Refactor: slot leadership lottery (#1867)

* refactor: babe
* fix: consensus selector
* refactor: block production consensus (prepare for common code extraction)
* fix: tests
* fix: mock object leaks

Signed-off-by: Dmitriy Khaustov aka xDimon <khaustov.dm@gmail.com>

core/blockchain/impl/block_tree_impl.hpp

@@ -20,12 +20,12 @@
 #include "blockchain/block_header_repository.hpp"
 #include "blockchain/block_storage.hpp"
 #include "blockchain/block_tree_error.hpp"
+#include "consensus/babe/types/babe_configuration.hpp"
 #include "consensus/timeline/types.hpp"
 #include "crypto/hasher.hpp"
 #include "log/logger.hpp"
 #include "metrics/metrics.hpp"
 #include "network/extrinsic_observer.hpp"
-#include "primitives/babe_configuration.hpp"
 #include "primitives/event_types.hpp"
 #include "storage/trie/trie_storage.hpp"
 #include "subscription/extrinsic_event_key_repository.hpp"

core/consensus/CMakeLists.txt

@@ -4,19 +4,26 @@
 # SPDX-License-Identifier: Apache-2.0
 #
 
+add_library(consensus_common
+    block_production_error.cpp
+)
+target_link_libraries(consensus_common
+    logger
+    metrics
+)
+kagome_install(consensus_common)
+
 add_subdirectory(timeline)
 add_subdirectory(babe)
 add_subdirectory(grandpa)
-#add_subdirectory(sassafras)
 
 add_library(consensus
     validation/babe_block_validator.cpp
-    )
+)
 target_link_libraries(consensus
     timeline
     babe
-#    sassafras
     grandpa
-    )
+)
 kagome_install(consensus)
 kagome_clear_objects(consensus)

core/consensus/babe/CMakeLists.txt

@@ -10,10 +10,8 @@ add_library(babe
     impl/threshold_util.cpp
     impl/babe_lottery_impl.cpp
     impl/babe_config_repository_impl.cpp
-    impl/babe_error.cpp
-    )
+)
 target_link_libraries(babe
-    logger
-    metrics
-    )
+    consensus_common
+)
 kagome_install(babe)

core/consensus/babe/babe_config_repository.hpp

@@ -6,7 +6,7 @@
 
 #pragma once
 
-#include "primitives/babe_configuration.hpp"
+#include "consensus/babe/types/babe_configuration.hpp"
 #include "primitives/block_data.hpp"
 
 namespace kagome::consensus::babe {
@@ -16,19 +16,11 @@ namespace kagome::consensus::babe {
    public:
     virtual ~BabeConfigRepository() = default;
 
-    /// Returns the duration of a slot in milliseconds
-    /// @return the duration of a slot in milliseconds
-    virtual Duration slotDuration() const = 0;
-
-    /// @return the epoch length in slots
-    virtual EpochLength epochLength() const = 0;
-
     /// Returns the actual babe configuration
     /// @return the actual babe configuration
-    virtual outcome::result<
-        std::shared_ptr<const primitives::BabeConfiguration>>
-    config(const primitives::BlockInfo &parent_info,
-           EpochNumber epoch_number) const = 0;
+    virtual outcome::result<std::shared_ptr<const BabeConfiguration>> config(
+        const primitives::BlockInfo &parent_info,
+        EpochNumber epoch_number) const = 0;
 
     virtual void warp(const primitives::BlockInfo &block) = 0;
   };

core/consensus/babe/babe_lottery.hpp

@@ -8,74 +8,33 @@
 
 #include <optional>
 
+#include "consensus/babe/types/babe_configuration.hpp"
+#include "consensus/babe/types/slot_leadership.hpp"
 #include "consensus/timeline/types.hpp"
 #include "crypto/sr25519_types.hpp"
-#include "primitives/babe_configuration.hpp"
 
