server: Move all the top level files into cmd folder. (#2490)

This change brings a change which was done for the 'mc'
package to allow for clean repo and have a cleaner
github drop in experience.

cmd/fs-v1-metadata.go

@@ -0,0 +1,174 @@
+/*
+ * Minio Cloud Storage, (C) 2016 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 (
+	"encoding/json"
+	"os"
+	"path"
+	"sort"
+	"strings"
+)
+
+const (
+	fsMetaJSONFile   = "fs.json"
+	fsFormatJSONFile = "format.json"
+)
+
+// A fsMetaV1 represents a metadata header mapping keys to sets of values.
+type fsMetaV1 struct {
+	Version string `json:"version"`
+	Format  string `json:"format"`
+	Minio   struct {
+		Release string `json:"release"`
+	} `json:"minio"`
+	// Metadata map for current object `fs.json`.
+	Meta  map[string]string `json:"meta,omitempty"`
+	Parts []objectPartInfo  `json:"parts,omitempty"`
+}
+
+// ObjectPartIndex - returns the index of matching object part number.
+func (m fsMetaV1) ObjectPartIndex(partNumber int) (partIndex int) {
+	for i, part := range m.Parts {
+		if partNumber == part.Number {
+			partIndex = i
+			return partIndex
+		}
+	}
+	return -1
+}
+
+// AddObjectPart - add a new object part in order.
+func (m *fsMetaV1) AddObjectPart(partNumber int, partName string, partETag string, partSize int64) {
+	partInfo := objectPartInfo{
+		Number: partNumber,
+		Name:   partName,
+		ETag:   partETag,
+		Size:   partSize,
+	}
+
+	// Update part info if it already exists.
+	for i, part := range m.Parts {
+		if partNumber == part.Number {
+			m.Parts[i] = partInfo
+			return
+		}
+	}
+
+	// Proceed to include new part info.
+	m.Parts = append(m.Parts, partInfo)
+
+	// Parts in fsMeta should be in sorted order by part number.
+	sort.Sort(byObjectPartNumber(m.Parts))
+}
+
+// readFSMetadata - returns the object metadata `fs.json` content.
+func readFSMetadata(disk StorageAPI, bucket, object string) (fsMeta fsMetaV1, err error) {
+	// Read all `fs.json`.
+	buf, err := disk.ReadAll(bucket, path.Join(object, fsMetaJSONFile))
+	if err != nil {
+		return fsMetaV1{}, err
+	}
+
+	// Decode `fs.json` into fsMeta structure.
+	if err = json.Unmarshal(buf, &fsMeta); err != nil {
+		return fsMetaV1{}, err
+	}
+
+	// Success.
+	return fsMeta, nil
+}
+
+// newFSMetaV1 - initializes new fsMetaV1.
+func newFSMetaV1() (fsMeta fsMetaV1) {
+	fsMeta = fsMetaV1{}
+	fsMeta.Version = "1.0.0"
+	fsMeta.Format = "fs"
+	fsMeta.Minio.Release = ReleaseTag
+	return fsMeta
+}
+
+// newFSFormatV1 - initializes new formatConfigV1 with FS format info.
+func newFSFormatV1() (format formatConfigV1) {
+	return formatConfigV1{
+		Version: "1",
+		Format:  "fs",
+		FS: &fsFormat{
+			Version: "1",
+		},
+	}
+}
+
+// isFSFormat - returns whether given formatConfigV1 is FS type or not.
+func isFSFormat(format formatConfigV1) bool {
+	return format.Format == "fs"
+}
+
+// writes FS format (format.json) into minioMetaBucket.
+func writeFSFormatData(storage StorageAPI, fsFormat formatConfigV1) error {
+	metadataBytes, err := json.Marshal(fsFormat)
+	if err != nil {
+		return err
+	}
+	// fsFormatJSONFile - format.json file stored in minioMetaBucket(.minio) directory.
+	if err = storage.AppendFile(minioMetaBucket, fsFormatJSONFile, metadataBytes); err != nil {
+		return err
+	}
+	return nil
+}
+
+// writeFSMetadata - writes `fs.json` metadata, marshals fsMeta object into json
+// and saves it to disk.
+func writeFSMetadata(storage StorageAPI, bucket, path string, fsMeta fsMetaV1) error {
+	metadataBytes, err := json.Marshal(fsMeta)
+	if err != nil {
+		return err
+	}
+	if err = storage.AppendFile(bucket, path, metadataBytes); err != nil {
+		return err
+	}
+	return nil
+}
+
+var extendedHeaders = []string{
+	"X-Amz-Meta-",
+	"X-Minio-Meta-",
+	// Add new extended headers.
+}
+
+// isExtendedHeader validates if input string matches extended headers.
+func isExtendedHeader(header string) bool {
+	for _, extendedHeader := range extendedHeaders {
+		if strings.HasPrefix(header, extendedHeader) {
+			return true
+		}
+	}
+	return false
+}
+
+// Return true if extended HTTP headers are set, false otherwise.
+func hasExtendedHeader(metadata map[string]string) bool {
+	if os.Getenv("MINIO_ENABLE_FSMETA") == "1" {
+		return true
+	}
+	for k := range metadata {
+		if isExtendedHeader(k) {
+			return true
+		}
+	}
+	return false
+}