Implement schedules

ref: eosnetworkfoundation/eos-system-contracts#136

contracts/eosio.system/include/eosio.system/eosio.system.hpp

@@ -197,6 +197,17 @@ namespace eosiosystem {
       EOSLIB_SERIALIZE( eosio_global_state4, (continuous_rate)(inflation_pay_factor)(votepay_factor) )
    };
 
+   // Defines the schedule for pre-determined annual rate changes.
+   struct [[eosio::table, eosio::contract("eosio.system")]] schedules_info {
+      time_point_sec start_time;
+      int64_t annual_rate;
+
+      uint64_t primary_key() const { return start_time.sec_since_epoch(); }
+
+      // explicit serialization macro is not necessary, used here only to improve compilation time
+      EOSLIB_SERIALIZE( schedules_info, (start_time)(annual_rate) )
+   };
+
    inline eosio::block_signing_authority convert_to_block_signing_authority( const eosio::public_key& producer_key ) {
       return eosio::block_signing_authority_v0{ .threshold = 1, .keys = {{producer_key, 1}} };
    }
@@ -329,6 +340,7 @@ namespace eosiosystem {
 
    typedef eosio::multi_index< "producers2"_n, producer_info2 > producers_table2;
 
+   typedef eosio::multi_index< "schedules"_n, schedules_info > schedules_table;
 
    typedef eosio::singleton< "global"_n, eosio_global_state >   global_state_singleton;
 
@@ -713,6 +725,7 @@ namespace eosiosystem {
          eosio_global_state2      _gstate2;
          eosio_global_state3      _gstate3;
          eosio_global_state4      _gstate4;
+         schedules_table          _schedules;
          rammarket                _rammarket;
          rex_pool_table           _rexpool;
          rex_return_pool_table    _rexretpool;
@@ -1429,6 +1442,35 @@ namespace eosiosystem {
          [[eosio::action]]
          void setinflation( int64_t annual_rate, int64_t inflation_pay_factor, int64_t votepay_factor );
 
+         /**
+          * Set the schedule for pre-determined annual rate changes.
+          *
+          * @param start_time - the time to start the schedule.
+          * @param annual_rate - the annual inflation rate of the core token supply.
+          *     (eg. For 5% Annual inflation => annual_rate=500
+          *          For 1.5% Annual inflation => annual_rate=150
+          */
+         [[eosio::action]]
+         void setschedule( const time_point_sec start_time, int64_t annual_rate );
+
+         /**
+          * Delete the schedule for pre-determined annual rate changes.
+          *
+          * @param start_time - the time to start the schedule.
+          */
+         [[eosio::action]]
+         void delschedule( const time_point_sec start_time );
+
+         /**
+          * Executes the next schedule for pre-determined annual rate changes.
+          *
+          * Start time of the schedule must be in the past.
+          *
+          * Can be executed by any account.
+          */
+         [[eosio::action]]
+         void execschedule();
+
          /**
           * Facilitates the removal of vested staked tokens from an account, ensuring that these tokens are reallocated to the system's pool.
           *
@@ -1542,6 +1584,9 @@ namespace eosiosystem {
          using cfgpowerup_action = eosio::action_wrapper<"cfgpowerup"_n, &system_contract::cfgpowerup>;
          using powerupexec_action = eosio::action_wrapper<"powerupexec"_n, &system_contract::powerupexec>;
          using powerup_action = eosio::action_wrapper<"powerup"_n, &system_contract::powerup>;
+         using execschedule_action = eosio::action_wrapper<"execschedule"_n, &system_contract::execschedule>;
+         using setschedule_action = eosio::action_wrapper<"setschedule"_n, &system_contract::setschedule>;
+         using delschedule_action = eosio::action_wrapper<"delschedule"_n, &system_contract::delschedule>;
 
       private:
          // Implementation details:
@@ -1557,6 +1602,7 @@ namespace eosiosystem {
          static eosio_global_state4 get_default_inflation_parameters();
          symbol core_symbol()const;
          void update_ram_supply();
+         bool execute_next_schedule();
 
          // defined in rex.cpp
          void runrex( uint16_t max );

contracts/eosio.system/ricardian/eosio.system.contracts.md.in

@@ -752,4 +752,40 @@ summary: 'User may powerup to reserve resources'
 icon: @ICON_BASE_URL@/@RESOURCE_ICON_URI@
 ---
 
