Change DataScan to accept Metadata and io (#581)

* Change DataScan to accept Metadata and io

For the partial deletes I want to do a scan on in
memory metadata. Changing this API allows this.

* fix name-mapping issue

---------

Co-authored-by: HonahX <[email protected]>

Author: Fokko

pyiceberg/io/pyarrow.py

@@ -159,7 +159,7 @@
 from pyiceberg.utils.truncate import truncate_upper_bound_binary_string, truncate_upper_bound_text_string
 
 if TYPE_CHECKING:
-    from pyiceberg.table import FileScanTask, Table
+    from pyiceberg.table import FileScanTask
 
 logger = logging.getLogger(__name__)
 
@@ -1046,7 +1046,8 @@ def _read_all_delete_files(fs: FileSystem, tasks: Iterable[FileScanTask]) -> Dic
 
 def project_table(
     tasks: Iterable[FileScanTask],
-    table: Table,
+    table_metadata: TableMetadata,
+    io: FileIO,
     row_filter: BooleanExpression,
     projected_schema: Schema,
     case_sensitive: bool = True,
@@ -1056,7 +1057,8 @@ def project_table(
 
     Args:
         tasks (Iterable[FileScanTask]): A URI or a path to a local file.
-        table (Table): The table that's being queried.
+        table_metadata (TableMetadata): The table metadata of the table that's being queried
+        io (FileIO): A FileIO to open streams to the object store
         row_filter (BooleanExpression): The expression for filtering rows.
         projected_schema (Schema): The output schema.
         case_sensitive (bool): Case sensitivity when looking up column names.
@@ -1065,24 +1067,24 @@ def project_table(
     Raises:
         ResolveError: When an incompatible query is done.
     """
-    scheme, netloc, _ = PyArrowFileIO.parse_location(table.location())
-    if isinstance(table.io, PyArrowFileIO):
-        fs = table.io.fs_by_scheme(scheme, netloc)
+    scheme, netloc, _ = PyArrowFileIO.parse_location(table_metadata.location)
+    if isinstance(io, PyArrowFileIO):
+        fs = io.fs_by_scheme(scheme, netloc)
     else:
         try:
             from pyiceberg.io.fsspec import FsspecFileIO
 
-            if isinstance(table.io, FsspecFileIO):
+            if isinstance(io, FsspecFileIO):
                 from pyarrow.fs import PyFileSystem
 
-                fs = PyFileSystem(FSSpecHandler(table.io.get_fs(scheme)))
+                fs = PyFileSystem(FSSpecHandler(io.get_fs(scheme)))
             else:
-                raise ValueError(f"Expected PyArrowFileIO or FsspecFileIO, got: {table.io}")
+                raise ValueError(f"Expected PyArrowFileIO or FsspecFileIO, got: {io}")
         except ModuleNotFoundError as e:
             # When FsSpec is not installed
-            raise ValueError(f"Expected PyArrowFileIO or FsspecFileIO, got: {table.io}") from e
+            raise ValueError(f"Expected PyArrowFileIO or FsspecFileIO, got: {io}") from e
 
-    bound_row_filter = bind(table.schema(), row_filter, case_sensitive=case_sensitive)
+    bound_row_filter = bind(table_metadata.schema(), row_filter, case_sensitive=case_sensitive)
 
     projected_field_ids = {
         id for id in projected_schema.field_ids if not isinstance(projected_schema.find_type(id), (MapType, ListType))
@@ -1101,7 +1103,7 @@ def project_table(
             deletes_per_file.get(task.file.file_path),
             case_sensitive,
             limit,
-            table.name_mapping(),
+            table_metadata.name_mapping(),
         )
         for task in tasks
     ]

pyiceberg/table/__init__.py

@@ -103,7 +103,6 @@
 )
 from pyiceberg.table.name_mapping import (
     NameMapping,
-    parse_mapping_from_json,
     update_mapping,
 )
 from pyiceberg.table.refs import MAIN_BRANCH, SnapshotRef
@@ -1215,7 +1214,8 @@ def scan(
         limit: Optional[int] = None,
     ) -> DataScan:
         return DataScan(
-            table=self,
+            table_metadata=self.metadata,
+            io=self.io,
             row_filter=row_filter,
             selected_fields=selected_fields,
             case_sensitive=case_sensitive,
@@ -1312,10 +1312,7 @@ def update_schema(self, allow_incompatible_changes: bool = False, case_sensitive
 
     def name_mapping(self) -> Optional[NameMapping]:
         """Return the table's field-id NameMapping."""
-        if name_mapping_json := self.properties.get(TableProperties.DEFAULT_NAME_MAPPING):
-            return parse_mapping_from_json(name_mapping_json)
-        else:
-            return None
+        return self.metadata.name_mapping()
 
     def append(self, df: pa.Table, snapshot_properties: Dict[str, str] = EMPTY_DICT) -> None:
         """
@@ -1468,7 +1465,8 @@ def _parse_row_filter(expr: Union[str, BooleanExpression]) -> BooleanExpression:
 
