S3: Add paging to list_object_versions() (#6896)

moto/s3/models.py

@@ -1820,13 +1820,19 @@ class S3Backend(BaseBackend, CloudWatchMetricProvider):
         bucket_name: str,
         delimiter: Optional[str] = None,
         key_marker: Optional[str] = None,
+        max_keys: Optional[int] = 1000,
         prefix: str = "",
-    ) -> Tuple[List[FakeKey], List[str], List[FakeDeleteMarker]]:
+        version_id_marker: Optional[str] = None,
+    ) -> Tuple[
+        List[FakeKey], List[str], List[FakeDeleteMarker], Optional[str], Optional[str]
+    ]:
         bucket = self.get_bucket(bucket_name)
 
-        common_prefixes: List[str] = []
+        common_prefixes: Set[str] = set()
         requested_versions: List[FakeKey] = []
         delete_markers: List[FakeDeleteMarker] = []
+        next_key_marker: Optional[str] = None
+        next_version_id_marker: Optional[str] = None
         all_versions = list(
             itertools.chain(
                 *(
@@ -1838,37 +1844,72 @@ class S3Backend(BaseBackend, CloudWatchMetricProvider):
         # sort by name, revert last-modified-date
         all_versions.sort(key=lambda r: (r.name, -unix_time_millis(r.last_modified)))
         last_name = None
-        for version in all_versions:
+
+        def key_or_version_match(ver: Union[FakeKey, FakeDeleteMarker]) -> bool:
+            if key_marker is None:
+                return True
+
+            if version_id_marker is None or version_id_marker == "":
+                return ver.name >= key_marker
+
+            return ver.name == key_marker and ver.version_id == version_id_marker
+
+        for version in itertools.dropwhile(
+            lambda ver: not key_or_version_match(ver),
+            all_versions,
+        ):
             name = version.name
             # guaranteed to be sorted - so the first key with this name will be the latest
             version.is_latest = name != last_name
             if version.is_latest:
                 last_name = name
-            # skip all keys that alphabetically come before keymarker
-            if key_marker and name < key_marker:
-                continue
+
             # Filter for keys that start with prefix
             if not name.startswith(prefix):
                 continue
             # separate keys that contain the same string between the prefix and the first occurrence of the delimiter
+            is_common_prefix = False
             if delimiter and delimiter in name[len(prefix) :]:
                 end_of_delimiter = (
                     len(prefix) + name[len(prefix) :].index(delimiter) + len(delimiter)
                 )
                 prefix_including_delimiter = name[0:end_of_delimiter]
-                common_prefixes.append(prefix_including_delimiter)
-                continue
 
-            # Differentiate between FakeKey and FakeDeleteMarkers
-            if not isinstance(version, FakeKey):
-                delete_markers.append(version)
-                continue
+                # Skip already-processed common prefix.
+                if prefix_including_delimiter == key_marker:
+                    continue
 
-            requested_versions.append(version)
+                common_prefixes.add(prefix_including_delimiter)
+                name = prefix_including_delimiter
+                is_common_prefix = True
 
-        common_prefixes = sorted(set(common_prefixes))
+            # Only return max_keys items.
+            if (
+                max_keys is not None
+                and len(requested_versions) + len(delete_markers) + len(common_prefixes)
+                >= max_keys
+            ):
+                next_key_marker = name
+                next_version_id_marker = (
+                    version.version_id if not is_common_prefix else None
+                )
+                break
 
-        return requested_versions, common_prefixes, delete_markers
+            if not is_common_prefix:
+                # Differentiate between FakeKey and FakeDeleteMarkers
+                if not isinstance(version, FakeKey):
+                    delete_markers.append(version)
+                    continue
+
+                requested_versions.append(version)
+
+        return (
+            requested_versions,
+            sorted(common_prefixes),
+            delete_markers,
+            next_key_marker,
+            next_version_id_marker,
+        )
 
     def get_bucket_policy(self, bucket_name: str) -> Optional[bytes]:
         return self.get_bucket(bucket_name).policy

moto/s3/responses.py

@@ -615,17 +615,31 @@ class S3Response(BaseResponse):
         elif "versions" in querystring:
             delimiter = querystring.get("delimiter", [None])[0]
             key_marker = querystring.get("key-marker", [None])[0]
+            max_keys = int(querystring.get("max-keys", [1000])[0])
             prefix = querystring.get("prefix", [""])[0]
+            version_id_marker = querystring.get("version-id-marker", [None])[0]
 
