list-objects and friends: micro-optimizations

Signed-off-by: Alex Aizman <[email protected]>

xact/xs/lrit.go

@@ -262,7 +262,7 @@ func (r *lrit) _prefix(wi lrwi, smap *meta.Smap) error {
 		ecode   int
 		lst     *cmn.LsoRes
 		lsmsg   = &apc.LsoMsg{Prefix: r.prefix, Props: apc.GetPropsStatus}
-		npg     = newNpgCtx(r.bck, lsmsg, noopCb, nil /*core.LsoInvCtx bucket inventory*/)
+		npg     = newNpgCtx(r.bck, lsmsg, noopCb, nil /*inventory*/, nil /*bp: see below*/)
 		bremote = r.bck.IsRemote()
 	)
 	lsmsg.SetFlag(apc.LsNoDirs)
@@ -272,6 +272,8 @@ func (r *lrit) _prefix(wi lrwi, smap *meta.Smap) error {
 	}
 	if !bremote {
 		smap = nil // not needed
+	} else {
+		npg.bp = core.T.Backend(r.bck)
 	}
 	for {
 		if r.done() {

xact/xs/lso.go

@@ -43,29 +43,31 @@ type (
 		streamingF
 	}
 	LsoXact struct {
-		msg       *apc.LsoMsg
-		msgCh     chan *apc.LsoMsg // incoming requests
+		lpis      lpi.Lpis
+		msg       *apc.LsoMsg      // first message
+		msgCh     chan *apc.LsoMsg // next messages
 		respCh    chan *LsoRsp     // responses - next pages
 		remtCh    chan *LsoRsp     // remote paging by the responsible target
-		stopCh    cos.StopCh       // to stop xaction
-		token     string           // continuation token -> last responded page
+		ctx       *core.LsoInvCtx  // bucket inventory
 		nextToken string           // next continuation token -> next pages
+		token     string           // continuation token -> last responded page
+		stopCh    cos.StopCh       // to stop xaction
 		page      cmn.LsoEntries   // current page (contents)
 		walk      struct {
 			pageCh       chan *cmn.LsoEnt // channel to accumulate listed object entries
 			stopCh       *cos.StopCh      // to abort bucket walk
 			wi           *walkInfo        // walking context and state
+			bp           core.Backend     // t.Backend(bck)
 			wg           sync.WaitGroup   // wait until this walk finishes
 			done         bool             // done walking (indication)
 			wor          bool             // wantOnlyRemote
 			dontPopulate bool             // when listing remote obj-s: don't include local MD (in re: LsDonAddRemote)
 			this         bool             // r.msg.SID == core.T.SID(): true when this target does remote paging
 			last         bool             // last remote page
+			remote       bool             // list remote
 		}
 		streamingX
-		lensgl int64
-		ctx    *core.LsoInvCtx
-		lpis   lpi.Lpis
+		lensgl int64 // channel to accumulate listed object entries
 	}
 	LsoRsp struct {
 		Err    error
@@ -190,8 +192,11 @@ func (p *lsoFactory) beginStreams(r *LsoXact) error {
 func (r *LsoXact) Run(wg *sync.WaitGroup) {
 	wg.Done()
 
-	if !lsoIsRemote(r.p.Bck, r.msg.IsFlagSet(apc.LsCached)) {
+	r.walk.remote = lsoIsRemote(r.p.Bck, r.msg.IsFlagSet(apc.LsCached))
+	if !r.walk.remote {
 		r.initWalk()
+	} else {
+		r.walk.bp = core.T.Backend(r.p.Bck)
 	}
 loop:
 	for {
@@ -203,8 +208,9 @@ loop:
 			r.msg.PageSize = msg.PageSize
 
