Merge pull request #38 from tidesdb/v0-9-0

extend api with column family clone method and transaction reset capa…

Author: guycipher

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "tidesdb"
-version = "0.8.0"
+version = "0.9.0"
 description = "Official Python bindings for TidesDB - A high-performance embedded key-value storage engine"
 readme = "README.md"
 requires-python = ">=3.10"

src/tidesdb/tidesdb.py

@@ -377,6 +377,12 @@ class _CCacheStats(Structure):
 _lib.tidesdb_rename_column_family.argtypes = [c_void_p, c_char_p, c_char_p]
 _lib.tidesdb_rename_column_family.restype = c_int
 
+_lib.tidesdb_clone_column_family.argtypes = [c_void_p, c_char_p, c_char_p]
+_lib.tidesdb_clone_column_family.restype = c_int
+
+_lib.tidesdb_txn_reset.argtypes = [c_void_p, c_int]
+_lib.tidesdb_txn_reset.restype = c_int
+
 _lib.tidesdb_cf_update_runtime_config.argtypes = [c_void_p, POINTER(_CColumnFamilyConfig), c_int]
 _lib.tidesdb_cf_update_runtime_config.restype = c_int
 
@@ -915,6 +921,28 @@ def rollback(self) -> None:
         if result != TDB_SUCCESS:
             raise TidesDBError.from_code(result, "failed to rollback transaction")
 
+    def reset(self, isolation: IsolationLevel = IsolationLevel.READ_COMMITTED) -> None:
+        """
+        Reset a committed or aborted transaction for reuse with a new isolation level.
+
+        This avoids the overhead of freeing and reallocating transaction resources
+        in hot loops. The transaction must be committed or rolled back before reset.
+
+        Args:
+            isolation: New isolation level for the reset transaction
+
+        Raises:
+            TidesDBError: If transaction is still active (not committed/aborted)
+        """
+        if self._closed:
+            raise TidesDBError("Transaction is closed")
+
+        result = _lib.tidesdb_txn_reset(self._txn, int(isolation))
+        if result != TDB_SUCCESS:
+            raise TidesDBError.from_code(result, "failed to reset transaction")
+
+        self._committed = False
+
     def savepoint(self, name: str) -> None:
         """Create a savepoint within the transaction."""
         if self._closed:
@@ -1295,6 +1323,30 @@ def rename_column_family(self, old_name: str, new_name: str) -> None:
         if result != TDB_SUCCESS:
             raise TidesDBError.from_code(result, "failed to rename column family")
 
+    def clone_column_family(self, source_name: str, dest_name: str) -> None:
+        """
+        Create a complete copy of an existing column family with a new name.
+
+        The clone contains all the data from the source at the time of cloning.
+        The clone is completely independent - modifications to one do not affect
+        the other.
+
+        Args:
+            source_name: Name of the source column family to clone
+            dest_name: Name for the new cloned column family
+
+        Raises:
+            TidesDBError: If clone fails (e.g., source not found, dest exists)
+        """
+        if self._closed:
+            raise TidesDBError("Database is closed")
+
+        result = _lib.tidesdb_clone_column_family(
+            self._db, source_name.encode("utf-8"), dest_name.encode("utf-8")
+        )
+        if result != TDB_SUCCESS:
+            raise TidesDBError.from_code(result, "failed to clone column family")
+
     def register_comparator(
         self,
         name: str,

tests/test_tidesdb.py

@@ -320,6 +320,150 @@ def test_no_ttl(self, db, cf):
             assert value == b"value"
 
