From 10ae089c467af65b3a3dc734ef21dfcffdcfbcec Mon Sep 17 00:00:00 2001
From: "Frederick F. Kautz IV" <fkautz@alumni.cmu.edu>
Date: Mon, 16 Mar 2015 17:40:59 -0700
Subject: [PATCH] Better handling of metadata in encoded

---
 pkg/storage/encoded/encoded.go | 77 +++++++++++++++++++++++++++-------
 1 file changed, 63 insertions(+), 14 deletions(-)

diff --git a/pkg/storage/encoded/encoded.go b/pkg/storage/encoded/encoded.go
index 0b34ddd48..c9cb0a5dc 100644
--- a/pkg/storage/encoded/encoded.go
+++ b/pkg/storage/encoded/encoded.go
@@ -18,6 +18,7 @@ package encoded
 
 import (
 	"bytes"
+	"encoding/hex"
 	"errors"
 	"github.com/minio-io/minio/pkg/donutbox"
 	"github.com/minio-io/minio/pkg/encoding/erasure"
@@ -25,6 +26,7 @@ import (
 	"github.com/minio-io/minio/pkg/utils/split"
 	"io"
 	"strconv"
+	"time"
 )
 
 // StorageDriver creates a new single disk storage driver using donut without encoding.
@@ -69,13 +71,24 @@ func (diskStorage StorageDriver) GetBucketPolicy(bucket string) (storage.BucketP
 // GetObject retrieves an object and writes it to a writer
 func (diskStorage StorageDriver) GetObject(target io.Writer, bucket, key string) (int64, error) {
 	metadata, err := diskStorage.donutBox.GetObjectMetadata(bucket, key, 0)
-	chunkCount, err := strconv.Atoi(metadata["chunkCount"])
-	columnCount, err := strconv.Atoi(metadata["columnCount"])
+	k, err := strconv.Atoi(metadata["erasureK"])
+	if err != nil {
+		return 0, errors.New("Cannot parse erasureK")
+	}
+	m, err := strconv.Atoi(metadata["erasureM"])
+	if err != nil {
+		return 0, errors.New("Cannot parse erasureM")
+	}
+	columnCount := k + m
 	blockSize, err := strconv.Atoi(metadata["blockSize"])
-	length, err := strconv.Atoi(metadata["length"])
 	if err != nil {
-		return 0, err
+		return 0, errors.New("Cannot parse blockSize")
 	}
+	size, err := strconv.Atoi(metadata["size"])
+	if err != nil {
+		return 0, errors.New("Cannot parse length")
+	}
+	chunkCount := size/blockSize + 1
 	var readers []io.Reader
 	for column := 0; column < columnCount; column++ {
 		reader, err := diskStorage.donutBox.GetObjectReader(bucket, key, uint(column))
@@ -85,8 +98,8 @@ func (diskStorage StorageDriver) GetObject(target io.Writer, bucket, key string)
 		readers = append(readers, reader)
 	}
 
-	totalWritten := int64(length)
-	totalRemaining := int64(length)
+	totalWritten := int64(size)
+	totalRemaining := int64(size)
 	if err != err {
 		return 0, err
 	}
@@ -127,8 +140,22 @@ func (diskStorage StorageDriver) GetPartialObject(w io.Writer, bucket, object st
 }
 
 // GetObjectMetadata retrieves an object's metadata
-func (diskStorage StorageDriver) GetObjectMetadata(bucket, key string, prefix string) (metadata storage.ObjectMetadata, err error) {
-	return metadata, errors.New("Not Implemented")
+func (diskStorage StorageDriver) GetObjectMetadata(bucket, key string, prefix string) (storage.ObjectMetadata, error) {
+	metadata, err := diskStorage.donutBox.GetObjectMetadata(bucket, key, 0)
+	if err != nil {
+		return storage.ObjectMetadata{}, err
+	}
+	created, err := time.Parse(metadata["created"], time.RFC3339Nano)
+	size, err := strconv.ParseInt(metadata["size"], 10, 64)
+	objectMetadata := storage.ObjectMetadata{
+		Bucket:      bucket,
+		Key:         key,
+		ContentType: metadata["contentType"],
+		Created:     created,
+		ETag:        hex.EncodeToString([]byte(metadata["md5"])),
+		Size:        size,
+	}
+	return objectMetadata, nil
 }
 
 // ListObjects lists objects
@@ -177,12 +204,18 @@ func (diskStorage StorageDriver) CreateObject(bucketKey string, objectKey string
 	}
 	// close connections
 
-	metadata := make(map[string]string)
-	metadata["length"] = strconv.FormatUint(totalLength, 10)
-	metadata["blockSize"] = strconv.FormatUint(uint64(blockSize), 10)
-	metadata["chunkCount"] = strconv.FormatUint(uint64(chunkCount), 10)
-	metadata["columnCount"] = strconv.FormatUint(uint64(16), 10)
-	//    metadata["md5"] := md5sum
+	metadataObj := storage.ObjectMetadata{
+		Bucket: bucketKey,
+		Key:    objectKey,
+
+		ContentType: contentType,
+		Created:     time.Now(),
+		ETag:        "md5",
+		Size:        int64(totalLength),
+	}
+
+	metadata := createMetadata(metadataObj, blockSize, 8, 8, "Cauchy")
+
 	for column := uint(0); column < 16; column++ {
 		writers[column].SetMetadata(metadata)
 	}
@@ -208,3 +241,19 @@ func closeAllWritersWithError(writers []*donutbox.NewObject, err error) {
 		}
 	}
 }
+
+func createMetadata(metadataObject storage.ObjectMetadata, blockSize int, k, m uint8, technique string) map[string]string {
+	metadata := make(map[string]string)
+	metadata["bucket"] = metadataObject.Bucket
+	metadata["key"] = metadataObject.Key
+	metadata["contentType"] = metadataObject.ContentType
+	metadata["created"] = metadataObject.Created.Format(time.RFC3339Nano)
+	metadata["md5"] = metadataObject.ETag
+	metadata["size"] = strconv.FormatInt(metadataObject.Size, 10)
+
+	metadata["blockSize"] = strconv.FormatUint(uint64(blockSize), 10)
+	metadata["erasureK"] = strconv.FormatUint(uint64(k), 10)
+	metadata["erasureM"] = strconv.FormatUint(uint64(m), 10)
+	metadata["erasureTechnique"] = technique
+	return metadata
+}