             bucket = self.backend.get_bucket(bucket_name)
             (
                 versions,
                 common_prefixes,
                 delete_markers,
+                next_key_marker,
+                next_version_id_marker,
             ) = self.backend.list_object_versions(
-                bucket_name, delimiter=delimiter, key_marker=key_marker, prefix=prefix
+                bucket_name,
+                delimiter=delimiter,
+                key_marker=key_marker,
+                max_keys=max_keys,
+                prefix=prefix,
+                version_id_marker=version_id_marker,
             )
             key_list = versions
+
+            is_truncated = False
+            if next_key_marker is not None:
+                is_truncated = True
+
             template = self.response_template(S3_BUCKET_GET_VERSIONS)
 
             return (
@@ -637,10 +651,13 @@ class S3Response(BaseResponse):
                     delete_marker_list=delete_markers,
                     bucket=bucket,
                     prefix=prefix,
-                    max_keys=1000,
+                    max_keys=max_keys,
                     delimiter=delimiter,
                     key_marker=key_marker,
-                    is_truncated="false",
+                    version_id_marker=version_id_marker,
+                    is_truncated=is_truncated,
+                    next_key_marker=next_key_marker,
+                    next_version_id_marker=next_version_id_marker,
                 ),
             )
         elif "encryption" in querystring:
@@ -2603,8 +2620,17 @@ S3_BUCKET_GET_VERSIONS = """<?xml version="1.0" encoding="UTF-8"?>
     {% endif %}
     <Delimiter>{{ delimiter }}</Delimiter>
     <KeyMarker>{{ key_marker or "" }}</KeyMarker>
+    <VersionIdMarker>{{ version_id_marker or "" }}</VersionIdMarker>
     <MaxKeys>{{ max_keys }}</MaxKeys>
-    <IsTruncated>{{ is_truncated }}</IsTruncated>
+    {% if is_truncated %}
+    <IsTruncated>true</IsTruncated>
+    <NextKeyMarker>{{ next_key_marker }}</NextKeyMarker>
+    {% if next_version_id_marker %}
+    <NextVersionIdMarker>{{ next_version_id_marker }}</NextVersionIdMarker>
+    {% endif %}
+    {% else %}
+    <IsTruncated>false</IsTruncated>
+    {% endif %}
     {% for key in key_list %}
     <Version>
         <Key>{{ key.name }}</Key>

tests/test_s3/test_s3.py

@@ -2626,6 +2626,245 @@ def test_list_object_versions_with_versioning_enabled_late():
     assert response["Body"].read() == items[-1]
 
