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kevinakevina
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Extract most of cid-fmt logic so it can be used as a library.
1 parent 36bab48 commit c4bfcd0

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5 files changed

+246
-242
lines changed

5 files changed

+246
-242
lines changed

‎cid-fmt/main.go

+4-169
Original file line numberDiff line numberDiff line change
@@ -1,46 +1,21 @@
11
package main
22

33
import (
4-
"bytes"
54
"fmt"
65
"os"
76
"strings"
87

98
c "github.com/ipfs/go-cid"
109

1110
mb "github.com/multiformats/go-multibase"
12-
mh "github.com/multiformats/go-multihash"
1311
)
1412

1513
func usage() {
1614
fmt.Fprintf(os.Stderr, "usage: %s [-b multibase-code] [-v cid-version] <fmt-str> <cid> ...\n\n", os.Args[0])
17-
fmt.Fprintf(os.Stderr, "<fmt-str> is either 'prefix' or a printf style format string:\n%s", fmtRef)
15+
fmt.Fprintf(os.Stderr, "<fmt-str> is either 'prefix' or a printf style format string:\n%s", c.FormatRef)
1816
os.Exit(2)
1917
}
2018

21-
const fmtRef = `
22-
%% literal %
23-
%b multibase name
24-
%B multibase code
25-
%v version string
26-
%V version number
27-
%c codec name
28-
%C codec code
29-
%h multihash name
30-
%H multihash code
31-
%L hash digest length
32-
%m multihash encoded in base %b (with multibase prefix)
33-
%M multihash encoded in base %b without multibase prefix
34-
%d hash digest encoded in base %b (with multibase prefix)
35-
%D hash digest encoded in base %b without multibase prefix
36-
%s cid string encoded in base %b (1)
37-
%S cid string encoded in base %b without multibase prefix
38-
%P cid prefix: %v-%c-%h-%L
39-
40-
(1) For CID version 0 the multibase must be base58btc and no prefix is
41-
used. For Cid version 1 the multibase prefix is included.
42-
`
43-
4419
func main() {
4520
if len(os.Args) < 2 {
4621
usage()
@@ -94,7 +69,7 @@ outer:
9469
}
9570
}
9671
for _, cidStr := range args[1:] {
97-
base, cid, err := decode(cidStr)
72+
base, cid, err := c.DecodeV2(cidStr)
9873
if err != nil {
9974
fmt.Fprintf(os.Stdout, "!INVALID_CID!\n")
10075
errorMsg("%s: %v", cidStr, err)
@@ -113,9 +88,9 @@ outer:
11388
continue
11489
}
11590
}
116-
str, err := fmtCid(fmtStr, base, cid)
91+
str, err := c.Format(fmtStr, base, cid)
11792
switch err.(type) {
118-
case FormatStringError:
93+
case c.FormatStringError:
11994
fmt.Fprintf(os.Stderr, "Error: %v\n", err)
12095
os.Exit(2)
12196
default:
@@ -140,146 +115,6 @@ func errorMsg(fmtStr string, a ...interface{}) {
140115
exitCode = 1
141116
}
142117

