Merge pull request #5385 from ipfs/kevina/cid-cmd

Provide new "cid" sub-command.

Author: Stebalien

cmd/ipfs/ipfs.go

@@ -92,4 +92,5 @@ var cmdDetailsMap = map[string]cmdDetails{
 	"diag/cmds":   {cannotRunOnClient: true},
 	"repo/fsck":   {cannotRunOnDaemon: true},
 	"config/edit": {cannotRunOnDaemon: true, doesNotUseRepo: true},
+	"cid":         {doesNotUseRepo: true},
 }

core/commands/cid.go

@@ -0,0 +1,349 @@
+package commands
+
+import (
+	"fmt"
+	"io"
+	"sort"
+	"strings"
+	"unicode"
+
+	"github.com/ipfs/go-ipfs/core/commands/e"
+
+	cid "gx/ipfs/QmPSQnBKM9g7BaUcZCvswUJVscQ1ipjmwxN5PXCjkp9EQ7/go-cid"
+	mhash "gx/ipfs/QmPnFwZ2JXKnXgMw8CdBPxn7FWh6LLdjUjxV1fKHuJnkr8/go-multihash"
+	cidutil "gx/ipfs/QmQJSeE3CX4zos9qeaG8EhecEK9zvrTEfTG84J8C5NVRwt/go-cidutil"
+	cmdkit "gx/ipfs/QmSP88ryZkHSRn1fnngAaV2Vcn63WUJzAavnRM9CVdU1Ky/go-ipfs-cmdkit"
+	verifcid "gx/ipfs/QmVkMRSkXrpjqrroEXWuYBvDBnXCdMMY6gsKicBGVGUqKT/go-verifcid"
+	cmds "gx/ipfs/QmXTmUCBtDUrzDYVzASogLiNph7EBuYqEgPL7QoHNMzUnz/go-ipfs-cmds"
+	mbase "gx/ipfs/QmekxXDhCxCJRNuzmHreuaT3BsuJcsjcXWNrtV9C8DRHtd/go-multibase"
+)
+
+var CidCmd = &cmds.Command{
+	Helptext: cmdkit.HelpText{
+		Tagline: "Convert and discover properties of CIDs",
+	},
+	Subcommands: map[string]*cmds.Command{
+		"format": cidFmtCmd,
+		"base32": base32Cmd,
+		"bases":  basesCmd,
+		"codecs": codecsCmd,
+		"hashes": hashesCmd,
+	},
+}
+
+var cidFmtCmd = &cmds.Command{
+	Helptext: cmdkit.HelpText{
+		Tagline: "Format and convert a CID in various useful ways.",
+		LongDescription: `
+Format and converts <cid>'s in various useful ways.
+
+The optional format string is a printf style format string:
+` + cidutil.FormatRef,
+	},
+	Arguments: []cmdkit.Argument{
+		cmdkit.StringArg("cid", true, true, "Cids to format.").EnableStdin(),
+	},
+	Options: []cmdkit.Option{
+		cmdkit.StringOption("f", "Printf style format string.").WithDefault("%s"),
+		cmdkit.StringOption("v", "CID version to convert to."),
+		cmdkit.StringOption("b", "Multibase to display CID in."),
+	},
+	Run: func(req *cmds.Request, resp cmds.ResponseEmitter, env cmds.Environment) error {
+		fmtStr, _ := req.Options["f"].(string)
+		verStr, _ := req.Options["v"].(string)
+		baseStr, _ := req.Options["b"].(string)
+
+		opts := cidFormatOpts{}
+
+		if strings.IndexByte(fmtStr, '%') == -1 {
+			return fmt.Errorf("invalid format string: %s", fmtStr)
+		}
+		opts.fmtStr = fmtStr
+
+		switch verStr {
+		case "":
+			// noop
+		case "0":
+			opts.verConv = toCidV0
+		case "1":
+			opts.verConv = toCidV1
+		default:
+			return fmt.Errorf("invalid cid version: %s", verStr)
+		}
+
+		if baseStr != "" {
+			encoder, err := mbase.EncoderByName(baseStr)
+			if err != nil {
+				return err
+			}
+			opts.newBase = encoder.Encoding()
+		} else {
+			opts.newBase = mbase.Encoding(-1)
+		}
+
+		return emitCids(req, resp, opts)
+	},
+	PostRun: cmds.PostRunMap{
+		cmds.CLI: streamResult(func(v interface{}, out io.Writer) nonFatalError {
+			r := v.(*CidFormatRes)
+			if r.ErrorMsg != "" {
+				return nonFatalError(fmt.Sprintf("%s: %s", r.CidStr, r.ErrorMsg))
+			}
+			fmt.Fprintf(out, "%s\n", r.Formatted)
+			return ""
+		}),
+	},
+	Type: CidFormatRes{},
+}
+
+type CidFormatRes struct {
+	CidStr    string // Original Cid String passed in
+	Formatted string // Formated Result