 namespace kagome::consensus::babe {
-  /**
-   * Interface for acquiring leadership information for the current Babe epoch.
-   * It is expected to be used as follows:
-   *    - first epoch is started, r (randomness) = 0
-   *    - blocks are being accepted
-   *    - when a block is finalized, submitVRFValue function is called for each
-   *      block in the finalized chain up to the last finalized one (in the
-   *      chronological order). The chain can be retrieved via calling
-   *      BlockTree::longestPath() firstly and only then BlockTree::finalize(..)
-   *    - at the end of the epoch, computeRandomness(..) is called, providing a
-   *      randomness value for the new epoch
-   *    - that value is then is used in slotsLeadership(..)
-   *
-   */
+  /// Interface for acquiring leadership information for the current Babe epoch.
   class BabeLottery {
    public:
     virtual ~BabeLottery() = default;
 
-    /**
-     * Set new epoch and corresponding randomness, threshold and keypair values
-     * @param epoch is an number of epoch where we calculate leadership
-     * @param randomness is an epoch random byte sequence
-     * @param threshold is a maximum value that is considered valid by vrf
-     * @param keypair is a current babe sign pair
-     */
-    virtual void changeEpoch(EpochNumber epoch,
-                             const Randomness &randomness,
-                             const Threshold &threshold,
-                             const crypto::Sr25519Keypair &keypair) = 0;
-
-    /**
-     * Return lottery current epoch
-     */
+    /// Return lottery current epoch
     virtual EpochNumber getEpoch() const = 0;
 
-    /**
-     * Compute leadership for the slot
-     * @param slot is a slot number
-     * @return none means the peer was not chosen as a leader
-     * for that slot, value contains VRF value and proof
-     */
-    virtual std::optional<crypto::VRFOutput> getSlotLeadership(
-        SlotNumber slot) const = 0;
-
-    /**
-     * Computes VRF proof for the slot regardless threshold.
-     * Used when secondary VRF slots are enabled
-     * @param slot is a slot number
-     * @return VRF output and proof
-     */
-    virtual crypto::VRFOutput slotVrfSignature(SlotNumber slot) const = 0;
-
-    /**
-     * Compute the expected author for secondary slot
-     * @param slot - slot to have secondary block produced
-     * @param authorities_count - quantity of authorities in current epoch
-     * @param randomness - current randomness
-     * @return - should always return some authority unless authorities list is
-     * empty
-     */
-    virtual std::optional<primitives::AuthorityIndex> secondarySlotAuthor(
-        SlotNumber slot,
-        primitives::AuthorityListSize authorities_count,
-        const Randomness &randomness) const = 0;
+    /// Changes epoch
+    /// @param epoch epoch that switch to
+    /// @param block that epoch data based on
+    /// @return true if epoch successfully switched and node validator in epoch
+    virtual bool changeEpoch(EpochNumber epoch,
+                             const primitives::BlockInfo &best_block) = 0;
+
+    /// Check slot leadership
+    /// @param block parent of block for which will produced new one if node is
+    /// slot-leader
+    /// @param slot for which leadership is checked
+    /// @return data needed for slot leadership or none
+    virtual std::optional<SlotLeadership> getSlotLeadership(
+        const primitives::BlockHash &block, SlotNumber slot) const = 0;
   };
 }  // namespace kagome::consensus::babe

core/consensus/babe/has_babe_consensus_digest.hpp

@@ -37,7 +37,7 @@ namespace kagome::consensus::babe {
         if (not babe) {
           continue;
         }
-        if (auto item = boost::get<primitives::NextEpochData>(babe)) {
+        if (auto item = boost::get<consensus::babe::EpochData>(babe)) {
           epoch = std::move(*item);
           continue;
         }
@@ -52,7 +52,7 @@ namespace kagome::consensus::babe {
       return epoch.has_value();
     }
 
-    std::optional<primitives::NextEpochData> epoch;
+    std::optional<consensus::babe::EpochData> epoch;
     std::optional<primitives::NextConfigDataV1> config;
   };
 }  // namespace kagome::consensus::babe