143-
func decode(v string) (mb.Encoding, *c.Cid, error) {
144-
if len(v) < 2 {
145-
return 0, nil, c.ErrCidTooShort
146-
}
147-
148-
if len(v) == 46 && v[:2] == "Qm" {
149-
hash, err := mh.FromB58String(v)
150-
if err != nil {
151-
return 0, nil, err
152-
}
153-
154-
return mb.Base58BTC, c.NewCidV0(hash), nil
155-
}
156-
157-
base, data, err := mb.Decode(v)
158-
if err != nil {
159-
return 0, nil, err
160-
}
161-
162-
cid, err := c.Cast(data)
163-
164-
return base, cid, err
165-
}
166-
167-
const ERR_STR = "!ERROR!"
168-
169-
type FormatStringError struct {
170-
Message string
171-
Specifier string
172-
}
173-
174-
func (e FormatStringError) Error() string {
175-
if e.Specifier == "" {
176-
return e.Message
177-
} else {
178-
return fmt.Sprintf("%s: %s", e.Message, e.Specifier)
179-
}
180-
}
181-
182-
func fmtCid(fmtStr string, base mb.Encoding, cid *c.Cid) (string, error) {
183-
p := cid.Prefix()
184-
out := new(bytes.Buffer)
185-
var err error
186-
encoder, err := mb.NewEncoder(base)
187-
if err != nil {
188-
return "", err
189-
}
190-
for i := 0; i < len(fmtStr); i++ {
191-
if fmtStr[i] != '%' {
192-
out.WriteByte(fmtStr[i])
193-
continue
194-
}
195-
i++
196-
if i >= len(fmtStr) {
197-
return "", FormatStringError{"premature end of format string", ""}
198-
}
199-
switch fmtStr[i] {
200-
case '%':
201-
out.WriteByte('%')
202-
case 'b': // base name
203-
out.WriteString(baseToString(base))
204-
case 'B': // base code
205-
out.WriteByte(byte(base))
206-
case 'v': // version string
207-
fmt.Fprintf(out, "cidv%d", p.Version)
208-
case 'V': // version num
209-
fmt.Fprintf(out, "%d", p.Version)
210-
case 'c': // codec name
211-
out.WriteString(codecToString(p.Codec))
212-
case 'C': // codec code
213-
fmt.Fprintf(out, "%d", p.Codec)
214-
case 'h': // hash fun name
215-
out.WriteString(hashToString(p.MhType))
216-
case 'H': // hash fun code
217-
fmt.Fprintf(out, "%d", p.MhType)
218-
case 'L': // hash length
219-
fmt.Fprintf(out, "%d", p.MhLength)
220-
case 'm', 'M': // multihash encoded in base %b
221-
out.WriteString(encode(encoder, cid.Hash(), fmtStr[i] == 'M'))
222-
case 'd', 'D': // hash digest encoded in base %b
223-
dec, err := mh.Decode(cid.Hash())
224-
if err != nil {
225-
return "", err
226-
}
227-
out.WriteString(encode(encoder, dec.Digest, fmtStr[i] == 'D'))
228-
case 's': // cid string encoded in base %b
229-
str, err := cid.StringOfBase(base)
230-
if err != nil {
231-
return "", err
232-
}
233-
out.WriteString(str)
234-
case 'S': // cid string without base prefix
235-
out.WriteString(encode(encoder, cid.Bytes(), true))
236-
case 'P': // prefix
237-
fmt.Fprintf(out, "cidv%d-%s-%s-%d",
238-
p.Version,
239-
codecToString(p.Codec),
240-
hashToString(p.MhType),
241-
p.MhLength,
242-
)
243-
default:
244-
return "", FormatStringError{"unrecognized specifier in format string", fmtStr[i-1 : i+1]}
245-
}
246-
247-
}
248-
return out.String(), err
249-
}
250-
251-
func baseToString(base mb.Encoding) string {
252-
baseStr, ok := mb.EncodingToStr[base]
253-
if !ok {
254-
return fmt.Sprintf("base?%c", base)
255-
}
256-
return baseStr
257-
}
258-
259-
func codecToString(num uint64) string {
260-
name, ok := c.CodecToStr[num]
261-
if !ok {
262-
return fmt.Sprintf("codec?%d", num)
263-
}
264-
return name
265-
}
266-
267-
func hashToString(num uint64) string {
268-
name, ok := mh.Codes[num]
269-
if !ok {
270-
return fmt.Sprintf("hash?%d", num)
271-
}
272-
return name
273-
}
274-
275-
func encode(base mb.Encoder, data []byte, strip bool) string {
276-
str := base.Encode(data)
277-
if strip {
278-
return str[1:]
279-
}
280-
return str
281-
}
282-
283118
func toCidV0(cid *c.Cid) (*c.Cid, error) {
284119
if cid.Type() != c.DagProtobuf {
285120
return nil, fmt.Errorf("can't convert non-protobuf nodes to cidv0")