 
+class TestCloneColumnFamily:
+    """Tests for column family clone operations."""
+
+    def test_clone_column_family(self, db, cf):
+        """Test cloning a column family with data."""
+        with db.begin_txn() as txn:
+            txn.put(cf, b"key1", b"value1")
+            txn.put(cf, b"key2", b"value2")
+            txn.commit()
+
+        db.clone_column_family("test_cf", "cloned_cf")
+
+        cloned = db.get_column_family("cloned_cf")
+        assert cloned is not None
+        assert cloned.name == "cloned_cf"
+
+        with db.begin_txn() as txn:
+            assert txn.get(cloned, b"key1") == b"value1"
+            assert txn.get(cloned, b"key2") == b"value2"
+
+        db.drop_column_family("cloned_cf")
+
+    def test_clone_independence(self, db, cf):
+        """Test that clone is independent from source."""
+        with db.begin_txn() as txn:
+            txn.put(cf, b"key1", b"original")
+            txn.commit()
+
+        db.clone_column_family("test_cf", "cloned_cf")
+        cloned = db.get_column_family("cloned_cf")
+
+        with db.begin_txn() as txn:
+            txn.put(cf, b"key1", b"modified")
+            txn.commit()
+
+        with db.begin_txn() as txn:
+            assert txn.get(cloned, b"key1") == b"original"
+            assert txn.get(cf, b"key1") == b"modified"
+
+        db.drop_column_family("cloned_cf")
+
+    def test_clone_nonexistent_source(self, db):
+        """Test cloning a non-existent column family raises error."""
+        with pytest.raises(tidesdb.TidesDBError):
+            db.clone_column_family("nonexistent", "cloned_cf")
+
+    def test_clone_to_existing_name(self, db, cf):
+        """Test cloning to an already existing name raises error."""
+        db.create_column_family("existing_cf")
+        with pytest.raises(tidesdb.TidesDBError):
+            db.clone_column_family("test_cf", "existing_cf")
+        db.drop_column_family("existing_cf")
+
+    def test_clone_listed(self, db, cf):
+        """Test that cloned column family appears in list."""
+        db.clone_column_family("test_cf", "cloned_cf")
+
+        names = db.list_column_families()
+        assert "test_cf" in names
+        assert "cloned_cf" in names
+
+        db.drop_column_family("cloned_cf")
+
+
+class TestTransactionReset:
+    """Tests for transaction reset operations."""
+
+    def test_reset_after_commit(self, db, cf):
+        """Test resetting a transaction after commit."""
+        txn = db.begin_txn()
+        txn.put(cf, b"key1", b"value1")
+        txn.commit()
+
+        txn.reset(tidesdb.IsolationLevel.READ_COMMITTED)
+
+        txn.put(cf, b"key2", b"value2")
+        txn.commit()
+        txn.close()
+
+        with db.begin_txn() as txn:
+            assert txn.get(cf, b"key1") == b"value1"
+            assert txn.get(cf, b"key2") == b"value2"
+
+    def test_reset_after_rollback(self, db, cf):
+        """Test resetting a transaction after rollback."""
+        txn = db.begin_txn()
+        txn.put(cf, b"key1", b"value1")
+        txn.rollback()
+
+        txn.reset(tidesdb.IsolationLevel.READ_COMMITTED)
+
+        txn.put(cf, b"key2", b"value2")
+        txn.commit()
+        txn.close()
+
+        with db.begin_txn() as txn:
+            with pytest.raises(tidesdb.TidesDBError):
+                txn.get(cf, b"key1")
+            assert txn.get(cf, b"key2") == b"value2"
+
+    def test_reset_with_different_isolation(self, db, cf):
+        """Test resetting with a different isolation level."""
+        txn = db.begin_txn()
+        txn.put(cf, b"key1", b"value1")
+        txn.commit()
+
+        txn.reset(tidesdb.IsolationLevel.SERIALIZABLE)
+
+        txn.put(cf, b"key2", b"value2")
+        txn.commit()
+        txn.close()
+
+        with db.begin_txn() as txn:
+            assert txn.get(cf, b"key1") == b"value1"
+            assert txn.get(cf, b"key2") == b"value2"
+
+    def test_reset_reuse_loop(self, db, cf):
+        """Test resetting in a loop for batch processing."""
+        txn = db.begin_txn()
+
+        for i in range(5):
+            txn.put(cf, f"batch_key_{i}".encode(), f"batch_value_{i}".encode())
+            txn.commit()
+            if i < 4:
+                txn.reset(tidesdb.IsolationLevel.READ_COMMITTED)
+
+        txn.close()
+
+        with db.begin_txn() as txn:
+            for i in range(5):
+                value = txn.get(cf, f"batch_key_{i}".encode())
+                assert value == f"batch_value_{i}".encode()
+
+    def test_reset_closed_transaction_raises(self, db, cf):
+        """Test that resetting a closed transaction raises error."""
+        txn = db.begin_txn()
+        txn.put(cf, b"key1", b"value1")
+        txn.commit()
+        txn.close()
+
+        with pytest.raises(tidesdb.TidesDBError):
+            txn.reset(tidesdb.IsolationLevel.READ_COMMITTED)
+
+
 class TestStats:
     """Tests for statistics operations."""