Block

This section shows how each block is constructed and what kinds of elements are creating the block.

Block 

The below is simple blockchain structure image.

Each block has a block_id and refers a previous block_id. And each block has more than one transaction(s).
Each transaction has more than one operation(s).
Each operation has “fee” and element(s). Each operation has different elements (processes).

Block Header - inheritance 

block_header 

// *Block Header Inheritance* (i.e.) 1.0.0.0
// graphene::chain

struct block_header
{
  digest_type                   digest()const;
  block_id_type                 previous;
  uint32_t                      block_num()const { return num_from_id(previous) + 1; }
  fc::time_point_sec            timestamp;
  witness_id_type               witness;
  checksum_type                 transaction_merkle_root;
  // Note: when we need to add data to `extensions`, remember to review `database::_generate_block()`.
  //       More info in https://github.com/bitshares/bitshares-core/issues/1136
  extensions_type               extensions;

  static uint32_t num_from_id(const block_id_type& id);
};
// (11/27/2018)

Note

when we need to add data to extensions, remember to review database::_generate_block(). - More info in https://github.com/bitshares/bitshares-core/issues/1136

signed_block_header 

// *Block Header Inheritance* (i.e.) 1.1.0.0
// graphene::chain

struct signed_block_header : public block_header
{
        block_id_type        id()const;
        fc::ecc::public_key  signee()const;
        void                 sign( const fc::ecc::private_key& signer );
        bool                 validate_signee( const fc::ecc::public_key& expected_signee )const;

        signature_type       witness_signature;
};

signed_block 

// *Block Header Inheritance* (i.e.) 1.1.1.0
// graphene::chain

struct signed_block : public signed_block_header
{
        checksum_type                 calculate_merkle_root()const;
        vector<processed_transaction> transactions;
};

signed_block_with_info 

// *Block Header Inheritance* (i.e.) 1.1.1.1
// graphene::wallet

struct signed_block_with_info : public signed_block
{
        signed_block_with_info( const signed_block& block );
        signed_block_with_info( const signed_block_with_info& block ) = default;

        block_id_type                  block_id;
        public_key_type                signing_key;
        vector< transaction_id_type >  transaction_ids;
};

Block (detail image)

(**ibraries/chain/include/graphene/chain/block_database.hpp)

block_database 

    namespace graphene { namespace chain {
       struct index_entry;

       class block_database
       {
              public:
                     void open( const fc::path& dbdir );
                     bool is_open()const;
                     void flush();
                     void close();

                     void store( const block_id_type& id, const signed_block& b );
                     void remove( const block_id_type& id );

                     bool                   contains( const block_id_type& id )const;
                     block_id_type          fetch_block_id( uint32_t block_num )const;
                     optional<signed_block> fetch_optional( const block_id_type& id )const;
                     optional<signed_block> fetch_by_number( uint32_t block_num )const;
                     optional<signed_block> last()const;
                     optional<block_id_type> last_id()const;
                     size_t                 blocks_current_position()const;
                     size_t                 total_block_size()const;
              private:
                     optional<index_entry> last_index_entry()const;
                     fc::path _index_filename;
                     mutable std::fstream _blocks;
                     mutable std::fstream _block_num_to_pos;
       };
    } }
//(11/27/2018)