dulwich/tests/test_archive.py

# test_archive.py -- tests for archive
# Copyright (C) 2015 Jelmer Vernooij <jelmer@jelmer.uk>
#
# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
# Dulwich is dual-licensed under the Apache License, Version 2.0 and the GNU
# General Public License as published by the Free Software Foundation; version 2.0
# or (at your option) any later version. You can redistribute it and/or
# modify it under the terms of either of these two licenses.
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# You should have received a copy of the licenses; if not, see
# <http://www.gnu.org/licenses/> for a copy of the GNU General Public License
# and <http://www.apache.org/licenses/LICENSE-2.0> for a copy of the Apache
# License, Version 2.0.
#

"""Tests for archive support."""

import struct
import tarfile
from io import BytesIO
from unittest.mock import patch

from dulwich.archive import ChunkedBytesIO, tar_stream
from dulwich.object_store import MemoryObjectStore
from dulwich.objects import Blob, Tree
from dulwich.tests.utils import build_commit_graph

from . import TestCase


class ArchiveTests(TestCase):
    def test_empty(self) -> None:
        store = MemoryObjectStore()
        _c1, _c2, c3 = build_commit_graph(store, [[1], [2, 1], [3, 1, 2]])
        tree = store[c3.tree]
        stream = b"".join(tar_stream(store, tree, 10))
        out = BytesIO(stream)
        tf = tarfile.TarFile(fileobj=out)
        self.addCleanup(tf.close)
        self.assertEqual([], tf.getnames())

    def _get_example_tar_stream(
        self, mtime: int, prefix: bytes = b"", format: str = ""
    ) -> BytesIO:
        store = MemoryObjectStore()
        b1 = Blob.from_string(b"somedata")
        store.add_object(b1)
        t1 = Tree()
        t1.add(b"somename", 0o100644, b1.id)
        store.add_object(t1)
        stream = b"".join(tar_stream(store, t1, mtime, prefix, format))
        return BytesIO(stream)

    def test_simple(self) -> None:
        stream = self._get_example_tar_stream(mtime=0)
        tf = tarfile.TarFile(fileobj=stream)
        self.addCleanup(tf.close)
        self.assertEqual(["somename"], tf.getnames())

    def test_unicode(self) -> None:
        store = MemoryObjectStore()
        b1 = Blob.from_string(b"somedata")
        store.add_object(b1)
        t1 = Tree()
        t1.add("ő".encode(), 0o100644, b1.id)
        store.add_object(t1)
        stream = b"".join(tar_stream(store, t1, mtime=0))
        tf = tarfile.TarFile(fileobj=BytesIO(stream))
        self.addCleanup(tf.close)
        self.assertEqual(["ő"], tf.getnames())

    def test_prefix(self) -> None:
        stream = self._get_example_tar_stream(mtime=0, prefix=b"blah")
        tf = tarfile.TarFile(fileobj=stream)
        self.addCleanup(tf.close)
        self.assertEqual(["blah/somename"], tf.getnames())

    def test_gzip_mtime(self) -> None:
        stream = self._get_example_tar_stream(mtime=1234, format="gz")
        expected_mtime = struct.pack("<L", 1234)
        self.assertEqual(stream.getvalue()[4:8], expected_mtime)

    def test_same_file(self) -> None:
        contents: list[bytes | None] = [None, None]
        for format in ["", "gz", "bz2"]:
            for i in [0, 1]:
                with patch("time.time", return_value=i):
                    stream = self._get_example_tar_stream(mtime=0, format=format)
                    contents[i] = stream.getvalue()
            self.assertEqual(
                contents[0],
                contents[1],
                f"Different file contents for format {format!r}",
            )

    def test_tar_stream_with_directory(self) -> None:
        """Test tar_stream with a tree containing directories."""
        store = MemoryObjectStore()

        # Create a blob for a file
        b1 = Blob.from_string(b"file in subdir")
        store.add_object(b1)

        # Create a subtree
        subtree = Tree()
        subtree.add(b"file.txt", 0o100644, b1.id)
        store.add_object(subtree)

