Refactor iterators to re-use consistent iterator interface

go.mod

@@ -9,7 +9,7 @@ require (
 	github.com/gin-gonic/gin v1.10.0
 	github.com/gobuffalo/packr/v2 v2.7.1
 	github.com/hashicorp/go-uuid v1.0.3
-	github.com/hyperledger-labs/fabric-smart-client v0.4.1-0.20250210153725-90e0fbb00133
+	github.com/hyperledger-labs/fabric-smart-client v0.4.1-0.20250214122853-be2854b10fed
 	github.com/hyperledger-labs/orion-sdk-go v0.2.10
 	github.com/hyperledger-labs/orion-server v0.2.10
 	github.com/hyperledger/fabric v1.4.0-rc1.0.20230405174026-695dd57e01c2

go.sum

@@ -1057,8 +1057,8 @@ github.com/hidal-go/hidalgo v0.0.0-20201109092204-05749a6d73df/go.mod h1:bPkrxDl
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
 github.com/huin/goupnp v1.3.0 h1:UvLUlWDNpoUdYzb2TCn+MuTWtcjXKSza2n6CBdQ0xXc=
 github.com/huin/goupnp v1.3.0/go.mod h1:gnGPsThkYa7bFi/KWmEysQRf48l2dvR5bxr2OFckNX8=
-github.com/hyperledger-labs/fabric-smart-client v0.4.1-0.20250210153725-90e0fbb00133 h1:UTyfnN+H+K9kK6TZw8ccal0+viXlf/RBHc7YiEY0XiU=
-github.com/hyperledger-labs/fabric-smart-client v0.4.1-0.20250210153725-90e0fbb00133/go.mod h1:EdiA1cY2eOOZjqPlutIlFPkueUMMJOxLoiRH5KwOW1c=
+github.com/hyperledger-labs/fabric-smart-client v0.4.1-0.20250214122853-be2854b10fed h1:KKKk7H9wKeCnJP6FR3G1X3rGOP6/PzK/rOeGvl6MAXk=
+github.com/hyperledger-labs/fabric-smart-client v0.4.1-0.20250214122853-be2854b10fed/go.mod h1:EdiA1cY2eOOZjqPlutIlFPkueUMMJOxLoiRH5KwOW1c=
 github.com/hyperledger-labs/orion-sdk-go v0.2.10 h1:lFgWgxyvngIhWnIqymYGBmtmq9D6uC5d0uLG9cbyh5s=
 github.com/hyperledger-labs/orion-sdk-go v0.2.10/go.mod h1:iN2xZB964AqwVJwL+EnwPOs8z1EkMEbbIg/qYeC7gDY=
 github.com/hyperledger-labs/orion-server v0.2.10 h1:G4zbQEL5Egk0Oj+TwHCZWdTOLDBHOjaAEvYOT4G7ozw=

integration/token/fungible/views/history.go

@@ -80,7 +80,7 @@ func (p *ListAuditedTransactionsView) Call(context view.Context) (interface{}, e
 	if err != nil {
 		return nil, errors.Wrapf(err, "failed querying transactions")
 	}
-	return ToSlice(it)
+	return collections.ToSlice(it)
 }
 
 type ListAuditedTransactionsViewFactory struct{}
@@ -123,7 +123,7 @@ func (p *ListAcceptedTransactionsView) Call(context view.Context) (interface{},
 		return nil, errors.Wrapf(err, "failed querying transactions")
 	}
 
-	return ToSlice(it)
+	return collections.ToSlice(it)
 }
 
 type ListAcceptedTransactionsViewFactory struct{}
@@ -165,18 +165,3 @@ func (p *TransactionInfoViewFactory) NewView(in []byte) (view.View, error) {
 	}
 	return f, nil
 }
-
-func ToSlice[T any](it collections.Iterator[*T]) ([]*T, error) {
-	defer it.Close()
-	var items []*T
-	for {
-		if tx, err := it.Next(); err != nil {
-			return nil, errors.Wrapf(err, "failed iterating over transactions")
-		} else if tx == nil {
-			break
-		} else {
-			items = append(items, tx)
-		}
-	}
-	return items, nil
-}

token/driver/vault.go

@@ -9,6 +9,7 @@ package driver
 import (
 	"context"
 
+	"github.com/hyperledger-labs/fabric-smart-client/platform/common/utils/collections"
 	"github.com/hyperledger-labs/fabric-token-sdk/token/token"
 )
 
