rpc: refactor rpc packages and backend to support cosmos namespace (#1070)

* rpc: refactor rpc packages and backend to support cosmos namespace

* changelog

* typo

rpc/namespaces/ethereum/txpool/api.go

@@ -0,0 +1,51 @@
+package txpool
+
+import (
+	"github.com/tendermint/tendermint/libs/log"
+
+	"github.com/ethereum/go-ethereum/common/hexutil"
+
+	"github.com/tharsis/ethermint/rpc/types"
+)
+
+// PublicAPI offers and API for the transaction pool. It only operates on data that is non-confidential.
+// NOTE: For more info about the current status of this endpoints see https://github.com/tharsis/ethermint/issues/124
+type PublicAPI struct {
+	logger log.Logger
+}
+
+// NewPublicAPI creates a new tx pool service that gives information about the transaction pool.
+func NewPublicAPI(logger log.Logger) *PublicAPI {
+	return &PublicAPI{
+		logger: logger.With("module", "txpool"),
+	}
+}
+
+// Content returns the transactions contained within the transaction pool
+func (api *PublicAPI) Content() (map[string]map[string]map[string]*types.RPCTransaction, error) {
+	api.logger.Debug("txpool_content")
+	content := map[string]map[string]map[string]*types.RPCTransaction{
+		"pending": make(map[string]map[string]*types.RPCTransaction),
+		"queued":  make(map[string]map[string]*types.RPCTransaction),
+	}
+	return content, nil
+}
+
+// Inspect returns the content of the transaction pool and flattens it into an
+func (api *PublicAPI) Inspect() (map[string]map[string]map[string]string, error) {
+	api.logger.Debug("txpool_inspect")
+	content := map[string]map[string]map[string]string{
+		"pending": make(map[string]map[string]string),
+		"queued":  make(map[string]map[string]string),
+	}
+	return content, nil
+}
+
+// Status returns the number of pending and queued transaction in the pool.
+func (api *PublicAPI) Status() map[string]hexutil.Uint {
+	api.logger.Debug("txpool_status")
+	return map[string]hexutil.Uint{
+		"pending": hexutil.Uint(0),
+		"queued":  hexutil.Uint(0),
+	}
+}