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, 12 insertions, 3 deletions

diff --git a/blame.go b/blame.go
index 7dc2cc0..3eb4c35 100644
--- a/blame.go
+++ b/blame.go
@@ -82,7 +82,10 @@ func (c *Commit) Blame(path string) (*Blame, error) {
 	if err != nil {
 		return nil, err
 	}
-	finalLines := file.Lines()
+	finalLines, err := file.Lines()
+	if err != nil {
+		return nil, err
+	}
 
 	lines, err := newLines(finalLines, b.sliceGraph(len(b.graph)-1))
 	if err != nil {
@@ -153,7 +156,10 @@ func (b *blame) fillGraphAndData() error {
 		if err != nil {
 			return nil
 		}
-		b.data[i] = file.Contents()
+		b.data[i], err = file.Contents()
+		if err != nil {
+			return err
+		}
 		nLines := countLines(b.data[i])
 		// create a node for each line
 		b.graph[i] = make([]*Commit, nLines)
@@ -221,7 +227,10 @@ func (b *blame) GoString() string {
 	if err != nil {
 		panic("PrettyPrint: internal error in repo.Data")
 	}
-	contents := file.Contents()
+	contents, err := file.Contents()
+	if err != nil {
+		panic("PrettyPrint: internal error in repo.Data")
+	}
 
 	lines := strings.Split(contents, "\n")
 	// max line number length