gx publish 0.7.24

cid-fmt Enhancments

.gx/lastpubver

@@ -1 +1 @@
-0.7.18: QmNp85zy9RLrQ5oQD4hPyS39ezrrXpcaa7R4Y9kxdWQLLQ
+0.7.24: Qmdu2AYUV7yMoVBQPxXNfe7FJcdx16kYtsx6jAPKWQYF1y

builder.go

@@ -0,0 +1,74 @@
+package cid
+
+import (
+	mh "github.com/multiformats/go-multihash"
+)
+
+type Builder interface {
+	Sum(data []byte) (*Cid, error)
+	GetCodec() uint64
+	WithCodec(uint64) Builder
+}
+
+type V0Builder struct{}
+
+type V1Builder struct {
+	Codec    uint64
+	MhType   uint64
+	MhLength int // MhLength <= 0 means the default length
+}
+
+func (p Prefix) GetCodec() uint64 {
+	return p.Codec
+}
+
+func (p Prefix) WithCodec(c uint64) Builder {
+	if c == p.Codec {
+		return p
+	}
+	p.Codec = c
+	if c != DagProtobuf {
+		p.Version = 1
+	}
+	return p
+}
+
+func (p V0Builder) Sum(data []byte) (*Cid, error) {
+	hash, err := mh.Sum(data, mh.SHA2_256, -1)
+	if err != nil {
+		return nil, err
+	}
+	return NewCidV0(hash), nil
+}
+
+func (p V0Builder) GetCodec() uint64 {
+	return DagProtobuf
+}
+
+func (p V0Builder) WithCodec(c uint64) Builder {
+	if c == DagProtobuf {
+		return p
+	}
+	return V1Builder{Codec: c, MhType: mh.SHA2_256}
+}
+
+func (p V1Builder) Sum(data []byte) (*Cid, error) {
+	mhLen := p.MhLength
+	if mhLen <= 0 {
+		mhLen = -1
+	}
+	hash, err := mh.Sum(data, p.MhType, mhLen)
+	if err != nil {
+		return nil, err
+	}
+	return NewCidV1(p.Codec, hash), nil
+}
+
+func (p V1Builder) GetCodec() uint64 {
+	return p.Codec
+}
+
+func (p V1Builder) WithCodec(c uint64) Builder {
+	p.Codec = c
+	return p
+}

builder_test.go

@@ -0,0 +1,92 @@
+package cid
+
+import (
+	"testing"
+
+	mh "github.com/multiformats/go-multihash"
+)
+
+func TestV0Builder(t *testing.T) {
+	data := []byte("this is some test content")
+
+	// Construct c1
+	format := V0Builder{}
+	c1, err := format.Sum(data)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Construct c2
+	hash, err := mh.Sum(data, mh.SHA2_256, -1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	c2 := NewCidV0(hash)
+
+	if !c1.Equals(c2) {
+		t.Fatal("cids mismatch")
+	}
+	if c1.Prefix() != c2.Prefix() {
+		t.Fatal("prefixes mismatch")
+	}
+}
+
+func TestV1Builder(t *testing.T) {
+	data := []byte("this is some test content")
+
+	// Construct c1
+	format := V1Builder{Codec: DagCBOR, MhType: mh.SHA2_256}
+	c1, err := format.Sum(data)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Construct c2
+	hash, err := mh.Sum(data, mh.SHA2_256, -1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	c2 := NewCidV1(DagCBOR, hash)
+
+	if !c1.Equals(c2) {
+		t.Fatal("cids mismatch")
+	}
+	if c1.Prefix() != c2.Prefix() {
+		t.Fatal("prefixes mismatch")
+	}
+}
+
+func TestCodecChange(t *testing.T) {
+	t.Run("Prefix-CidV0", func(t *testing.T) {
+		p := Prefix{Version: 0, Codec: DagProtobuf, MhType: mh.SHA2_256, MhLength: mh.DefaultLengths[mh.SHA2_256]}
+		testCodecChange(t, p)
+	})
+	t.Run("Prefix-CidV1", func(t *testing.T) {
+		p := Prefix{Version: 1, Codec: DagProtobuf, MhType: mh.SHA2_256, MhLength: mh.DefaultLengths[mh.SHA2_256]}
+		testCodecChange(t, p)
+	})
+	t.Run("V0Builder", func(t *testing.T) {
+		testCodecChange(t, V0Builder{})
+	})
+	t.Run("V1Builder", func(t *testing.T) {
+		testCodecChange(t, V1Builder{Codec: DagProtobuf, MhType: mh.SHA2_256})
+	})
+}
+
+func testCodecChange(t *testing.T, b Builder) {
+	data := []byte("this is some test content")
+
+	if b.GetCodec() != DagProtobuf {
+		t.Fatal("original builder not using Protobuf codec")
+	}
+
+	b = b.WithCodec(Raw)
+	c, err := b.Sum(data)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if c.Type() != Raw {
+		t.Fatal("new cid codec did not change to Raw")
+	}
+}

