Implement Unixfs.Get()

Author: magik6k

apifile.go

@@ -0,0 +1,231 @@
+package httpapi
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"github.com/ipfs/go-cid"
+	"io"
+
+	"github.com/ipfs/go-ipfs/core/coreapi/interface"
+
+	"github.com/ipfs/go-ipfs-files"
+	unixfspb "github.com/ipfs/go-unixfs/pb"
+)
+
+func (api *UnixfsAPI) Get(ctx context.Context, p iface.Path) (files.Node, error) {
+	if p.Mutable() { // use resolved path in case we are dealing with IPNS / MFS
+		var err error
+		p, err = api.core().ResolvePath(ctx, p)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	var stat struct{
+		Hash string
+		Type string
+		Size int64 // unixfs size
+	}
+	err := api.core().request("files/stat", p.String()).	Exec(ctx, &stat)
+	if err != nil {
+		return nil, err
+	}
+
+	switch stat.Type {
+	case "file":
+		return api.getFile(ctx, p, stat.Size)
+	case "directory":
+		return api.getDir(ctx, p, stat.Size)
+	default:
+		return nil, fmt.Errorf("unsupported file type '%s'", stat.Type)
+	}
+}
+
+type apiFile struct {
+	ctx context.Context
+	core *HttpApi
+	size int64
+	path iface.Path
+
+	r io.ReadCloser
+	at int64
+}
+
+func (f *apiFile) reset() error {
+	if f.r != nil {
+		f.r.Close()
+	}
+	req := f.core.request("cat", f.path.String())
+	if f.at != 0 {
+		req.Option("offset", f.at)
+	}
+	resp, err := req.Send(f.ctx)
+	if err != nil {
+		return err
+	}
+	if resp.Error != nil {
+		return resp.Error
+	}
+	f.r = resp.Output
+	return nil
+}
+
+func (f *apiFile) Read(p []byte) (int, error) {
+	n, err := f.r.Read(p)
+	if n > 0 {
+		f.at += int64(n)
+	}
+	return n, err
+}
+
+func (f *apiFile) Seek(offset int64, whence int) (int64, error) {
+	panic("implement me") //TODO
+}
+
+func (f *apiFile) Close() error {
+	if f.r != nil {
+		return f.r.Close()
+	}
+	return nil
+}
+
+func (f *apiFile) Size() (int64, error) {
+	return f.size, nil
+}
+
+func (api *UnixfsAPI) getFile(ctx context.Context, p iface.Path, size int64) (files.Node, error) {
+	f := &apiFile{
+		ctx: ctx,
+		core: api.core(),
+		size: size,
+		path: p,
+	}
+
+	return f, f.reset()
+}
+
+type apiIter struct {
+	ctx context.Context
+	core *UnixfsAPI
+
+	err error
+
+	dec *json.Decoder
+	curFile files.Node
+	cur lsLink
+}
+
+func (it *apiIter) Err() error {
+	return it.err
+}
+
+func (it *apiIter) Name() string {
+	return it.cur.Name
+}
+
+func (it *apiIter) Next() bool {
+	var out lsOutput
+	if err := it.dec.Decode(&out); err != nil {
+		if err != io.EOF {
+			it.err = err
+		}
+		return false
+	}
+
+	if len(out.Objects) != 1 {
+		it.err = fmt.Errorf("len(out.Objects) != 1 (is %d)", len(out.Objects))
+		return false
+	}
+
+	if len(out.Objects[0].Links) != 1 {
+		it.err = fmt.Errorf("len(out.Objects[0].Links) != 1 (is %d)", len(out.Objects[0].Links))
+		return false
+	}
+
+	it.cur = out.Objects[0].Links[0]
+	c, err := cid.Parse(it.cur.Hash)
+	if err != nil {
+		it.err = err
+		return false
+	}
+
+	switch it.cur.Type {
+	case unixfspb.Data_HAMTShard:
+		fallthrough
+	case unixfspb.Data_Metadata:
+		fallthrough
+	case unixfspb.Data_Directory:
+		it.curFile, err = it.core.getDir(it.ctx, iface.IpfsPath(c), int64(it.cur.Size))
+		if err != nil {
+			it.err = err
+			return false
+		}
+	case unixfspb.Data_File:
+		it.curFile, err = it.core.getFile(it.ctx, iface.IpfsPath(c), int64(it.cur.Size))
+		if err != nil {
+			it.err = err
+			return false
+		}
+	default:
+		it.err = fmt.Errorf("file type %d not supported", it.cur.Type)
+		return false
+	}
+	return true
+}
+
+func (it *apiIter) Node() files.Node {
+	return it.curFile
+}
+
+type apiDir struct {
+	ctx context.Context
+	core *UnixfsAPI
+	size int64
+	path iface.Path
+
+	dec *json.Decoder
+}
+
+func (d *apiDir) Close() error {
+	return nil
+}
+
+func (d *apiDir) Size() (int64, error) {
+	return d.size, nil
+}
+
+func (d *apiDir) Entries() files.DirIterator {
+	return &apiIter{
+		ctx: d.ctx,
+		core: d.core,
+		dec: d.dec,
+	}
+}
+
+func (api *UnixfsAPI) getDir(ctx context.Context, p iface.Path, size int64) (files.Node, error) {
+	resp, err := api.core().request("ls", p.String()).
+		Option("resolve-size", true).
+		Option("stream", true).Send(ctx)
+
+	if err != nil {
+		return nil, err
+	}
+	if resp.Error != nil {
+		return nil, resp.Error
+	}
+
+	d := &apiDir{
+		ctx: ctx,
+		core: api,
+		size: size,
+		path: p,
+
+		dec: json.NewDecoder(resp.Output),
+	}
+
+	return d, nil
+}
+
+var _ files.File = &apiFile{}
+var _ files.Directory = &apiDir{}

unixfs.go

@@ -85,10 +85,6 @@ func (api *UnixfsAPI) Add(ctx context.Context, f files.Node, opts ...caopts.Unix
 	return iface.IpfsPath(c), nil
 }
 
-func (api *UnixfsAPI) Get(context.Context, iface.Path) (files.Node, error) {
-	panic("implement me")
-}
-
 type lsLink struct {
 	Name, Hash string
 	Size       uint64