@@ -32,20 +33,11 @@ const (
 
 //go:generate counterfeiter -o mock/uti.go -fake-name UnspentTokensIterator . UnspentTokensIterator
 
-type UnspentTokensIterator interface {
-	Close()
-	Next() (*token.UnspentToken, error)
-}
-
-type SpendableTokensIterator interface {
-	Close()
-	Next() (*token.UnspentTokenInWallet, error)
-}
-
-type UnsupportedTokensIterator interface {
-	Close()
-	Next() (*token.LedgerToken, error)
-}
+type (
+	UnspentTokensIterator     = collections.Iterator[*token.UnspentToken]
+	SpendableTokensIterator   = collections.Iterator[*token.UnspentTokenInWallet]
+	UnsupportedTokensIterator = collections.Iterator[*token.LedgerToken]
+)
 
 type Vault interface {
 	QueryEngine() QueryEngine

token/services/auditdb/db.go

@@ -96,29 +96,6 @@ type MovementRecord = driver.MovementRecord
 // in that action.
 type TransactionRecord = driver.TransactionRecord
 
-// TransactionIterator is an iterator over transaction records
-type TransactionIterator struct {
-	it driver.TransactionIterator
-}
-
-// Close closes the iterator. It must be called when done with the iterator.
-func (t *TransactionIterator) Close() {
-	t.it.Close()
-}
-
-// Next returns the next transaction record, if any.
-// It returns nil, nil if there are no more records.
-func (t *TransactionIterator) Next() (*TransactionRecord, error) {
-	next, err := t.it.Next()
-	if err != nil {
-		return nil, err
-	}
-	if next == nil {
-		return nil, nil
-	}
-	return next, nil
-}
-
 // QueryTransactionsParams defines the parameters for querying movements
 type QueryTransactionsParams = driver.QueryTransactionsParams
 

token/services/certifier/interactive/client.go

@@ -10,6 +10,8 @@ import (
 	"context"
 	"time"
 
+	"github.com/hyperledger-labs/fabric-smart-client/platform/common/utils/collections"
+	"github.com/hyperledger-labs/fabric-smart-client/platform/common/utils/functions"
 	"github.com/hyperledger-labs/fabric-smart-client/platform/view"
 	"github.com/hyperledger-labs/fabric-smart-client/platform/view/services/events"
 	view2 "github.com/hyperledger-labs/fabric-smart-client/platform/view/view"
@@ -143,23 +145,20 @@ func (cc *CertificationClient) Scan() error {
 	if err != nil {
 		return errors.WithMessagef(err, "failed to get an iterator over unspent tokens")
 	}
+	tokenIds := collections.Map[*token.UnspentToken, *token.ID](tokens, func(t *token.UnspentToken) (*token.ID, error) { return t.Id, nil })
+	uncertifiedTokenIds := collections.Filter(tokenIds, functions.Not(cc.certificationStorage.Exists))
+
 	defer tokens.Close()
 
 	var toBeCertified []*token.ID
 	for {
-		token, err := tokens.Next()
-		if err != nil {
+		if tokenId, err := uncertifiedTokenIds.Next(); err != nil {
 			logger.Errorf("failed to get next unspent tokens, stop here [%s]", err)
 			break
-		}
-		if token == nil {
+		} else if tokenId == nil {
 			break
-		}
-
-		// does token have a certification?
-		if !cc.certificationStorage.Exists(token.Id) {
-			// if no, batch it
-			toBeCertified = append(toBeCertified, token.Id)
+		} else {
+			toBeCertified = append(toBeCertified, tokenId)
 		}
 	}
 

token/services/db/common/checks.go

@@ -12,14 +12,18 @@ import (
 	"fmt"
 
 	"github.com/hyperledger-labs/fabric-smart-client/pkg/utils/errors"
+	"github.com/hyperledger-labs/fabric-smart-client/platform/common/utils/collections"
 	"github.com/hyperledger-labs/fabric-smart-client/platform/view/services/hash"
 	"github.com/hyperledger-labs/fabric-token-sdk/token"
 	"github.com/hyperledger-labs/fabric-token-sdk/token/services/db/driver"
+	"github.com/hyperledger-labs/fabric-token-sdk/token/services/logging"
 	"github.com/hyperledger-labs/fabric-token-sdk/token/services/network"
 	"github.com/hyperledger-labs/fabric-token-sdk/token/services/tokens"
 	token2 "github.com/hyperledger-labs/fabric-token-sdk/token/token"
 )
 
