @@ Response for a request with **id** `68656d69` and **height** `43111`:
 
 ---
 
-## 👉 Best Block Headers
+## 👉 Best Block Header
 
 Retrieve the best block headers.
 
 ### 🗂 Raw Data
 
-| Type     | `command` value                          |
-|----------|------------------------------------------|
-| Request  | `tbcapi-block-headers-best-raw-request`  |
-| Response | `tbcapi-block-headers-best-raw-response` |
+| Type     | `command` value                         |
+|----------|-----------------------------------------|
+| Request  | `tbcapi-block-header-best-raw-request`  |
+| Response | `tbcapi-block-header-best-raw-response` |
 
 #### 📤 Request
 
@@ -350,7 +350,7 @@ Retrieve the best block headers:
 ```json
 {
   "header": {
-    "command": "tbcapi-block-headers-best-raw-request",
+    "command": "tbcapi-block-header-best-raw-request",
     "id": "68656d69"
   }
 }
@@ -361,7 +361,7 @@ Retrieve the best block headers:
 ##### Payload
 
 - **`height`**: The best-known height.
-- **`block_headers`**: An array of the best-known block headers encoded as hexadecimal strings.
+- **`block_header`**: The best-known block header encoded as a hexadecimal string.
 
 ##### Example Response
 
@@ -370,24 +370,22 @@ Response for a request with **id** `68656d69` and **best height** `2182000`:
 ```json
 {
   "header": {
-    "command": "tbcapi-block-headers-best-raw-response",
+    "command": "tbcapi-block-header-best-raw-response",
     "id": "68656d69"
   },
   "payload": {
     "height": 2182000,
-    "block_headers": [
-      "0420002075089ac1ab1cab70cf6e6b774a86703a8d7127c0ebed1d3dfa2c00000000000086105509ec4a79457a400451290ad2a019fec4c76b47512623f1bb17a0ced76f38d82662bef4001b07d86700"
-    ]
+    "block_header": "0420002075089ac1ab1cab70cf6e6b774a86703a8d7127c0ebed1d3dfa2c00000000000086105509ec4a79457a400451290ad2a019fec4c76b47512623f1bb17a0ced76f38d82662bef4001b07d86700"
   }
 }
 ```
 
 #### 🗂 Serialized Data
 
-| Type     | `command` value                      |
-|----------|--------------------------------------|
-| Request  | `tbcapi-block-headers-best-request`  |
-| Response | `tbcapi-block-headers-best-response` |
+| Type     | `command` value                     |
+|----------|-------------------------------------|
+| Request  | `tbcapi-block-header-best-request`  |
+| Response | `tbcapi-block-header-best-response` |
 
 #### 📤 Request
 
@@ -398,7 +396,7 @@ Retrieve the best block headers:
 ```json
 {
   "header": {
-    "command": "tbcapi-block-headers-best-request",
+    "command": "tbcapi-block-header-best-request",
     "id": "68656d69"
   }
 }
@@ -409,7 +407,7 @@ Retrieve the best block headers:
 ##### Payload
 
 - **`height`**: The best-known height.
-- **`block_headers`**: An array of best-known [block headers](#block-header).
+- **`block_header`**: The best-known [block header](#block-header).
 
 ##### Example Response
 
@@ -418,21 +416,19 @@ Response for a request with **id** `68656d69` and **height** `2587400`:
 ```json
 {
   "header": {
-    "command": "tbcapi-block-headers-best-response",
+    "command": "tbcapi-block-header-best-response",
     "id": "68656d69"
   },
   "payload": {
     "height": 2587400,
-    "block_headers": [
-      {
-        "version": 536887296,
-        "prev_hash": "000000000000002bbbbec8f126dc76a82109d898383bca5013a2386c8675ce34",
-        "merkle_root": "b9d74efdafb5436330b47478b2df28251057da5a9bc11c5509410950253d4f0e",
-        "timestamp": 1713461092,
-        "bits": "192e17d5",
-        "nonce": 3365605040
-      }
-    ]
+    "block_header": {
+      "version": 536887296,
+      "prev_hash": "000000000000002bbbbec8f126dc76a82109d898383bca5013a2386c8675ce34",
+      "merkle_root": "b9d74efdafb5436330b47478b2df28251057da5a9bc11c5509410950253d4f0e",
+      "timestamp": 1713461092,
+      "bits": "192e17d5",
+      "nonce": 3365605040
+    }
   }
 }
 ```

api/tbcapi/tbcapi.go

@@ -26,11 +26,11 @@ const (
 	CmdBlockHeadersByHeightRequest  = "tbcapi-block-headers-by-height-request"
 	CmdBlockHeadersByHeightResponse = "tbcapi-block-headers-by-height-response"
 
