add cmd/dump - a dumper

Walk needed to be added to NeedleMap and CompactMap, to be able to add WalkKeys and WalkValues to volume. This is needed for iterating through all the stored needles in a volume - this was dump's purpose.

weed-fs/src/cmd/weed/command.go

@@ -1,53 +1,52 @@
 package main
 
 import (
-  "flag"
-  "fmt"
-  "os"
-  "strings"
+	"flag"
+	"fmt"
+	"os"
+	"strings"
 )
 
 type Command struct {
-  // Run runs the command.
-  // The args are the arguments after the command name.
-  Run func(cmd *Command, args []string) bool
+	// Run runs the command.
+	// The args are the arguments after the command name.
+	Run func(cmd *Command, args []string) bool
 
-  // UsageLine is the one-line usage message.
-  // The first word in the line is taken to be the command name.
-  UsageLine string
+	// UsageLine is the one-line usage message.
+	// The first word in the line is taken to be the command name.
+	UsageLine string
 
-  // Short is the short description shown in the 'go help' output.
-  Short string
+	// Short is the short description shown in the 'go help' output.
+	Short string
 
-  // Long is the long message shown in the 'go help <this-command>' output.
-  Long string
-
-  // Flag is a set of flags specific to this command.
-  Flag flag.FlagSet
+	// Long is the long message shown in the 'go help <this-command>' output.
+	Long string
 
+	// Flag is a set of flags specific to this command.
+	Flag flag.FlagSet
 }
 
 // Name returns the command's name: the first word in the usage line.
 func (c *Command) Name() string {
-  name := c.UsageLine
-  i := strings.Index(name, " ")
-  if i >= 0 {
-    name = name[:i]
-  }
-  return name
+	name := c.UsageLine
+	i := strings.Index(name, " ")
+	if i >= 0 {
+		name = name[:i]
+	}
+	return name
 }
 
 func (c *Command) Usage() {
-  fmt.Fprintf(os.Stderr, "Example: weed %s\n", c.UsageLine)
-  fmt.Fprintf(os.Stderr, "Default Usage:\n")
-  c.Flag.PrintDefaults()
-  fmt.Fprintf(os.Stderr, "Description:\n")
-  fmt.Fprintf(os.Stderr, "  %s\n", strings.TrimSpace(c.Long))
-  os.Exit(2)
+	fmt.Fprintf(os.Stderr, "Example: weed %s\n", c.UsageLine)
+	fmt.Fprintf(os.Stderr, "Default Usage:\n")
+	c.Flag.PrintDefaults()
+	fmt.Fprintf(os.Stderr, "Description:\n")
+	fmt.Fprintf(os.Stderr, "  %s\n", strings.TrimSpace(c.Long))
+	os.Exit(2)
 }
 
 // Runnable reports whether the command can be run; otherwise
 // it is a documentation pseudo-command such as importpath.
 func (c *Command) Runnable() bool {
-  return c.Run != nil
+	return c.Run != nil
 }