[FAB-11294] Prover Service - List Tokens

This change-set does the following:
- Update prover.proto to support ListUnspentTokens command
- Implement ListUnspentTokens for Prover service
- Add transactor interface to reduce dependency on TMS

Change-Id: Ib8b9d8564933aadd85aacc05267f10ca3a1274b8
Signed-off-by: Wenjian Qiao <wenjianq@gmail.com>

protos/token/prover.proto

@@ -35,6 +35,28 @@ message RecipientTransferShare {
  uint64 quantity = 2;
 }
 
+// TokenOutput is used to specify a token returned by ListRequest
+message TokenOutput {
+ // ID is used to uniquely identify the token
+ bytes id = 1;
+
+ // Type is the type of the token
+ string type = 2;
+
+ // Quantity represents the number for this type of token
+ uint64 quantity = 3;
+}
+
+// UnspentTokens is used to hold the output of listRequest
+message UnspentTokens {
+ repeated TokenOutput tokens = 1;
+}
+
+// ListRequest is used to request a list of unspent tokens
+message ListRequest {
+ bytes credential = 1;
+}
+
 // ImportRequest is used to request creation of imports
 message ImportRequest {
  // Credential contains information about the party who is requesting the operation
@@ -82,6 +104,7 @@ message Command {
  oneof payload {
  ImportRequest import_request = 2;
  TransferRequest transfer_request = 3;
+ ListRequest list_request = 4;
  }
 }
 
@@ -109,7 +132,7 @@ message CommandResponseHeader {
  bytes creator = 3;
 }
 
-// Error reports an applicaton error
+// Error reports an application error
 message Error {
  // Message associated with this response.
  string message = 1;
@@ -127,6 +150,7 @@ message CommandResponse {
  oneof payload {
  Error err = 2;
  TokenTransaction token_transaction = 3;
+ UnspentTokens unspent_tokens = 4;
  }
 }
 

token/server/manager.go

@@ -21,3 +21,9 @@ type Manager struct {
 func (t *Manager) GetIssuer(channel string, privateCredential, publicCredential []byte) (Issuer, error) {
  return &plain.Issuer{}, nil
 }
+
+// GetTransactor returns a Transactor bound to the passed channel and whose credential
+// is the tuple (privateCredential, publicCredential).
+func (t *Manager) GetTransactor(channel string, privateCredential, publicCredential []byte) (Transactor, error) {
+ panic("not implemented yet")
+}

token/server/prover.go

@@ -55,6 +55,8 @@ func (s *Prover) ProcessCommand(ctx context.Context, sc *token.SignedCommand) (*
  switch t := command.GetPayload().(type) {
  case *token.Command_ImportRequest:
  payload, err = s.RequestImport(ctx, command.Header, t.ImportRequest)
+ case *token.Command_ListRequest:
+ payload, err = s.ListUnspentTokens(ctx, command.Header, t.ListRequest)
  default:
  err = errors.Errorf("command type not recognized: %T", t)
  }
@@ -82,6 +84,23 @@ func (s *Prover) RequestImport(ctx context.Context, header *token.Header, reques
  return &token.CommandResponse_TokenTransaction{TokenTransaction: tokenTransaction}, nil
 }
 
+func (s *Prover) ListUnspentTokens(ctxt context.Context, header *token.Header, listRequest *token.ListRequest) (*token.CommandResponse_UnspentTokens, error) {
+ trasactor, err := s.TMSManager.GetTransactor(header.ChannelId, listRequest.Credential, header.Creator)
+ if err != nil {
+ return nil, err
+ }
+
+ tokens, err := trasactor.ListUnspentTokens()
+ if err != nil {
+ return nil, err
+ }
+
+ return &token.CommandResponse_UnspentTokens{
+ UnspentTokens: &token.UnspentTokens{
+ Tokens: tokens,
+ }}, nil
+}
+
 func (s *Prover) ValidateHeader(header *token.Header) error {
  if header == nil {
  return errors.New("command header is required")