-	CmdBlockHeadersBestRawRequest  = "tbcapi-block-headers-best-raw-request"
-	CmdBlockHeadersBestRawResponse = "tbcapi-block-headers-best-raw-response"
+	CmdBlockHeaderBestRawRequest  = "tbcapi-block-header-best-raw-request"
+	CmdBlockHeaderBestRawResponse = "tbcapi-block-header-best-raw-response"
 
-	CmdBlockHeadersBestRequest  = "tbcapi-block-headers-best-request"
-	CmdBlockHeadersBestResponse = "tbcapi-block-headers-best-response"
+	CmdBlockHeaderBestRequest  = "tbcapi-block-header-best-request"
+	CmdBlockHeaderBestResponse = "tbcapi-block-header-best-response"
 
 	CmdBalanceByAddressRequest  = "tbcapi-balance-by-address-request"
 	CmdBalanceByAddressResponse = "tbcapi-balance-by-address-response"
@@ -88,20 +88,20 @@ type BlockHeadersByHeightResponse struct {
 	Error        *protocol.Error `json:"error,omitempty"`
 }
 
-type BlockHeadersBestRawRequest struct{}
+type BlockHeaderBestRawRequest struct{}
 
-type BlockHeadersBestRawResponse struct {
-	Height       uint64          `json:"height"`
-	BlockHeaders []api.ByteSlice `json:"block_headers"`
-	Error        *protocol.Error `json:"error,omitempty"`
+type BlockHeaderBestRawResponse struct {
+	Height      uint64          `json:"height"`
+	BlockHeader api.ByteSlice   `json:"block_header"`
+	Error       *protocol.Error `json:"error,omitempty"`
 }
 
-type BlockHeadersBestRequest struct{}
+type BlockHeaderBestRequest struct{}
 
-type BlockHeadersBestResponse struct {
-	Height       uint64          `json:"height"`
-	BlockHeaders []*BlockHeader  `json:"block_headers"`
-	Error        *protocol.Error `json:"error,omitempty"`
+type BlockHeaderBestResponse struct {
+	Height      uint64          `json:"height"`
+	BlockHeader *BlockHeader    `json:"block_header"`
+	Error       *protocol.Error `json:"error,omitempty"`
 }
 
 type BalanceByAddressRequest struct {
@@ -192,10 +192,10 @@ var commands = map[protocol.Command]reflect.Type{
 	CmdBlockHeadersByHeightRawResponse: reflect.TypeOf(BlockHeadersByHeightRawResponse{}),
 	CmdBlockHeadersByHeightRequest:     reflect.TypeOf(BlockHeadersByHeightRequest{}),
 	CmdBlockHeadersByHeightResponse:    reflect.TypeOf(BlockHeadersByHeightResponse{}),
-	CmdBlockHeadersBestRawRequest:      reflect.TypeOf(BlockHeadersBestRawRequest{}),
-	CmdBlockHeadersBestRawResponse:     reflect.TypeOf(BlockHeadersBestRawResponse{}),
-	CmdBlockHeadersBestRequest:         reflect.TypeOf(BlockHeadersBestRequest{}),
-	CmdBlockHeadersBestResponse:        reflect.TypeOf(BlockHeadersBestResponse{}),
+	CmdBlockHeaderBestRawRequest:       reflect.TypeOf(BlockHeaderBestRawRequest{}),
+	CmdBlockHeaderBestRawResponse:      reflect.TypeOf(BlockHeaderBestRawResponse{}),
+	CmdBlockHeaderBestRequest:          reflect.TypeOf(BlockHeaderBestRequest{}),
+	CmdBlockHeaderBestResponse:         reflect.TypeOf(BlockHeaderBestResponse{}),
 	CmdBalanceByAddressRequest:         reflect.TypeOf(BalanceByAddressRequest{}),
 	CmdBalanceByAddressResponse:        reflect.TypeOf(BalanceByAddressResponse{}),
 	CmdUtxosByAddressRawRequest:        reflect.TypeOf(UtxosByAddressRawRequest{}),