+	ErrorMsg  string // Error
+}
+
+var base32Cmd = &cmds.Command{
+	Helptext: cmdkit.HelpText{
+		Tagline: "Convert CIDs to Base32 CID version 1.",
+	},
+	Arguments: []cmdkit.Argument{
+		cmdkit.StringArg("cid", true, true, "Cids to convert.").EnableStdin(),
+	},
+	Run: func(req *cmds.Request, resp cmds.ResponseEmitter, env cmds.Environment) error {
+		opts := cidFormatOpts{
+			fmtStr:  "%s",
+			newBase: mbase.Encoding(mbase.Base32),
+			verConv: toCidV1,
+		}
+		return emitCids(req, resp, opts)
+	},
+	PostRun: cidFmtCmd.PostRun,
+	Type:    cidFmtCmd.Type,
+}
+
+type cidFormatOpts struct {
+	fmtStr  string
+	newBase mbase.Encoding
+	verConv func(cid cid.Cid) (cid.Cid, error)
+}
+
+type argumentIterator struct {
+	args []string
+	body cmds.StdinArguments
+}
+
+func (i *argumentIterator) next() (string, bool) {
+	if len(i.args) > 0 {
+		arg := i.args[0]
+		i.args = i.args[1:]
+		return arg, true
+	}
+	if i.body == nil || !i.body.Scan() {
+		return "", false
+	}
+	return strings.TrimSpace(i.body.Argument()), true
+}
+
+func (i *argumentIterator) err() error {
+	if i.body == nil {
+		return nil
+	}
+	return i.body.Err()
+}
+
+func emitCids(req *cmds.Request, resp cmds.ResponseEmitter, opts cidFormatOpts) error {
+	itr := argumentIterator{req.Arguments, req.BodyArgs()}
+	var emitErr error
+	for emitErr == nil {
+		cidStr, ok := itr.next()
+		if !ok {
+			break
+		}
+		res := &CidFormatRes{CidStr: cidStr}
+		c, err := cid.Decode(cidStr)
+		if err != nil {
+			res.ErrorMsg = err.Error()
+			emitErr = resp.Emit(res)
+			continue
+		}
+		base := opts.newBase
+		if base == -1 {
+			base, _ = cid.ExtractEncoding(cidStr)
+		}
+		if opts.verConv != nil {
+			c, err = opts.verConv(c)
+			if err != nil {
+				res.ErrorMsg = err.Error()
+				emitErr = resp.Emit(res)
+				continue
+			}
+		}
+		str, err := cidutil.Format(opts.fmtStr, base, c)
+		if _, ok := err.(cidutil.FormatStringError); ok {
+			// no point in continuing if there is a problem with the format string
+			return err
+		}
+		if err != nil {
+			res.ErrorMsg = err.Error()
+		} else {
+			res.Formatted = str
+		}
+		emitErr = resp.Emit(res)
+	}
+	if emitErr != nil {
+		return emitErr
+	}
+	err := itr.err()
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func toCidV0(c cid.Cid) (cid.Cid, error) {
+	if c.Type() != cid.DagProtobuf {
+		return cid.Cid{}, fmt.Errorf("can't convert non-protobuf nodes to cidv0")
+	}
+	return cid.NewCidV0(c.Hash()), nil
+}
+
+func toCidV1(c cid.Cid) (cid.Cid, error) {
+	return cid.NewCidV1(c.Type(), c.Hash()), nil
+}
+
+type CodeAndName struct {
+	Code int
+	Name string
+}
+
+var basesCmd = &cmds.Command{
+	Helptext: cmdkit.HelpText{
+		Tagline: "List available multibase encodings.",
+	},
+	Options: []cmdkit.Option{
+		cmdkit.BoolOption("prefix", "also include the single leter prefixes in addition to the code"),
+		cmdkit.BoolOption("numeric", "also include numeric codes"),
+	},
+	Run: func(req *cmds.Request, resp cmds.ResponseEmitter, env cmds.Environment) error {
+		var res []CodeAndName
+		// use EncodingToStr in case at some point there are multiple names for a given code
+		for code, name := range mbase.EncodingToStr {
+			res = append(res, CodeAndName{int(code), name})
+		}
+		cmds.EmitOnce(resp, res)
+		return nil
+	},
+	Encoders: cmds.EncoderMap{
