From 278f52b1d072d4657ce38f6f11488e1f4c6f22c1 Mon Sep 17 00:00:00 2001
From: Harshavardhana <harsha@minio.io>
Date: Fri, 16 Jun 2017 01:34:04 -0700
Subject: [PATCH] For GCS the size limit of S3 is not useful.

This change allows for the GCS server to reject
if needed.

For size == -1 we just use `Transfer-Encoding: chunked`
For size >= 0 we just use regular upload operation.

Related to https://github.com/restic/restic/issues/996
---
 api-put-object-file.go     | 11 +----------
 api-put-object-progress.go | 14 +-------------
 api-put-object.go          | 15 +++++----------
 api.go                     |  8 +++++---
 4 files changed, 12 insertions(+), 36 deletions(-)

diff --git a/api-put-object-file.go b/api-put-object-file.go
index fc475c9a3..eafa302fc 100644
--- a/api-put-object-file.go
+++ b/api-put-object-file.go
@@ -77,17 +77,8 @@ func (c Client) FPutObject(bucketName, objectName, filePath, contentType string)
 	objMetadata["Content-Type"] = []string{contentType}
 
 	// NOTE: Google Cloud Storage multipart Put is not compatible with Amazon S3 APIs.
-	// Current implementation will only upload a maximum of 5GiB to Google Cloud Storage servers.
 	if s3utils.IsGoogleEndpoint(c.endpointURL) {
-		if fileSize > int64(maxSinglePutObjectSize) {
-			return 0, ErrorResponse{
-				Code:       "NotImplemented",
-				Message:    fmt.Sprintf("Invalid Content-Length %d for file uploads to Google Cloud Storage.", fileSize),
-				Key:        objectName,
-				BucketName: bucketName,
-			}
-		}
-		// Do not compute MD5 for Google Cloud Storage. Uploads up to 5GiB in size.
+		// Do not compute MD5 for Google Cloud Storage.
 		return c.putObjectNoChecksum(bucketName, objectName, fileReader, fileSize, objMetadata, nil)
 	}
 
diff --git a/api-put-object-progress.go b/api-put-object-progress.go
index e5b24ad2a..abf5b75d5 100644
--- a/api-put-object-progress.go
+++ b/api-put-object-progress.go
@@ -83,20 +83,8 @@ func (c Client) PutObjectWithMetadata(bucketName, objectName string, reader io.R
 	}
 
 	// NOTE: Google Cloud Storage does not implement Amazon S3 Compatible multipart PUT.
-	// So we fall back to single PUT operation with the maximum limit of 5GiB.
 	if s3utils.IsGoogleEndpoint(c.endpointURL) {
-		if size <= -1 {
-			return 0, ErrorResponse{
-				Code:       "NotImplemented",
-				Message:    "Content-Length cannot be negative for file uploads to Google Cloud Storage.",
-				Key:        objectName,
-				BucketName: bucketName,
-			}
-		}
-		if size > maxSinglePutObjectSize {
-			return 0, ErrEntityTooLarge(size, maxSinglePutObjectSize, bucketName, objectName)
-		}
-		// Do not compute MD5 for Google Cloud Storage. Uploads up to 5GiB in size.
+		// Do not compute MD5 for Google Cloud Storage.
 		return c.putObjectNoChecksum(bucketName, objectName, reader, size, metaData, progress)
 	}
 
diff --git a/api-put-object.go b/api-put-object.go
index e61f305cb..1668768e1 100644
--- a/api-put-object.go
+++ b/api-put-object.go
@@ -166,8 +166,11 @@ func (c Client) putObjectNoChecksum(bucketName, objectName string, reader io.Rea
 	if err := isValidObjectName(objectName); err != nil {
 		return 0, err
 	}
-	if size > maxSinglePutObjectSize {
-		return 0, ErrEntityTooLarge(size, maxSinglePutObjectSize, bucketName, objectName)
+	if size > 0 {
+		readerAt, ok := reader.(io.ReaderAt)
+		if ok {
+			reader = io.NewSectionReader(readerAt, 0, size)
+		}
 	}
 
 	// Update progress reader appropriately to the latest offset as we
@@ -260,14 +263,6 @@ func (c Client) putObjectDo(bucketName, objectName string, reader io.Reader, md5
 		return ObjectInfo{}, err
 	}
 
-	if size <= -1 {
-		return ObjectInfo{}, ErrEntityTooSmall(size, bucketName, objectName)
-	}
-
-	if size > maxSinglePutObjectSize {
-		return ObjectInfo{}, ErrEntityTooLarge(size, maxSinglePutObjectSize, bucketName, objectName)
-	}
-
 	// Set headers.
 	customHeader := make(http.Header)
 
diff --git a/api.go b/api.go
index 0e89cfa55..f9bfe7ccc 100644
--- a/api.go
+++ b/api.go
@@ -632,9 +632,11 @@ func (c Client) newRequest(method string, metadata requestMetadata) (req *http.R
 		req.Header.Set(k, v[0])
 	}
 
-	// set incoming content-length.
-	if metadata.contentLength > 0 {
-		req.ContentLength = metadata.contentLength
+	// Set incoming content-length.
+	req.ContentLength = metadata.contentLength
+	if req.ContentLength <= -1 {
+		// For unknown content length, we upload using transfer-encoding: chunked.
+		req.TransferEncoding = []string{"chunked"}
 	}
 
 	// set md5Sum for content protection.