cmd/hemictl/hemictl.go

@@ -241,14 +241,16 @@ func tbcdb() error {
 		fmt.Printf("height: %v\n", bh.Height)
 
 	case "blockheadersbest":
-		bhs, err := s.DB().BlockHeadersBest(ctx)
+		bhb, err := s.DB().BlockHeaderBest(ctx)
 		if err != nil {
 			return fmt.Errorf("block headers best: %w", err)
 		}
-		for k := range bhs {
-			fmt.Printf("hash   (%v): %v\n", k, bhs[k])
-			fmt.Printf("height (%v): %v\n", k, bhs[k].Height)
+		hash, err := chainhash.NewHash(bhb.Hash)
+		if err != nil {
+			return fmt.Errorf("block headers best chainhash: %w", err)
 		}
+		fmt.Printf("hash  : %v\n", hash)
+		fmt.Printf("height: %v\n", bhb.Height)
 
 	case "blockheadersbyheight":
 		height := args["height"]

cmd/tbcd/tbcd.go

@@ -75,6 +75,12 @@ var (
 			Help:         "bitcoin network; mainnet or testnet3",
 			Print:        config.PrintAll,
 		},
+		"TBC_PEERS_WANTED": config.Config{
+			Value:        &cfg.PeersWanted,
+			DefaultValue: 64,
+			Help:         "number of wanted p2p peers",
+			Print:        config.PrintAll,
+		},
 		"TBC_PROMETHEUS_ADDRESS": config.Config{
 			Value:        &cfg.PrometheusListenAddress,
 			DefaultValue: "",

database/tbcd/database.go

@@ -11,6 +11,7 @@ import (
 	"encoding/hex"
 	"errors"
 	"fmt"
+	"math/big"
 	"time"
 
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
@@ -19,6 +20,26 @@ import (
 	"github.com/hemilabs/heminetwork/database"
 )
 
+type InsertType int
+
+const (
+	ITInvalid     InsertType = 0 // Invalid insert
+	ITChainExtend InsertType = 1 // Normal insert, does not require further action.
+	ITChainFork   InsertType = 2 // Chain forked, unwind and rewind indexes.
+	ITForkExtend  InsertType = 3 // Extended a fork, does not require further action.
+)
+
+var itStrings = map[InsertType]string{
+	ITInvalid:     "invalid",
+	ITChainExtend: "chain extended",
+	ITChainFork:   "chain forked",
+	ITForkExtend:  "fork extended",
+}
+
+func (it InsertType) String() string {
+	return itStrings[it]
+}
+
 type Database interface {
 	database.Database
 
@@ -28,10 +49,13 @@ type Database interface {
 	MetadataPut(ctx context.Context, key, value []byte) error
 
 	// Block header
+	BlockHeaderBest(ctx context.Context) (*BlockHeader, error) // return canonical
 	BlockHeaderByHash(ctx context.Context, hash []byte) (*BlockHeader, error)
-	BlockHeadersBest(ctx context.Context) ([]BlockHeader, error)
+	BlockHeaderGenesisInsert(ctx context.Context, bh [80]byte) error
+
+	// Block headers
 	BlockHeadersByHeight(ctx context.Context, height uint64) ([]BlockHeader, error)
-	BlockHeadersInsert(ctx context.Context, bhs []BlockHeader) error
+	BlockHeadersInsert(ctx context.Context, bhs [][80]byte) (InsertType, *BlockHeader, *BlockHeader, error)
 
 	// Block
 	BlocksMissing(ctx context.Context, count int) ([]BlockIdentifier, error)
@@ -58,12 +82,13 @@ type Database interface {
 	UtxosByScriptHash(ctx context.Context, sh ScriptHash, start uint64, count uint64) ([]Utxo, error)
 }
 
-// BlockHeader contains the first 80 raw bytes of a bitcoin block and its
-// location information (hash+height).
+// BlockHeader contains the first 80 raw bytes of a bitcoin block plus its
+// location information (hash+height) and the cumulative difficulty.
 type BlockHeader struct {
-	Hash   database.ByteArray
-	Height uint64
-	Header database.ByteArray
+	Hash       database.ByteArray
+	Height     uint64
+	Header     database.ByteArray
+	Difficulty big.Int
 }
 
 func (bh BlockHeader) String() string {