Stable version to replace the shadow service in darwinia.js (#7)

* update: adapt lowercase request method with slash

* add: double node with merkle proof format

* add: basic scale lib

* add: proof encode

* update: adapt darwinia ethereum header

* update: support scale codec for darwinia ethereum header

* update: README

* update: add homebrew guide

.gitignore

@@ -1 +1,3 @@
+.DS_Store
 target
+go.sum

README.md

@@ -4,12 +4,6 @@
 
 [![Golang CI][workflow-badge]][github]
 
-## Install
-
-```
-go get install "github.com/darwinia-network/darwinia.go/dargo"
-```
-
 ## Config
 
 `dargo` use the same config file with `darwinia.js`, if you don't know what 
@@ -20,12 +14,28 @@ mkdir ~/.darwinia
 echo '{"eth": { "api": "infura api with your key"}}' > ~/.darwinia/config.json
 ```
 
+## Installation
+
+Just supports OSX now
+
+```
+# Tap darwinia homebrew
+brew tap darwinia-network/darwinia
+
+# Install
+brew install dargo
+```
+
 ## Contribute and Build
 
 ```
+# Clone darwinia.go
 git clone https://github.com/darwinia-network/darwinia.go.git
-cd darwinia.go/dargo
-make
+
+# Make the binary
+cd darwinia.go/dargo && make
+
+# Check the version
 ./target/dargo version
 ```
 
@@ -65,23 +75,25 @@ Fill the `~/.darwinia/config.json`
 }
 ```
 
-Run the service
+## Shadow Service
 
 ```
 # Start shadow service at port 3000
 dargo shadow 3000
 ```
 
+The shadow service of dargo follows the [spec][spec].
+
 ### Shadow.GetEthHeaderByNumber
 
 ```
-curl -d '{"method":"Shadow.GetEthHeaderByNumber","params":[{"number": 0}], "id": 0}' http://127.0.0.1:3000
+curl -d '{"method":"shadow_getEthHeaderByNumber","params":{"block_num": 0}, "id": 0}' http://127.0.0.1:3000
 ```
 
 ### Shadow.GetEthHeaderWithProofByNumber
 
 ```
-curl -d '{"method":"Shadow.GetEthHeaderWithProofByNumber","params":[{"number": 1, "transcation": false, "options": {"format": "json"}}], "id": 0}' http://127.0.0.1:3000
+curl -d '{"method":"shadow_getEthHeaderWithProofByNumber","params":{"block_num": 1, "transcation": false, "options": {"format": "json"}}, "id": 0}' http://127.0.0.1:3000
 ```
 
 ## Trouble Shooting
@@ -95,4 +107,5 @@ GPL-3.0
 
 
 [github]: https://github.com/darwinia-network/darwinia.go
+[spec]: https://github.com/darwinia-network/darwinia/wiki/Darwinia-offchain-worker-shadow-service-spec
 [workflow-badge]: https://github.com/darwinia-network/darwinia.go/workflows/Golang%20CI/badge.svg

cmd/shadow.go

@@ -4,7 +4,7 @@ import (
 	"fmt"
 
 	"github.com/darwinia-network/darwinia.go/core"
-	"github.com/darwinia-network/darwinia.go/lib"
+	"github.com/darwinia-network/darwinia.go/rpc"
 	"github.com/darwinia-network/darwinia.go/util"
 	"github.com/spf13/cobra"
 )
@@ -19,8 +19,8 @@ var cmdShadow = &cobra.Command{
 			args = []string{"3000"}
 		}
 
-		fmt.Printf("Shadow service start at %s", args[0])
-		err := lib.Serve(
+		fmt.Printf("Shadow service start at %s\n", args[0])
+		err := rpc.ServeHTTP(
 			new(core.Shadow),
 			fmt.Sprintf(":%s", args[0]),
 		)

cmd/version.go

@@ -11,6 +11,6 @@ var cmdVersion = &cobra.Command{
 	Short: "Print the version number of dargo",
 	Long:  `All software has versions. This is dargo's`,
 	Run: func(cmd *cobra.Command, args []string) {
-		fmt.Println("dargo 0.9")
+		fmt.Println("dargo 0.1.1")
 	},
 }