‎cid-fmt/main_test.go

+3-67
Original file line numberDiff line numberDiff line change
@@ -4,77 +4,13 @@ import (
44
"fmt"
55
"testing"
66

7-
mb "github.com/multiformats/go-multibase"
7+
c "github.com/ipfs/go-cid"
88
)
99

10-
func TestFmt(t *testing.T) {
11-
cids := map[string]string{
12-
"cidv0": "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn",
13-
"cidv1": "zdj7WfLr9DhLrb1hsoSi4fSdjjxuZmeqgEtBPWxMLtPbDNbFD",
14-
}
15-
tests := []struct {
16-
cidId string
17-
newBase mb.Encoding
18-
fmtStr string
19-
result string
20-
}{
21-
{"cidv0", -1, "%P", "cidv0-protobuf-sha2-256-32"},
22-
{"cidv0", -1, "%b-%v-%c-%h-%L", "base58btc-cidv0-protobuf-sha2-256-32"},
23-
{"cidv0", -1, "%s", "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn"},
24-
{"cidv0", -1, "%S", "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn"},
25-
{"cidv0", -1, "ver#%V/#%C/#%H/%L", "ver#0/#112/#18/32"},
26-
{"cidv0", -1, "%m", "zQmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn"},
27-
{"cidv0", -1, "%M", "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn"},
28-
{"cidv0", -1, "%d", "z72gdmFAgRzYHkJzKiL8MgMMRW3BTSCGyDHroPxJbxMJn"},
29-
{"cidv0", -1, "%D", "72gdmFAgRzYHkJzKiL8MgMMRW3BTSCGyDHroPxJbxMJn"},
30-
{"cidv0", 'B', "%S", "CIQFTFEEHEDF6KLBT32BFAGLXEZL4UWFNWM4LFTLMXQBCERZ6CMLX3Y"},
31-
{"cidv0", 'B', "%B%S", "BCIQFTFEEHEDF6KLBT32BFAGLXEZL4UWFNWM4LFTLMXQBCERZ6CMLX3Y"},
32-
{"cidv1", -1, "%P", "cidv1-protobuf-sha2-256-32"},
33-
{"cidv1", -1, "%b-%v-%c-%h-%L", "base58btc-cidv1-protobuf-sha2-256-32"},
34-
{"cidv1", -1, "%s", "zdj7WfLr9DhLrb1hsoSi4fSdjjxuZmeqgEtBPWxMLtPbDNbFD"},
35-
{"cidv1", -1, "%S", "dj7WfLr9DhLrb1hsoSi4fSdjjxuZmeqgEtBPWxMLtPbDNbFD"},
36-
{"cidv1", -1, "ver#%V/#%C/#%H/%L", "ver#1/#112/#18/32"},
37-
{"cidv1", -1, "%m", "zQmYFbmndVP7QqAVWyKhpmMuQHMaD88pkK57RgYVimmoh5H"},
38-
{"cidv1", -1, "%M", "QmYFbmndVP7QqAVWyKhpmMuQHMaD88pkK57RgYVimmoh5H"},
39-
{"cidv1", -1, "%d", "zAux4gVVsLRMXtsZ9fd3tFEZN4jGYB6kP37fgoZNTc11H"},
40-
{"cidv1", -1, "%D", "Aux4gVVsLRMXtsZ9fd3tFEZN4jGYB6kP37fgoZNTc11H"},
41-
{"cidv1", 'B', "%s", "BAFYBEIETJGSRL3EQPQPCABV3G6IUBYTSIFVQ24XRRHD3JUETSKLTGQ7DJA"},
42-
{"cidv1", 'B', "%S", "AFYBEIETJGSRL3EQPQPCABV3G6IUBYTSIFVQ24XRRHD3JUETSKLTGQ7DJA"},
43-
{"cidv1", 'B', "%B%S", "BAFYBEIETJGSRL3EQPQPCABV3G6IUBYTSIFVQ24XRRHD3JUETSKLTGQ7DJA"},
44-
}
45-
for _, tc := range tests {
46-
name := fmt.Sprintf("%s/%s", tc.cidId, tc.fmtStr)
47-
if tc.newBase != -1 {
48-
name = fmt.Sprintf("%s/%c", name, tc.newBase)
49-
}
50-
cidStr := cids[tc.cidId]
51-
t.Run(name, func(t *testing.T) {
52-
testFmt(t, cidStr, tc.newBase, tc.fmtStr, tc.result)
53-
})
54-
}
55-
}
56-
57-
func testFmt(t *testing.T, cidStr string, newBase mb.Encoding, fmtStr string, result string) {
58-
base, cid, err := decode(cidStr)
59-
if newBase != -1 {
60-
base = newBase
61-
}
62-
if err != nil {
63-
t.Fatal(err)
64-
}
65-
str, err := fmtCid(fmtStr, base, cid)
66-
if err != nil {
67-
t.Fatal(err)
68-
}
69-
if str != result {
70-
t.Error(fmt.Sprintf("expected: %s; but got: %s", result, str))
71-
}
72-
}
73-
7410
func TestCidConv(t *testing.T) {
7511
cidv0 := "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn"
7612
cidv1 := "zdj7WbTaiJT1fgatdet9Ei9iDB5hdCxkbVyhyh8YTUnXMiwYi"
77-
_, cid, err := decode(cidv0)
13+
_, cid, err := c.DecodeV2(cidv0)
7814
if err != nil {
7915
t.Fatal(err)
8016
}
@@ -98,7 +34,7 @@ func TestCidConv(t *testing.T) {
9834
func TestBadCidConv(t *testing.T) {
9935
// this cid is a raw leaf and should not be able to convert to cidv0
10036
cidv1 := "zb2rhhzX7uSKrtQ2ZZXFAabKiKFYZrJqKY2KE1cJ8yre2GSWZ"
101-
_, cid, err := decode(cidv1)
37+
_, cid, err := c.DecodeV2(cidv1)
10238
if err != nil {
10339
t.Fatal(err)
10440
}