-Users may use the powerup action to reserve resources.
+Users may use the powerup action to reserve resources.
+
+<h1 class="contract">setschedule</h1>
+
+---
+spec_version: "0.2.0"
+title: Set Annual Rate Schedule
+summary: 'Set annual rate parameters'
+icon: @ICON_BASE_URL@/@ADMIN_ICON_URI@
+---
+
+{{$action.account}} sets a pre-determined inflation schedule to adjust parameters as follows:
+
+* Start time of the schedule: {{start_time}}
+* Annual inflation rate (in units of a hundredth of a percent): {{annual_rate}}
+
+<h1 class="contract">delschedule</h1>
+
+---
+spec_version: "0.2.0"
+title: Delete Annual Rate Schedule
+summary: 'Delete annual rate schedule'
+icon: @ICON_BASE_URL@/@ADMIN_ICON_URI@
+---
+
+{{$action.account}} to delete a pre-determined inflation schedule from {{start_time}} start time.
+
+<h1 class="contract">execschedule</h1>
+
+---
+spec_version: "0.2.0"
+title: Execute Next Annual Rate Schedule
+summary: 'Execute next annual rate schedule'
+icon: @ICON_BASE_URL@/@ADMIN_ICON_URI@
+---
+
+{{$action.account}} to execute the next upcoming annual rate schedule.

contracts/eosio.system/src/eosio.system.cpp

@@ -24,6 +24,7 @@ namespace eosiosystem {
     _global2(get_self(), get_self().value),
     _global3(get_self(), get_self().value),
     _global4(get_self(), get_self().value),
+    _schedules(get_self(), get_self().value),
     _rammarket(get_self(), get_self().value),
     _rexpool(get_self(), get_self().value),
     _rexretpool(get_self(), get_self().value),
@@ -423,6 +424,52 @@ namespace eosiosystem {
       _global4.set( _gstate4, get_self() );
    }
 
+   void system_contract::setschedule( const time_point_sec start_time, int64_t annual_rate )
+   {
+      require_auth( get_self() );
+
+      check(annual_rate >= 0, "annual_rate can't be negative");
+
+      auto itr = _schedules.find( start_time.sec_since_epoch() );
+
+      if( itr == _schedules.end() ) {
+         _schedules.emplace( get_self(), [&]( auto& s ) {
+            s.start_time = start_time;
+            s.annual_rate = annual_rate;
+         });
+      } else {
+         _schedules.modify( itr, same_payer, [&]( auto& s ) {
+            check( annual_rate != s.annual_rate, "annual_rate was not modified");
+            s.annual_rate = annual_rate;
+         });
+      }
+   }
+
+   void system_contract::delschedule( const time_point_sec start_time )
+   {
+      require_auth( get_self() );
+
+      auto itr = _schedules.require_find( start_time.sec_since_epoch(), "schedule not found" );
+      _schedules.erase( itr );
+   }
+
+   void system_contract::execschedule()
+   {
+      check(execute_next_schedule(), "no schedule to execute");
+   }
+
+   bool system_contract::execute_next_schedule()
+   {
+      auto itr = _schedules.begin();
+      if ( itr->annual_rate == 0 ) return false; // row is empty
+      if ( current_time_point().sec_since_epoch() >= itr->start_time.sec_since_epoch() ) {
+         _gstate4.continuous_rate = get_continuous_rate(itr->annual_rate);
+         _schedules.erase( itr );
+         return true;
+      }
+      return false;
+   }
+
    /**
     *  Called after a new account is created. This code enforces resource-limits rules
     *  for new accounts as well as new account naming conventions.

contracts/eosio.system/src/producer_pay.cpp

@@ -76,6 +76,7 @@ namespace eosiosystem {
    void system_contract::claimrewards( const name& owner ) {
       require_auth( owner );
 
+      execute_next_schedule();
       const auto& prod = _producers.get( owner.value );
       check( prod.active(), "producer does not have an active key" );
 

