release list paritioning

pkg/tiller/release_list.go

@@ -18,11 +18,11 @@ package tiller
 
 import (
 	"fmt"
-	"regexp"
-
+	"github.com/golang/protobuf/proto"
 	"k8s.io/helm/pkg/proto/hapi/release"
 	"k8s.io/helm/pkg/proto/hapi/services"
 	relutil "k8s.io/helm/pkg/releaseutil"
+	"regexp"
 )
 
 // ListReleases lists the releases found by the server.
@@ -107,21 +107,52 @@ func (s *ReleaseServer) ListReleases(req *services.ListReleasesRequest, stream s
 		rels = rels[0:req.Limit]
 		l = int64(len(rels))
 	}
-
-	for i := 0; i < min(len(rels), int(req.Limit)); i++ {
-		res := &services.ListReleasesResponse{
-			Next:     next,
-			Count:    l,
-			Total:    total,
-			Releases: []*release.Release{rels[i]},
-		}
+	res := &services.ListReleasesResponse{
+		Next:  next,
+		Count: l,
+		Total: total,
+	}
+	chunks := s.partition(rels[:min(len(rels), int(req.Limit))], maxMsgSize-proto.Size(res))
+	for res.Releases = range chunks {
 		if err := stream.Send(res); err != nil {
+			for range chunks { // drain
+			}
 			return err
 		}
 	}
 	return nil
 }
 
+// partition packs releases into slices upto the capacity cap in bytes.
+func (s *ReleaseServer) partition(rels []*release.Release, cap int) <-chan []*release.Release {
+	chunks := make(chan []*release.Release, 1)
+	go func() {
+		var (
+			fill = 0 // fill is space available to fill
+			size int // size is size of a release
+		)
+		var chunk []*release.Release
+		for _, rls := range rels {
+			if size = proto.Size(rls); size+fill > cap {
+				// Over-cap, push chunk onto channel to send over gRPC stream
+				s.Log("partitioned at %d with %d releases (cap=%d)", fill, len(chunk), cap)
+				chunks <- chunk
+				// reset paritioning state
+				chunk = chunk[:0]
+				fill = 0
+			}
+			chunk = append(chunk, rls)
+			fill += size
+		}
+		if len(chunk) > 0 {
+			// send remaining if any
+			chunks <- chunk
+		}
+		close(chunks)
+	}()
+	return chunks
+}
+
 func filterByNamespace(namespace string, rels []*release.Release) ([]*release.Release, error) {
 	matches := []*release.Release{}
 	for _, r := range rels {