swarm: ctx propagation; bmt fixes; pss generic notification framework (#17150)

* cmd/swarm: minor cli flag text adjustments

* swarm/api/http: sticky footer for swarm landing page using flex

* swarm/api/http: sticky footer for error pages and fix for multiple choices

* cmd/swarm, swarm/storage, swarm: fix  mingw on windows test issues

* cmd/swarm: update description of swarm cmd

* swarm: added network ID test

* cmd/swarm: support for smoke tests on the production swarm cluster

* cmd/swarm/swarm-smoke: simplify cluster logic as per suggestion

* swarm: propagate ctx to internal apis (#754)

* swarm/metrics: collect disk measurements

* swarm/bmt: fix io.Writer interface

  * Write now tolerates arbitrary variable buffers
  * added variable buffer tests
  * Write loop and finalise optimisation
  * refactor / rename
  * add tests for empty input

* swarm/pss: (UPDATE) Generic notifications package (#744)

swarm/pss: Generic package for creating pss notification svcs

* swarm: Adding context to more functions

* swarm/api: change colour of landing page in templates

* swarm/api: change landing page to react to enter keypress

swarm/bmt/bmt_test.go

@@ -34,12 +34,12 @@ import (
 // the actual data length generated (could be longer than max datalength of the BMT)
 const BufferSize = 4128
 
+var counts = []int{1, 2, 3, 4, 5, 8, 9, 15, 16, 17, 32, 37, 42, 53, 63, 64, 65, 111, 127, 128}
+
+// calculates the Keccak256 SHA3 hash of the data
 func sha3hash(data ...[]byte) []byte {
 	h := sha3.NewKeccak256()
-	for _, v := range data {
-		h.Write(v)
-	}
-	return h.Sum(nil)
+	return doHash(h, nil, data...)
 }
 
 // TestRefHasher tests that the RefHasher computes the expected BMT hash for
@@ -129,31 +129,48 @@ func TestRefHasher(t *testing.T) {
 	}
 }
 
-func TestHasherCorrectness(t *testing.T) {
-	err := testHasher(testBaseHasher)
-	if err != nil {
-		t.Fatal(err)
+// tests if hasher responds with correct hash
+func TestHasherEmptyData(t *testing.T) {
+	hasher := sha3.NewKeccak256
+	var data []byte
+	for _, count := range counts {
+		t.Run(fmt.Sprintf("%d_segments", count), func(t *testing.T) {
+			pool := NewTreePool(hasher, count, PoolSize)
+			defer pool.Drain(0)
+			bmt := New(pool)
+			rbmt := NewRefHasher(hasher, count)
+			refHash := rbmt.Hash(data)
+			expHash := Hash(bmt, nil, data)
+			if !bytes.Equal(expHash, refHash) {
+				t.Fatalf("hash mismatch with reference. expected %x, got %x", refHash, expHash)
+			}
+		})
 	}
 }
 
-func testHasher(f func(BaseHasherFunc, []byte, int, int) error) error {
+func TestHasherCorrectness(t *testing.T) {
 	data := newData(BufferSize)
 	hasher := sha3.NewKeccak256
 	size := hasher().Size()
-	counts := []int{1, 2, 3, 4, 5, 8, 16, 32, 64, 128}
 
 	var err error
 	for _, count := range counts {
-		max := count * size
-		incr := 1
-		for n := 1; n <= max; n += incr {
-			err = f(hasher, data, n, count)
-			if err != nil {
-				return err
+		t.Run(fmt.Sprintf("segments_%v", count), func(t *testing.T) {
+			max := count * size
+			incr := 1
+			capacity := 1
+			pool := NewTreePool(hasher, count, capacity)
+			defer pool.Drain(0)
+			for n := 0; n <= max; n += incr {
+				incr = 1 + rand.Intn(5)
+				bmt := New(pool)
+				err = testHasherCorrectness(bmt, hasher, data, n, count)
+				if err != nil {
+					t.Fatal(err)
+				}
 			}
-		}
+		})
 	}
-	return nil
 }
 
 // Tests that the BMT hasher can be synchronously reused with poolsizes 1 and PoolSize
@@ -215,12 +232,69 @@ LOOP:
 	}
 }
 
-// helper function that creates  a tree pool
-func testBaseHasher(hasher BaseHasherFunc, d []byte, n, count int) error {
-	pool := NewTreePool(hasher, count, 1)
-	defer pool.Drain(0)
-	bmt := New(pool)
-	return testHasherCorrectness(bmt, hasher, d, n, count)
+// Tests BMT Hasher io.Writer interface is working correctly
+// even multiple short random write buffers
+func TestBMTHasherWriterBuffers(t *testing.T) {
+	hasher := sha3.NewKeccak256
+
+	for _, count := range counts {
+		t.Run(fmt.Sprintf("%d_segments", count), func(t *testing.T) {
+			errc := make(chan error)
+			pool := NewTreePool(hasher, count, PoolSize)
+			defer pool.Drain(0)
+			n := count * 32
+			bmt := New(pool)
+			data := newData(n)
+			rbmt := NewRefHasher(hasher, count)
+			refHash := rbmt.Hash(data)
+			expHash := Hash(bmt, nil, data)
+			if !bytes.Equal(expHash, refHash) {
+				t.Fatalf("hash mismatch with reference. expected %x, got %x", refHash, expHash)
+			}
+			attempts := 10
+			f := func() error {
+				bmt := New(pool)
+				bmt.Reset()
+				var buflen int
+				for offset := 0; offset < n; offset += buflen {
+					buflen = rand.Intn(n-offset) + 1
+					read, err := bmt.Write(data[offset : offset+buflen])
+					if err != nil {
+						return err
+					}
+					if read != buflen {
+						return fmt.Errorf("incorrect read. expected %v bytes, got %v", buflen, read)
+					}
+				}
+				hash := bmt.Sum(nil)
+				if !bytes.Equal(hash, expHash) {
+					return fmt.Errorf("hash mismatch. expected %x, got %x", hash, expHash)
+				}
+				return nil
+			}
+
+			for j := 0; j < attempts; j++ {
+				go func() {
+					errc <- f()
+				}()
+			}
+			timeout := time.NewTimer(2 * time.Second)
+			for {
+				select {
+				case err := <-errc:
+					if err != nil {
+						t.Fatal(err)
+					}
+					attempts--
+					if attempts == 0 {
+						return
+					}
+				case <-timeout.C:
+					t.Fatalf("timeout")
+				}
+			}
+		})
+	}
 }
 
 // helper function that compares reference and optimised implementations on