 
+@mock_s3
+def test_list_object_versions_with_paging():
+    s3_client = boto3.client("s3", region_name=DEFAULT_REGION_NAME)
+    bucket_name = "000" + str(uuid4())
+    s3_client.create_bucket(Bucket=bucket_name)
+    s3_client.put_bucket_versioning(
+        Bucket=bucket_name, VersioningConfiguration={"Status": "Enabled"}
+    )
+
+    obj1ver1 = s3_client.put_object(Bucket=bucket_name, Key="obj1", Body=b"ver1")
+    obj1ver2 = s3_client.put_object(Bucket=bucket_name, Key="obj1", Body=b"ver2")
+    obj1ver3 = s3_client.put_object(Bucket=bucket_name, Key="obj1", Body=b"ver3")
+
+    page1 = s3_client.list_object_versions(
+        Bucket=bucket_name,
+        MaxKeys=2,
+    )
+
+    # Page should have two versions only, and should be truncated.
+    assert len(page1["Versions"]) == 2
+    assert "DeleteMarkers" not in page1
+    assert page1["IsTruncated"] is True
+
+    # This should be obj1 ver3 (latest).
+    assert page1["Versions"][0]["VersionId"] == obj1ver3["VersionId"]
+    assert page1["Versions"][0]["IsLatest"] is True
+
+    # This should be obj1 ver2.
+    assert page1["Versions"][1]["VersionId"] == obj1ver2["VersionId"]
+
+    # The next key/version markers should point to obj1 ver1.
+    assert "NextKeyMarker" in page1
+    assert page1["NextKeyMarker"] == "obj1"
+    assert "NextVersionIdMarker" in page1
+    assert page1["NextVersionIdMarker"] == obj1ver1["VersionId"]
+
+    # Second page should be the last page and have the oldest version.
+    page2 = s3_client.list_object_versions(
+        Bucket=bucket_name,
+        MaxKeys=2,
+        KeyMarker=page1["NextKeyMarker"],
+        VersionIdMarker=page1["NextVersionIdMarker"],
+    )
+
+    # Page should have one version only, and not be truncated.
+    assert len(page2["Versions"]) == 1
+    assert "DeleteMarkers" not in page2
+    assert page2["IsTruncated"] is False
+    assert "NextKeyMarker" not in page2
+    assert "NextVersionIdMarker" not in page2
+
+    # This should be obj1 ver1.
+    assert page2["Versions"][0]["VersionId"] == obj1ver1["VersionId"]
+
+
+@mock_s3
+def test_list_object_versions_with_paging_and_delete_markers():
+    s3_client = boto3.client("s3", region_name=DEFAULT_REGION_NAME)
+    bucket_name = "000" + str(uuid4())
+    s3_client.create_bucket(Bucket=bucket_name)
+    s3_client.put_bucket_versioning(
+        Bucket=bucket_name, VersioningConfiguration={"Status": "Enabled"}
+    )
+
+    # A mix of versions and delete markers.
+    obj1ver1 = s3_client.put_object(Bucket=bucket_name, Key="obj1", Body=b"ver1")
+    obj2ver1 = s3_client.put_object(Bucket=bucket_name, Key="obj2", Body=b"ver1")
+    obj1dmk1 = s3_client.delete_object(Bucket=bucket_name, Key="obj1")
+    obj1dmk2 = s3_client.delete_object(Bucket=bucket_name, Key="obj1")
+    obj1dmk3 = s3_client.delete_object(Bucket=bucket_name, Key="obj1")
+    obj2dmk1 = s3_client.delete_object(Bucket=bucket_name, Key="obj2")
+
+    page1 = s3_client.list_object_versions(
+        Bucket=bucket_name,
+        MaxKeys=2,
+    )
+
+    # Page should have one version and one delete marker, and be truncated.
+    assert "Versions" not in page1
+    assert len(page1["DeleteMarkers"]) == 2
+    assert page1["IsTruncated"] is True
+
+    # This should be obj1 dmk3 (latest).
+    assert page1["DeleteMarkers"][0]["VersionId"] == obj1dmk3["VersionId"]
+    assert page1["DeleteMarkers"][0]["IsLatest"] is True
+
+    # This should be obj1 dmk2.
+    assert page1["DeleteMarkers"][1]["VersionId"] == obj1dmk2["VersionId"]
+
+    # The next key/version markers should point to obj1 dmk1.
+    assert "NextKeyMarker" in page1
+    assert page1["NextKeyMarker"] == "obj1"
+    assert "NextVersionIdMarker" in page1
+    assert page1["NextVersionIdMarker"] == obj1dmk1["VersionId"]
+
+    page2 = s3_client.list_object_versions(
+        Bucket=bucket_name,
+        MaxKeys=2,
+        KeyMarker=page1["NextKeyMarker"],
+        VersionIdMarker=page1["NextVersionIdMarker"],
+    )
+
+    # Page should have one version and one delete marker, and be truncated.
+    assert len(page2["Versions"]) == 1
+    assert len(page2["DeleteMarkers"]) == 1
+    assert page2["IsTruncated"] is True
+
+    # This should be obj1 ver1.
+    assert page2["Versions"][0]["VersionId"] == obj1ver1["VersionId"]
+
