// Buckets meta prefix.
	bucketMetaPrefix = "buckets"

	// Deleted Buckets prefix.
	deletedBucketsPrefix = ".deleted"

	// ETag (hex encoded md5sum) of empty string.
	emptyETag = "d41d8cd98f00b204e9800998ecf8427e"
)

// Global object layer mutex, used for safely updating object layer.
var globalObjLayerMutex sync.RWMutex

// Global object layer, only accessed by globalObjectAPI.
var globalObjectAPI ObjectLayer

		6: {
			bucketName: bucket, objName: object, inputData: []byte(""),
			inputMeta:     map[string]string{"etag": "d41d8cd98f00b204e9800998ecf8427f"},
			expectedError: hash.BadDigest{ExpectedMD5: "d41d8cd98f00b204e9800998ecf8427f", CalculatedMD5: "d41d8cd98f00b204e9800998ecf8427e"},
		},

		// With incorrect sha256.
		7: {
			bucketName: bucket, objName: object, inputData: []byte("abcd"),

		// Test case - 12.
		// Input to replicate Md5 mismatch.
		{
			bucketName: bucket, objName: object, uploadID: uploadID, PartID: 1, inputMd5: "d41d8cd98f00b204e9800998ecf8427f",
			expectedError: hash.BadDigest{ExpectedMD5: "d41d8cd98f00b204e9800998ecf8427f", CalculatedMD5: "d41d8cd98f00b204e9800998ecf8427e"},
		},
		// Test case - 13.
		// When incorrect sha256 is provided.
		{