Indexer plugin extension and custom flags support (#117)

* indexer: ReadOnlyBlockchain returns underlying engine

* indexer: plugin configs support custom flags

5 files changed, 13 insertions, 0 deletions

diff --git a/cmd/gdex/main.go b/cmd/gdex/main.go
index 2579e6f61..273c38838 100644
--- a/cmd/gdex/main.go
+++ b/cmd/gdex/main.go
@@ -139,6 +139,7 @@ var (
 		utils.EVMInterpreterFlag,
 		utils.IndexerEnableFlag,
 		utils.IndexerPluginFlag,
+		utils.IndexerPluginFlagsFlag,
 		configFileFlag,
 	}
 
diff --git a/cmd/gdex/usage.go b/cmd/gdex/usage.go
index 23afaa933..6427fd870 100644
--- a/cmd/gdex/usage.go
+++ b/cmd/gdex/usage.go
@@ -243,6 +243,7 @@ var AppHelpFlagGroups = []flagGroup{
 		Flags: []cli.Flag{
 			utils.IndexerEnableFlag,
 			utils.IndexerPluginFlag,
+			utils.IndexerPluginFlagsFlag,
 		},
 	},
 	{
diff --git a/cmd/utils/flags.go b/cmd/utils/flags.go
index ee5a3be6d..e4beb9cd4 100644
--- a/cmd/utils/flags.go
+++ b/cmd/utils/flags.go
@@ -654,6 +654,11 @@ var (
 		Usage: "External indexer plugin shared object path",
 		Value: "",
 	}
+	IndexerPluginFlagsFlag = cli.StringFlag{
+		Name:  "indexer.plugin-flags",
+		Usage: "External indexer plugin's flags if needed",
+		Value: "",
+	}
 )
 
 // MakeDataDir retrieves the currently requested data directory, terminating
@@ -1297,6 +1302,7 @@ func setIndexerConfig(ctx *cli.Context, cfg *dex.Config) {
 	}
 
 	cfg.Indexer.Plugin = ctx.GlobalString(IndexerPluginFlag.Name)
+	cfg.Indexer.PluginFlags = ctx.GlobalString(IndexerPluginFlagsFlag.Name)
 }
 
 // SetDashboardConfig applies dashboard related command line flags to the config.
diff --git a/indexer/blockchain.go b/indexer/blockchain.go
index a762ef67d..421535184 100644
--- a/indexer/blockchain.go
+++ b/indexer/blockchain.go
@@ -7,6 +7,7 @@ import (
 	coreTypes "github.com/dexon-foundation/dexon-consensus/core/types"
 
 	"github.com/dexon-foundation/dexon/common"
+	"github.com/dexon-foundation/dexon/consensus"
 	"github.com/dexon-foundation/dexon/core"
 	"github.com/dexon-foundation/dexon/core/state"
 	"github.com/dexon-foundation/dexon/core/types"
@@ -24,6 +25,7 @@ type ReadOnlyBlockChain interface {
 	CurrentBlock() *types.Block
 	CurrentFastBlock() *types.Block
 	CurrentHeader() *types.Header
+	Engine() consensus.Engine
 	GasLimit() uint64
 	Genesis() *types.Block
 	GetAncestor(common.Hash, uint64, uint64, *uint64) (common.Hash, uint64)
diff --git a/indexer/config.go b/indexer/config.go
index 3b626272a..396a23b66 100644
--- a/indexer/config.go
+++ b/indexer/config.go
@@ -11,6 +11,9 @@ type Config struct {
 
 	// Plugin path for building components.
 	Plugin string
+
+	// PluginFlags for construction if needed.
+	PluginFlags string
 }
 
 // NewIndexerFromConfig initialize exporter according to given config.