Merge pull request #260 from fkautz/pr_out_erasure_layer_now_writes_using_new_technique

pkg/storage/donut/erasure/erasure1/erasure.go

@@ -0,0 +1,98 @@
+/*
+ * Mini Object 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 erasure1
+
+import (
+	"bytes"
+	"encoding/binary"
+	"encoding/gob"
+	"errors"
+	"io"
+)
+
+// DataHeader represents the structure serialized to gob.
+type DataHeader struct {
+	// object + block stored
+	Key string
+	// chunk index of encoded block
+	ChunkIndex uint8
+	// Original Length of the block output
+	OriginalLength uint32
+	// Data Blocks
+	EncoderK uint8
+	// Parity Blocks
+	EncoderM uint8
+	// Matrix Technique
+	EncoderTechnique EncoderTechnique
+}
+
+// EncoderTechnique specified the Matrix type used in encoding
+type EncoderTechnique int
+
+const (
+	// Vandermonde matrix type
+	Vandermonde EncoderTechnique = iota
+	// Cauchy matrix type
+	Cauchy
+)
+
+// validate populated header
+func validateHeader(header DataHeader) error {
+	if header.Key == "" {
+		return errors.New("Empty Key")
+	}
+
+	if header.EncoderTechnique > 1 {
+		return errors.New("Invalid encoder technique")
+	}
+
+	return nil
+}
+
+// WriteData returns error upon any failure
+func Write(target io.Writer, key string, part uint8, length uint32, k, m uint8, technique EncoderTechnique, data io.Reader) error {
+	header := DataHeader{
+		Key:              key,
+		ChunkIndex:       part,
+		OriginalLength:   length,
+		EncoderK:         k,
+		EncoderM:         m,
+		EncoderTechnique: technique,
+	}
+
+	if err := validateHeader(header); err != nil {
+		return err
+	}
+
+	var headerBuffer bytes.Buffer
+	// encode header
+	encoder := gob.NewEncoder(&headerBuffer)
+	encoder.Encode(header)
+
+	// write version
+	binary.Write(target, binary.LittleEndian, uint32(1))
+
+	// write encoded header
+	if _, err := io.Copy(target, &headerBuffer); err != nil {
+		return err
+	}
+	// write data
+	if _, err := io.Copy(target, data); err != nil {
+		return err
+	}
+	return nil
+}

pkg/storage/donut/erasure/erasure1/erasure_test.go

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package erasure
+package erasure1
 
 import (
 	"bytes"
@@ -35,19 +35,16 @@ var _ = Suite(&MySuite{})
 func (s *MySuite) TestSingleWrite(c *C) {
 	var testBuffer bytes.Buffer
 	testData := "Hello, World"
-	encoderParams := EncoderParams{
-		Length:    uint32(len(testData)),
-		K:         8,
-		M:         8,
-		Technique: Cauchy,
+	testHeader := DataHeader{
+		Key:              "testobj",
+		ChunkIndex:       1,
+		OriginalLength:   uint32(len(testData)),
+		EncoderK:         8,
+		EncoderM:         8,
+		EncoderTechnique: Cauchy,
 	}
-	metadata := make(Metadata)
-	metadata["Content-Type"] = "application/octet-stream"
-	metadata["Content-MD5"] = "testing"
 
-	header := NewHeader("testobj", 1, metadata, encoderParams)
-
-	err := WriteData(&testBuffer, header, bytes.NewBufferString(testData))
+	err := Write(&testBuffer, testHeader.Key, testHeader.ChunkIndex, testHeader.OriginalLength, testHeader.EncoderK, testHeader.EncoderM, testHeader.EncoderTechnique, bytes.NewBufferString(testData))
 	c.Assert(err, IsNil)
 
 	actualVersion := make([]byte, 4)
@@ -60,7 +57,7 @@ func (s *MySuite) TestSingleWrite(c *C) {
 	decoder := gob.NewDecoder(&testBuffer)
 	decoder.Decode(&actualHeader)
 
-	c.Assert(actualHeader, DeepEquals, header)
+	c.Assert(actualHeader, DeepEquals, testHeader)
 
 	var actualData bytes.Buffer
 

pkg/storage/donut/erasure/erasure_v1/erasure.go

@@ -1,106 +0,0 @@
-/*
- * Mini Object 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 erasure
-
-import (
-	"bytes"
-	"encoding/binary"
-	"encoding/gob"
-	"fmt"
-	"io"
-)
-
-// Metadata map
-type Metadata map[string]string
-
-// DataHeader struct
-type DataHeader struct {
-	Key           string
-	Part          uint8
-	Metadata      Metadata
-	EncoderParams EncoderParams
-}
-
-// EncoderTechnique type
-type EncoderTechnique int
-
-// EncoderTechniques
-const (
-	Vandermonde EncoderTechnique = iota
-	Cauchy
-)
-
-// EncoderParams struct
-type EncoderParams struct {
-	Length    uint32
-	K         uint8
-	M         uint8
-	Technique EncoderTechnique
-}
-
-// NewHeader populate new header
-func NewHeader(key string, part uint8, metadata Metadata, encoderParams EncoderParams) DataHeader {
-	header := DataHeader{}
-	header.Key = key
-	header.Part = part
-	header.Metadata = metadata
-	header.EncoderParams = EncoderParams{
-		Length:    encoderParams.Length,
-		K:         encoderParams.K,
-		M:         encoderParams.M,
-		Technique: encoderParams.Technique,
-	}
-	return header
-}
-
-// ValidateHeader validate populated header
-func ValidateHeader(header DataHeader) bool {
-	if header.Key == "" || header.Part < 0 || len(header.Metadata) < 2 {
-		return false
-	}
-
-	if header.EncoderParams.Length < 0 || header.EncoderParams.Technique > 1 {
-		return false
-	}
-
-	return true
-}
-
-// WriteData write data, returns error upon any failure
-func WriteData(target io.Writer, header DataHeader, data io.Reader) error {
-	if !ValidateHeader(header) {
-		return fmt.Errorf("Invalid header")
-	}
-
-	var headerBuffer bytes.Buffer
-	// encode header
-	encoder := gob.NewEncoder(&headerBuffer)
-	encoder.Encode(header)
-
-	// write version
-	binary.Write(target, binary.LittleEndian, uint32(1))
-
-	// write encoded header
-	if _, err := io.Copy(target, &headerBuffer); err != nil {
-		return err
-	}
-	// write data
-	if _, err := io.Copy(target, data); err != nil {
-		return err
-	}
-	return nil
-}