Export context constructed from Raw MFT file. (#92)

It is possible to create an ntfs context from an MFT raw file.

parser/easy.go

@@ -44,6 +44,27 @@ type FileInfo struct {
 	SlackOffset int64 `json:"SlackOffset,omitempty"`
 }
 
+// Build an NTFS Context from the raw MFT file. NOTE: This approach
+// has some shortcomings which callers should be aware of:
+
+// 1. There is no image other than the provided MFT so any MFT
+// attributes with external clusters will return empty data.
+
+// 2. The cluster size and MFT record size are not known (These are
+// specified in the boot sector) so callers will have to guess those.
+func GetNTFSContextFromRawMFT(reader io.ReaderAt,
+	cluster_size int64,
+	record_size int64) *NTFSContext {
+
+	ntfs := newNTFSContext(&NullReader{}, "NullReader")
+
+	ntfs.MFTReader = reader
+	ntfs.ClusterSize = cluster_size
+	ntfs.RecordSize = record_size
+
+	return ntfs
+}
+
 func GetNTFSContext(image io.ReaderAt, offset int64) (*NTFSContext, error) {
 	ntfs := newNTFSContext(image, "GetNTFSContext")
 

parser/mft.go

@@ -444,12 +444,10 @@ func ParseMFTFileWithOptions(
 	go func() {
 		defer close(output)
 
-		ntfs := newNTFSContext(&NullReader{}, "NullReader")
+		ntfs := GetNTFSContextFromRawMFT(
+			reader, cluster_size, record_size)
 		defer ntfs.Close()
 
-		ntfs.MFTReader = reader
-		ntfs.ClusterSize = cluster_size
-		ntfs.RecordSize = record_size
 		ntfs.SetOptions(options)
 
 		for id := start_entry; id < size/record_size+1; id++ {