From 6b1990b9a19b0784264a10896d44d1ee26fb018d Mon Sep 17 00:00:00 2001 From: Kevin Atkinson Date: Tue, 31 Jul 2018 22:45:12 -0400 Subject: [PATCH] Extract most of `cid-fmt` logic so it can be used as a library. --- cid-fmt/main.go | 173 +------------------------------------------ cid-fmt/main_test.go | 70 +---------------- cid.go | 21 ++++-- 3 files changed, 22 insertions(+), 242 deletions(-) diff --git a/cid-fmt/main.go b/cid-fmt/main.go index 44bfb44..8d7f53b 100644 --- a/cid-fmt/main.go +++ b/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] ...\n\n", os.Args[0]) - fmt.Fprintf(os.Stderr, " is either 'prefix' or a printf style format string:\n%s", fmtRef) + fmt.Fprintf(os.Stderr, " 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() @@ -94,7 +69,7 @@ outer: } } for _, cidStr := range args[1:] { - base, cid, err := decode(cidStr) + base, cid, err := c.DecodeV2(cidStr) if err != nil { fmt.Fprintf(os.Stdout, "!INVALID_CID!\n") errorMsg("%s: %v", cidStr, err) @@ -113,9 +88,9 @@ outer: continue } } - str, err := fmtCid(fmtStr, base, cid) + str, err := c.Format(fmtStr, base, cid) switch err.(type) { - case FormatStringError: + case c.FormatStringError: fmt.Fprintf(os.Stderr, "Error: %v\n", err) os.Exit(2) default: @@ -140,146 +115,6 @@ 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!" - -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 fmtCid(fmtStr string, base mb.Encoding, cid *c.Cid) (string, error) { - p := cid.Prefix() - out := new(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 -} - -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 := 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.Encoder, data []byte, strip bool) string { - str := base.Encode(data) - 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") diff --git a/cid-fmt/main_test.go b/cid-fmt/main_test.go index 568b21a..5161258 100644 --- a/cid-fmt/main_test.go +++ b/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.DecodeV2(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.DecodeV2(cidv1) if err != nil { t.Fatal(err) } diff --git a/cid.go b/cid.go index 7859f75..0d319d4 100644 --- a/cid.go +++ b/cid.go @@ -213,25 +213,34 @@ func Parse(v interface{}) (*Cid, error) { // starting with "Qm" are considered CidV0 and treated directly // as B58-encoded multihashes. func Decode(v string) (*Cid, error) { + _, cid, err := DecodeV2(v) + return cid, err +} + +// DecodeV2 is like Decide but also returns the Multibase encoding the +// Cid was encoded in +func DecodeV2(v string) (mbase.Encoding, *Cid, error) { if len(v) < 2 { - return nil, ErrCidTooShort + return 0, nil, ErrCidTooShort } if len(v) == 46 && v[:2] == "Qm" { hash, err := mh.FromB58String(v) if err != nil { - return nil, err + return 0, nil, err } - return NewCidV0(hash), nil + return mbase.Base58BTC, NewCidV0(hash), nil } - _, data, err := mbase.Decode(v) + base, data, err := mbase.Decode(v) if err != nil { - return nil, err + return 0, nil, err } - return Cast(data) + cid, err := Cast(data) + + return base, cid, err } func uvError(read int) error {