Transaction - smart contract¶

In this section, we examine how worker proposal smart contract was constructed. There are items and helpful steps to construct a smart contract. We want to list those items by examining BitShares blockchain components.

Smart contract items
- Object
- Object Index and Call
- Operations
- Validations
- Initialize Evaluators and Index
- Evaluators
- API call

Items¶

Object¶

account_object

Create Object Index and Search Call¶

class transaction_object : public abstract_object<transaction_object>

Object Index and Search Call¶

account_create_operation
signed_transaction tx; - struct signed_transaction : public transaction

Operations¶

Validations¶

tx.validate();

Initialize Evaluators and Index¶

void database::initialize_evaluators()
{
   _operation_evaluators.resize(255);
   register_evaluator<account_create_evaluator>()
   .......
}

class generic_evaluator
class op_evaluator

void database::initialize_indexes()
{
   reset_indexes();
   _undo_db.set_max_size( GRAPHENE_MIN_UNDO_HISTORY );

   .....
}


void database::init_genesis(const genesis_state_type& genesis_state)
{ try {
.....

}}

Evaluators¶

class database;
struct signed_transaction;

class transaction_evaluation_state
{
   public:
          transaction_evaluation_state( database* db = nullptr )
          :_db(db){}


          database& db()const { assert( _db ); return *_db; }
          vector<operation_result> operation_results;

          const signed_transaction*        _trx = nullptr;
          database*                        _db = nullptr;
          bool                             _is_proposed_trx = false;
          bool                             skip_fee = false;
          bool                             skip_fee_schedule_check = false;
};