adds segmentStore Get, List, Delete (#143)

* adds segmentStore Get, List, Delete

* adds proper ecclient delete call in segmentstore delete, adds overlayHelper function

pkg/segment/segment.go

@@ -5,10 +5,10 @@ package segment
 
 import (
 	"context"
-	"fmt"
 	"io"
 	"time"
 
+	"github.com/gogo/protobuf/proto"
 	"go.uber.org/zap"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
@@ -43,16 +43,16 @@ type Store interface {
 }
 
 type segmentStore struct {
-	oc opb.OverlayClient
-	ec ecclient.Client
-	pc ppb.PointerDBClient
-	rs eestream.RedundancyStrategy
+	oc  opb.OverlayClient
+	ec  ecclient.Client
+	pdb ppb.PointerDBClient
+	rs  eestream.RedundancyStrategy
 }
 
 // NewSegmentStore creates a new instance of segmentStore
-func NewSegmentStore(oc opb.OverlayClient, ec ecclient.Client, pc ppb.PointerDBClient,
+func NewSegmentStore(oc opb.OverlayClient, ec ecclient.Client, pdb ppb.PointerDBClient,
 	rs eestream.RedundancyStrategy) Store {
-	return &segmentStore{oc: oc, ec: ec, pc: pc, rs: rs}
+	return &segmentStore{oc: oc, ec: ec, pdb: pdb, rs: rs}
 }
 
 // Put uploads a file to an erasure code client
@@ -85,7 +85,7 @@ func (s *segmentStore) Put(ctx context.Context, path paths.Path, data io.Reader,
 
 	// creates pointer
 	pr := ppb.PutRequest{
-		Path: []byte(fmt.Sprintf("%s", path)),
+		Path: []byte(path.String()),
 		Pointer: &ppb.Pointer{
 			Type: ppb.Pointer_REMOTE,
 			Remote: &ppb.RemoteSegment{
@@ -105,7 +105,7 @@ func (s *segmentStore) Put(ctx context.Context, path paths.Path, data io.Reader,
 	}
 
 	// puts pointer to pointerDB
-	_, err = s.pc.Put(ctx, &pr)
+	_, err = s.pdb.Put(ctx, &pr)
 	if err != nil || status.Code(err) == codes.Internal {
 		zap.L().Error("failed to put", zap.Error(err))
 		return Error.Wrap(err)
@@ -113,21 +113,128 @@ func (s *segmentStore) Put(ctx context.Context, path paths.Path, data io.Reader,
 	return nil
 }
 
-// Get retrieves a file from the erasure code client with help from overlay and pointerdb
+// Get retrieves a file using erasure code, overlay, and pointerdb clients
 func (s *segmentStore) Get(ctx context.Context, path paths.Path) (ranger.Ranger, Meta, error) {
-	m := Meta{
-		Data: []byte(""),
+	m := Meta{}
+	// TODO: remove this chunk after pointerdb client interface merged
+	gr := &ppb.GetRequest{
+		Path:   []byte(path.String()),
+		APIKey: nil,
 	}
-	return nil, m, nil
+
+	pdbRes, err := s.pdb.Get(ctx, gr)
+	if err != nil {
+		return nil, m, err
+	}
+
+	// TODO: remove this chunk after pointerdb client interface merged
+	pointer := &ppb.Pointer{}
+	err = proto.Unmarshal(pdbRes.Pointer, pointer)
+	if err != nil {
+		return nil, m, err
+	}
+
+	if pointer.Type != ppb.Pointer_REMOTE {
+		zap.L().Error("TODO: only getting remote pointers supported")
+		return nil, m, err
+	}
+
+	nodes, err := s.overlayHelper(ctx, pointer.Remote)
+	if err != nil {
+		return nil, m, err
+	}
+
+	pid := client.PieceID(pointer.Remote.PieceId)
+	ecRes, err := s.ec.Get(ctx, nodes, s.rs, pid, pointer.Size)
+	if err != nil {
+		return nil, m, err
+	}
+
+	m.Data = pointer.Metadata
+
+	return ecRes, m, nil
 }
 
-// Delete issues deletes of a file to all piece stores and deletes from pointerdb
+// Delete tells piece stores to delete a segment and deletes pointer from pointerdb
 func (s *segmentStore) Delete(ctx context.Context, path paths.Path) error {
+	// TODO: remove this chunk after pointerdb client interface merged
+	gr := &ppb.GetRequest{
+		Path:   []byte(path.String()),
+		APIKey: nil,
+	}
+
+	// gets pointer from pointerdb
+	pdbRes, err := s.pdb.Get(ctx, gr)
+	if err != nil {
+		return err
+	}
+
+	// TODO: remove this chunk after pointerdb client interface merged
+	pointer := &ppb.Pointer{}
+	err = proto.Unmarshal(pdbRes.Pointer, pointer)
+	if err != nil {
+		return err
+	}
+
+	nodes, err := s.overlayHelper(ctx, pointer.Remote)
+	if err != nil {
+		return err
+	}
+
+	// ecclient sends delete request
+	err = s.ec.Delete(ctx, nodes, client.PieceID(pointer.Remote.PieceId))
+	if err != nil {
+		return err
+	}
+
+	// TODO: remove this chunk after pointerdb client interface merged
+	dr := &ppb.DeleteRequest{
+		Path:   []byte(path.String()),
+		APIKey: nil,
+	}
+
+	// deletes pointer from pointerdb
+	_, err = s.pdb.Delete(ctx, dr)
+	if err != nil {
+		return err
+	}
+
 	return nil
 }
 
+// overlayHelper calls Lookup to get node addresses from the overlay
+func (s *segmentStore) overlayHelper(ctx context.Context, rem *ppb.RemoteSegment) (nodes []*opb.Node, err error) {
+	for i := 0; i < len(rem.RemotePieces); i++ {
+		overlayRes, err := s.oc.Lookup(ctx, &opb.LookupRequest{NodeID: rem.RemotePieces[i].NodeId})
+		if err != nil {
+			return nil, err
+		}
+		nodes = append(nodes, overlayRes.Node)
+	}
+	return nodes, nil
+}
+
 // List lists paths stored in the pointerdb
 func (s *segmentStore) List(ctx context.Context, startingPath, endingPath paths.Path) (
-	paths []paths.Path, truncated bool, err error) {
-	return nil, true, nil
+	listPaths []paths.Path, truncated bool, err error) {
+
+	// TODO: remove this chunk after pointerdb client interface merged
+	lr := &ppb.ListRequest{
+		StartingPathKey: []byte(startingPath.String()),
+		// TODO: change limit to endingPath when supported
+		Limit:  1,
+		APIKey: nil,
+	}
+
+	res, err := s.pdb.List(ctx, lr)
+	if err != nil {
+		return nil, false, err
+	}
+
+	for _, path := range res.Paths {
+		np := paths.New(string(path[:]))
+		listPaths = append(listPaths, np)
+	}
+
+	return listPaths, res.Truncated, nil
 }