 			// cannot change
-			debug.Assert((r.msg.SID == core.T.SID()) == r.walk.this)
-			debug.Assert(r.walk.wor == r.msg.WantOnlyRemoteProps())
+			debug.Assert(r.msg.SID == msg.SID, r.msg.SID, " vs ", msg.SID)
+			debug.Assert(r.walk.wor == msg.WantOnlyRemoteProps(), msg.Str(r.p.Bck.Cname("")))
+			debug.Assert(r.walk.remote == lsoIsRemote(r.p.Bck, msg.IsFlagSet(apc.LsCached)), msg.Str(r.p.Bck.Cname("")))
 
 			r.IncPending()
 			resp := r.doPage()
@@ -345,7 +351,7 @@ func (r *LsoXact) Do(msg *apc.LsoMsg) *LsoRsp {
 }
 
 func (r *LsoXact) doPage() *LsoRsp {
-	if lsoIsRemote(r.p.Bck, r.msg.IsFlagSet(apc.LsCached)) {
+	if r.walk.remote {
 		if r.msg.ContinuationToken == "" || r.msg.ContinuationToken != r.token {
 			// can't extract the next-to-list object name from the remotely generated
 			// continuation token, keeping and returning the entire last page
@@ -405,7 +411,7 @@ func (r *LsoXact) havePage(token string, cnt int64) bool {
 func (r *LsoXact) nextPageR() (err error) {
 	var (
 		page *cmn.LsoRes
-		npg  = newNpgCtx(r.p.Bck, r.msg, r.LomAdd, r.ctx)
+		npg  = newNpgCtx(r.p.Bck, r.msg, r.LomAdd, r.ctx, r.walk.bp)
 		smap = core.T.Sowner().Get()
 		tsi  = smap.GetActiveNode(r.msg.SID)
 	)

xact/xs/nextpage.go

@@ -18,15 +18,17 @@ import (
 )
 
 type npgCtx struct {
+	bp   core.Backend
 	bck  *meta.Bck
 	ctx  *core.LsoInvCtx
 	wi   walkInfo
 	page cmn.LsoRes
 	idx  int
 }
 
-func newNpgCtx(bck *meta.Bck, msg *apc.LsoMsg, cb lomVisitedCb, ctx *core.LsoInvCtx) (npg *npgCtx) {
+func newNpgCtx(bck *meta.Bck, msg *apc.LsoMsg, cb lomVisitedCb, ctx *core.LsoInvCtx, bp core.Backend) (npg *npgCtx) {
 	npg = &npgCtx{
+		bp:  bp,
 		bck: bck,
 		wi: walkInfo{
 			msg:          msg.Clone(),
@@ -89,13 +91,13 @@ func (npg *npgCtx) nextPageR(nentries cmn.LsoEntries) (lst *cmn.LsoRes, err erro
 	lst = &cmn.LsoRes{Entries: nentries}
 	if npg.ctx != nil {
 		if npg.ctx.Lom == nil {
-			_, err = core.T.Backend(npg.bck).GetBucketInv(npg.bck, npg.ctx)
+			_, err = npg.bp.GetBucketInv(npg.bck, npg.ctx)
 		}
 		if err == nil {
-			err = core.T.Backend(npg.bck).ListObjectsInv(npg.bck, npg.wi.msg, lst, npg.ctx)
+			err = npg.bp.ListObjectsInv(npg.bck, npg.wi.msg, lst, npg.ctx)
 		}
 	} else {
-		_, err = core.T.Backend(npg.bck).ListObjects(npg.bck, npg.wi.msg, lst)
+		_, err = npg.bp.ListObjects(npg.bck, npg.wi.msg, lst)
 	}
 	if err != nil {
 		freeLsoEntries(nentries)

xact/xs/nsumm.go

@@ -351,8 +351,9 @@ func (r *XactNsumm) visitObj(lom *core.LOM, _ []byte) error {
 func (r *XactNsumm) runCloudBck(bck *meta.Bck, res *cmn.BsummResult) {
 	lsmsg := &apc.LsoMsg{Props: apc.GetPropsSize, Prefix: r.p.msg.Prefix}
 	lsmsg.SetFlag(apc.LsNameSize | apc.LsNoDirs)
+	bp := core.T.Backend(bck)
 	for !r.IsAborted() {
-		npg := newNpgCtx(bck, lsmsg, noopCb, nil) // TODO: inventory offset
+		npg := newNpgCtx(bck, lsmsg, noopCb, nil, bp) // TODO: inventory offset
 		nentries := allocLsoEntries()
 		lst, err := npg.nextPageR(nentries)
 		if err != nil {