cid-fmt/main.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"bytes"
 	"fmt"
 	"os"
 	"strings"
@@ -9,38 +8,14 @@ import (
 	c "github.com/ipfs/go-cid"
 
 	mb "github.com/multiformats/go-multibase"
-	mh "github.com/multiformats/go-multihash"
 )
 
 func usage() {
 	fmt.Fprintf(os.Stderr, "usage: %s [-b multibase-code] [-v cid-version] <fmt-str> <cid> ...\n\n", os.Args[0])
-	fmt.Fprintf(os.Stderr, "<fmt-str> is either 'prefix' or a printf style format string:\n%s", fmtRef)
+	fmt.Fprintf(os.Stderr, "<fmt-str> is either 'prefix' or a printf style format string:\n%s", c.FormatRef)
 	os.Exit(2)
 }
 
-const fmtRef = `
-   %% literal %
-   %b multibase name 
-   %B multibase code
-   %v version string
-   %V version number
-   %c codec name
-   %C codec code
-   %h multihash name
-   %H multihash code
-   %L hash digest length
-   %m multihash encoded in base %b (with multibase prefix)
-   %M multihash encoded in base %b without multibase prefix
-   %d hash digest encoded in base %b (with multibase prefix)
-   %D hash digest encoded in base %b without multibase prefix
-   %s cid string encoded in base %b (1)
-   %s cid string encoded in base %b without multibase prefix
-   %P cid prefix: %v-%c-%h-%L
-
-(1) For CID version 0 the multibase must be base58btc and no prefix is
-used.  For Cid version 1 the multibase prefix is included.
-`
-
 func main() {
 	if len(os.Args) < 2 {
 		usage()
@@ -55,11 +30,12 @@ outer:
 			if len(args) < 2 {
 				usage()
 			}
-			if len(args[1]) != 1 {
-				fmt.Fprintf(os.Stderr, "Error: Invalid multibase code: %s\n", args[1])
+			encoder, err := mb.EncoderByName(args[1])
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "Error: %s\n", err.Error())
 				os.Exit(2)
 			}
-			newBase = mb.Encoding(args[1][0])
+			newBase = encoder.Encoding()
 			args = args[2:]
 		case "-v":
 			if len(args) < 2 {
@@ -93,15 +69,16 @@ outer:
 		}
 	}
 	for _, cidStr := range args[1:] {
-		base, cid, err := decode(cidStr)
+		cid, err := c.Decode(cidStr)
 		if err != nil {
 			fmt.Fprintf(os.Stdout, "!INVALID_CID!\n")
 			errorMsg("%s: %v", cidStr, err)
 			// Don't abort on a bad cid
 			continue
 		}
-		if newBase != -1 {
-			base = newBase
+		base := newBase
+		if newBase == -1 {
+			base, _ = c.ExtractEncoding(cidStr)
 		}
 		if verConv != nil {
 			cid, err = verConv(cid)
@@ -112,11 +89,18 @@ outer:
 				continue
 			}
 		}
-		str, err := fmtCid(fmtStr, base, cid)
-		if err != nil {
+		str, err := c.Format(fmtStr, base, cid)
+		switch err.(type) {
+		case c.FormatStringError:
 			fmt.Fprintf(os.Stderr, "Error: %v\n", err)
-			// An error here means a bad format string, no point in continuing
 			os.Exit(2)
+		default:
+			fmt.Fprintf(os.Stdout, "!ERROR!\n")
+			errorMsg("%s: %v", cidStr, err)
+			// Don't abort on cid specific errors
+			continue
+		case nil:
+			// no error
 		}
 		fmt.Fprintf(os.Stdout, "%s\n", str)
 	}
@@ -132,139 +116,6 @@ func errorMsg(fmtStr string, a ...interface{}) {
 	exitCode = 1
 }
 
