handler type documenation improvements

Fixes pkg#221

request-interfaces.go

@@ -8,22 +8,29 @@ import (
 // Interfaces are differentiated based on required returned values.
 // All input arguments are to be pulled from Request (the only arg).
 
-// FileReader should return an io.Reader for the filepath
+// FileReader should return an io.ReaderAt for the filepath
+// Note in cases of an error, the error text will be sent to the client.
 type FileReader interface {
 	Fileread(*Request) (io.ReaderAt, error)
 }
 
-// FileWriter should return an io.Writer for the filepath
+// FileWriter should return an io.WriterAt for the filepath.
+//
+// The request server code will call Close() on the returned io.WriterAt
+// ojbect if an io.Closer type assertion succeeds.
+// Note in cases of an error, the error text will be sent to the client.
 type FileWriter interface {
 	Filewrite(*Request) (io.WriterAt, error)
 }
 
-// FileCmder should return an error (rename, remove, setstate, etc.)
+// FileCmder should return an error
+// Note in cases of an error, the error text will be sent to the client.
 type FileCmder interface {
 	Filecmd(*Request) error
 }
 
-// FileLister should return file info interface and errors (readdir, stat)
+// FileLister should return an object that fulfils the ListerAt interface
+// Note in cases of an error, the error text will be sent to the client.
 type FileLister interface {
 	Filelist(*Request) (ListerAt, error)
 }
@@ -33,6 +40,7 @@ type FileLister interface {
 // error if at end of list. This is testable by comparing how many you
 // copied to how many could be copied (eg. n < len(ls) below).
 // The copy() builtin is best for the copying.
+// Note in cases of an error, the error text will be sent to the client.
 type ListerAt interface {
 	ListAt([]os.FileInfo, int64) (int, error)
 }