+		cmds.Text: cmds.MakeEncoder(func(req *cmds.Request, w io.Writer, val0 interface{}) error {
+			prefixes, _ := req.Options["prefix"].(bool)
+			numeric, _ := req.Options["numeric"].(bool)
+			val, ok := val0.([]CodeAndName)
+			if !ok {
+				return e.TypeErr(val, val0)
+			}
+			sort.Sort(multibaseSorter{val})
+			for _, v := range val {
+				code := v.Code
+				if code < 32 || code >= 127 {
+					// don't display non-printable prefixes
+					code = ' '
+				}
+				switch {
+				case prefixes && numeric:
+					fmt.Fprintf(w, "%c %5d  %s\n", code, v.Code, v.Name)
+				case prefixes:
+					fmt.Fprintf(w, "%c  %s\n", code, v.Name)
+				case numeric:
+					fmt.Fprintf(w, "%5d  %s\n", v.Code, v.Name)
+				default:
+					fmt.Fprintf(w, "%s\n", v.Name)
+				}
+			}
+			return nil
+		}),
+	},
+	Type: []CodeAndName{},
+}
+
+var codecsCmd = &cmds.Command{
+	Helptext: cmdkit.HelpText{
+		Tagline: "List available CID codecs.",
+	},
+	Options: []cmdkit.Option{
+		cmdkit.BoolOption("numeric", "also include numeric codes"),
+	},
+	Run: func(req *cmds.Request, resp cmds.ResponseEmitter, env cmds.Environment) error {
+		var res []CodeAndName
+		// use CodecToStr as there are multiple names for a given code
+		for code, name := range cid.CodecToStr {
+			res = append(res, CodeAndName{int(code), name})
+		}
+		cmds.EmitOnce(resp, res)
+		return nil
+	},
+	Encoders: cmds.EncoderMap{
+		cmds.Text: cmds.MakeEncoder(func(req *cmds.Request, w io.Writer, val0 interface{}) error {
+			numeric, _ := req.Options["numeric"].(bool)
+			val, ok := val0.([]CodeAndName)
+			if !ok {
+				return e.TypeErr(val, val0)
+			}
+			sort.Sort(codeAndNameSorter{val})
+			for _, v := range val {
+				if numeric {
+					fmt.Fprintf(w, "%5d  %s\n", v.Code, v.Name)
+				} else {
+					fmt.Fprintf(w, "%s\n", v.Name)
+				}
+			}
+			return nil
+		}),
+	},
+	Type: []CodeAndName{},
+}
+
+var hashesCmd = &cmds.Command{
+	Helptext: cmdkit.HelpText{
+		Tagline: "List available multihashes.",
+	},
+	Options: codecsCmd.Options,
+	Run: func(req *cmds.Request, resp cmds.ResponseEmitter, env cmds.Environment) error {
+		var res []CodeAndName
+		// use mhash.Codes in case at some point there are multiple names for a given code
+		for code, name := range mhash.Codes {
+			if !verifcid.IsGoodHash(code) {
+				continue
+			}
+			res = append(res, CodeAndName{int(code), name})
+		}
+		cmds.EmitOnce(resp, res)
+		return nil
+	},
+	Encoders: codecsCmd.Encoders,
+	Type:     codecsCmd.Type,
+}
+
+type multibaseSorter struct {
+	data []CodeAndName
+}
+
+func (s multibaseSorter) Len() int      { return len(s.data) }
+func (s multibaseSorter) Swap(i, j int) { s.data[i], s.data[j] = s.data[j], s.data[i] }
+
+func (s multibaseSorter) Less(i, j int) bool {
+	a := unicode.ToLower(rune(s.data[i].Code))
+	b := unicode.ToLower(rune(s.data[j].Code))
+	if a != b {
+		return a < b
+	}
+	// lowecase letters should come before uppercase
+	return s.data[i].Code > s.data[j].Code
+}
+
+type codeAndNameSorter struct {
+	data []CodeAndName
+}
+
+func (s codeAndNameSorter) Len() int           { return len(s.data) }
+func (s codeAndNameSorter) Swap(i, j int)      { s.data[i], s.data[j] = s.data[j], s.data[i] }
+func (s codeAndNameSorter) Less(i, j int) bool { return s.data[i].Code < s.data[j].Code }