From a589ddaddf3cf6d9d18e5d331a33a257658251af Mon Sep 17 00:00:00 2001
From: "Frederick F. Kautz IV" <fkautz@alumni.cmu.edu>
Date: Sun, 15 Mar 2015 19:02:00 -0700
Subject: [PATCH] Decoding and returning objects now works

---
 pkg/storage/encoded/encoded.go | 61 ++++++++++++++++++++++++++++++++--
 1 file changed, 59 insertions(+), 2 deletions(-)

diff --git a/pkg/storage/encoded/encoded.go b/pkg/storage/encoded/encoded.go
index 0a1cecc58..0b34ddd48 100644
--- a/pkg/storage/encoded/encoded.go
+++ b/pkg/storage/encoded/encoded.go
@@ -17,6 +17,7 @@
 package encoded
 
 import (
+	"bytes"
 	"errors"
 	"github.com/minio-io/minio/pkg/donutbox"
 	"github.com/minio-io/minio/pkg/encoding/erasure"
@@ -67,7 +68,57 @@ 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) {
-	return 0, errors.New("Not Implemented")
+	metadata, err := diskStorage.donutBox.GetObjectMetadata(bucket, key, 0)
+	chunkCount, err := strconv.Atoi(metadata["chunkCount"])
+	columnCount, err := strconv.Atoi(metadata["columnCount"])
+	blockSize, err := strconv.Atoi(metadata["blockSize"])
+	length, err := strconv.Atoi(metadata["length"])
+	if err != nil {
+		return 0, err
+	}
+	var readers []io.Reader
+	for column := 0; column < columnCount; column++ {
+		reader, err := diskStorage.donutBox.GetObjectReader(bucket, key, uint(column))
+		if err != nil {
+			return 0, err
+		}
+		readers = append(readers, reader)
+	}
+
+	totalWritten := int64(length)
+	totalRemaining := int64(length)
+	if err != err {
+		return 0, err
+	}
+	params, err := erasure.ParseEncoderParams(8, 8, erasure.Cauchy)
+	decoder := erasure.NewEncoder(params)
+	for chunk := 0; chunk < chunkCount; chunk++ {
+		blocks := make([][]byte, columnCount)
+		for column := 0; column < columnCount; column++ {
+			var block bytes.Buffer
+			limitReader := io.LimitReader(readers[column], int64(blockSize))
+			_, err := io.Copy(&block, limitReader)
+			if err != nil {
+				return totalWritten, err
+			}
+			blocks[column] = block.Bytes()
+		}
+		curBlockSize := blockSize
+		if totalRemaining < int64(blockSize) {
+			curBlockSize = int(totalRemaining)
+		}
+		original, err := decoder.Decode(blocks, curBlockSize)
+		if err != nil {
+			return totalWritten, err
+		}
+		curWritten, err := io.Copy(target, bytes.NewBuffer(original))
+		totalRemaining = totalRemaining - curWritten
+		if err != nil {
+			return totalWritten, err
+		}
+	}
+
+	return totalWritten, nil
 }
 
 // GetPartialObject retrieves an object and writes it to a writer
@@ -100,12 +151,14 @@ func (diskStorage StorageDriver) CreateObject(bucketKey string, objectKey string
 		writers[i] = newWriter
 	}
 	totalLength := uint64(0)
+	chunkCount := 0
 	for chunk := range splitStream {
 		params, err := erasure.ParseEncoderParams(8, 8, erasure.Cauchy)
 		if err != nil {
 			return err
 		}
 		totalLength = totalLength + uint64(len(chunk.Data))
+		chunkCount = chunkCount + 1
 		encoder := erasure.NewEncoder(params)
 		if chunk.Err == nil {
 			parts, _ := encoder.Encode(chunk.Data)
@@ -123,16 +176,20 @@ func (diskStorage StorageDriver) CreateObject(bucketKey string, objectKey string
 		// write
 	}
 	// close connections
-	closeAllWriters(writers)
 
 	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
 	for column := uint(0); column < 16; column++ {
 		writers[column].SetMetadata(metadata)
 	}
 
+	// TODO capture errors in writers, enough should pass before returning
+	closeAllWriters(writers)
+
 	return nil
 }