+var logger = logging.MustGetLogger("tokensdk.common-checks")
+
 type TokenTransactionDB interface {
 	GetTokenRequest(txID string) ([]byte, error)
 	Transactions(params driver.QueryTransactionsParams) (driver.TransactionIterator, error)
@@ -168,24 +172,27 @@ func (a *DefaultCheckers) checkUnspentTokens(context context.Context) ([]string,
 	if err != nil {
 		return nil, errors.WithMessagef(err, "failed querying utxo engine")
 	}
-	defer uit.Close()
-	var unspentTokenIDs []*token2.ID
-	for {
-		tok, err := uit.Next()
-		if err != nil {
-			return nil, errors.WithMessagef(err, "failed querying next unspent token")
-		}
-		if tok == nil {
-			break
+	unspentTokenIDs, err := collections.ToSlice(collections.Map(uit, func(t *token2.UnspentToken) (*token2.ID, error) {
+		if t == nil {
+			return nil, nil
 		}
-		unspentTokenIDs = append(unspentTokenIDs, tok.Id)
+		return t.Id, nil
+	}))
+
+	if err != nil {
+		return nil, errors.WithMessagef(err, "failed querying next unspent token")
 	}
 	ledgerTokenContent, err := net.QueryTokens(context, tms.Namespace(), unspentTokenIDs)
 	if err != nil {
 		errorMessages = append(errorMessages, fmt.Sprintf("failed to query tokens: [%s]", err))
 	} else {
 		if len(unspentTokenIDs) != len(ledgerTokenContent) {
-			return nil, errors.Errorf("length diffrence")
+			for _, id := range unspentTokenIDs {
+				if id != nil {
+					logger.Infof("unspent token id: [%s]", *id)
+				}
+			}
+			return nil, errors.Errorf("length difference: %d:%d", len(unspentTokenIDs), len(ledgerTokenContent))
 		}
 		index := 0
 		if err := tv.QueryEngine().GetTokenOutputs(unspentTokenIDs, func(id *token2.ID, tokenRaw []byte) error {

token/services/db/dbtest/transactions.go

@@ -15,9 +15,11 @@ import (
 	"testing"
 	"time"
 
+	"github.com/hyperledger-labs/fabric-smart-client/platform/common/utils/collections"
 	"github.com/hyperledger-labs/fabric-token-sdk/token"
 	driver2 "github.com/hyperledger-labs/fabric-token-sdk/token/driver"
 	"github.com/hyperledger-labs/fabric-token-sdk/token/services/db/driver"
+	"github.com/hyperledger-labs/fabric-token-sdk/token/services/utils/slices"
 	"github.com/test-go/testify/assert"
 )
 
@@ -389,86 +391,62 @@ func TTokenRequest(t *testing.T, db driver.TokenTransactionDB) {
 	// iterate over all
 	it, err := db.QueryTokenRequests(driver.QueryTokenRequestsParams{})
 	assert.NoError(t, err)
-	counter := 0
-	for {
-		record, err := it.Next()
-		assert.NoError(t, err)
-		if record == nil {
-			break
-		}
+	records, err := collections.ToSlice(it)
+	assert.NoError(t, err)
+
+	for _, record := range records {
 		if record.TxID == "id1" {
 			assert.Equal(t, tr1, record.TokenRequest)
 			assert.Equal(t, driver.Pending, record.Status)
-			counter++
-			continue
-		}
-		if record.TxID == "id2" {
+		} else if record.TxID == "id2" {
 			assert.Equal(t, tr2, record.TokenRequest)
 			assert.Equal(t, driver.Confirmed, record.Status)
-			counter++
-			continue
 		}
 	}
-	assert.Equal(t, 2, counter)
-	it.Close()
+	assert.Len(t, records, 2)
 
 	// iterate over pending and confirmed
 	it, err = db.QueryTokenRequests(driver.QueryTokenRequestsParams{Statuses: []driver.TxStatus{driver.Confirmed, driver.Pending}})
 	assert.NoError(t, err)
-	counter = 0
-	for {
-		record, err := it.Next()
-		assert.NoError(t, err)
-		if record == nil {
-			break
-		}
+	records, err = collections.ToSlice(it)
+	assert.NoError(t, err)
+	for _, record := range records {
 		if record.TxID == "id1" {
 			assert.Equal(t, tr1, record.TokenRequest)
 			assert.Equal(t, driver.Pending, record.Status)
-			counter++
-			continue
-		}
-		if record.TxID == "id2" {
+		} else if record.TxID == "id2" {
 			assert.Equal(t, tr2, record.TokenRequest)
 			assert.Equal(t, driver.Confirmed, record.Status)
-			counter++
-			continue
 		}
 	}
-	assert.Equal(t, 2, counter)
-	it.Close()
+	assert.Len(t, records, 2)
 