 
 class TableScan(ABC):
-    table: Table
+    table_metadata: TableMetadata
+    io: FileIO
     row_filter: BooleanExpression
     selected_fields: Tuple[str, ...]
     case_sensitive: bool
@@ -1478,15 +1476,17 @@ class TableScan(ABC):
 
     def __init__(
         self,
-        table: Table,
+        table_metadata: TableMetadata,
+        io: FileIO,
         row_filter: Union[str, BooleanExpression] = ALWAYS_TRUE,
         selected_fields: Tuple[str, ...] = ("*",),
         case_sensitive: bool = True,
         snapshot_id: Optional[int] = None,
         options: Properties = EMPTY_DICT,
         limit: Optional[int] = None,
     ):
-        self.table = table
+        self.table_metadata = table_metadata
+        self.io = io
         self.row_filter = _parse_row_filter(row_filter)
         self.selected_fields = selected_fields
         self.case_sensitive = case_sensitive
@@ -1496,19 +1496,20 @@ def __init__(
 
     def snapshot(self) -> Optional[Snapshot]:
         if self.snapshot_id:
-            return self.table.snapshot_by_id(self.snapshot_id)
-        return self.table.current_snapshot()
+            return self.table_metadata.snapshot_by_id(self.snapshot_id)
+        return self.table_metadata.current_snapshot()
 
     def projection(self) -> Schema:
-        current_schema = self.table.schema()
+        current_schema = self.table_metadata.schema()
         if self.snapshot_id is not None:
-            snapshot = self.table.snapshot_by_id(self.snapshot_id)
+            snapshot = self.table_metadata.snapshot_by_id(self.snapshot_id)
             if snapshot is not None:
                 if snapshot.schema_id is not None:
-                    snapshot_schema = self.table.schemas().get(snapshot.schema_id)
-                    if snapshot_schema is not None:
-                        current_schema = snapshot_schema
-                    else:
+                    try:
+                        current_schema = next(
+                            schema for schema in self.table_metadata.schemas if schema.schema_id == snapshot.schema_id
+                        )
+                    except StopIteration:
                         warnings.warn(f"Metadata does not contain schema with id: {snapshot.schema_id}")
             else:
                 raise ValueError(f"Snapshot not found: {self.snapshot_id}")
@@ -1534,7 +1535,7 @@ def update(self: S, **overrides: Any) -> S:
     def use_ref(self: S, name: str) -> S:
         if self.snapshot_id:
             raise ValueError(f"Cannot override ref, already set snapshot id={self.snapshot_id}")
-        if snapshot := self.table.snapshot_by_name(name):
+        if snapshot := self.table_metadata.snapshot_by_name(name):
             return self.update(snapshot_id=snapshot.snapshot_id)
 
         raise ValueError(f"Cannot scan unknown ref={name}")
@@ -1626,33 +1627,21 @@ def _match_deletes_to_data_file(data_entry: ManifestEntry, positional_delete_ent
 
 
 class DataScan(TableScan):
-    def __init__(
-        self,
-        table: Table,
-        row_filter: Union[str, BooleanExpression] = ALWAYS_TRUE,
-        selected_fields: Tuple[str, ...] = ("*",),
-        case_sensitive: bool = True,
-        snapshot_id: Optional[int] = None,
-        options: Properties = EMPTY_DICT,
-        limit: Optional[int] = None,
-    ):
-        super().__init__(table, row_filter, selected_fields, case_sensitive, snapshot_id, options, limit)
-
     def _build_partition_projection(self, spec_id: int) -> BooleanExpression:
-        project = inclusive_projection(self.table.schema(), self.table.specs()[spec_id])
+        project = inclusive_projection(self.table_metadata.schema(), self.table_metadata.specs()[spec_id])
         return project(self.row_filter)
 
     @cached_property
     def partition_filters(self) -> KeyDefaultDict[int, BooleanExpression]:
         return KeyDefaultDict(self._build_partition_projection)
 
     def _build_manifest_evaluator(self, spec_id: int) -> Callable[[ManifestFile], bool]:
-        spec = self.table.specs()[spec_id]
-        return manifest_evaluator(spec, self.table.schema(), self.partition_filters[spec_id], self.case_sensitive)
+        spec = self.table_metadata.specs()[spec_id]
+        return manifest_evaluator(spec, self.table_metadata.schema(), self.partition_filters[spec_id], self.case_sensitive)
 
     def _build_partition_evaluator(self, spec_id: int) -> Callable[[DataFile], bool]:
-        spec = self.table.specs()[spec_id]
-        partition_type = spec.partition_type(self.table.schema())
+        spec = self.table_metadata.specs()[spec_id]
+        partition_type = spec.partition_type(self.table_metadata.schema())
         partition_schema = Schema(*partition_type.fields)
         partition_expr = self.partition_filters[spec_id]
 
@@ -1687,16 +1676,14 @@ def plan_files(self) -> Iterable[FileScanTask]:
         if not snapshot:
             return iter([])
 
