Progress #14: Add get_block call

Add get_block call to chain read_only api

plugins/chain_api_plugin/chain_api_plugin.cpp

@@ -29,6 +29,9 @@ void chain_api_plugin::plugin_initialize(const variables_map&) {}
              if (body.empty()) body = "{}"; \
              auto result = api_handle.call_name(fc::json::from_string(body).as<api_namespace::call_name ## _params>()); \
              cb(200, fc::json::to_string(result)); \
+          } catch (fc::eof_exception) { \
+             cb(400, "Invalid arguments"); \
+             elog("Unable to parse arguments: ${args}", ("args", body)); \
           } catch (fc::exception& e) { \
              cb(500, e.what()); \
              elog("Exception encountered while processing ${call}: ${e}", ("call", #api_name "." #call_name)("e", e)); \
@@ -39,7 +42,8 @@ void chain_api_plugin::plugin_startup() {
    auto ro_api = app().get_plugin<chain_plugin>().get_read_only_api();
 
    app().get_plugin<http_plugin>().add_api({
-      CALL(chain, ro_api, chain_apis::read_only, get_info)
+      CALL(chain, ro_api, chain_apis::read_only, get_info),
+      CALL(chain, ro_api, chain_apis::read_only, get_block)
    });
 }
 

plugins/chain_plugin/chain_plugin.cpp

@@ -159,5 +159,19 @@ read_only::get_info_results read_only::get_info(const read_only::get_info_params
    };
 }
 
+read_only::get_block_results read_only::get_block(const read_only::get_block_params& params) const {
+   try {
+      if (auto block = db.fetch_block_by_id(fc::json::from_string(params.block_num_or_id).as<chain::block_id_type>()))
+         return *block;
+   } catch (fc::bad_cast_exception) {/* do nothing */}
+   try {
+      if (auto block = db.fetch_block_by_number(fc::to_uint64(params.block_num_or_id)))
+         return *block;
+   } catch (fc::bad_cast_exception) {/* do nothing */}
+
+   FC_THROW_EXCEPTION(chain::unknown_block_exception,
+                      "Could not find block: ${block}", ("block", params.block_num_or_id));
+}
+
 } // namespace chain_apis
 } // namespace eos

plugins/chain_plugin/include/eos/chain_plugin/chain_plugin.hpp

@@ -27,6 +27,12 @@ class read_only {
       double participation_rate;
    };
    get_info_results get_info(const get_info_params&) const;
+
+   struct get_block_params {
+      string block_num_or_id;
+   };
+   using get_block_results = chain::signed_block;
+   get_block_results get_block(const get_block_params& params) const;
 };
 } // namespace chain_apis
 
@@ -65,3 +71,4 @@ FC_REFLECT(eos::chain_apis::empty, )
 FC_REFLECT(eos::chain_apis::read_only::get_info_results,
            (head_block_num)(head_block_id)(head_block_time)(head_block_producer)
            (recent_slots)(participation_rate))
+FC_REFLECT(eos::chain_apis::read_only::get_block_params, (block_num_or_id))