Rename delegate_signature->witness_signature #147

- changed secret hash of block headers from 224 to 160 to save 16 bytes
per header which will add up to 1 MB per day in savings.

libraries/chain/db_witness_schedule.cpp

@@ -90,7 +90,7 @@ vector<witness_id_type> database::get_near_witness_schedule()const
    return result;
 }
 
-void database::update_witness_schedule(signed_block next_block)
+void database::update_witness_schedule(const signed_block& next_block)
 {
    const global_property_object& gpo = get_global_properties();
    const witness_schedule_object& wso = get(witness_schedule_id_type());
@@ -109,6 +109,7 @@ void database::update_witness_schedule(signed_block next_block)
    witness_id_type wit;
 
    const dynamic_global_property_object& dpo = get_dynamic_global_properties();
+   
    assert( dpo.random.data_size() == witness_scheduler_rng::seed_length );
    assert( witness_scheduler_rng::seed_length == wso.rng_seed.size() );
 

libraries/chain/include/graphene/chain/config.hpp

@@ -122,7 +122,7 @@
 
 // counter used to determine bits of entropy
 // must be less than or equal to secret_hash_type::data_length()
-#define GRAPHENE_RNG_SEED_LENGTH (224 / 8)
+#define GRAPHENE_RNG_SEED_LENGTH (160 / 8)
 
 /**
  * every second, the fraction of burned core asset which cycles is

libraries/chain/include/graphene/chain/database.hpp

@@ -422,7 +422,7 @@ namespace graphene { namespace chain {
          void update_withdraw_permissions();
 
          //////////////////// db_witness_schedule.cpp ////////////////////
-         void update_witness_schedule(signed_block next_block);    /// no-op except for scheduling blocks
+         void update_witness_schedule(const signed_block& next_block);    /// no-op except for scheduling blocks
 
          ///Steps performed only at maintenance intervals
          ///@{

libraries/chain/include/graphene/chain/protocol/block.hpp

@@ -42,7 +42,7 @@ namespace graphene { namespace chain {
       void                       sign( const fc::ecc::private_key& signer );
       bool                       validate_signee( const fc::ecc::public_key& expected_signee )const;
 
-      signature_type             delegate_signature;
+      signature_type             witness_signature;
    };
 
    struct signed_block : public signed_block_header
@@ -55,5 +55,5 @@ namespace graphene { namespace chain {
 
 FC_REFLECT( graphene::chain::block_header, (previous)(timestamp)(witness)
             (next_secret_hash)(previous_secret)(transaction_merkle_root)(extensions) )
-FC_REFLECT_DERIVED( graphene::chain::signed_block_header, (graphene::chain::block_header), (delegate_signature) )
+FC_REFLECT_DERIVED( graphene::chain::signed_block_header, (graphene::chain::block_header), (witness_signature) )
 FC_REFLECT_DERIVED( graphene::chain::signed_block, (graphene::chain::signed_block_header), (transactions) )

libraries/chain/include/graphene/chain/protocol/types.hpp

@@ -220,7 +220,7 @@ namespace graphene { namespace chain {
    typedef fc::sha256                                           digest_type;
    typedef fc::ecc::compact_signature                           signature_type;
    typedef safe<int64_t>                                        share_type;
-   typedef fc::sha224                                           secret_hash_type;
+   typedef fc::ripemd160                                        secret_hash_type;
    typedef uint16_t                                             weight_type;
 
    /**

libraries/chain/include/graphene/chain/witness_schedule_object.hpp

@@ -56,7 +56,7 @@ class witness_schedule_object : public abstract_object<witness_schedule_object>
       witness_scheduler scheduler;
       uint32_t last_scheduling_block;
       uint64_t slots_since_genesis = 0;
-      fc::array< char, GRAPHENE_RNG_SEED_LENGTH > rng_seed;
+      fc::array< char, sizeof(secret_hash_type) > rng_seed;
 };
 
 } }

libraries/chain/include/graphene/chain/witness_scheduler_rng.hpp

@@ -38,7 +38,7 @@ class nullary_rng
  * The sha256_ctr_rng generates bits using SHA256 in counter (CTR)
  * mode.
  */
-template< class HashClass, int SeedLength=32 >
+template< class HashClass, int SeedLength=sizeof(secret_hash_type) >
 class hash_ctr_rng
 {
    public:

libraries/chain/protocol/block.cpp

@@ -42,12 +42,12 @@ namespace graphene { namespace chain {
 
    fc::ecc::public_key signed_block_header::signee()const
    {
-      return fc::ecc::public_key( delegate_signature, digest(), true/*enforce canonical*/ );
+      return fc::ecc::public_key( witness_signature, digest(), true/*enforce canonical*/ );
    }
 
    void signed_block_header::sign( const fc::ecc::private_key& signer )
    {
-      delegate_signature = signer.sign_compact( digest() );
+      witness_signature = signer.sign_compact( digest() );
    }
 
    bool signed_block_header::validate_signee( const fc::ecc::public_key& expected_signee )const