-func decode(v string) (mb.Encoding, *c.Cid, error) {
-	if len(v) < 2 {
-		return 0, nil, c.ErrCidTooShort
-	}
-
-	if len(v) == 46 && v[:2] == "Qm" {
-		hash, err := mh.FromB58String(v)
-		if err != nil {
-			return 0, nil, err
-		}
-
-		return mb.Base58BTC, c.NewCidV0(hash), nil
-	}
-
-	base, data, err := mb.Decode(v)
-	if err != nil {
-		return 0, nil, err
-	}
-
-	cid, err := c.Cast(data)
-
-	return base, cid, err
-}
-
-const ERR_STR = "!ERROR!"
-
-func fmtCid(fmtStr string, base mb.Encoding, cid *c.Cid) (string, error) {
-	p := cid.Prefix()
-	out := new(bytes.Buffer)
-	var err error
-	for i := 0; i < len(fmtStr); i++ {
-		if fmtStr[i] != '%' {
-			out.WriteByte(fmtStr[i])
-			continue
-		}
-		i++
-		if i >= len(fmtStr) {
-			return "", fmt.Errorf("premature end of format string")
-		}
-		switch fmtStr[i] {
-		case '%':
-			out.WriteByte('%')
-		case 'b': // base name
-			out.WriteString(baseToString(base))
-		case 'B': // base code
-			out.WriteByte(byte(base))
-		case 'v': // version string
-			fmt.Fprintf(out, "cidv%d", p.Version)
-		case 'V': // version num
-			fmt.Fprintf(out, "%d", p.Version)
-		case 'c': // codec name
-			out.WriteString(codecToString(p.Codec))
-		case 'C': // codec code
-			fmt.Fprintf(out, "%d", p.Codec)
-		case 'h': // hash fun name
-			out.WriteString(hashToString(p.MhType))
-		case 'H': // hash fun code
-			fmt.Fprintf(out, "%d", p.MhType)
-		case 'L': // hash length
-			fmt.Fprintf(out, "%d", p.MhLength)
-		case 'm', 'M': // multihash encoded in base %b
-			out.WriteString(encode(base, cid.Hash(), fmtStr[i] == 'M'))
-		case 'd', 'D': // hash digest encoded in base %b
-			dec, err := mh.Decode(cid.Hash())
-			if err != nil {
-				out.WriteString(ERR_STR)
-				errorMsg("%v", err)
-				continue
-			}
-			out.WriteString(encode(base, dec.Digest, fmtStr[i] == 'D'))
-		case 's': // cid string encoded in base %b
-			str, err := cid.StringOfBase(base)
-			if err != nil {
-				out.WriteString(ERR_STR)
-				errorMsg("%v", err)
-				continue
-			}
-			out.WriteString(str)
-		case 'S': // cid string without base prefix
-			out.WriteString(encode(base, cid.Bytes(), true))
-		case 'P': // prefix
-			fmt.Fprintf(out, "cidv%d-%s-%s-%d",
-				p.Version,
-				codecToString(p.Codec),
-				hashToString(p.MhType),
-				p.MhLength,
-			)
-		default:
-			return "", fmt.Errorf("unrecognized specifier in format string: %c", fmtStr[i])
-		}
-
-	}
-	return out.String(), err
-}
-
-func baseToString(base mb.Encoding) string {
-	// FIXME: Use lookup tables when they are added to go-multibase
-	switch base {
-	case mb.Base58BTC:
-		return "base58btc"
-	default:
-		return fmt.Sprintf("base?%c", base)
-	}
-}
-
-func codecToString(num uint64) string {
-	name, ok := c.CodecToStr[num]
-	if !ok {
-		return fmt.Sprintf("codec?%d", num)
-	}
-	return name
-}
-
-func hashToString(num uint64) string {
-	name, ok := mh.Codes[num]
-	if !ok {
-		return fmt.Sprintf("hash?%d", num)
-	}
-	return name
-}
-
-func encode(base mb.Encoding, data []byte, strip bool) string {
-	str, err := mb.Encode(base, data)
-	if err != nil {
-		errorMsg("%v", err)
-		return ERR_STR
-	}
-	if strip {
-		return str[1:]
-	}
-	return str
-}
-
 func toCidV0(cid *c.Cid) (*c.Cid, error) {
 	if cid.Type() != c.DagProtobuf {
 		return nil, fmt.Errorf("can't convert non-protobuf nodes to cidv0")

cid-fmt/main_test.go

@@ -4,77 +4,13 @@ import (
 	"fmt"
 	"testing"
 
-	mb "github.com/multiformats/go-multibase"
+	c "github.com/ipfs/go-cid"
 )
 
