add --regtest and --fixed-difficulty for regression testing

on_generateblocks RPC call combines functionality from the on_getblocktemplate and on_submitblock RPC calls to allow rapid block creation. Difficulty is set permanently to 1 for regtest.
Makes use of FAKECHAIN network type, but takes hard fork heights from mainchain
Default reserve_size in generate_blocks RPC call is now 1. If it is 0, the following error occurs 'Failed to calculate offset for'.
Queries hard fork heights info of other network types

src/rpc/core_rpc_server.cpp

@@ -1209,6 +1209,68 @@ namespace cryptonote
     return true;
   }
   //------------------------------------------------------------------------------------------------------------------------------
+  bool core_rpc_server::on_generateblocks(const COMMAND_RPC_GENERATEBLOCKS::request& req, COMMAND_RPC_GENERATEBLOCKS::response& res, epee::json_rpc::error& error_resp)
+  {
+    PERF_TIMER(on_generateblocks);
+
+    CHECK_CORE_READY();
+    
+    res.status = CORE_RPC_STATUS_OK;
+
+    if(m_core.get_nettype() != FAKECHAIN)
+    {
+      error_resp.code = CORE_RPC_ERROR_CODE_REGTEST_REQUIRED;
+      error_resp.message = "Regtest required when generating blocks";      
+      return false;
+    }
+
+    COMMAND_RPC_GETBLOCKTEMPLATE::request template_req;
+    COMMAND_RPC_GETBLOCKTEMPLATE::response template_res;
+    COMMAND_RPC_SUBMITBLOCK::request submit_req;
+    COMMAND_RPC_SUBMITBLOCK::response submit_res;
+
+    template_req.reserve_size = 1;
+    template_req.wallet_address = req.wallet_address;
+    submit_req.push_back(boost::value_initialized<std::string>());
+    res.height = m_core.get_blockchain_storage().get_current_blockchain_height();
+
+    bool r;
+
+    for(size_t i = 0; i < req.amount_of_blocks; i++)
+    {
+      r = on_getblocktemplate(template_req, template_res, error_resp);
+      res.status = template_res.status;
+      
+      if (!r) return false;
+
+      blobdata blockblob;
+      if(!string_tools::parse_hexstr_to_binbuff(template_res.blocktemplate_blob, blockblob))
+      {
+        error_resp.code = CORE_RPC_ERROR_CODE_WRONG_BLOCKBLOB;
+        error_resp.message = "Wrong block blob";
+        return false;
+      }
+      block b = AUTO_VAL_INIT(b);
+      if(!parse_and_validate_block_from_blob(blockblob, b))
+      {
+        error_resp.code = CORE_RPC_ERROR_CODE_WRONG_BLOCKBLOB;
+        error_resp.message = "Wrong block blob";
+        return false;
+      }
+      miner::find_nonce_for_given_block(b, template_res.difficulty, template_res.height);
+
+      submit_req.front() = string_tools::buff_to_hex_nodelimer(block_to_blob(b));
+      r = on_submitblock(submit_req, submit_res, error_resp);
+      res.status = submit_res.status;
+
+      if (!r) return false;
+
+      res.height = template_res.height;
+    }
+
+    return true;
+  }
+  //------------------------------------------------------------------------------------------------------------------------------
   uint64_t core_rpc_server::get_block_reward(const block& blk)
   {
     uint64_t reward = 0;

src/rpc/core_rpc_server.h

@@ -129,6 +129,7 @@ namespace cryptonote
         MAP_JON_RPC_WE("getblocktemplate",       on_getblocktemplate,           COMMAND_RPC_GETBLOCKTEMPLATE)
         MAP_JON_RPC_WE("submit_block",           on_submitblock,                COMMAND_RPC_SUBMITBLOCK)
         MAP_JON_RPC_WE("submitblock",            on_submitblock,                COMMAND_RPC_SUBMITBLOCK)
+        MAP_JON_RPC_WE_IF("generateblocks",         on_generateblocks,             COMMAND_RPC_GENERATEBLOCKS, !m_restricted)
         MAP_JON_RPC_WE("get_last_block_header",  on_get_last_block_header,      COMMAND_RPC_GET_LAST_BLOCK_HEADER)
         MAP_JON_RPC_WE("getlastblockheader",     on_get_last_block_header,      COMMAND_RPC_GET_LAST_BLOCK_HEADER)
         MAP_JON_RPC_WE("get_block_header_by_hash", on_get_block_header_by_hash,   COMMAND_RPC_GET_BLOCK_HEADER_BY_HASH)
@@ -196,6 +197,7 @@ namespace cryptonote
     bool on_getblockhash(const COMMAND_RPC_GETBLOCKHASH::request& req, COMMAND_RPC_GETBLOCKHASH::response& res, epee::json_rpc::error& error_resp);
     bool on_getblocktemplate(const COMMAND_RPC_GETBLOCKTEMPLATE::request& req, COMMAND_RPC_GETBLOCKTEMPLATE::response& res, epee::json_rpc::error& error_resp);
     bool on_submitblock(const COMMAND_RPC_SUBMITBLOCK::request& req, COMMAND_RPC_SUBMITBLOCK::response& res, epee::json_rpc::error& error_resp);
+    bool on_generateblocks(const COMMAND_RPC_GENERATEBLOCKS::request& req, COMMAND_RPC_GENERATEBLOCKS::response& res, epee::json_rpc::error& error_resp);
     bool on_get_last_block_header(const COMMAND_RPC_GET_LAST_BLOCK_HEADER::request& req, COMMAND_RPC_GET_LAST_BLOCK_HEADER::response& res, epee::json_rpc::error& error_resp);
     bool on_get_block_header_by_hash(const COMMAND_RPC_GET_BLOCK_HEADER_BY_HASH::request& req, COMMAND_RPC_GET_BLOCK_HEADER_BY_HASH::response& res, epee::json_rpc::error& error_resp);
     bool on_get_block_header_by_height(const COMMAND_RPC_GET_BLOCK_HEADER_BY_HEIGHT::request& req, COMMAND_RPC_GET_BLOCK_HEADER_BY_HEIGHT::response& res, epee::json_rpc::error& error_resp);

src/rpc/core_rpc_server_commands_defs.h

@@ -1149,6 +1149,31 @@ namespace cryptonote
       END_KV_SERIALIZE_MAP()
     };
   };
+
+  struct COMMAND_RPC_GENERATEBLOCKS
+  {
+    struct request
+    {
+      uint64_t amount_of_blocks;
+      std::string wallet_address;
+
+      BEGIN_KV_SERIALIZE_MAP()
+        KV_SERIALIZE(amount_of_blocks)
+        KV_SERIALIZE(wallet_address)
+      END_KV_SERIALIZE_MAP()
+    };
+    
+    struct response
+    {
+      uint64_t height;
+      std::string status;
+      
+      BEGIN_KV_SERIALIZE_MAP()
+        KV_SERIALIZE(height)
+        KV_SERIALIZE(status)
+      END_KV_SERIALIZE_MAP()
+    };
+  };
   
   struct block_header_response
   {

src/rpc/core_rpc_server_error_codes.h

@@ -42,5 +42,6 @@
 #define CORE_RPC_ERROR_CODE_WRONG_BLOCKBLOB_SIZE  -10
 #define CORE_RPC_ERROR_CODE_UNSUPPORTED_RPC       -11
 #define CORE_RPC_ERROR_CODE_MINING_TO_SUBADDRESS  -12
+#define CORE_RPC_ERROR_CODE_REGTEST_REQUIRED      -13