From aee408086a89ff0107e112152d7e678179ed5373 Mon Sep 17 00:00:00 2001
From: Jeeyong Um <conr2d@gmail.com>
Date: Thu, 8 Nov 2018 03:24:40 +0900
Subject: [PATCH] Add support for removal of table without multi_index typedefs
 to eosio.system

---
 .../include/eosio.system/eosio.system.hpp     | 31 +++++++++++++++++++
 eosio.system/src/eosio.system.cpp             | 28 ++++++++++++++++-
 2 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/eosio.system/include/eosio.system/eosio.system.hpp b/eosio.system/include/eosio.system/eosio.system.hpp
index 32ccdce76..ca0c67416 100644
--- a/eosio.system/include/eosio.system/eosio.system.hpp
+++ b/eosio.system/include/eosio.system/eosio.system.hpp
@@ -176,6 +176,34 @@ namespace eosiosystem {
    //   static constexpr uint32_t     max_inflation_rate = 5;  // 5% annual inflation
    static constexpr uint32_t     seconds_per_day = 24 * 3600;
 
+   template <typename T>
+   int32_t remove_secondary_index( uint64_t code, uint64_t scope, uint64_t table ) {
+      using namespace eosio::_multi_index_detail;
+
+      uint64_t pk;
+
+      auto min = secondary_key_traits<T>::lowest();
+      auto itr = secondary_index_db_functions<T>::db_idx_lowerbound( code, scope, table, min, pk );
+
+      // itr == -1, no secondary index
+      // itr < -1, type mismatch
+      if( itr <= -1 ) return itr;
+
+      while( itr > -1 ) {
+         auto next_itr = secondary_index_db_functions<T>::db_idx_next( itr, &pk );
+         secondary_index_db_functions<T>::db_idx_remove( itr );
+         itr = next_itr;
+      }
+
+      // secondary index is removed
+      return 0;
+   }
+
+#define REMOVE_SECONDARY_INDEX( ITR, TYPE, CODE, SCOPE, TABLE ) \
+   ITR = remove_secondary_index<TYPE>( CODE, SCOPE, TABLE ); \
+   if ( ITR == -1 ) break; \
+   else if ( ITR == 0 ) continue;
+
    class [[eosio::contract("eosio.system")]] system_contract : public native {
       private:
          voters_table            _voters;
@@ -317,6 +345,9 @@ namespace eosiosystem {
          [[eosio::action]]
          void bidrefund( name bidder, name newname );
 
+         [[eosio::action]]
+         void removetable( name code, uint64_t scope, name table );
+
       private:
          // Implementation details:
 
diff --git a/eosio.system/src/eosio.system.cpp b/eosio.system/src/eosio.system.cpp
index eb99a2081..97089bb88 100644
--- a/eosio.system/src/eosio.system.cpp
+++ b/eosio.system/src/eosio.system.cpp
@@ -218,6 +218,32 @@ namespace eosiosystem {
       refunds_table.erase( it );
    }
 
+   void system_contract::removetable( name code, uint64_t scope, name table ) {
+      require_auth( code );
+
+      auto itr = db_end_i64( code.value, scope, table.value );
+      eosio_assert( itr != -1, "table not found" );
+
+      for( uint64_t i = 0; i < 0x10; ++i ) {
+         REMOVE_SECONDARY_INDEX( itr, uint64_t, code.value, scope, table.value | i )
+         REMOVE_SECONDARY_INDEX( itr, uint128_t, code.value, scope, table.value | i )
+         REMOVE_SECONDARY_INDEX( itr, double, code.value, scope, table.value | i )
+         REMOVE_SECONDARY_INDEX( itr, long double, code.value, scope, table.value | i )
+         REMOVE_SECONDARY_INDEX( itr, eosio::key256, code.value, scope, table.value | i )
+         //REMOVE_SECONDARY_INDEX( itr, eosio::digest256, code.value, scope, table.value | i )
+      }
+
+      uint64_t pk;
+
+      itr = db_lowerbound_i64( code.value, scope, table.value, std::numeric_limits<uint64_t>::min() );
+
+      while( itr > -1 ) {
+         auto next_itr = db_next_i64( itr, &pk );
+         db_remove_i64( itr );
+         itr = next_itr;
+      }
+   }
+
    /**
     *  Called after a new account is created. This code enforces resource-limits rules
     *  for new accounts as well as new account naming conventions.
@@ -308,7 +334,7 @@ EOSIO_DISPATCH( eosiosystem::system_contract,
      // native.hpp (newaccount definition is actually in eosio.system.cpp)
      (newaccount)(updateauth)(deleteauth)(linkauth)(unlinkauth)(canceldelay)(onerror)(setabi)
      // eosio.system.cpp
-     (init)(setram)(setramrate)(setparams)(setpriv)(setalimits)(rmvproducer)(updtrevision)(bidname)(bidrefund)
+     (init)(setram)(setramrate)(setparams)(setpriv)(setalimits)(rmvproducer)(updtrevision)(bidname)(bidrefund)(removetable)
      // delegate_bandwidth.cpp
      (buyrambytes)(buyram)(sellram)(delegatebw)(undelegatebw)(refund)
      // voting.cpp