-func TestFmt(t *testing.T) {
-	cids := map[string]string{
-		"cidv0": "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn",
-		"cidv1": "zdj7WfLr9DhLrb1hsoSi4fSdjjxuZmeqgEtBPWxMLtPbDNbFD",
-	}
-	tests := []struct {
-		cidId   string
-		newBase mb.Encoding
-		fmtStr  string
-		result  string
-	}{
-		{"cidv0", -1, "%P", "cidv0-protobuf-sha2-256-32"},
-		{"cidv0", -1, "%b-%v-%c-%h-%L", "base58btc-cidv0-protobuf-sha2-256-32"},
-		{"cidv0", -1, "%s", "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn"},
-		{"cidv0", -1, "%S", "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn"},
-		{"cidv0", -1, "ver#%V/#%C/#%H/%L", "ver#0/#112/#18/32"},
-		{"cidv0", -1, "%m", "zQmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn"},
-		{"cidv0", -1, "%M", "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn"},
-		{"cidv0", -1, "%d", "z72gdmFAgRzYHkJzKiL8MgMMRW3BTSCGyDHroPxJbxMJn"},
-		{"cidv0", -1, "%D", "72gdmFAgRzYHkJzKiL8MgMMRW3BTSCGyDHroPxJbxMJn"},
-		{"cidv0", 'B', "%S", "CIQFTFEEHEDF6KLBT32BFAGLXEZL4UWFNWM4LFTLMXQBCERZ6CMLX3Y"},
-		{"cidv0", 'B', "%B%S", "BCIQFTFEEHEDF6KLBT32BFAGLXEZL4UWFNWM4LFTLMXQBCERZ6CMLX3Y"},
-		{"cidv1", -1, "%P", "cidv1-protobuf-sha2-256-32"},
-		{"cidv1", -1, "%b-%v-%c-%h-%L", "base58btc-cidv1-protobuf-sha2-256-32"},
-		{"cidv1", -1, "%s", "zdj7WfLr9DhLrb1hsoSi4fSdjjxuZmeqgEtBPWxMLtPbDNbFD"},
-		{"cidv1", -1, "%S", "dj7WfLr9DhLrb1hsoSi4fSdjjxuZmeqgEtBPWxMLtPbDNbFD"},
-		{"cidv1", -1, "ver#%V/#%C/#%H/%L", "ver#1/#112/#18/32"},
-		{"cidv1", -1, "%m", "zQmYFbmndVP7QqAVWyKhpmMuQHMaD88pkK57RgYVimmoh5H"},
-		{"cidv1", -1, "%M", "QmYFbmndVP7QqAVWyKhpmMuQHMaD88pkK57RgYVimmoh5H"},
-		{"cidv1", -1, "%d", "zAux4gVVsLRMXtsZ9fd3tFEZN4jGYB6kP37fgoZNTc11H"},
-		{"cidv1", -1, "%D", "Aux4gVVsLRMXtsZ9fd3tFEZN4jGYB6kP37fgoZNTc11H"},
-		{"cidv1", 'B', "%s", "BAFYBEIETJGSRL3EQPQPCABV3G6IUBYTSIFVQ24XRRHD3JUETSKLTGQ7DJA"},
-		{"cidv1", 'B', "%S", "AFYBEIETJGSRL3EQPQPCABV3G6IUBYTSIFVQ24XRRHD3JUETSKLTGQ7DJA"},
-		{"cidv1", 'B', "%B%S", "BAFYBEIETJGSRL3EQPQPCABV3G6IUBYTSIFVQ24XRRHD3JUETSKLTGQ7DJA"},
-	}
-	for _, tc := range tests {
-		name := fmt.Sprintf("%s/%s", tc.cidId, tc.fmtStr)
-		if tc.newBase != -1 {
-			name = fmt.Sprintf("%s/%c", name, tc.newBase)
-		}
-		cidStr := cids[tc.cidId]
-		t.Run(name, func(t *testing.T) {
-			testFmt(t, cidStr, tc.newBase, tc.fmtStr, tc.result)
-		})
-	}
-}
-
-func testFmt(t *testing.T, cidStr string, newBase mb.Encoding, fmtStr string, result string) {
-	base, cid, err := decode(cidStr)
-	if newBase != -1 {
-		base = newBase
-	}
-	if err != nil {
-		t.Fatal(err)
-	}
-	str, err := fmtCid(fmtStr, base, cid)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if str != result {
-		t.Error(fmt.Sprintf("expected: %s; but got: %s", result, str))
-	}
-}
-
 func TestCidConv(t *testing.T) {
 	cidv0 := "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn"
 	cidv1 := "zdj7WbTaiJT1fgatdet9Ei9iDB5hdCxkbVyhyh8YTUnXMiwYi"
-	_, cid, err := decode(cidv0)
+	cid, err := c.Decode(cidv0)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -98,7 +34,7 @@ func TestCidConv(t *testing.T) {
 func TestBadCidConv(t *testing.T) {
 	// this cid is a raw leaf and should not be able to convert to cidv0
 	cidv1 := "zb2rhhzX7uSKrtQ2ZZXFAabKiKFYZrJqKY2KE1cJ8yre2GSWZ"
-	_, cid, err := decode(cidv1)
+	cid, err := c.Decode(cidv1)
 	if err != nil {
 		t.Fatal(err)
 	}

cid.go

@@ -77,6 +77,8 @@ const (
 	BitcoinTx          = 0xb1
 	ZcashBlock         = 0xc0
 	ZcashTx            = 0xc1
+	DecredBlock        = 0xe0
+	DecredTx           = 0xe1
 )
 
