beacon: move beacon-chain to geth-sharding repo (#250)

Former-commit-id: 689de6935d724226eb9125d597831d7b274d79c1 [formerly 4e0c0d671c4e6284cd33300231cc0f7aba99d314]
Former-commit-id: c3079b352bc938c12708b81cdc0130909456ea27

beacon-chain/types/state.go

@@ -0,0 +1,62 @@
+package types
+
+import (
+	"crypto/ecdsa"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+// ActiveState contains fields of current state of beacon chain,
+// it changes every block.
+type ActiveState struct {
+	Height            uint64                   // Height of the current block.
+	Randao            common.Hash              // Randao beacon state from global's point of view.
+	FfgVoterBitmask   []byte                   // FfgVoterBitmask records the validators that voted for this epoch as bitfield.
+	BalanceDeltas     []uint                   // BalanceDeltas is the deltas to validator balances.
+	PartialCrosslinks []PartialCrosslinkRecord // PartialCrosslinks records data about crosslinks in progress.
+	TotalSkipCount    uint64                   // TotalSkipCount records total number of skips to determine minimal time stamp.
+}
+
+// PartialCrosslinkRecord contains information about cross links
+// that are being put together during this epoch.
+type PartialCrosslinkRecord struct {
+	ShardID        uint16      // ShardID is the shard crosslink being made for.
+	ShardBlockHash common.Hash // ShardBlockHash is the hash of the block.
+	VoterBitmask   []byte      // VoterBitmask determines which of the eligible voters are voting for it.
+}
+
+// CrystallizedState contains fields of every epoch state,
+// it changes every epoch.
+type CrystallizedState struct {
+	ActiveValidators       []ValidatorRecord // ActiveValidators is the list of active validators.
+	QueuedValidators       []ValidatorRecord // QueuedValidators is the list of joined but not yet inducted validators.
+	ExitedValidators       []ValidatorRecord // ExitedValidators is the list of removed validators pending withdrawal.
+	CurrentShuffling       []uint16          // CurrentShuffling is hhe permutation of validators used to determine who cross-links what shard in this epoch.
+	CurrentEpoch           uint64            // CurrentEpoch is the current epoch.
+	LastJustifiedEpoch     uint64            // LastJustifiedEpoch is the last justified epoch.
+	LastFinalizedEpoch     uint64            // LastFinalizedEpoch is the last finalized epoch.
+	Dynasty                uint64            // Dynasty is the current dynasty.
+	NextShard              uint16            // NextShard is the next shard that cross-linking assignment will start from.
+	CurrentCheckpoint      common.Hash       // CurrentCheckpoint is the current FFG checkpoint.
+	CrosslinkRecords       []CrosslinkRecord // CrosslinkRecords records about the most recent crosslink for each shard.
+	TotalDeposits          uint              // TotalDeposits is the Total balance of deposits.
+	CrosslinkSeed          common.Hash       // CrosslinkSeed is used to select the committees for each shard.
+	CrosslinkSeedLastReset uint64            // CrosslinkSeedLastReset is the last epoch the crosslink seed was reset.
+}
+
+// ValidatorRecord contains information about a validator
+type ValidatorRecord struct {
+	PubKey           ecdsa.PublicKey // PubKey is the validator's public key.
+	ReturnShard      uint16          // ReturnShard is the shard balance will be sent to after withdrawal.
+	ReturnAddress    common.Address  // ReturnAddress is the address balance will be sent to after withdrawal.
+	RandaoCommitment common.Hash     // RandaoCommitment is validator's current RANDAO beacon commitment.
+	Balance          uint64          // Balance is validator's current balance.
+	SwitchDynasty    uint64          // SwitchDynasty is the dynasty where the validator can (be inducted | be removed | withdraw their balance).
+}
+
+// CrosslinkRecord contains the fields of last fully formed
+// crosslink to be submitted into the chain.
+type CrosslinkRecord struct {
+	Epoch uint64      // Epoch records the epoch the crosslink was submitted in.
+	Hash  common.Hash // Hash is the block hash.
+}