xl: Moved to minio/minio - fixes #1112

pkg/xl/common.go

@@ -0,0 +1,190 @@
+/*
+ * Minio Cloud Storage, (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 xl
+
+import (
+	"bufio"
+	"bytes"
+	"io"
+	"regexp"
+	"sort"
+	"strings"
+	"unicode/utf8"
+
+	"github.com/minio/minio/pkg/atomic"
+)
+
+// IsValidXL - verify xl name is correct
+func IsValidXL(xlName string) bool {
+	if len(xlName) < 3 || len(xlName) > 63 {
+		return false
+	}
+	if xlName[0] == '.' || xlName[len(xlName)-1] == '.' {
+		return false
+	}
+	if match, _ := regexp.MatchString("\\.\\.", xlName); match == true {
+		return false
+	}
+	// We don't support xlNames with '.' in them
+	match, _ := regexp.MatchString("^[a-zA-Z][a-zA-Z0-9\\-]+[a-zA-Z0-9]$", xlName)
+	return match
+}
+
+// IsValidBucket - verify bucket name in accordance with
+//  - http://docs.aws.amazon.com/AmazonS3/latest/dev/UsingBucket.html
+func IsValidBucket(bucket string) bool {
+	if len(bucket) < 3 || len(bucket) > 63 {
+		return false
+	}
+	if bucket[0] == '.' || bucket[len(bucket)-1] == '.' {
+		return false
+	}
+	if match, _ := regexp.MatchString("\\.\\.", bucket); match == true {
+		return false
+	}
+	// We don't support buckets with '.' in them
+	match, _ := regexp.MatchString("^[a-zA-Z][a-zA-Z0-9\\-]+[a-zA-Z0-9]$", bucket)
+	return match
+}
+
+// IsValidObjectName - verify object name in accordance with
+//   - http://docs.aws.amazon.com/AmazonS3/latest/dev/UsingMetadata.html
+func IsValidObjectName(object string) bool {
+	if strings.TrimSpace(object) == "" {
+		return false
+	}
+	if len(object) > 1024 || len(object) == 0 {
+		return false
+	}
+	if !utf8.ValidString(object) {
+		return false
+	}
+	return true
+}
+
+// IsValidPrefix - verify prefix name is correct, an empty prefix is valid
+func IsValidPrefix(prefix string) bool {
+	if strings.TrimSpace(prefix) == "" {
+		return true
+	}
+	return IsValidObjectName(prefix)
+}
+
+// ProxyWriter implements io.Writer to trap written bytes
+type ProxyWriter struct {
+	writer       io.Writer
+	writtenBytes []byte
+}
+
+func (r *ProxyWriter) Write(p []byte) (n int, err error) {
+	n, err = r.writer.Write(p)
+	if err != nil {
+		return
+	}
+	r.writtenBytes = append(r.writtenBytes, p[0:n]...)
+	return
+}
+
+// NewProxyWriter - wrap around a given writer with ProxyWriter
+func NewProxyWriter(w io.Writer) *ProxyWriter {
+	return &ProxyWriter{writer: w, writtenBytes: nil}
+}
+
+// Delimiter delims the string at delimiter
+func Delimiter(object, delimiter string) string {
+	readBuffer := bytes.NewBufferString(object)
+	reader := bufio.NewReader(readBuffer)
+	stringReader := strings.NewReader(delimiter)
+	delimited, _ := stringReader.ReadByte()
+	delimitedStr, _ := reader.ReadString(delimited)
+	return delimitedStr
+}
+
+// RemoveDuplicates removes duplicate elements from a slice
+func RemoveDuplicates(slice []string) []string {
+	newSlice := []string{}
+	seen := make(map[string]struct{})
+	for _, val := range slice {
+		if _, ok := seen[val]; !ok {
+			newSlice = append(newSlice, val)
+			seen[val] = struct{}{} // avoiding byte allocation
+		}
+	}
+	return newSlice
+}
+
+// TrimPrefix trims off a prefix string from all the elements in a given slice
+func TrimPrefix(objects []string, prefix string) []string {
+	var results []string
+	for _, object := range objects {
+		results = append(results, strings.TrimPrefix(object, prefix))
+	}
+	return results
+}
+
+// HasNoDelimiter provides a new slice from an input slice which has elements without delimiter
+func HasNoDelimiter(objects []string, delim string) []string {
+	var results []string
+	for _, object := range objects {
+		if !strings.Contains(object, delim) {
+			results = append(results, object)
+		}
+	}
+	return results
+}
+
+// HasDelimiter provides a new slice from an input slice which has elements with a delimiter
+func HasDelimiter(objects []string, delim string) []string {
+	var results []string
+	for _, object := range objects {
+		if strings.Contains(object, delim) {
+			results = append(results, object)
+		}
+	}
+	return results
+}
+
+// SplitDelimiter provides a new slice from an input slice by splitting a delimiter
+func SplitDelimiter(objects []string, delim string) []string {
+	var results []string
+	for _, object := range objects {
+		parts := strings.Split(object, delim)
+		results = append(results, parts[0]+delim)
+	}
+	return results
+}
+
+// SortUnique sort a slice in lexical order, removing duplicate elements
+func SortUnique(objects []string) []string {
+	objectMap := make(map[string]string)
+	for _, v := range objects {
+		objectMap[v] = v
+	}
+	var results []string
+	for k := range objectMap {
+		results = append(results, k)
+	}
+	sort.Strings(results)
+	return results
+}
+
+// CleanupWritersOnError purge writers on error
+func CleanupWritersOnError(writers []io.WriteCloser) {
+	for _, writer := range writers {
+		writer.(*atomic.File).CloseAndPurge()
+	}
+}