 // Codecs maps the name of a codec to its type
@@ -99,6 +101,8 @@ var Codecs = map[string]uint64{
 	"bitcoin-tx":           BitcoinTx,
 	"zcash-block":          ZcashBlock,
 	"zcash-tx":             ZcashTx,
+	"decred-block":         DecredBlock,
+	"decred-tx":            DecredTx,
 }
 
 // CodecToStr maps the numeric codec to its name
@@ -120,6 +124,8 @@ var CodecToStr = map[uint64]string{
 	BitcoinTx:          "bitcoin-tx",
 	ZcashBlock:         "zcash-block",
 	ZcashTx:            "zcash-tx",
+	DecredBlock:        "decred-block",
+	DecredTx:           "decred-tx",
 }
 
 // NewCidV0 returns a Cid-wrapped multihash.
@@ -207,6 +213,28 @@ func Decode(v string) (*Cid, error) {
 	return Cast(data)
 }
 
+// Extract the encoding from a Cid.  If Decode on the same string did
+// not return an error neither will this function.
+func ExtractEncoding(v string) (mbase.Encoding, error) {
+	if len(v) < 2 {
+		return -1, ErrCidTooShort
+	}
+
+	if len(v) == 46 && v[:2] == "Qm" {
+		return mbase.Base58BTC, nil
+	}
+
+	encoding := mbase.Encoding(v[0])
+
+	// check encoding is valid
+	_, err := mbase.NewEncoder(encoding)
+	if err != nil {
+		return -1, err
+	}
+
+	return encoding, nil
+}
+
 func uvError(read int) error {
 	switch {
 	case read == 0:
@@ -389,7 +417,7 @@ func (c *Cid) UnmarshalJSON(b []byte) error {
 //
 // Note that this formatting comes from the IPLD specification
 // (https://github.com/ipld/specs/tree/master/ipld)
-func (c *Cid) MarshalJSON() ([]byte, error) {
+func (c Cid) MarshalJSON() ([]byte, error) {
 	return []byte(fmt.Sprintf("{\"/\":\"%s\"}", c.String())), nil
 }
 
@@ -421,6 +449,8 @@ func (c *Cid) Prefix() Prefix {
 // that is, the Version, the Codec, the Multihash type
 // and the Multihash length. It does not contains
 // any actual content information.
+// NOTE: The use -1 in MhLength to mean default length is deprecated,
+//   use the V0Builder or V1Builder structures instead
 type Prefix struct {
 	Version  uint64
 	Codec    uint64

cid_test.go

@@ -33,6 +33,8 @@ var tCodecs = map[uint64]string{
 	BitcoinTx:          "bitcoin-tx",
 	ZcashBlock:         "zcash-block",
 	ZcashTx:            "zcash-tx",
+	DecredBlock:        "decred-block",
+	DecredTx:           "decred-tx",
 }
 
 func assertEqual(t *testing.T, a, b *Cid) {
@@ -189,6 +191,64 @@ func TestV0ErrorCases(t *testing.T) {
 	}
 }
 
+func TestNewPrefixV1(t *testing.T) {
+	data := []byte("this is some test content")
+
+	// Construct c1
+	prefix := NewPrefixV1(DagCBOR, mh.SHA2_256)
+	c1, err := prefix.Sum(data)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if c1.Prefix() != prefix {
+		t.Fatal("prefix not preserved")
+	}
+
+	// Construct c2
+	hash, err := mh.Sum(data, mh.SHA2_256, -1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	c2 := NewCidV1(DagCBOR, hash)
+
+	if !c1.Equals(c2) {
+		t.Fatal("cids mismatch")
+	}
+	if c1.Prefix() != c2.Prefix() {
+		t.Fatal("prefixes mismatch")
+	}
+}
+
+func TestNewPrefixV0(t *testing.T) {
+	data := []byte("this is some test content")
+
+	// Construct c1
+	prefix := NewPrefixV0(mh.SHA2_256)
+	c1, err := prefix.Sum(data)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if c1.Prefix() != prefix {
+		t.Fatal("prefix not preserved")
+	}
+
+	// Construct c2
+	hash, err := mh.Sum(data, mh.SHA2_256, -1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	c2 := NewCidV0(hash)
+
+	if !c1.Equals(c2) {
+		t.Fatal("cids mismatch")
+	}
+	if c1.Prefix() != c2.Prefix() {
+		t.Fatal("prefixes mismatch")
+	}
+}
+
 func TestPrefixRoundtrip(t *testing.T) {
 	data := []byte("this is some test content")
 	hash, _ := mh.Sum(data, mh.SHA2_256, -1)
@@ -325,3 +385,32 @@ func TestFromJson(t *testing.T) {
 		t.Fatal("json parsing failed")
 	}
 }
+
+func TestJsonRoundTrip(t *testing.T) {
+	exp, err := Decode("zb2rhhFAEMepUBbGyP1k8tGfz7BSciKXP6GHuUeUsJBaK6cqG")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Verify it works for a *Cid.
+	enc, err := json.Marshal(exp)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var actual Cid
+	err = json.Unmarshal(enc, &actual)
+	if !exp.Equals(&actual) {
+		t.Fatal("cids not equal for *Cid")
+	}
+
+	// Verify it works for a Cid.
+	enc, err = json.Marshal(*exp)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var actual2 Cid
+	err = json.Unmarshal(enc, &actual2)
+	if !exp.Equals(&actual2) {
+		t.Fatal("cids not equal for Cid")
+	}
+}

