feat(database): Track transaction Datum (#1053)

Signed-off-by: Akhil Repala <arepala@blinklabs.io>

Author: arepala-uml

database/datum.go

@@ -15,6 +15,9 @@
 package database
 
 import (
+	"errors"
+
+	"github.com/blinklabs-io/dingo/database/models"
 	lcommon "github.com/blinklabs-io/gouroboros/ledger/common"
 )
 
@@ -33,3 +36,26 @@ func (d *Database) SetDatum(
 	}
 	return d.metadata.SetDatum(datumHash, rawDatum, addedSlot, txn.Metadata())
 }
+
+// GetDatum retrieves a datum by its hash.
+func (d *Database) GetDatum(
+	hash []byte,
+	txn *Txn,
+) (*models.Datum, error) {
+	if len(hash) == 0 {
+		return nil, errors.New("datum not found")
+	}
+	if txn == nil {
+		txn = d.Transaction(false)
+		defer txn.Commit() //nolint:errcheck
+	}
+	tmpHash := lcommon.NewBlake2b256(hash)
+	ret, err := d.metadata.GetDatum(tmpHash, txn.Metadata())
+	if err != nil {
+		return nil, err
+	}
+	if ret == nil {
+		return nil, errors.New("datum not found")
+	}
+	return ret, nil
+}

database/plugin/metadata/sqlite/transaction.go

@@ -752,5 +752,61 @@ func (d *MetadataStoreSqlite) SetTransaction(
 		}
 	}
 
+	if err := d.storeTransactionDatums(tx, point.Slot, txn); err != nil {
+		return fmt.Errorf("store datums failed: %w", err)
+	}
+
+	return nil
+}
+
+// Traverse each utxo and check for inline datum & calls storeDatum
+func (d *MetadataStoreSqlite) storeTransactionDatums(
+	tx lcommon.Transaction,
+	slot uint64,
+	txn *gorm.DB,
+) error {
+	for _, utxo := range tx.Produced() {
+		if err := d.storeDatum(utxo.Output.Datum(), slot, txn); err != nil {
+			return err
+		}
+	}
+	witnesses := tx.Witnesses()
+	if witnesses == nil {
+		return nil
+	}
+	// Looks over the transaction witness set & store each datum.
+	for _, datum := range witnesses.PlutusData() {
+		datumCopy := datum
+		if err := d.storeDatum(&datumCopy, slot, txn); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Marshal the raw CBOR and hashes with Blake2b256Hash & calls SetDatum of metadata store.
+func (d *MetadataStoreSqlite) storeDatum(
+	datum *lcommon.Datum,
+	slot uint64,
+	txn *gorm.DB,
+) error {
+	if datum == nil {
+		return nil
+	}
+	rawDatum := datum.Cbor()
+	if len(rawDatum) == 0 {
+		var err error
+		rawDatum, err = datum.MarshalCBOR()
+		if err != nil {
+			return fmt.Errorf("marshal datum: %w", err)
+		}
+	}
+	if len(rawDatum) == 0 {
+		return nil
+	}
+	datumHash := lcommon.Blake2b256Hash(rawDatum)
+	if err := d.SetDatum(datumHash, rawDatum, slot, txn); err != nil {
+		return err
+	}
 	return nil
 }

ledger/state.go

@@ -195,6 +195,11 @@ func (ls *LedgerState) Chain() *chain.Chain {
 	return ls.chain
 }
 
+// Datum looks up a datum by hash & adding this for implementing query.ReadData #741
+func (ls *LedgerState) Datum(hash []byte) (*models.Datum, error) {
+	return ls.db.GetDatum(hash, nil)
+}
+
 func (ls *LedgerState) Close() error {
 	return ls.db.Close()
 }