diff - dump the sorted list of source and destination to local disk file and then diff from the local files

sorted-list.go

@@ -0,0 +1,135 @@
+/*
+ * Minio Client (C) 2015 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 main
+
+import (
+	"encoding/gob"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+
+	"github.com/minio/mc/pkg/client"
+	"github.com/minio/minio/pkg/probe"
+)
+
+type sortedList struct {
+	name string
+	file *os.File
+	dec  *gob.Decoder
+	enc  *gob.Encoder
+}
+
+func getSortedListDir() (string, *probe.Error) {
+	configDir, err := getMcConfigDir()
+	if err != nil {
+		return "", err.Trace()
+	}
+	sortedListDir := filepath.Join(configDir, golbalSortedListDir)
+	return sortedListDir, nil
+}
+
+func createSortedListDir() *probe.Error {
+	sortedListDir, err := getSortedListDir()
+	if err != nil {
+		return err.Trace()
+	}
+	if _, err := os.Stat(sortedListDir); err == nil {
+		return nil
+	}
+	if err := os.MkdirAll(sortedListDir, 0700); err != nil {
+		return probe.NewError(err)
+	}
+	return nil
+}
+
+// Create create an on disk sorted file from clnt
+func (sl *sortedList) Create(clnt client.Client, id string) *probe.Error {
+	var e error
+	if err := createSortedListDir(); err != nil {
+		return err.Trace()
+	}
+	sortedListDir, err := getSortedListDir()
+	if err != nil {
+		return err.Trace()
+	}
+	sl.name = filepath.Join(sortedListDir, id)
+	sl.file, e = os.OpenFile(sl.name, os.O_CREATE|os.O_EXCL|os.O_RDWR, 0666)
+	if e != nil {
+		return probe.NewError(e)
+	}
+	sl.enc = gob.NewEncoder(sl.file)
+	sl.dec = gob.NewDecoder(sl.file)
+	for content := range clnt.List(true) {
+		if content.Err != nil {
+			switch err := content.Err.ToGoError().(type) {
+			case client.ISBrokenSymlink:
+				// FIXME: send the error to caller using channel
+				errorIf(content.Err.Trace(), fmt.Sprintf("Skipping broken Symlink ‘%s’.", err.Path))
+				continue
+			}
+			if os.IsNotExist(content.Err.ToGoError()) || os.IsPermission(content.Err.ToGoError()) {
+				// FIXME: abstract this at fs.go layer
+				if content.Content != nil {
+					if content.Content.Type.IsDir() && (content.Content.Type&os.ModeSymlink == os.ModeSymlink) {
+						continue
+					}
+				}
+				errorIf(content.Err.Trace(), fmt.Sprintf("Skipping ‘%s’.", content.Content.Name))
+				continue
+			}
+			return content.Err.Trace()
+		}
+		sl.enc.Encode(*content.Content)
+	}
+	if _, err := sl.file.Seek(0, os.SEEK_SET); err != nil {
+		return probe.NewError(err)
+	}
+	return nil
+}
+
+// List list the entries from the sorted file
+func (sl *sortedList) List(recursive bool) <-chan client.ContentOnChannel {
+	ch := make(chan client.ContentOnChannel)
+	go func() {
+		defer close(ch)
+		for {
+			var c client.Content
+			err := sl.dec.Decode(&c)
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				ch <- client.ContentOnChannel{Content: nil, Err: probe.NewError(err)}
+				break
+			}
+			ch <- client.ContentOnChannel{Content: &c, Err: nil}
+		}
+	}()
+	return ch
+}
+
+// Delete close and delete the ondisk file
+func (sl *sortedList) Delete() *probe.Error {
+	if err := sl.file.Close(); err != nil {
+		return probe.NewError(err)
+	}
+	if err := os.Remove(sl.name); err != nil {
+		return probe.NewError(err)
+	}
+	return nil
+}