deprecated.go

@@ -0,0 +1,28 @@
+package cid
+
+import (
+	mh "github.com/multiformats/go-multihash"
+)
+
+// NewPrefixV0 returns a CIDv0 prefix with the specified multihash type.
+// DEPRECATED: Use V0Builder
+func NewPrefixV0(mhType uint64) Prefix {
+	return Prefix{
+		MhType:   mhType,
+		MhLength: mh.DefaultLengths[mhType],
+		Version:  0,
+		Codec:    DagProtobuf,
+	}
+}
+
+// NewPrefixV1 returns a CIDv1 prefix with the specified codec and multihash
+// type.
+// DEPRECATED: Use V1Builder
+func NewPrefixV1(codecType uint64, mhType uint64) Prefix {
+	return Prefix{
+		MhType:   mhType,
+		MhLength: mh.DefaultLengths[mhType],
+		Version:  1,
+		Codec:    codecType,
+	}
+}

format.go

@@ -0,0 +1,151 @@
+package cid
+
+import (
+	"bytes"
+	"fmt"
+
+	mb "github.com/multiformats/go-multibase"
+	mh "github.com/multiformats/go-multihash"
+)
+
+// FormatRef is a string documenting the format string for the Format function
+const FormatRef = `
+   %% literal %
+   %b multibase name
+   %B multibase code
+   %v version string
+   %V version number
+   %c codec name
+   %C codec code
+   %h multihash name
+   %H multihash code
+   %L hash digest length
+   %m multihash encoded in base %b (with multibase prefix)
+   %M multihash encoded in base %b without multibase prefix
+   %d hash digest encoded in base %b (with multibase prefix)
+   %D hash digest encoded in base %b without multibase prefix
+   %s cid string encoded in base %b (1)
+   %S cid string encoded in base %b without multibase prefix
+   %P cid prefix: %v-%c-%h-%L
+
+(1) For CID version 0 the multibase must be base58btc and no prefix is
+used.  For Cid version 1 the multibase prefix is included.
+`
+
+// Format formats a cid according to the format specificer as
+// documented in the FormatRef constant
+func Format(fmtStr string, base mb.Encoding, cid *Cid) (string, error) {
+	p := cid.Prefix()
+	var out bytes.Buffer
+	var err error
+	encoder, err := mb.NewEncoder(base)
+	if err != nil {
+		return "", err
+	}
+	for i := 0; i < len(fmtStr); i++ {
+		if fmtStr[i] != '%' {
+			out.WriteByte(fmtStr[i])
+			continue
+		}
+		i++
+		if i >= len(fmtStr) {
+			return "", FormatStringError{"premature end of format string", ""}
+		}
+		switch fmtStr[i] {
+		case '%':
+			out.WriteByte('%')
+		case 'b': // base name
+			out.WriteString(baseToString(base))
+		case 'B': // base code
+			out.WriteByte(byte(base))
+		case 'v': // version string
+			fmt.Fprintf(&out, "cidv%d", p.Version)
+		case 'V': // version num
+			fmt.Fprintf(&out, "%d", p.Version)
+		case 'c': // codec name
+			out.WriteString(codecToString(p.Codec))
+		case 'C': // codec code
+			fmt.Fprintf(&out, "%d", p.Codec)
+		case 'h': // hash fun name
+			out.WriteString(hashToString(p.MhType))
+		case 'H': // hash fun code
+			fmt.Fprintf(&out, "%d", p.MhType)
+		case 'L': // hash length
+			fmt.Fprintf(&out, "%d", p.MhLength)
+		case 'm', 'M': // multihash encoded in base %b
+			out.WriteString(encode(encoder, cid.Hash(), fmtStr[i] == 'M'))
+		case 'd', 'D': // hash digest encoded in base %b
+			dec, err := mh.Decode(cid.Hash())
+			if err != nil {
+				return "", err
+			}
+			out.WriteString(encode(encoder, dec.Digest, fmtStr[i] == 'D'))
+		case 's': // cid string encoded in base %b
+			str, err := cid.StringOfBase(base)
+			if err != nil {
+				return "", err
+			}
+			out.WriteString(str)
+		case 'S': // cid string without base prefix
+			out.WriteString(encode(encoder, cid.Bytes(), true))
+		case 'P': // prefix
+			fmt.Fprintf(&out, "cidv%d-%s-%s-%d",
+				p.Version,
+				codecToString(p.Codec),
+				hashToString(p.MhType),
+				p.MhLength,
+			)
+		default:
+			return "", FormatStringError{"unrecognized specifier in format string", fmtStr[i-1 : i+1]}
+		}
+
+	}
+	return out.String(), err
+}
+
+// FormatStringError is the error return from Format when the format
+// string is ill formed
+type FormatStringError struct {
+	Message   string
+	Specifier string
+}
+
+func (e FormatStringError) Error() string {
+	if e.Specifier == "" {
+		return e.Message
+	} else {
+		return fmt.Sprintf("%s: %s", e.Message, e.Specifier)
+	}
+}
+
+func baseToString(base mb.Encoding) string {
+	baseStr, ok := mb.EncodingToStr[base]
+	if !ok {
+		return fmt.Sprintf("base?%c", base)
+	}
+	return baseStr
+}
+
+func codecToString(num uint64) string {
+	name, ok := CodecToStr[num]
+	if !ok {
+		return fmt.Sprintf("codec?%d", num)
+	}
+	return name
+}
+
+func hashToString(num uint64) string {
+	name, ok := mh.Codes[num]
+	if !ok {
+		return fmt.Sprintf("hash?%d", num)
+	}
+	return name
+}
+
+func encode(base mb.Encoder, data []byte, strip bool) string {
+	str := base.Encode(data)
+	if strip {
+		return str[1:]
+	}
+	return str
+}

