swarm: integrate OpenTracing; propagate ctx to internal APIs (#17169)

* swarm: propagate ctx, enable opentracing

* swarm/tracing: log error when tracing is misconfigured

swarm/storage/chunker.go

@@ -26,6 +26,9 @@ import (
 
 	"github.com/ethereum/go-ethereum/metrics"
 	"github.com/ethereum/go-ethereum/swarm/log"
+	"github.com/ethereum/go-ethereum/swarm/spancontext"
+	opentracing "github.com/opentracing/opentracing-go"
+	olog "github.com/opentracing/opentracing-go/log"
 )
 
 /*
@@ -93,9 +96,12 @@ type JoinerParams struct {
 	getter Getter
 	// TODO: there is a bug, so depth can only be 0 today, see: https://github.com/ethersphere/go-ethereum/issues/344
 	depth int
+	ctx   context.Context
 }
 
 type TreeChunker struct {
+	ctx context.Context
+
 	branches int64
 	hashFunc SwarmHasher
 	dataSize int64
@@ -136,6 +142,7 @@ func TreeJoin(ctx context.Context, addr Address, getter Getter, depth int) *Lazy
 		addr:   addr,
 		getter: getter,
 		depth:  depth,
+		ctx:    ctx,
 	}
 
 	return NewTreeJoiner(jp).Join(ctx)
@@ -174,6 +181,8 @@ func NewTreeJoiner(params *JoinerParams) *TreeChunker {
 	tc.errC = make(chan error)
 	tc.quitC = make(chan bool)
 
+	tc.ctx = params.ctx
+
 	return tc
 }
 
@@ -351,7 +360,7 @@ func (tc *TreeChunker) runWorker() {
 					return
 				}
 
-				h, err := tc.putter.Put(job.chunk)
+				h, err := tc.putter.Put(tc.ctx, job.chunk)
 				if err != nil {
 					tc.errC <- err
 					return
@@ -371,6 +380,7 @@ func (tc *TreeChunker) Append() (Address, func(), error) {
 
 // LazyChunkReader implements LazySectionReader
 type LazyChunkReader struct {
+	Ctx       context.Context
 	key       Address // root key
 	chunkData ChunkData
 	off       int64 // offset
@@ -389,16 +399,28 @@ func (tc *TreeChunker) Join(ctx context.Context) *LazyChunkReader {
 		hashSize:  tc.hashSize,
 		depth:     tc.depth,
 		getter:    tc.getter,
+		Ctx:       tc.ctx,
 	}
 }
 
+func (r *LazyChunkReader) Context() context.Context {
+	return r.Ctx
+}
+
 // Size is meant to be called on the LazySectionReader
-func (r *LazyChunkReader) Size(quitC chan bool) (n int64, err error) {
+func (r *LazyChunkReader) Size(ctx context.Context, quitC chan bool) (n int64, err error) {
 	metrics.GetOrRegisterCounter("lazychunkreader.size", nil).Inc(1)
 
+	var sp opentracing.Span
+	var cctx context.Context
+	cctx, sp = spancontext.StartSpan(
+		ctx,
+		"lcr.size")
+	defer sp.Finish()
+
 	log.Debug("lazychunkreader.size", "key", r.key)
 	if r.chunkData == nil {
-		chunkData, err := r.getter.Get(Reference(r.key))
+		chunkData, err := r.getter.Get(cctx, Reference(r.key))
 		if err != nil {
 			return 0, err
 		}
@@ -421,12 +443,25 @@ func (r *LazyChunkReader) Size(quitC chan bool) (n int64, err error) {
 func (r *LazyChunkReader) ReadAt(b []byte, off int64) (read int, err error) {
 	metrics.GetOrRegisterCounter("lazychunkreader.readat", nil).Inc(1)
 
+	var sp opentracing.Span
+	var cctx context.Context
+	cctx, sp = spancontext.StartSpan(
+		r.Ctx,
+		"lcr.read")
+	defer sp.Finish()
+
+	defer func() {
+		sp.LogFields(
+			olog.Int("off", int(off)),
+			olog.Int("read", read))
+	}()
+
 	// this is correct, a swarm doc cannot be zero length, so no EOF is expected
 	if len(b) == 0 {
 		return 0, nil
 	}
 	quitC := make(chan bool)
-	size, err := r.Size(quitC)
+	size, err := r.Size(cctx, quitC)
 	if err != nil {
 		log.Error("lazychunkreader.readat.size", "size", size, "err", err)
 		return 0, err
@@ -449,7 +484,7 @@ func (r *LazyChunkReader) ReadAt(b []byte, off int64) (read int, err error) {
 		length *= r.chunkSize
 	}
 	wg.Add(1)
-	go r.join(b, off, off+length, depth, treeSize/r.branches, r.chunkData, &wg, errC, quitC)
+	go r.join(cctx, b, off, off+length, depth, treeSize/r.branches, r.chunkData, &wg, errC, quitC)
 	go func() {
 		wg.Wait()
 		close(errC)
@@ -467,7 +502,7 @@ func (r *LazyChunkReader) ReadAt(b []byte, off int64) (read int, err error) {
 	return len(b), nil
 }
 
-func (r *LazyChunkReader) join(b []byte, off int64, eoff int64, depth int, treeSize int64, chunkData ChunkData, parentWg *sync.WaitGroup, errC chan error, quitC chan bool) {
+func (r *LazyChunkReader) join(ctx context.Context, b []byte, off int64, eoff int64, depth int, treeSize int64, chunkData ChunkData, parentWg *sync.WaitGroup, errC chan error, quitC chan bool) {
 	defer parentWg.Done()
 	// find appropriate block level
 	for chunkData.Size() < treeSize && depth > r.depth {
@@ -514,7 +549,7 @@ func (r *LazyChunkReader) join(b []byte, off int64, eoff int64, depth int, treeS
 		wg.Add(1)
 		go func(j int64) {
 			childKey := chunkData[8+j*r.hashSize : 8+(j+1)*r.hashSize]
-			chunkData, err := r.getter.Get(Reference(childKey))
+			chunkData, err := r.getter.Get(ctx, Reference(childKey))
 			if err != nil {
 				log.Error("lazychunkreader.join", "key", fmt.Sprintf("%x", childKey), "err", err)
 				select {
@@ -533,7 +568,7 @@ func (r *LazyChunkReader) join(b []byte, off int64, eoff int64, depth int, treeS
 			if soff < off {
 				soff = off
 			}
-			r.join(b[soff-off:seoff-off], soff-roff, seoff-roff, depth-1, treeSize/r.branches, chunkData, wg, errC, quitC)
+			r.join(ctx, b[soff-off:seoff-off], soff-roff, seoff-roff, depth-1, treeSize/r.branches, chunkData, wg, errC, quitC)
 		}(i)
 	} //for
 }
@@ -570,7 +605,7 @@ func (r *LazyChunkReader) Seek(offset int64, whence int) (int64, error) {
 		offset += r.off
 	case 2:
 		if r.chunkData == nil { //seek from the end requires rootchunk for size. call Size first
-			_, err := r.Size(nil)
+			_, err := r.Size(context.TODO(), nil)
 			if err != nil {
 				return 0, fmt.Errorf("can't get size: %v", err)
 			}