        # Create root tree with a directory
        root_tree = Tree()
        root_tree.add(b"subdir", 0o040000, subtree.id)
        store.add_object(root_tree)

        # Generate tar stream
        stream = b"".join(tar_stream(store, root_tree, 0))
        tf = tarfile.TarFile(fileobj=BytesIO(stream))
        self.addCleanup(tf.close)

        # Should contain the file in the subdirectory
        self.assertEqual(["subdir/file.txt"], tf.getnames())

    def test_tar_stream_with_submodule(self) -> None:
        """Test tar_stream handles missing objects (submodules) gracefully."""
        store = MemoryObjectStore()

        # Create a tree with an entry that doesn't exist in the store
        # (simulating a submodule reference)
        root_tree = Tree()
        # Use a valid hex SHA (40 hex chars = 20 bytes)
        nonexistent_sha = b"a" * 40
        root_tree.add(b"submodule", 0o160000, nonexistent_sha)
        store.add_object(root_tree)

        # Should not raise, just skip the missing entry
        stream = b"".join(tar_stream(store, root_tree, 0))
        tf = tarfile.TarFile(fileobj=BytesIO(stream))
        self.addCleanup(tf.close)

        # Submodule should be skipped
        self.assertEqual([], tf.getnames())


class ChunkedBytesIOTests(TestCase):
    """Tests for ChunkedBytesIO class."""

    def test_read_all(self) -> None:
        """Test reading all bytes from ChunkedBytesIO."""
        chunks = [b"hello", b" ", b"world"]
        chunked = ChunkedBytesIO(chunks)

        result = chunked.read()
        self.assertEqual(b"hello world", result)

    def test_read_with_limit(self) -> None:
        """Test reading limited bytes from ChunkedBytesIO."""
        chunks = [b"hello", b" ", b"world"]
        chunked = ChunkedBytesIO(chunks)

        # Read first 5 bytes
        result = chunked.read(5)
        self.assertEqual(b"hello", result)

        # Read next 3 bytes
        result = chunked.read(3)
        self.assertEqual(b" wo", result)

        # Read remaining
        result = chunked.read()
        self.assertEqual(b"rld", result)

    def test_read_negative_maxbytes(self) -> None:
        """Test reading with negative maxbytes reads all."""
        chunks = [b"hello", b" ", b"world"]
        chunked = ChunkedBytesIO(chunks)

        result = chunked.read(-1)
        self.assertEqual(b"hello world", result)

    def test_read_across_chunks(self) -> None:
        """Test reading across multiple chunks."""
        chunks = [b"abc", b"def", b"ghi"]
        chunked = ChunkedBytesIO(chunks)

        # Read 7 bytes (spans three chunks)
        result = chunked.read(7)
        self.assertEqual(b"abcdefg", result)

        # Read remaining
        result = chunked.read()
        self.assertEqual(b"hi", result)

    def test_read_empty_chunks(self) -> None:
        """Test reading from empty chunks list."""
        chunked = ChunkedBytesIO([])

        result = chunked.read()
        self.assertEqual(b"", result)

    def test_read_with_empty_chunks_mixed(self) -> None:
        """Test reading with some empty chunks in the list."""
        chunks = [b"hello", b"", b"world", b""]
        chunked = ChunkedBytesIO(chunks)

        result = chunked.read()
        self.assertEqual(b"helloworld", result)

    def test_read_exact_chunk_boundary(self) -> None:
        """Test reading exactly to a chunk boundary."""
        chunks = [b"abc", b"def", b"ghi"]
        chunked = ChunkedBytesIO(chunks)

        # Read exactly first chunk
        result = chunked.read(3)
        self.assertEqual(b"abc", result)

        # Read exactly second chunk
        result = chunked.read(3)
        self.assertEqual(b"def", result)

        # Read exactly third chunk
        result = chunked.read(3)
        self.assertEqual(b"ghi", result)

        # Should be at end
        result = chunked.read()
        self.assertEqual(b"", result)