-        io = self.table.io
-
         # step 1: filter manifests using partition summaries
         # the filter depends on the partition spec used to write the manifest file, so create a cache of filters for each spec id
 
         manifest_evaluators: Dict[int, Callable[[ManifestFile], bool]] = KeyDefaultDict(self._build_manifest_evaluator)
 
         manifests = [
             manifest_file
-            for manifest_file in snapshot.manifests(io)
+            for manifest_file in snapshot.manifests(self.io)
             if manifest_evaluators[manifest_file.partition_spec_id](manifest_file)
         ]
 
@@ -1705,7 +1692,7 @@ def plan_files(self) -> Iterable[FileScanTask]:
 
         partition_evaluators: Dict[int, Callable[[DataFile], bool]] = KeyDefaultDict(self._build_partition_evaluator)
         metrics_evaluator = _InclusiveMetricsEvaluator(
-            self.table.schema(), self.row_filter, self.case_sensitive, self.options.get("include_empty_files") == "true"
+            self.table_metadata.schema(), self.row_filter, self.case_sensitive, self.options.get("include_empty_files") == "true"
         ).eval
 
         min_data_sequence_number = _min_data_file_sequence_number(manifests)
@@ -1719,7 +1706,7 @@ def plan_files(self) -> Iterable[FileScanTask]:
                 lambda args: _open_manifest(*args),
                 [
                     (
-                        io,
+                        self.io,
                         manifest,
                         partition_evaluators[manifest.partition_spec_id],
                         metrics_evaluator,
@@ -1755,7 +1742,8 @@ def to_arrow(self) -> pa.Table:
 
         return project_table(
             self.plan_files(),
-            self.table,
+            self.table_metadata,
+            self.io,
             self.row_filter,
             self.projection(),
             case_sensitive=self.case_sensitive,

pyiceberg/table/metadata.py

@@ -35,6 +35,7 @@
 from pyiceberg.exceptions import ValidationError
 from pyiceberg.partitioning import PARTITION_FIELD_ID_START, PartitionSpec, assign_fresh_partition_spec_ids
 from pyiceberg.schema import Schema, assign_fresh_schema_ids
+from pyiceberg.table.name_mapping import NameMapping, parse_mapping_from_json
 from pyiceberg.table.refs import MAIN_BRANCH, SnapshotRef, SnapshotRefType
 from pyiceberg.table.snapshots import MetadataLogEntry, Snapshot, SnapshotLogEntry
 from pyiceberg.table.sorting import (
@@ -237,6 +238,13 @@ def schema(self) -> Schema:
         """Return the schema for this table."""
         return next(schema for schema in self.schemas if schema.schema_id == self.current_schema_id)
 
+    def name_mapping(self) -> Optional[NameMapping]:
+        """Return the table's field-id NameMapping."""
+        if name_mapping_json := self.properties.get("schema.name-mapping.default"):
+            return parse_mapping_from_json(name_mapping_json)
+        else:
+            return None
+
     def spec(self) -> PartitionSpec:
         """Return the partition spec of this table."""
         return next(spec for spec in self.partition_specs if spec.spec_id == self.default_spec_id)
@@ -278,6 +286,12 @@ def new_snapshot_id(self) -> int:
 
         return snapshot_id
 
+    def snapshot_by_name(self, name: str) -> Optional[Snapshot]:
+        """Return the snapshot referenced by the given name or null if no such reference exists."""
+        if ref := self.refs.get(name):
+            return self.snapshot_by_id(ref.snapshot_id)
+        return None
+
     def current_snapshot(self) -> Optional[Snapshot]:
         """Get the current snapshot for this table, or None if there is no current snapshot."""
         if self.current_snapshot_id is not None:

tests/integration/test_add_files.py

@@ -158,6 +158,9 @@ def test_add_files_to_unpartitioned_table(spark: SparkSession, session_catalog:
     for col in df.columns:
         assert df.filter(df[col].isNotNull()).count() == 5, "Expected all 5 rows to be non-null"
 
+    # check that the table can be read by pyiceberg
+    assert len(tbl.scan().to_arrow()) == 5, "Expected 5 rows"
+
 
 @pytest.mark.integration
 @pytest.mark.parametrize("format_version", [1, 2])
@@ -255,6 +258,9 @@ def test_add_files_to_unpartitioned_table_with_schema_updates(
         value_count = 1 if col == "quux" else 6
         assert df.filter(df[col].isNotNull()).count() == value_count, f"Expected {value_count} rows to be non-null"
 
+    # check that the table can be read by pyiceberg
+    assert len(tbl.scan().to_arrow()) == 6, "Expected 6 rows"
+
 
 @pytest.mark.integration
 @pytest.mark.parametrize("format_version", [1, 2])
@@ -324,6 +330,9 @@ def test_add_files_to_partitioned_table(spark: SparkSession, session_catalog: Ca
     assert [row.file_count for row in partition_rows] == [5]
     assert [(row.partition.baz, row.partition.qux_month) for row in partition_rows] == [(123, 650)]
 
+    # check that the table can be read by pyiceberg
+    assert len(tbl.scan().to_arrow()) == 5, "Expected 5 rows"
+
 
 @pytest.mark.integration
 @pytest.mark.parametrize("format_version", [1, 2])