 	// iterator over confirmed
 	it, err = db.QueryTokenRequests(driver.QueryTokenRequestsParams{Statuses: []driver.TxStatus{driver.Confirmed}})
 	assert.NoError(t, err)
-	record, err := it.Next()
+	records, err = collections.ToSlice(it)
 	assert.NoError(t, err)
+	assert.Len(t, records, 1)
+	record := slices.GetUnique(records)
 	assert.Equal(t, tr2, record.TokenRequest)
 	assert.Equal(t, driver.Confirmed, record.Status)
-	record, err = it.Next()
-	assert.NoError(t, err)
-	assert.Nil(t, record)
-	it.Close()
 
 	// iterator over pending
 	it, err = db.QueryTokenRequests(driver.QueryTokenRequestsParams{Statuses: []driver.TxStatus{driver.Pending}})
 	assert.NoError(t, err)
-	record, err = it.Next()
+	records, err = collections.ToSlice(it)
 	assert.NoError(t, err)
+	assert.Len(t, records, 1)
+	record = slices.GetUnique(records)
 	assert.Equal(t, tr1, record.TokenRequest)
 	assert.Equal(t, driver.Pending, record.Status)
-	record, err = it.Next()
-	assert.NoError(t, err)
-	assert.Nil(t, record)
-	it.Close()
 
 	// iterator over deleted
 	it, err = db.QueryTokenRequests(driver.QueryTokenRequestsParams{Statuses: []driver.TxStatus{driver.Deleted}})
 	assert.NoError(t, err)
-	record, err = it.Next()
+	records, err = collections.ToSlice(it)
 	assert.NoError(t, err)
-	assert.Nil(t, record)
-	it.Close()
+	assert.Empty(t, records)
 }
 
 func TAllowsSameTxID(t *testing.T, db driver.TokenTransactionDB) {
@@ -778,16 +756,9 @@ func TTransactionQueries(t *testing.T, db driver.TokenTransactionDB) {
 func getTransactions(t *testing.T, db driver.TokenTransactionDB, params driver.QueryTransactionsParams) []*driver.TransactionRecord {
 	records, err := db.QueryTransactions(params)
 	assert.NoError(t, err)
-	defer records.Close()
-	var txs []*driver.TransactionRecord
-	for {
-		r, err := records.Next()
-		assert.NoError(t, err)
-		if r == nil {
-			return txs
-		}
-		txs = append(txs, r)
-	}
+	txs, err := collections.ToSlice(records)
+	assert.NoError(t, err)
+	return txs
 }
 
 func TValidationRecordQueries(t *testing.T, db driver.TokenTransactionDB) {
@@ -873,16 +844,9 @@ func TValidationRecordQueries(t *testing.T, db driver.TokenTransactionDB) {
 func getValidationRecords(t *testing.T, db driver.TokenTransactionDB, params driver.QueryValidationRecordsParams) []*driver.ValidationRecord {
 	records, err := db.QueryValidations(params)
 	assert.NoError(t, err)
-	defer records.Close()
-	var txs []*driver.ValidationRecord
-	for {
-		r, err := records.Next()
-		assert.NoError(t, err)
-		if r == nil {
-			return txs
-		}
-		txs = append(txs, r)
-	}
+	txs, err := collections.ToSlice(records)
+	assert.NoError(t, err)
+	return txs
 }
 
 func TEndorserAcks(t *testing.T, db driver.TokenTransactionDB) {

token/services/db/driver/identity.go

@@ -40,7 +40,7 @@ type IdentityDB interface {
 	// ConfigurationExists returns true if a configuration with the given id and type exists.
 	ConfigurationExists(id, typ, url string) (bool, error)
 	// IteratorConfigurations returns an iterator to all configurations stored
-	IteratorConfigurations(configurationType string) (Iterator[IdentityConfiguration], error)
+	IteratorConfigurations(configurationType string) (Iterator[driver.IdentityConfiguration], error)
 	// StoreIdentityData stores the passed identity and token information
 	StoreIdentityData(id []byte, identityAudit []byte, tokenMetadata []byte, tokenMetadataAudit []byte) error
 	// GetAuditInfo retrieves the audit info bounded to the given identity