Support bucket versioning (#9377)

- Implement a new xl.json 2.0.0 format to support,
  this moves the entire marshaling logic to POSIX
  layer, top layer always consumes a common FileInfo
  construct which simplifies the metadata reads.
- Implement list object versions
- Migrate to siphash from crchash for new deployments
  for object placements.

Fixes #2111

cmd/xl-storage-format-utils.go

@@ -0,0 +1,81 @@
+/*
+ * MinIO Cloud Storage, (C) 2020 MinIO, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.
+ */
+
+package cmd
+
+import (
+	jsoniter "github.com/json-iterator/go"
+)
+
+func getFileInfoVersions(xlMetaBuf []byte, volume, path string) (FileInfoVersions, error) {
+	if isXL2V1Format(xlMetaBuf) {
+		var xlMeta xlMetaV2
+		if err := xlMeta.Load(xlMetaBuf); err != nil {
+			return FileInfoVersions{}, err
+		}
+		versions, deletedVersions, latestModTime, err := xlMeta.ListVersions(volume, path)
+		if err != nil {
+			return FileInfoVersions{}, err
+		}
+		return FileInfoVersions{
+			Volume:        volume,
+			Name:          path,
+			Versions:      versions,
+			Deleted:       deletedVersions,
+			LatestModTime: latestModTime,
+		}, nil
+	}
+
+	xlMeta := &xlMetaV1Object{}
+	var json = jsoniter.ConfigCompatibleWithStandardLibrary
+	if err := json.Unmarshal(xlMetaBuf, xlMeta); err != nil {
+		return FileInfoVersions{}, errFileCorrupt
+	}
+
+	fi, err := xlMeta.ToFileInfo(volume, path)
+	if err != nil {
+		return FileInfoVersions{}, err
+	}
+
+	fi.IsLatest = true // No versions so current version is latest.
+	return FileInfoVersions{
+		Volume:        volume,
+		Name:          path,
+		Versions:      []FileInfo{fi},
+		LatestModTime: fi.ModTime,
+	}, nil
+}
+
+func getFileInfo(xlMetaBuf []byte, volume, path, versionID string) (FileInfo, error) {
+	if isXL2V1Format(xlMetaBuf) {
+		var xlMeta xlMetaV2
+		if err := xlMeta.Load(xlMetaBuf); err != nil {
+			return FileInfo{}, err
+		}
+		return xlMeta.ToFileInfo(volume, path, versionID)
+	}
+
+	xlMeta := &xlMetaV1Object{}
+	var json = jsoniter.ConfigCompatibleWithStandardLibrary
+	if err := json.Unmarshal(xlMetaBuf, xlMeta); err != nil {
+		return FileInfo{}, errFileCorrupt
+	}
+	fi, err := xlMeta.ToFileInfo(volume, path)
+	if err == errFileNotFound && versionID != "" {
+		return fi, errFileVersionNotFound
+	}
+	return fi, err
+}