format_test.go

@@ -0,0 +1,73 @@
+package cid
+
+import (
+	"fmt"
+	"testing"
+
+	mb "github.com/multiformats/go-multibase"
+)
+
+func TestFmt(t *testing.T) {
+	cids := map[string]string{
+		"cidv0": "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn",
+		"cidv1": "zdj7WfLr9DhLrb1hsoSi4fSdjjxuZmeqgEtBPWxMLtPbDNbFD",
+	}
+	tests := []struct {
+		cidId   string
+		newBase mb.Encoding
+		fmtStr  string
+		result  string
+	}{
+		{"cidv0", -1, "%P", "cidv0-protobuf-sha2-256-32"},
+		{"cidv0", -1, "%b-%v-%c-%h-%L", "base58btc-cidv0-protobuf-sha2-256-32"},
+		{"cidv0", -1, "%s", "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn"},
+		{"cidv0", -1, "%S", "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn"},
+		{"cidv0", -1, "ver#%V/#%C/#%H/%L", "ver#0/#112/#18/32"},
+		{"cidv0", -1, "%m", "zQmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn"},
+		{"cidv0", -1, "%M", "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn"},
+		{"cidv0", -1, "%d", "z72gdmFAgRzYHkJzKiL8MgMMRW3BTSCGyDHroPxJbxMJn"},
+		{"cidv0", -1, "%D", "72gdmFAgRzYHkJzKiL8MgMMRW3BTSCGyDHroPxJbxMJn"},
+		{"cidv0", 'B', "%S", "CIQFTFEEHEDF6KLBT32BFAGLXEZL4UWFNWM4LFTLMXQBCERZ6CMLX3Y"},
+		{"cidv0", 'B', "%B%S", "BCIQFTFEEHEDF6KLBT32BFAGLXEZL4UWFNWM4LFTLMXQBCERZ6CMLX3Y"},
+		{"cidv1", -1, "%P", "cidv1-protobuf-sha2-256-32"},
+		{"cidv1", -1, "%b-%v-%c-%h-%L", "base58btc-cidv1-protobuf-sha2-256-32"},
+		{"cidv1", -1, "%s", "zdj7WfLr9DhLrb1hsoSi4fSdjjxuZmeqgEtBPWxMLtPbDNbFD"},
+		{"cidv1", -1, "%S", "dj7WfLr9DhLrb1hsoSi4fSdjjxuZmeqgEtBPWxMLtPbDNbFD"},
+		{"cidv1", -1, "ver#%V/#%C/#%H/%L", "ver#1/#112/#18/32"},
+		{"cidv1", -1, "%m", "zQmYFbmndVP7QqAVWyKhpmMuQHMaD88pkK57RgYVimmoh5H"},
+		{"cidv1", -1, "%M", "QmYFbmndVP7QqAVWyKhpmMuQHMaD88pkK57RgYVimmoh5H"},
+		{"cidv1", -1, "%d", "zAux4gVVsLRMXtsZ9fd3tFEZN4jGYB6kP37fgoZNTc11H"},
+		{"cidv1", -1, "%D", "Aux4gVVsLRMXtsZ9fd3tFEZN4jGYB6kP37fgoZNTc11H"},
+		{"cidv1", 'B', "%s", "BAFYBEIETJGSRL3EQPQPCABV3G6IUBYTSIFVQ24XRRHD3JUETSKLTGQ7DJA"},
+		{"cidv1", 'B', "%S", "AFYBEIETJGSRL3EQPQPCABV3G6IUBYTSIFVQ24XRRHD3JUETSKLTGQ7DJA"},
+		{"cidv1", 'B', "%B%S", "BAFYBEIETJGSRL3EQPQPCABV3G6IUBYTSIFVQ24XRRHD3JUETSKLTGQ7DJA"},
+	}
+	for _, tc := range tests {
+		name := fmt.Sprintf("%s/%s", tc.cidId, tc.fmtStr)
+		if tc.newBase != -1 {
+			name = fmt.Sprintf("%s/%c", name, tc.newBase)
+		}
+		cidStr := cids[tc.cidId]
+		t.Run(name, func(t *testing.T) {
+			testFmt(t, cidStr, tc.newBase, tc.fmtStr, tc.result)
+		})
+	}
+}
+
+func testFmt(t *testing.T, cidStr string, newBase mb.Encoding, fmtStr string, result string) {
+	cid, err := Decode(cidStr)
+	if err != nil {
+		t.Fatal(err)
+	}
+	base := newBase
+	if newBase == -1 {
+		base, _ = ExtractEncoding(cidStr)
+	}
+	str, err := Format(fmtStr, base, cid)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if str != result {
+		t.Error(fmt.Sprintf("expected: %s; but got: %s", result, str))
+	}
+}

