Merge fe8530c into 6509bf5

blockchain/mod.go

@@ -15,7 +15,7 @@ type Block interface {
 	// GetIndex returns the index since the genesis block.
 	GetIndex() uint64
 
-	// GetHash returns the footprint of the block.
+	// GetHash returns the fingerprint of the block.
 	GetHash() []byte
 
 	// GetPayload returns the payload of the block.

blockchain/skipchain/mod_test.go

@@ -352,13 +352,14 @@ func (rand fakeRandGenerator) Read(buffer []byte) (int, error) {
 }
 
 type fakeGovernance struct {
+	viewchange.Governance
 	authority fake.CollectiveAuthority
 }
 
 func (gov fakeGovernance) GetAuthority(index uint64) (viewchange.EvolvableAuthority, error) {
 	return gov.authority, nil
 }
 
-func (gov fakeGovernance) GetChangeSet(uint64) viewchange.ChangeSet {
-	return viewchange.ChangeSet{}
+func (gov fakeGovernance) GetChangeSet(uint64) (viewchange.ChangeSet, error) {
+	return viewchange.ChangeSet{}, nil
 }

consensus/cosipbft/mod.go

@@ -136,7 +136,11 @@ func (a pbftActor) Propose(p consensus.Proposal) error {
 		return nil
 	}
 
-	changeset := a.governance.GetChangeSet(p.GetIndex() - 1)
+	changeset, err := a.governance.GetChangeSet(p.GetIndex() - 1)
+	if err != nil {
+		return xerrors.Errorf("couldn't get change set: %v", err)
+	}
+
 	changeset.Leader = leader
 
 	ctx := context.Background()
@@ -249,10 +253,15 @@ func (h handler) Hash(addr mino.Address, in proto.Message) (Digest, error) {
 				last.GetTo(), proposal.GetPreviousHash())
 		}
 
+		changeset, err := h.governance.GetChangeSet(proposal.GetIndex() - 1)
+		if err != nil {
+			return nil, xerrors.Errorf("couldn't get change set: %v", err)
+		}
+
 		forwardLink := forwardLink{
 			from:      proposal.GetPreviousHash(),
 			to:        proposal.GetHash(),
-			changeset: h.governance.GetChangeSet(proposal.GetIndex() - 1),
+			changeset: changeset,
 		}
 
 		leader := h.viewchange.Verify(proposal, authority)

consensus/cosipbft/mod_test.go

@@ -502,8 +502,8 @@ func (gov fakeGovernance) GetAuthority(index uint64) (viewchange.EvolvableAuthor
 	return gov.authority, gov.err
 }
 
-func (gov fakeGovernance) GetChangeSet(uint64) viewchange.ChangeSet {
-	return gov.changeset
+func (gov fakeGovernance) GetChangeSet(uint64) (viewchange.ChangeSet, error) {
+	return gov.changeset, nil
 }
 
 type fakeQueue struct {

consensus/viewchange/mod.go

@@ -1,8 +1,10 @@
 package viewchange
 
 import (
+	"github.com/golang/protobuf/proto"
 	"go.dedis.ch/fabric/consensus"
 	"go.dedis.ch/fabric/crypto"
+	"go.dedis.ch/fabric/encoding"
 	"go.dedis.ch/fabric/mino"
 )
 
@@ -35,22 +37,32 @@ type ChangeSet struct {
 // EvolvableAuthority is an extension of the collective authority to provide
 // primitives to append new players to it.
 type EvolvableAuthority interface {
+	encoding.Packable
 	crypto.CollectiveAuthority
 
 	// Apply must apply the change set to the collective authority. It should
 	// first remove, then add the new players.
 	Apply(ChangeSet) EvolvableAuthority
 }
 
+// AuthorityFactory is an interface to instantiate evolvable authorities.
+type AuthorityFactory interface {
+	New(crypto.CollectiveAuthority) EvolvableAuthority
+
+	FromProto(proto.Message) (EvolvableAuthority, error)
+}
+
 // Governance is an interface to get information about the collective authority
 // of a proposal.
 type Governance interface {
+	GetAuthorityFactory() AuthorityFactory
+
 	// GetAuthority must return the authority that governs the proposal at the
 	// given index. It will be used to sign the forward link to the next
 	// proposal.
 	GetAuthority(index uint64) (EvolvableAuthority, error)
 
 	// GetChangeSet must return the changes to the authority that will be
 	// applied for the proposal following the given index.
-	GetChangeSet(index uint64) ChangeSet
+	GetChangeSet(index uint64) (ChangeSet, error)
 }

docs/introduction.md

@@ -25,7 +25,7 @@ definitions of modular pieces that build a blockchain.
   of signature from multiple key pairs and it can be verified by the
   corresponding aggregate of public keys.
 
