-
Notifications
You must be signed in to change notification settings - Fork 46
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Add carve utility for updating the index of a car{v1,v2} file (#219)
* add car utility for updating the index of a car{v1,v2} file- Loading branch information
Showing
3 changed files
with
175 additions
and
3 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,158 @@ | ||
| package main | ||
|
|
||
| import ( | ||
| "bufio" | ||
| "fmt" | ||
| "io" | ||
| "log" | ||
| "os" | ||
|
|
||
| "github.com/ipfs/go-cid" | ||
| carv2 "github.com/ipld/go-car/v2" | ||
| "github.com/ipld/go-car/v2/index" | ||
| icarv1 "github.com/ipld/go-car/v2/internal/carv1" | ||
| "github.com/multiformats/go-multicodec" | ||
| "github.com/multiformats/go-varint" | ||
| "github.com/urfave/cli/v2" | ||
| ) | ||
|
|
||
| func main() { | ||
| app := &cli.App{ | ||
| Name: "car", | ||
| Usage: "Utility for working with car files", | ||
| Flags: []cli.Flag{ | ||
| &cli.StringFlag{ | ||
| Name: "codec", | ||
| Aliases: []string{"c"}, | ||
| Usage: "The type of index to write", | ||
| Value: multicodec.CarMultihashIndexSorted.String(), | ||
| }, | ||
| }, | ||
| Commands: []*cli.Command{ | ||
| { | ||
| Name: "index", | ||
| Aliases: []string{"i"}, | ||
| Usage: "write out the car with an index", | ||
| Action: func(c *cli.Context) error { | ||
| r, err := carv2.OpenReader(c.Args().Get(0)) | ||
| if err != nil { | ||
| return err | ||
| } | ||
| defer r.Close() | ||
|
|
||
| var idx index.Index | ||
| if c.String("codec") != "none" { | ||
| var mc multicodec.Code | ||
| if err := mc.Set(c.String("codec")); err != nil { | ||
| return err | ||
| } | ||
| idx, err = index.New(mc) | ||
| if err != nil { | ||
| return err | ||
| } | ||
| } | ||
|
|
||
| outStream := os.Stdout | ||
| if c.Args().Len() >= 2 { | ||
| outStream, err = os.Create(c.Args().Get(1)) | ||
| if err != nil { | ||
| return err | ||
| } | ||
| } | ||
| defer outStream.Close() | ||
|
|
||
| v1r := r.DataReader() | ||
|
|
||
| v2Header := carv2.NewHeader(r.Header.DataSize) | ||
| if c.String("codec") == "none" { | ||
| v2Header.IndexOffset = 0 | ||
| if _, err := outStream.Write(carv2.Pragma); err != nil { | ||
| return err | ||
| } | ||
| if _, err := v2Header.WriteTo(outStream); err != nil { | ||
| return err | ||
| } | ||
| if _, err := io.Copy(outStream, v1r); err != nil { | ||
| return err | ||
| } | ||
| return nil | ||
| } | ||
|
|
||
| if _, err := outStream.Write(carv2.Pragma); err != nil { | ||
| return err | ||
| } | ||
| if _, err := v2Header.WriteTo(outStream); err != nil { | ||
| return err | ||
| } | ||
|
|
||
| // collect records as we go through the v1r | ||
| hdr, err := icarv1.ReadHeader(v1r) | ||
| if err != nil { | ||
| return fmt.Errorf("error reading car header: %w", err) | ||
| } | ||
| if err := icarv1.WriteHeader(hdr, outStream); err != nil { | ||
| return err | ||
| } | ||
|
|
||
| records := make([]index.Record, 0) | ||
| var sectionOffset int64 | ||
| if sectionOffset, err = v1r.Seek(0, io.SeekCurrent); err != nil { | ||
| return err | ||
| } | ||
|
|
||
| br := bufio.NewReader(v1r) | ||
| for { | ||
| // Read the section's length. | ||
| sectionLen, err := varint.ReadUvarint(br) | ||
| if err != nil { | ||
| if err == io.EOF { | ||
| break | ||
| } | ||
| return err | ||
| } | ||
| if _, err := outStream.Write(varint.ToUvarint(sectionLen)); err != nil { | ||
| return err | ||
| } | ||
|
|
||
| // Null padding; by default it's an error. | ||
| // TODO: integrate corresponding ReadOption | ||
| if sectionLen == 0 { | ||
| // TODO: pad writer to expected length. | ||
| break | ||
| } | ||
|
|
||
| // Read the CID. | ||
| cidLen, c, err := cid.CidFromReader(br) | ||
| if err != nil { | ||
| return err | ||
| } | ||
| records = append(records, index.Record{Cid: c, Offset: uint64(sectionOffset)}) | ||
| if _, err := c.WriteBytes(outStream); err != nil { | ||
| return err | ||
| } | ||
|
|
||
| // Seek to the next section by skipping the block. | ||
| // The section length includes the CID, so subtract it. | ||
| remainingSectionLen := int64(sectionLen) - int64(cidLen) | ||
| if _, err := io.CopyN(outStream, br, remainingSectionLen); err != nil { | ||
| return err | ||
| } | ||
| sectionOffset += int64(sectionLen) + int64(varint.UvarintSize(sectionLen)) | ||
| } | ||
|
|
||
| if err := idx.Load(records); err != nil { | ||
| return err | ||
| } | ||
|
|
||
| return index.WriteTo(idx, outStream) | ||
| }, | ||
| }, | ||
| }, | ||
| } | ||
|
|
||
| err := app.Run(os.Args) | ||
| if err != nil { | ||
| log.Fatal(err) | ||
| os.Exit(1) | ||
| } | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters