rdblue commented on code in PR #6933:
URL: https://github.com/apache/iceberg/pull/6933#discussion_r1117790748
##########
python/pyiceberg/table/snapshots.py:
##########
@@ -117,12 +125,369 @@ def manifests(self, io: FileIO) -> List[ManifestFile]:
return list(read_manifest_list(file))
return []
+ def added_data_files(self, io: FileIO) -> Generator[DataFile, None, None]:
+ for manifest in self.manifests(io):
+ yield from [entry.data_file for entry in
manifest.fetch_manifest_entry(io)]
+
class MetadataLogEntry(IcebergBaseModel):
metadata_file: str = Field(alias="metadata-file")
timestamp_ms: int = Field(alias="timestamp-ms")
class SnapshotLogEntry(IcebergBaseModel):
- snapshot_id: str = Field(alias="snapshot-id")
+ snapshot_id: int = Field(alias="snapshot-id")
timestamp_ms: int = Field(alias="timestamp-ms")
+
+
+def is_ancestor_of(table: "Table", snapshot_id: int, ancestor_snapshot_id:
int) -> bool:
+ """
+ Returns whether ancestor_snapshot_id is an ancestor of snapshot_id using
the given lookup function.
+
+ Args:
+ table: The table
+ snapshot_id: The snapshot id of the snapshot
+ ancestor_snapshot_id: The snapshot id of the possible ancestor
+
+ Returns:
+ True if it is an ancestor or not
+ """
+ snapshots = ancestors_of(snapshot_id, table.snapshot_by_id)
+ for snapshot in snapshots:
+ if snapshot.snapshot_id == ancestor_snapshot_id:
+ return True
+ return False
+
+
+def is_parent_ancestor_of(table: "Table", snapshot_id: int,
ancestor_parent_snapshot_id: int) -> bool:
+ """
+ Returns whether some ancestor of snapshot_id has parent_id matches
ancestor_parent_snapshot_id
+
+ Args:
+ table: The table
+ snapshot_id: The snapshot id of the snapshot
+ ancestor_parent_snapshot_id: The snapshot id of the possible parent
ancestor
+
+ Returns:
+ True if there is an ancestor with a parent
+ """
+ snapshots = ancestors_of(snapshot_id, table.snapshot_by_id)
+ for snapshot in snapshots:
+ if snapshot.parent_snapshot_id == ancestor_parent_snapshot_id:
+ return True
+ return False
+
+
+def current_ancestors(table: "Table") -> Iterable[Snapshot]:
+ """
+ Returns an iterable that traverses the table's snapshots from the current
to the last known ancestor.
+
+ Args:
+ table: The table
+
+ Returns:
+ An iterable of all the ancestors
+ """
+ if current_snapshot := table.current_snapshot():
+ return ancestors_of(current_snapshot, table.snapshot_by_id)
+ return []
+
+
+def current_ancestor_ids(table: "Table") -> Iterable[int]:
+ """
+ Return the snapshot IDs for the ancestors of the current table state.
+
+ Ancestor IDs are ordered by commit time, descending. The first ID is
+ the current snapshot, followed by its parent, and so on.
+
+ Args:
+ table: The table
+
+ Returns:
+ An iterable of all the snapshot IDs
+ """
+ if current_snapshot := table.current_snapshot():
+ return ancestor_ids(current_snapshot, table.snapshot_by_id)
+ return []
+
+
+def oldest_ancestor(table: "Table") -> Optional[Snapshot]:
+ """
+ Traverses the history of the table's current snapshot and finds the oldest
Snapshot.
+
+ Args:
+ table: The table
+
+ Returns:
+ None if there is no current snapshot in the table, else the oldest
Snapshot.
+ """
+ oldest_snapshot: Optional[Snapshot] = None
+
+ for snapshot in current_ancestors(table):
+ oldest_snapshot = snapshot
+
+ return oldest_snapshot
+
+
+def oldest_ancestor_of(table: "Table", snapshot_id: int) -> Optional[Snapshot]:
+ """
+ Traverses the history and finds the oldest ancestor of the specified
snapshot.