‎cid.go

+15-6
Original file line numberDiff line numberDiff line change
@@ -213,25 +213,34 @@ func Parse(v interface{}) (*Cid, error) {
213213
// starting with "Qm" are considered CidV0 and treated directly
214214
// as B58-encoded multihashes.
215215
func Decode(v string) (*Cid, error) {
216+
_, cid, err := DecodeV2(v)
217+
return cid, err
218+
}
219+
220+
// DecodeV2 is like Decide but also returns the Multibase encoding the
221+
// Cid was encoded in. EXPERIMENTAL and interface may change at any time.
222+
func DecodeV2(v string) (mbase.Encoding, *Cid, error) {
216223
if len(v) < 2 {
217-
return nil, ErrCidTooShort
224+
return 0, nil, ErrCidTooShort
218225
}
219226

220227
if len(v) == 46 && v[:2] == "Qm" {
221228
hash, err := mh.FromB58String(v)
222229
if err != nil {
223-
return nil, err
230+
return 0, nil, err
224231
}
225232

226-
return NewCidV0(hash), nil
233+
return mbase.Base58BTC, NewCidV0(hash), nil
227234
}
228235

229-
_, data, err := mbase.Decode(v)
236+
base, data, err := mbase.Decode(v)
230237
if err != nil {
231-
return nil, err
238+
return 0, nil, err
232239
}
233240

234-
return Cast(data)
241+
cid, err := Cast(data)
242+
243+
return base, cid, err
235244
}
236245

237246
func uvError(read int) error {

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