core/scale.go

@@ -0,0 +1,70 @@
+package core
+
+import (
+	"encoding/binary"
+	"encoding/hex"
+	"strings"
+
+	"github.com/darwinia-network/darwinia.go/util"
+)
+
+// Pack encode proof
+func encodeProofArray(arr []util.DoubleNodeWithMerkleProof) string {
+	hex := "0x0101"
+	for _, v := range arr {
+		hex += encodeProof(v)
+	}
+
+	return hex
+}
+
+// Encode proof to hex with exist hex
+func encodeProof(dnmp util.DoubleNodeWithMerkleProof) string {
+	hex := ""
+	for _, v := range dnmp.DagNodes {
+		hex += v[2:]
+	}
+
+	// pad the length
+	hex += "64"
+	for _, v := range dnmp.Proof {
+		hex += v[2:]
+	}
+
+	return hex
+}
+
+// Encode Darwinia Eth Header
+func encodeDarwiniaEthHeader(header util.DarwiniaEthHeader) string {
+	hex := "0x"
+	hex += header.ParentHash[2:]
+	hex += encodeUint(header.TimeStamp, 64)
+	hex += encodeUint(header.Number, 64)
+	hex += strings.ToLower(header.Author[2:])
+	hex += header.TransactionsRoot[2:]
+	hex += header.UnclesHash[2:]
+	hex += "7c"
+	hex += header.ExtraData[2:]
+	hex += header.StateRoot[2:]
+	hex += header.ReceiptsRoot[2:]
+	hex += header.LogBloom[2:]
+	hex += encodeUint(header.GasUsed, 256)
+	hex += encodeUint(header.GasLimited, 256)
+	hex += encodeUint(header.Difficulty, 256)
+	hex += "0884"
+	hex += header.Seal[0][2:]
+	hex += "24"
+	hex += header.Seal[1][2:]
+	hex += "01"
+	hex += header.Hash[2:]
+
+	return hex
+}
+
+// Encode uint to hex
+func encodeUint(n uint64, d int16) string {
+	b := make([]byte, d/8)
+	binary.LittleEndian.PutUint64(b, n)
+
+	return hex.EncodeToString(b)
+}

core/shadow.go

@@ -1,6 +1,9 @@
 package core
 
 import (
+	// "encoding/hex"
+	// "fmt"
+
 	"github.com/darwinia-network/darwinia.go/util"
 	"github.com/ethereum/go-ethereum/core/types"
 )
@@ -31,27 +34,64 @@ func (s *Shadow) GetEthHeaderByNumber(
 /**
  * GetEthHeaderWithProofByNumber
  */
+type GetEthHeaderWithProofByNumberOptions struct {
+	Format string `json:"format"`
+}
+
 type GetEthHeaderWithProofByNumberParams struct {
-	Number uint64 `json:"number"`
+	Number  uint64                               `json:"block_num"`
+	Options GetEthHeaderWithProofByNumberOptions `json:"options"`
+}
+
+type GetEthHeaderWithProofByNumberRawResp struct {
+	Header util.DarwiniaEthHeader           `json:"eth_header"`
+	Proof  []util.DoubleNodeWithMerkleProof `json:"proof"`
+}
+
+type GetEthHeaderWithProofByNumberJSONResp struct {
+	Header util.DarwiniaEthHeaderHexFormat  `json:"eth_header"`
+	Proof  []util.DoubleNodeWithMerkleProof `json:"proof"`
 }
 
-type GetEthHeaderWithProofByNumberResp struct {
-	Header types.Header     `json:"header"`
-	Proof  util.ProofOutput `json:"proof"`
+type GetEthHeaderWithProofByNumberCodecResp struct {
+	Header string `json:"header"`
+	Proof  string `json:"proof"`
 }
 
 func (s *Shadow) GetEthHeaderWithProofByNumber(
 	params GetEthHeaderWithProofByNumberParams,
-	resp *GetEthHeaderWithProofByNumberResp,
+	resp *interface{},
 ) error {
 	header, err := util.Header(params.Number)
-	resp.Header = header
+	if err != nil {
+		return err
+	}
+
+	rawResp := GetEthHeaderWithProofByNumberRawResp{}
+	rawResp.Header, err = util.IntoDarwiniaEthHeader(header)
 	if err != nil {
 		return err
 	}
 
 	// Proof header
 	proof, err := util.Proof(&header)
-	resp.Proof = proof
+	rawResp.Proof = proof.Format()
+
+	// Set response
+	*resp = rawResp
+
+	// Check if need codec
+	if params.Options.Format == "scale" {
+		*resp = GetEthHeaderWithProofByNumberCodecResp{
+			encodeDarwiniaEthHeader(rawResp.Header),
+			encodeProofArray(rawResp.Proof),
+		}
+	} else if params.Options.Format == "json" {
+		*resp = GetEthHeaderWithProofByNumberJSONResp{
+			rawResp.Header.HexFormat(),
+			rawResp.Proof,
+		}
+	}
+
 	return err
 }