Merge branch 'slim' into currency-test-fixes

contracts/eosio.system/delegate_bandwidth.cpp

@@ -113,6 +113,26 @@ namespace eosiosystem {
                     //       r->cpu_weight.amount );
    }
 
+   /**
+    *  This action will buy an exact amount of ram and bill the payer the current market price.
+    */
+   void system_contract::buyrambytes( account_name payer, account_name receiver, uint32_t bytes ) {
+      const double system_token_supply   = eosio::token(N(eosio.token)).get_supply(eosio::symbol_type(system_token_symbol).name()).amount;
+      const double unstaked_token_supply = system_token_supply - _gstate.total_storage_stake.amount;
+
+      const double R = unstaked_token_supply;
+      const double C = _gstate.free_ram() + bytes;
+      const double F = _gstate.storage_reserve_ratio / 10000.0;
+      const double T = bytes;
+      const double ONE(1.0);
+
+      double E = -R * (ONE - std::pow( ONE + T/C, F ) );
+      
+      int64_t tokens_out = int64_t(E*1.0105);
+      print( "desired ram: ", bytes, "\n" );
+      
+      buyram( payer, receiver, asset(tokens_out) );
+   }
 
 
    /**
@@ -176,7 +196,7 @@ namespace eosiosystem {
     *  refunds the purchase price to the account. In this way there is no profit to be made through buying
     *  and selling ram.
     */
-   void system_contract::sellram( account_name account, uint64_t bytes ) {
+   void system_contract::sellram( account_name account, uint32_t bytes ) {
       user_resources_table  userres( _self, account );
       auto res_itr = userres.find( account );
       eosio_assert( res_itr != userres.end(), "no resource row" );

contracts/eosio.system/eosio.system.abi

@@ -6,6 +6,21 @@
        "fields": [
           {"name":"value", "type":"string"}
       ]
+    },{
+      "name": "buyrambytes",
+      "base": "",
+      "fields": [
+         {"name":"payer", "type":"account_name"},
+         {"name":"receiver", "type":"account_name"},
+         {"name":"bytes", "type":"uint32"}
+      ]
+    },{
+      "name": "sellram",
+      "base": "",
+      "fields": [
+         {"name":"account", "type":"account_name"},
+         {"name":"bytes", "type":"uint32"}
+      ]
     },{
       "name": "buyram",
       "base": "",
@@ -179,9 +194,17 @@
   ],
   "actions": [
     {
+      "name": "buyrambytes",
+      "type": "buyrambytes",
+      "ricardian_contract": ""
+    },{
       "name": "buyram",
       "type": "buyram",
       "ricardian_contract": ""
+    },{
+      "name": "sellram",
+      "type": "sellram",
+      "ricardian_contract": ""
     },{
       "name": "delegatebw",
       "type": "delegatebw",

contracts/eosio.system/eosio.system.cpp

@@ -38,7 +38,7 @@ EOSIO_ABI( eosiosystem::system_contract,
      (setparams)
      // delegate_bandwith.cpp
      (delegatebw)(undelegatebw)(refund)
-     (buyram)(sellram)
+     (buyram)(buyrambytes)(sellram)
      // voting.cpp
      (regproxy)(regproducer)(unregprod)(voteproducer)
      // producer_pay.cpp

contracts/eosio.system/eosio.system.hpp

@@ -156,12 +156,13 @@ namespace eosiosystem {
           * tokens will be executed.
           */
          void buyram( account_name buyer, account_name receiver, asset tokens );
+         void buyrambytes( account_name buyer, account_name receiver, uint32_t bytes );
 
          /**
           *  Reduces quota my bytes and then performs an inline transfer of tokens
           *  to receiver based upon the average purchase price of the original quota.
           */
-         void sellram( account_name receiver, uint64_t bytes );
+         void sellram( account_name receiver, uint32_t bytes );
 
          /**
           *  This action is called after the delegation-period to claim all pending

unittests/eosio.system_tests.cpp

@@ -102,6 +102,17 @@ public:
       return push_transaction( trx );
    }
 
+   action_result buyram( const account_name& payer, account_name receiver, string eosin ) {
+      return push_action( payer, N(buyram), mvo()( "payer",payer)("receiver",receiver)("quant",eosin) );
+   }
+   action_result buyrambytes( const account_name& payer, account_name receiver, uint32_t numbytes ) {
+      return push_action( payer, N(buyrambytes), mvo()( "payer",payer)("receiver",receiver)("bytes",numbytes) );
+   }
+
+   action_result sellram( const account_name& account, uint32_t numbytes ) {
+      return push_action( account, N(sellram), mvo()( "account", account)("bytes",numbytes) );
+   }
+
    action_result push_action( const account_name& signer, const action_name &name, const variant_object &data, bool auth = true ) {
          string action_type_name = abi_ser.get_action_type(name);
 
@@ -297,6 +308,9 @@ BOOST_FIXTURE_TEST_CASE( stake_unstake, eosio_system_tester ) try {
    BOOST_REQUIRE_EQUAL( asset::from_string("1000.0000 EOS"), get_balance( "alice" ) );
    BOOST_REQUIRE_EQUAL( success(), stake( "alice", "bob", "200.0000 EOS", "100.0000 EOS" ) );
    BOOST_REQUIRE_EQUAL( asset::from_string("700.0000 EOS"), get_balance( "alice" ) );
+   BOOST_REQUIRE_EQUAL( success(), buyram( "alice", "bob", "200.0000 EOS" ) );
+   BOOST_REQUIRE_EQUAL( success(), buyrambytes( "alice", "bob", 100 ) );
+   BOOST_REQUIRE_EQUAL( success(), sellram( "bob", 100 ) );