package.json

@@ -9,15 +9,15 @@
   "gxDependencies": [
     {
       "author": "whyrusleeping",
-      "hash": "QmU9a9NV9RdPNwZQDYd5uKsm6N6LJLSvLbywDDYFbaaC6P",
+      "hash": "QmPnFwZ2JXKnXgMw8CdBPxn7FWh6LLdjUjxV1fKHuJnkr8",
       "name": "go-multihash",
-      "version": "1.0.5"
+      "version": "1.0.8"
     },
     {
       "author": "whyrusleeping",
-      "hash": "QmafgXF3u3QSWErQoZ2URmQp5PFG384htoE7J338nS2H7T",
+      "hash": "QmSbvata2WqNkqGtZNg8MR3SKwnB8iQ7vTPJgWqB8bC5kR",
       "name": "go-multibase",
-      "version": "0.2.5"
+      "version": "0.2.7"
     }
   ],
   "gxVersion": "0.8.0",
@@ -25,6 +25,6 @@
   "license": "MIT",
   "name": "go-cid",
   "releaseCmd": "git commit -a -m \"gx publish $VERSION\"",
-  "version": "0.7.18"
+  "version": "0.7.24"
 }
 

set_test.go

@@ -0,0 +1,92 @@
+package cid
+
+import (
+	"crypto/rand"
+	"errors"
+	"testing"
+
+	mh "github.com/multiformats/go-multihash"
+)
+
+func makeRandomCid(t *testing.T) *Cid {
+	p := make([]byte, 256)
+	_, err := rand.Read(p)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	h, err := mh.Sum(p, mh.SHA3, 4)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	cid := &Cid{
+		codec:   7,
+		version: 1,
+		hash:    h,
+	}
+
+	return cid
+}
+
+func TestSet(t *testing.T) {
+	cid := makeRandomCid(t)
+	cid2 := makeRandomCid(t)
+	s := NewSet()
+
+	s.Add(cid)
+
+	if !s.Has(cid) {
+		t.Error("should have the CID")
+	}
+
+	if s.Len() != 1 {
+		t.Error("should report 1 element")
+	}
+
+	keys := s.Keys()
+
+	if len(keys) != 1 || !keys[0].Equals(cid) {
+		t.Error("key should correspond to Cid")
+	}
+
+	if s.Visit(cid) {
+		t.Error("visit should return false")
+	}
+
+	foreach := []*Cid{}
+	foreachF := func(c *Cid) error {
+		foreach = append(foreach, c)
+		return nil
+	}
+
+	if err := s.ForEach(foreachF); err != nil {
+		t.Error(err)
+	}
+
+	if len(foreach) != 1 {
+		t.Error("ForEach should have visited 1 element")
+	}
+
+	foreachErr := func(c *Cid) error {
+		return errors.New("test")
+	}
+
+	if err := s.ForEach(foreachErr); err == nil {
+		t.Error("Should have returned an error")
+	}
+
+	if !s.Visit(cid2) {
+		t.Error("should have visited a new Cid")
+	}
+
+	if s.Len() != 2 {
+		t.Error("len should be 2 now")
+	}
+
+	s.Remove(cid2)
+
+	if s.Len() != 1 {
+		t.Error("len should be 1 now")
+	}
+}