kubo/cmd/ipfs/refs.go

package main

import (
	"github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/gonuts/flag"
	"github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/commander"
	mh "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multihash"
	mdag "github.com/jbenet/go-ipfs/merkledag"
	u "github.com/jbenet/go-ipfs/util"
)

var cmdIpfsRefs = &commander.Command{
	UsageLine: "refs",
	Short:     "List link hashes from an object.",
	Long: `ipfs refs <ipfs-path> - List link hashes from an object..

    Retrieves the object named by <ipfs-path> and displays the link
    hashes it contains, with the following format:

    <link base58 hash>

    Note: list all refs recursively with -r.

`,
	Run:  refCmd,
	Flag: *flag.NewFlagSet("ipfs-refs", flag.ExitOnError),
}

func init() {
	cmdIpfsRefs.Flag.Bool("r", false, "recursive: list refs recursively")
	cmdIpfsRefs.Flag.Bool("u", false, "unique: list each ref only once")
}

func refCmd(c *commander.Command, inp []string) error {
	if len(inp) < 1 {
		u.POut(c.Long)
		return nil
	}

	n, err := localNode(false)
	if err != nil {
		return err
	}

	recursive := c.Flag.Lookup("r").Value.Get().(bool)
	unique := c.Flag.Lookup("u").Value.Get().(bool)
	refsSeen := map[u.Key]bool{}

	printRef := func(h mh.Multihash) {
		if unique {
			_, found := refsSeen[u.Key(h)]
			if found {
				return
			}
			refsSeen[u.Key(h)] = true
		}

		u.POut("%s\n", h.B58String())
	}

	var printRefs func(nd *mdag.Node, recursive bool)
	printRefs = func(nd *mdag.Node, recursive bool) {

		for _, link := range nd.Links {
			printRef(link.Hash)

			if recursive {
				nd, err := n.DAG.Get(u.Key(link.Hash))
				if err != nil {
					u.PErr("error: cannot retrieve %s (%s)\n", link.Hash.B58String(), err)
					return
				}

				printRefs(nd, recursive)
			}
		}
	}

	for _, fn := range inp {
		nd, err := n.Resolver.ResolvePath(fn)
		if err != nil {
			return err
		}

		printRefs(nd, recursive)
	}
	return nil
}