tests/eosio.system_schedules_tests.cpp

@@ -0,0 +1,54 @@
+#include <boost/test/unit_test.hpp>
+
+#include "eosio.system_tester.hpp"
+
+using namespace eosio_system;
+
+BOOST_AUTO_TEST_SUITE(eosio_system_vesting_tests)
+
+BOOST_FIXTURE_TEST_CASE(set_schedules, eosio_system_tester) try {
+
+   const std::vector<account_name> accounts = { "alice"_n };
+   create_accounts_with_resources( accounts );
+   const account_name alice = accounts[0];
+
+   const uint32_t YEAR = 86400 * 365;
+   const uint32_t initial_start_time = 1577836856; // 2020-01-01T00:00
+   const time_point_sec start_time = time_point_sec(initial_start_time);
+
+   // action validation
+   BOOST_REQUIRE_EQUAL( success(), setschedule(start_time, 500) ); // 5% annual rate
+   BOOST_REQUIRE_EQUAL( wasm_assert_msg("annual_rate was not modified"), setschedule(start_time, 500) );
+   BOOST_REQUIRE_EQUAL( wasm_assert_msg("annual_rate can't be negative"), setschedule(start_time, -1) );
+   BOOST_REQUIRE_EQUAL( wasm_assert_msg("schedule not found"), delschedule(time_point_sec(0)) );
+   BOOST_REQUIRE_EQUAL( success(), setschedule(start_time, 200) ); // allow override existing schedules
+   BOOST_REQUIRE_EQUAL( success(), delschedule(start_time) );
+
+   // set 3 future schedules
+   BOOST_REQUIRE_EQUAL( success(), setschedule(time_point_sec(start_time), 200) );
+   BOOST_REQUIRE_EQUAL( success(), setschedule(time_point_sec(initial_start_time + YEAR * 4), 100) );
+   BOOST_REQUIRE_EQUAL( success(), setschedule(time_point_sec(initial_start_time + YEAR * 8), 50) );
+
+   // current state prior to first schedule
+   const double before = get_global_state4()["continuous_rate"].as_double();
+   BOOST_REQUIRE_EQUAL( before, 0.048790164169432007 ); // 5% annual rate
+   const uint32_t current_time_sec = control->pending_block_time().sec_since_epoch();
+   BOOST_REQUIRE_EQUAL( current_time_sec, initial_start_time ); // 2020-01-01T00:00
+
+   // advance to halvening schedules
+   produce_block( fc::days(365 * 4) ); // advance to year 4
+   BOOST_REQUIRE_EQUAL( control->pending_block_time().sec_since_epoch(), initial_start_time + YEAR * 4 ); // 2024-01-01T00:00
+   BOOST_REQUIRE_EQUAL( success(), execschedule(alice) );
+   BOOST_REQUIRE_EQUAL( get_global_state4()["continuous_rate"].as_double(), 0.019802627296179712 ); // 2% annual rate
+
+   produce_block( fc::days(365 * 4) ); // advanced to year 8
+   BOOST_REQUIRE_EQUAL( success(), execschedule(alice) );
+   BOOST_REQUIRE_EQUAL( get_global_state4()["continuous_rate"].as_double(), 0.0099503308531680833 ); // 1% annual rate
+
+   produce_block( fc::days(365 * 4) ); // advanced to year 12
+   BOOST_REQUIRE_EQUAL( success(), execschedule(alice) );
+   BOOST_REQUIRE_EQUAL( get_global_state4()["continuous_rate"].as_double(), 0.0049875415110390738 ); // 0.5% annual rate
+
+} FC_LOG_AND_RETHROW()
+
+BOOST_AUTO_TEST_SUITE_END()

tests/eosio.system_tester.hpp

@@ -1271,6 +1271,11 @@ class eosio_system_tester : public TESTER {
       return data.empty() ? fc::variant() : abi_ser.binary_to_variant( "eosio_global_state3", data, abi_serializer::create_yield_function(abi_serializer_max_time) );
    }
 
+   fc::variant get_global_state4() {
+      vector<char> data = get_row_by_account( config::system_account_name, config::system_account_name, "global4"_n, "global4"_n );
+      return data.empty() ? fc::variant() : abi_ser.binary_to_variant( "eosio_global_state4", data, abi_serializer::create_yield_function(abi_serializer_max_time) );
+   }
+
    fc::variant get_refund_request( name account ) {
       vector<char> data = get_row_by_account( config::system_account_name, account, "refunds"_n, account );
       return data.empty() ? fc::variant() : abi_ser.binary_to_variant( "refund_request", data, abi_serializer::create_yield_function(abi_serializer_max_time) );
@@ -1406,6 +1411,23 @@ class eosio_system_tester : public TESTER {
       );
    }
 
+   action_result setschedule( const time_point_sec start_time, int64_t annual_rate ) {
+      return push_action( "eosio"_n, "setschedule"_n, mvo()
+               ("start_time", start_time)
+               ("annual_rate",     annual_rate)
+      );
+   }
+
+   action_result delschedule( const time_point_sec start_time ) {
+      return push_action( "eosio"_n, "delschedule"_n, mvo()
+               ("start_time", start_time)
+      );
+   }
+
+   action_result execschedule( const name executor ) {
+      return push_action( executor, "execschedule"_n, mvo());
+   }
+
    abi_serializer abi_ser;
    abi_serializer token_abi_ser;
 };