diff/patch features in readme, c4 fixes

Author: mrjoshuak

Readme.md

@@ -4,14 +4,38 @@ Work in progress.
 
 ## Features
 
-- Walk 
-    + Walk walks a absfs.FileSystem similar to the filepath Walk standard library function.
+- Walk
+    + Walk walks a absfs.FileSystem similar to the filepath Walk standard
+      library function.
 
 - WalkWithOptions
-    + Adds the ability to specify options for how a walk is performed. Such as if directories are sorted and in what order, normal or fast walk, traversal order, symbolic link handling and more.
+    + Adds the ability to specify options for how a walk is performed. Such as
+      if directories are sorted and in what order, normal or fast walk,
+      traversal order, symbolic link handling and more.
 
-- Copy
-    + Copy copies filesystem structures form one filesystem to another with a options to filter what is copied, and transform the data during the copy process.
+- PreOrder, PostOrder, InOrder and BreadthFirst Walkers
+    + Additional walking strategies for ordered traversal of file systems.
 
+- Copy
+    + Copy copies filesystem structures form one filesystem to another with
+      options for selecting and transforming what is copied.
+
+- Describe
+    + Creates a data structure that describes a file system. The description
+      contains basic metadata as found in `os.FileInfo`, the identification
+      of file data and directories using a (c4 Id)[https://github.com/Avalanche-io/c4],
+      and can be serialized into JSON, YAML, CUE and other formats.
+
+- Diff
+    + Returns the difference between two file system descriptions.
+
+- Patch
+    + Given a file system that matches the first file system in a Diff, and a
+      c4 data source Patch will transform the file system to match the second
+      file system in a diff. Requires a c4 data source.
+
+- Apply
+    + Apply takes a file system, c4 data source, and file system description and
+      transforms the file system to match the description.
 
 

time_test.go

@@ -22,7 +22,7 @@ import (
 )
 
 type fileinfo struct {
-	Digest     c4.Digest   // 64
+	Id         c4.ID       // 64
 	Size       int64       // 8
 	TotalSize  int64       // 8
 	Mode       os.FileMode // 4
@@ -34,7 +34,7 @@ type fileinfo struct {
 
 func (i *fileinfo) MarshalBinary() (data []byte, err error) {
 	data = make([]byte, 118+len(i.Name))
-	copy(data[0:64], i.Digest)
+	copy(data[0:64], i.Id[:])
 	binary.LittleEndian.PutUint64(data[64:72], uint64(i.Size))
 	binary.LittleEndian.PutUint64(data[72:80], uint64(i.TotalSize))
 	binary.LittleEndian.PutUint32(data[80:84], uint32(i.Mode))
@@ -56,7 +56,7 @@ func (i *fileinfo) MarshalBinary() (data []byte, err error) {
 }
 
 func (i *fileinfo) UnmarshalBinary(data []byte) error {
-	copy(i.Digest, data[0:64])
+	copy(i.Id[:], data[0:64])
 	i.Size = int64(binary.LittleEndian.Uint64(data[64:72]))
 	i.TotalSize = int64(binary.LittleEndian.Uint64(data[72:80]))
 	i.Mode = os.FileMode(binary.LittleEndian.Uint32(data[80:84]))
@@ -68,7 +68,10 @@ func (i *fileinfo) UnmarshalBinary(data []byte) error {
 }
 
 func TestTime(t *testing.T) {
-	var fs, localfs absfs.FileSystem
+
+	t.Skip("skipping test, not fully implemented")
+
+	var fs, localfs absfs.SymlinkFileSystem // FileSystem
 	var err error
 	localfs, err = osfs.NewFS()
 	if err != nil {
@@ -111,9 +114,10 @@ func TestTime(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	fmt.Printf("local walk: %s\n", time.Now().Sub(start_time))
+
+	// fmt.Printf("local walk: %s\n", time.Now().Sub(start_time))
 	start_time = time.Now()
-	fmt.Printf("cnt: %d\n", cnt)
+	// fmt.Printf("cnt: %d\n", cnt)
 	err = fstools.PostOrder(fs, nil, "/", func(path string, info os.FileInfo, err error) error {
 		metadata, err := LoadMetadata(fs, path)
 		if err != nil {