XL/FS: Rewrite in new format.

erasure.go

@@ -0,0 +1,60 @@
+/*
+ * 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 main
+
+import (
+	"errors"
+
+	"github.com/klauspost/reedsolomon"
+)
+
+// erasure storage layer.
+type erasure struct {
+	ReedSolomon  reedsolomon.Encoder // Erasure encoder/decoder.
+	DataBlocks   int
+	ParityBlocks int
+	storageDisks []StorageAPI
+}
+
+// errUnexpected - returned for any unexpected error.
+var errUnexpected = errors.New("Unexpected error - please report at https://github.com/minio/minio/issues")
+
+// newErasure instantiate a new erasure.
+func newErasure(disks []StorageAPI) (*erasure, error) {
+	// Initialize E.
+	e := &erasure{}
+
+	// Calculate data and parity blocks.
+	dataBlocks, parityBlocks := len(disks)/2, len(disks)/2
+
+	// Initialize reed solomon encoding.
+	rs, err := reedsolomon.New(dataBlocks, parityBlocks)
+	if err != nil {
+		return nil, err
+	}
+
+	// Save the reedsolomon.
+	e.DataBlocks = dataBlocks
+	e.ParityBlocks = parityBlocks
+	e.ReedSolomon = rs
+
+	// Save all the initialized storage disks.
+	e.storageDisks = disks
+
+	// Return successfully initialized.
+	return e, nil
+}