initial release

internal/store/store.go

@@ -0,0 +1,91 @@
+package store
+
+import (
+	"encoding/json"
+	"errors"
+	"time"
+
+	badger "github.com/dgraph-io/badger/v4"
+)
+
+type Entry struct {
+	TokenIDs  []string  `json:"token_ids"`
+	UpdatedAt time.Time `json:"updated_at"`
+}
+
+// ContractEntry stores all token ownership data for a contract
+type ContractEntry struct {
+	// Map of tokenId -> owner address (canonical)
+	TokenOwners map[string]string `json:"token_owners"`
+	UpdatedAt   time.Time         `json:"updated_at"`
+	MaxScanned  int              `json:"max_scanned"`
+}
+
+type Cache struct {
+	db *badger.DB
+}
+
+func New(dir string) (*Cache, error) {
+	opts := badger.DefaultOptions(dir)
+	opts.Logger = nil
+	db, err := badger.Open(opts)
+	if err != nil { return nil, err }
+	return &Cache{db: db}, nil
+}
+
+func (c *Cache) Close() error { return c.db.Close() }
+
+func (c *Cache) Get(key string) (*Entry, bool) {
+	var e Entry
+	err := c.db.View(func(txn *badger.Txn) error {
+		item, err := txn.Get([]byte(key))
+		if err != nil { return err }
+		return item.Value(func(v []byte) error { return json.Unmarshal(v, &e) })
+	})
+	if err != nil { return nil, false }
+	return &e, true
+}
+
+func (c *Cache) Set(key string, ids []string) error {
+	val, _ := json.Marshal(Entry{TokenIDs: ids, UpdatedAt: time.Now().UTC()})
+	return c.db.Update(func(txn *badger.Txn) error {
+		return txn.Set([]byte(key), val)
+	})
+}
+
+// SetContract stores all token ownership data for a contract
+func (c *Cache) SetContract(key string, tokenOwners map[string]string, maxScanned int) error {
+	val, _ := json.Marshal(ContractEntry{
+		TokenOwners: tokenOwners,
+		UpdatedAt:   time.Now().UTC(),
+		MaxScanned:  maxScanned,
+	})
+	return c.db.Update(func(txn *badger.Txn) error {
+		return txn.Set([]byte(key), val)
+	})
+}
+
+// GetContract retrieves contract ownership data
+func (c *Cache) GetContract(key string) (*ContractEntry, bool) {
+	var e ContractEntry
+	err := c.db.View(func(txn *badger.Txn) error {
+		item, err := txn.Get([]byte(key))
+		if err != nil { return err }
+		return item.Value(func(v []byte) error { return json.Unmarshal(v, &e) })
+	})
+	if err != nil { return nil, false }
+	return &e, true
+}
+
+func (c *Cache) Delete(key string) error {
+	return c.db.Update(func(txn *badger.Txn) error {
+		err := txn.Delete([]byte(key))
+		if errors.Is(err, badger.ErrKeyNotFound) { return nil }
+		return err
+	})
+}
+
+// DeleteContract removes contract cache entry
+func (c *Cache) DeleteContract(key string) error {
+	return c.Delete(key)
+}