dex: replace total difficulty with block number (#73)

In dexon, we don't "mine" and the blockchain won't and shouldn't fork, so
there is no difficulty concept, just replace it with block number.

Note: this commit only replace total difficulty related logic and code
in dex, dex/downloader package.

1 files changed, 4 insertions, 4 deletions

diff --git a/dex/protocol_test.go b/dex/protocol_test.go
index 1b380cac7..686ba372f 100644
--- a/dex/protocol_test.go
+++ b/dex/protocol_test.go
@@ -54,7 +54,7 @@ func testStatusMsgErrors(t *testing.T, protocol int) {
 	var (
 		genesis = pm.blockchain.Genesis()
 		head    = pm.blockchain.CurrentHeader()
-		td      = pm.blockchain.GetTd(head.Hash(), head.Number.Uint64())
+		number  = head.Number.Uint64()
 	)
 	defer pm.Stop()
 
@@ -68,15 +68,15 @@ func testStatusMsgErrors(t *testing.T, protocol int) {
 			wantError: errResp(ErrNoStatusMsg, "first msg has code 2 (!= 0)"),
 		},
 		{
-			code: StatusMsg, data: statusData{10, DefaultConfig.NetworkId, td, head.Hash(), genesis.Hash()},
+			code: StatusMsg, data: statusData{10, DefaultConfig.NetworkId, number, head.Hash(), genesis.Hash()},
 			wantError: errResp(ErrProtocolVersionMismatch, "10 (!= %d)", protocol),
 		},
 		{
-			code: StatusMsg, data: statusData{uint32(protocol), 999, td, head.Hash(), genesis.Hash()},
+			code: StatusMsg, data: statusData{uint32(protocol), 999, number, head.Hash(), genesis.Hash()},
 			wantError: errResp(ErrNetworkIdMismatch, "999 (!= 237)"),
 		},
 		{
-			code: StatusMsg, data: statusData{uint32(protocol), DefaultConfig.NetworkId, td, head.Hash(), common.Hash{3}},
+			code: StatusMsg, data: statusData{uint32(protocol), DefaultConfig.NetworkId, number, head.Hash(), common.Hash{3}},
 			wantError: errResp(ErrGenesisBlockMismatch, "0300000000000000 (!= %x)", genesis.Hash().Bytes()[:8]),
 		},
 	}