Refactor to use core.ObjectReader and core.ObjectWriter

* New function signatures provide the necessary interface to stream data from disk when using filesystem-based storage in the future
* New function signatures provide proper error handling
* ObjectReader and ObjectWriter interfaces added to avoid future refactoring, currently are type aliases for io.ReadCloser and io.WriteCloser respectively
* Object.Reader now returns (ObjectReader, error)
* Object.Writer now returns (ObjectWriter, error)
* File.Contents now returns (string, error)
* File.Lines now returns ([]string, error)
* Blob.Reader now returns (core.ObjectReader, error)
* Added internal close helper function for deferred calls to Close that need to check the return value

1 files changed, 8 insertions, 2 deletions

diff --git a/references.go b/references.go
index 593b975..29f9a71 100644
--- a/references.go
+++ b/references.go
@@ -178,7 +178,10 @@ func patch(c *Commit, path string) ([]diffmatchpatch.Diff, error) {
 	if err != nil {
 		return nil, err
 	}
-	content := file.Contents()
+	content, err := file.Contents()
+	if err != nil {
+		return nil, err
+	}
 
 	// get contents of the file in the first parent of the commit
 	var contentParent string
@@ -191,7 +194,10 @@ func patch(c *Commit, path string) ([]diffmatchpatch.Diff, error) {
 	if err != nil {
 		contentParent = ""
 	} else {
-		contentParent = file.Contents()
+		contentParent, err = file.Contents()
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	// compare the contents of parent and child