-- **footprint** - Footprint defines a digest commonly produced by a hash
+- **fingerprint** - Fingerprint defines a digest commonly produced by a hash
   algorithm that can be used to verify the integrity of some data. One example
   is the inventory page integrity to prove which instances are stored.
 
@@ -66,3 +66,6 @@ definitions of modular pieces that build a blockchain.
 
 - **skipchain** - A skipchain is a specific implementation of the blockchain
   that is using collective signings to create shortcuts between blocks.
+
+- **task** - A task is an order of execution that is stored inside a
+  transaction. It will define how the transaction will update the inventory.

encoding/mod.go

@@ -49,6 +49,12 @@ type ProtoMarshaler interface {
 	UnmarshalDynamicAny(any *any.Any) (proto.Message, error)
 }
 
+// Fingerprinter is an interface to perform fingerprinting on object.
+type Fingerprinter interface {
+	// Fingerprint writes itself to the writer in a deterministic way.
+	Fingerprint(io.Writer, ProtoMarshaler) error
+}
+
 // ProtoEncoder is a default implementation of protobug encoding/decoding.
 type ProtoEncoder struct {
 	marshaler *jsonpb.Marshaler

internal/testing/fake/mod.go

@@ -30,16 +30,28 @@ type Call struct {
 
 // Get returns the nth call ith parameter.
 func (c *Call) Get(n, i int) interface{} {
+	if c == nil {
+		return nil
+	}
+
 	return c.calls[n][i]
 }
 
 // Len returns the number of calls.
 func (c *Call) Len() int {
+	if c == nil {
+		return 0
+	}
+
 	return len(c.calls)
 }
 
 // Add adds a call to the list.
 func (c *Call) Add(args ...interface{}) {
+	if c == nil {
+		return
+	}
+
 	c.calls = append(c.calls, args)
 }
 
@@ -123,6 +135,7 @@ func (i *PublicKeyIterator) GetNext() crypto.PublicKey {
 // CollectiveAuthority is a fake implementation of the cosi.CollectiveAuthority
 // interface.
 type CollectiveAuthority struct {
+	encoding.Packable
 	crypto.CollectiveAuthority
 	addrs   []mino.Address
 	signers []crypto.AggregateSigner
@@ -379,6 +392,11 @@ func (pk PublicKey) Pack(encoding.ProtoMarshaler) (proto.Message, error) {
 	return &empty.Empty{}, pk.err
 }
 
+// String implements fmt.Stringer.
+func (pk PublicKey) String() string {
+	return "fake.PublicKey"
+}
+
 // Signer is a fake implementation of the crypto.AggregateSigner interface.
 type Signer struct {
 	crypto.AggregateSigner
@@ -489,6 +507,24 @@ func (f VerifierFactory) FromAuthority(ca crypto.CollectiveAuthority) (crypto.Ve
 	return f.verifier, f.err
 }
 
+// Counter is a helper to delay errors or actions. It can be nil without panics.
+type Counter struct {
+	Value int
+}
+
+// Done returns true when the counter reached zero.
+func (c *Counter) Done() bool {
+	return c == nil || c.Value <= 0
+}
+
+// Decrease decrements the counter.
+func (c *Counter) Decrease() {
+	if c == nil {
+		return
+	}
+	c.Value--
+}
+
 // BadPackEncoder is a fake implementation of encoding.ProtoMarshaler.
 type BadPackEncoder struct {
 	encoding.ProtoEncoder
@@ -502,10 +538,15 @@ func (e BadPackEncoder) Pack(encoding.Packable) (proto.Message, error) {
 // BadPackAnyEncoder is a fake implementation of encoding.ProtoMarshaler.
 type BadPackAnyEncoder struct {
 	encoding.ProtoEncoder
+	Counter *Counter
 }
 
 // PackAny implements encoding.ProtoMarshaler.
 func (e BadPackAnyEncoder) PackAny(encoding.Packable) (*any.Any, error) {
+	defer e.Counter.Decrease()
+	if !e.Counter.Done() {
+		return &any.Any{}, nil
+	}
 	return nil, xerrors.New("fake error")
 }
 

ledger/arc/common/mod.go

@@ -28,7 +28,7 @@ func NewAccessControlFactory() *AccessControlFactory {
 		factories: make(map[reflect.Type]arc.AccessControlFactory),
 	}
 
-	factory.Register((*darc.AccessControlProto)(nil), darc.Factory{})
+	factory.Register((*darc.AccessProto)(nil), darc.Factory{})
 
 	return factory
 }