+
+ Oldest ancestor is defined as the ancestor snapshot whose parent is null
or has been
+ expired. If the specified snapshot has no parent or parent has been
expired, the specified
+ snapshot itself is returned.
+
+ Args:
+ table: The table
+ snapshot_id: the ID of the snapshot to find the oldest ancestor
+
+ Returns:
+ None if there is no current snapshot in the table, else the oldest
Snapshot.
+ """
+ oldest_snapshot: Optional[Snapshot] = None
+
+ for snapshot in ancestors_of(snapshot_id, table.snapshot_by_id):
+ oldest_snapshot = snapshot
+
+ return oldest_snapshot
+
+
+def oldest_ancestor_after(table: "Table", timestamp_ms: int) -> Snapshot:
+ """
+ Looks up the snapshot after a given point in time
+
+ Args:
+ table: The table
+ timestamp_ms: The timestamp in millis since the Unix epoch
+
+ Returns:
+ The snapshot after the given point in time
+
+ Raises:
+ ValueError: When there is no snapshot older than the given time
+ """
+ if last_snapshot := table.current_snapshot():
+ for snapshot in current_ancestors(table):
+ if snapshot.timestamp_ms < timestamp_ms:
+ return last_snapshot
+ elif snapshot.timestamp_ms == timestamp_ms:
+ return snapshot
+
+ last_snapshot = snapshot
+
+ if last_snapshot is not None and last_snapshot.parent_snapshot_id is
None:
+ return last_snapshot
+
+ raise ValueError(f"Cannot find snapshot older than: {timestamp_ms}")
+
+
+def snapshots_ids_between(table: "Table", from_snapshot_id: int,
to_snapshot_id: int) -> Iterable[int]:
+ """
+ Returns list of snapshot ids in the range - (fromSnapshotId, toSnapshotId]
+
+ This method assumes that fromSnapshotId is an ancestor of toSnapshotId.
+
+ Args:
+ table: The table
+ from_snapshot_id: The starting snapshot ID
+ to_snapshot_id: The ending snapshot ID
+
+ Returns:
+ The list of snapshot IDs that are between the given snapshot IDs
+ """
+
+ def lookup(snapshot_id: int) -> Optional[Snapshot]:
+ return table.snapshot_by_id(snapshot_id) if snapshot_id !=
from_snapshot_id else None
+
+ return ancestor_ids(table.snapshot_by_id(snapshot_id=to_snapshot_id),
lookup)
+
+
+def ancestor_ids(latest_snapshot: Union[int, Snapshot], lookup:
Callable[[int], Optional[Snapshot]]) -> Iterable[int]:
+ """
+ Returns list of the snapshot IDs of the ancestors
+
+ Args:
+ latest_snapshot: The snapshot where to start from
+ lookup: Lookup function to get the snapshot for the snapshot ID
+
+ Returns:
+ The list of snapshot IDs that are ancestor of the given snapshot
+ """
+
+ def get_id(snapshot: Snapshot) -> int:
+ return snapshot.snapshot_id
+
+ return map(get_id, ancestors_of(latest_snapshot, lookup))
+
+
+def ancestors_of(latest_snapshot: Union[int, Snapshot], lookup:
Callable[[int], Optional[Snapshot]]) -> Iterable[Snapshot]:
+ """
+ Returns list of snapshot that are ancestor of the given snapshot
+
+ Args:
+ latest_snapshot: The snapshot where to start from
+ lookup: Lookup function to get the snapshot for the snapshot ID
+
+ Returns:
+ The list of snapshots that are ancestor of the given snapshot
+ """
+ if isinstance(latest_snapshot, int):
+ start = lookup(latest_snapshot)
+ if start is None:
+ raise ValueError(f"Cannot find snapshot: {latest_snapshot}")
Review Comment:
I think `lookup` will probably be `table.snapshot_by_id` and this PR changes
that method to throw `ValueError` instead of returning `None`. Doesn't that
conflict? Why change the behavior of `snapshot_by_id`?
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