+    # This should be obj1 dmk1.
+    assert page2["DeleteMarkers"][0]["VersionId"] == obj1dmk1["VersionId"]
+
+    # The next key/version markers should point to obj2 dmk1.
+    assert "NextKeyMarker" in page2
+    assert page2["NextKeyMarker"] == "obj2"
+    assert "NextVersionIdMarker" in page2
+    assert page2["NextVersionIdMarker"] == obj2dmk1["VersionId"]
+
+    page3 = s3_client.list_object_versions(
+        Bucket=bucket_name,
+        MaxKeys=2,
+        KeyMarker=page2["NextKeyMarker"],
+        VersionIdMarker=page2["NextVersionIdMarker"],
+    )
+
+    # Page should have one version and one delete marker, and not be truncated.
+    assert len(page3["Versions"]) == 1
+    assert len(page3["DeleteMarkers"]) == 1
+    assert page3["IsTruncated"] is False
+
+    # This should be obj2 ver1.
+    assert page3["Versions"][0]["VersionId"] == obj2ver1["VersionId"]
+
+    # This should be obj2 dmk1 (latest).
+    assert page3["DeleteMarkers"][0]["VersionId"] == obj2dmk1["VersionId"]
+    assert page3["DeleteMarkers"][0]["IsLatest"]
+
+    # There should not be any next key/version marker.
+    assert "NextKeyMarker" not in page3
+    assert "NextVersionIdMarker" not in page3
+
+
+@mock_s3
+def test_list_object_versions_with_paging_and_delimiter():
+    s3_client = boto3.client("s3", region_name=DEFAULT_REGION_NAME)
+    bucket_name = "000" + str(uuid4())
+    s3_client.create_bucket(Bucket=bucket_name)
+    s3_client.put_bucket_versioning(
+        Bucket=bucket_name, VersioningConfiguration={"Status": "Enabled"}
+    )
+
+    # Copied from test_list_object_versions_with_delimiter.
+    for key_index in list(range(1, 5)) + list(range(10, 14)):
+        for version_index in range(1, 4):
+            body = f"data-{version_index}".encode("UTF-8")
+            s3_client.put_object(
+                Bucket=bucket_name, Key=f"key{key_index}-with-data", Body=body
+            )
+            s3_client.put_object(
+                Bucket=bucket_name, Key=f"key{key_index}-without-data", Body=b""
+            )
+
+    page1 = s3_client.list_object_versions(
+        Bucket=bucket_name,
+        Delimiter="with-",
+        Prefix="key1",
+        KeyMarker="key11",
+        MaxKeys=5,
+    )
+
+    assert "Versions" in page1
+    assert len(page1["Versions"]) == 3
+    assert [v["Key"] for v in page1["Versions"]] == [
+        "key11-without-data",
+        "key11-without-data",
+        "key11-without-data",
+    ]
+
+    assert "CommonPrefixes" in page1
+    assert [p["Prefix"] for p in page1["CommonPrefixes"]] == [
+        "key11-with-",
+        "key12-with-",
+    ]
+
+    assert page1["IsTruncated"] is True
+    assert page1["NextKeyMarker"] == "key12-with-"
+    assert "NextVersionIdMarker" not in page1
+
+    page2 = s3_client.list_object_versions(
+        Bucket=bucket_name,
+        Delimiter="with-",
+        Prefix="key1",
+        KeyMarker="key12-with-",
+        VersionIdMarker="",
+        MaxKeys=5,
+    )
+
+    assert "Versions" in page2
+    assert len(page2["Versions"]) == 4
+    assert [v["Key"] for v in page2["Versions"]] == [
+        "key12-without-data",
+        "key12-without-data",
+        "key12-without-data",
+        "key13-without-data",
+    ]
+
+    assert "CommonPrefixes" in page2
+    assert [p["Prefix"] for p in page2["CommonPrefixes"]] == [
+        "key13-with-",
+    ]
+
+    assert page2["IsTruncated"] is True
+    assert page2["NextKeyMarker"] == "key13-without-data"
+    assert "NextVersionIdMarker" in page2  # FIXME check VersionId?
+
+    page3 = s3_client.list_object_versions(
+        Bucket=bucket_name,
+        Delimiter="with-",
+        Prefix="key1",
+        KeyMarker="key13-without-data",
+        VersionIdMarker=page2["NextVersionIdMarker"],
+        MaxKeys=5,
+    )
+
+    assert "Versions" in page3
+    assert len(page3["Versions"]) == 2
+    assert [v["Key"] for v in page3["Versions"]] == [
+        "key13-without-data",
+        "key13-without-data",
+    ]
+
+    assert "CommonPrefixes" not in page3
+
+    assert page3["IsTruncated"] is False
+    assert "NextKeyMarker" not in page3
+    assert "NextVersionIdMarker" not in page3
+
+
 @mock_s3
 def test_bad_prefix_list_object_versions():
     s3_client = boto3.client("s3", region_name=DEFAULT_REGION_NAME)