PR comments

pyiceberg/table/puffin.py

@@ -152,27 +152,34 @@ def to_vector(self) -> dict[str, "pa.ChunkedArray"]:
 class PuffinWriter:
     _blobs: list[PuffinBlobMetadata]
     _blob_payloads: list[bytes]
+    _created_by: str | None
 
-    def __init__(self) -> None:
+    def __init__(self, created_by: str | None = None) -> None:
         self._blobs = []
         self._blob_payloads = []
+        self._created_by = created_by
 
-    def add(
+    def set_blob(
         self,
         positions: Iterable[int],
         referenced_data_file: str,
     ) -> None:
+        # We only support one blob at the moment
+        self._blobs = []
+        self._blob_payloads = []
+
         # 1. Create bitmaps from positions
         bitmaps: dict[int, BitMap] = {}
-        cardinality = 0
         for pos in positions:
-            cardinality += 1
             key = pos >> 32
             low_bits = pos & 0xFFFFFFFF
             if key not in bitmaps:
                 bitmaps[key] = BitMap()
             bitmaps[key].add(low_bits)
 
+        # Calculate the cardinality from the bitmaps
+        cardinality = sum(len(bm) for bm in bitmaps.values())
+
         # 2. Serialize bitmaps for the vector payload
         vector_payload = _serialize_bitmaps(bitmaps)
 
@@ -204,13 +211,13 @@ def add(
         self._blobs.append(
             PuffinBlobMetadata(
                 type="deletion-vector-v1",
-                fields=[],
+                fields=[2147483645], # Java INT_MAX - 2, reserved field id for deletion vectors
                 snapshot_id=-1,
                 sequence_number=-1,
-                offset=0,  # Will be set later
-                length=0,  # Will be set later
+                offset=0, # TODO: Use DeleteFileIndex data
+                length=0, # TODO: Use DeleteFileIndex data
                 properties=properties,
-                compression_codec=None,  # Explicitly None
+                compression_codec=None,
             )
         )
 
@@ -229,12 +236,15 @@ def finish(self) -> bytes:
                 updated_blobs_metadata.append(PuffinBlobMetadata(**original_metadata_dict))
                 current_offset += len(blob_payload)
 
-            footer = Footer(blobs=updated_blobs_metadata)
+            footer = Footer(
+                blobs=updated_blobs_metadata, properties={"created-by": self._created_by} if self._created_by else {}
+            )
             footer_payload_bytes = footer.model_dump_json(by_alias=True, exclude_none=True).encode("utf-8")
 
             # Final assembly
             out.write(MAGIC_BYTES)
             out.write(payload_buffer.getvalue())
+            out.write(MAGIC_BYTES)
             out.write(footer_payload_bytes)
             out.write(len(footer_payload_bytes).to_bytes(4, "little"))
             out.write((0).to_bytes(4, "little"))  # flags

tests/table/test_puffin.py

@@ -74,68 +74,55 @@ def test_map_high_vals() -> None:
 
 
 def test_puffin_round_trip() -> None:
-    # Define some deletion positions for multiple files
-    deletions1 = [10, 20, 30]
-    deletions2 = [5, (1 << 32) + 1]  # Test with a high-bit position
+    # Define some deletion positions for a file
+    deletions = [5, (1 << 32) + 1, 5]  # Test with a high-bit position and duplicate
 
-    file1_path = "path/to/data1.parquet"
-    file2_path = "path/to/data2.parquet"
+    file_path = "path/to/data.parquet"
 
     # Write the Puffin file
-    writer = PuffinWriter()
-    writer.add(positions=deletions1, referenced_data_file=file1_path)
-    writer.add(positions=deletions2, referenced_data_file=file2_path)
+    writer = PuffinWriter(created_by="my-test-app")
+    writer.set_blob(positions=deletions, referenced_data_file=file_path)
     puffin_bytes = writer.finish()
 
     # Read the Puffin file back
     reader = PuffinFile(puffin_bytes)
 
     # Assert footer metadata
-    assert len(reader.footer.blobs) == 2
-
-    blob1_meta = reader.footer.blobs[0]
-    assert blob1_meta.properties[PROPERTY_REFERENCED_DATA_FILE] == file1_path
-    assert blob1_meta.properties["cardinality"] == str(len(deletions1))
+    assert reader.footer.properties["created-by"] == "my-test-app"
+    assert len(reader.footer.blobs) == 1
 
-    blob2_meta = reader.footer.blobs[1]
-    assert blob2_meta.properties[PROPERTY_REFERENCED_DATA_FILE] == file2_path
-    assert blob2_meta.properties["cardinality"] == str(len(deletions2))
+    blob_meta = reader.footer.blobs[0]
+    assert blob_meta.properties[PROPERTY_REFERENCED_DATA_FILE] == file_path
+    assert blob_meta.properties["cardinality"] == str(len(set(deletions)))
 
     # Assert the content of deletion vectors
     read_vectors = reader.to_vector()
 
-    assert file1_path in read_vectors
-    assert file2_path in read_vectors
-
-    assert read_vectors[file1_path].to_pylist() == sorted(deletions1)
-    assert read_vectors[file2_path].to_pylist() == sorted(deletions2)
+    assert file_path in read_vectors
+    assert read_vectors[file_path].to_pylist() == sorted(list(set(deletions)))
 
 
 def test_write_and_read_puffin_file() -> None:
     writer = PuffinWriter()
-    writer.add(positions=[1, 2, 3], referenced_data_file="file1.parquet")
-    writer.add(positions=[4, 5, 6], referenced_data_file="file2.parquet")
+    writer.set_blob(positions=[1, 2, 3], referenced_data_file="file1.parquet")
+    writer.set_blob(positions=[4, 5, 6], referenced_data_file="file2.parquet")
     puffin_bytes = writer.finish()
 
     reader = PuffinFile(puffin_bytes)
 
-    assert len(reader.footer.blobs) == 2
-    blob1 = reader.footer.blobs[0]
-    blob2 = reader.footer.blobs[1]
-
-    assert blob1.properties["referenced-data-file"] == "file1.parquet"
-    assert blob1.properties["cardinality"] == "3"
-    assert blob1.type == "deletion-vector-v1"
-    assert blob1.snapshot_id == -1
-    assert blob1.sequence_number == -1
-    assert blob1.compression_codec is None
+    assert len(reader.footer.blobs) == 1
+    blob = reader.footer.blobs[0]
 
-    assert blob2.properties["referenced-data-file"] == "file2.parquet"
-    assert blob2.properties["cardinality"] == "3"
+    assert blob.properties["referenced-data-file"] == "file2.parquet"
+    assert blob.properties["cardinality"] == "3"
+    assert blob.type == "deletion-vector-v1"
+    assert blob.snapshot_id == -1
+    assert blob.sequence_number == -1
+    assert blob.compression_codec is None
 
     vectors = reader.to_vector()
-    assert len(vectors) == 2
-    assert vectors["file1.parquet"].to_pylist() == [1, 2, 3]
+    assert len(vectors) == 1
+    assert "file1.parquet" not in vectors
     assert vectors["file2.parquet"].to_pylist() == [4, 5, 6]
 
 
@@ -146,3 +133,4 @@ def test_puffin_file_with_no_blobs() -> None:
     reader = PuffinFile(puffin_bytes)
     assert len(reader.footer.blobs) == 0
     assert len(reader.to_vector()) == 0
+    assert "created-by" not in reader.footer.properties