Merge branch 'master' into upload-defaultpath-once

p2p/discover/table.go

@@ -160,7 +160,7 @@ func (tab *Table) ReadRandomNodes(buf []*Node) (n int) {
 
 	// Find all non-empty buckets and get a fresh slice of their entries.
 	var buckets [][]*Node
-	for _, b := range tab.buckets {
+	for _, b := range &tab.buckets {
 		if len(b.entries) > 0 {
 			buckets = append(buckets, b.entries[:])
 		}
@@ -508,7 +508,7 @@ func (tab *Table) copyLiveNodes() {
 	defer tab.mutex.Unlock()
 
 	now := time.Now()
-	for _, b := range tab.buckets {
+	for _, b := range &tab.buckets {
 		for _, n := range b.entries {
 			if now.Sub(n.addedAt) >= seedMinTableTime {
 				tab.db.updateNode(n)
@@ -524,7 +524,7 @@ func (tab *Table) closest(target common.Hash, nresults int) *nodesByDistance {
 	// obviously correct. I believe that tree-based buckets would make
 	// this easier to implement efficiently.
 	close := &nodesByDistance{target: target}
-	for _, b := range tab.buckets {
+	for _, b := range &tab.buckets {
 		for _, n := range b.entries {
 			close.push(n, nresults)
 		}
@@ -533,7 +533,7 @@ func (tab *Table) closest(target common.Hash, nresults int) *nodesByDistance {
 }
 
 func (tab *Table) len() (n int) {
-	for _, b := range tab.buckets {
+	for _, b := range &tab.buckets {
 		n += len(b.entries)
 	}
 	return n

p2p/discv5/net_test.go

@@ -355,7 +355,7 @@ func (tn *preminedTestnet) mine(target NodeID) {
 	fmt.Printf("	target: %#v,\n", tn.target)
 	fmt.Printf("	targetSha: %#v,\n", tn.targetSha)
 	fmt.Printf("	dists: [%d][]NodeID{\n", len(tn.dists))
-	for ld, ns := range tn.dists {
+	for ld, ns := range &tn.dists {
 		if len(ns) == 0 {
 			continue
 		}

p2p/discv5/table.go

@@ -81,7 +81,7 @@ func (tab *Table) chooseBucketRefreshTarget() common.Hash {
 	if printTable {
 		fmt.Println()
 	}
-	for i, b := range tab.buckets {
+	for i, b := range &tab.buckets {
 		entries += len(b.entries)
 		if printTable {
 			for _, e := range b.entries {
@@ -93,7 +93,7 @@ func (tab *Table) chooseBucketRefreshTarget() common.Hash {
 	prefix := binary.BigEndian.Uint64(tab.self.sha[0:8])
 	dist := ^uint64(0)
 	entry := int(randUint(uint32(entries + 1)))
-	for _, b := range tab.buckets {
+	for _, b := range &tab.buckets {
 		if entry < len(b.entries) {
 			n := b.entries[entry]
 			dist = binary.BigEndian.Uint64(n.sha[0:8]) ^ prefix
@@ -121,7 +121,7 @@ func (tab *Table) readRandomNodes(buf []*Node) (n int) {
 	// TODO: tree-based buckets would help here
 	// Find all non-empty buckets and get a fresh slice of their entries.
 	var buckets [][]*Node
-	for _, b := range tab.buckets {
+	for _, b := range &tab.buckets {
 		if len(b.entries) > 0 {
 			buckets = append(buckets, b.entries[:])
 		}
@@ -175,7 +175,7 @@ func (tab *Table) closest(target common.Hash, nresults int) *nodesByDistance {
 	// obviously correct. I believe that tree-based buckets would make
 	// this easier to implement efficiently.
 	close := &nodesByDistance{target: target}
-	for _, b := range tab.buckets {
+	for _, b := range &tab.buckets {
 		for _, n := range b.entries {
 			close.push(n, nresults)
 		}

swarm/README.md

@@ -7,6 +7,21 @@ Swarm is a distributed storage platform and content distribution service, a nati
 [![Travis](https://travis-ci.org/ethereum/go-ethereum.svg?branch=master)](https://travis-ci.org/ethereum/go-ethereum)
 [![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/ethersphere/orange-lounge?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
 
+## Table of Contents
+
+*  [Building the source](#building-the-source)
+*  [Running Swarm](#running-swarm)
+*  [Documentation](#documentation)
+*  [Developers Guide](#developers-guide)
+   *  [Go Environment](#development-environment)
+   *  [Vendored Dependencies](#vendored-dependencies)
+   *  [Testing](#testing)
+   *  [Profiling Swarm](#profiling-swarm)
+   *  [Metrics and Instrumentation in Swarm](#metrics-and-instrumentation-in-swarm)
+*  [Public Gateways](#public-gateways)
+*  [Swarm Dapps](#swarm-dapps)
+*  [Contributing](#contributing)
+*  [License](#license)
 
 ## Building the source
 
@@ -16,13 +31,187 @@ Building Swarm requires Go (version 1.10 or later).
 
     go install github.com/ethereum/go-ethereum/cmd/swarm
 
+## Running Swarm
+
+Going through all the possible command line flags is out of scope here, but we've enumerated a few common parameter combos to get you up to speed quickly on how you can run your own Swarm node.
+
+To run Swarm you need an Ethereum account. You can create a new account by running the following command:
+
+    geth account new
+
+You will be prompted for a password:
+
+    Your new account is locked with a password. Please give a password. Do not forget this password.
+    Passphrase:
+    Repeat passphrase:
+
+Once you have specified the password, the output will be the Ethereum address representing that account. For example:
+
+    Address: {2f1cd699b0bf461dcfbf0098ad8f5587b038f0f1}
+
+Using this account, connect to Swarm with
+
+    swarm --bzzaccount <your-account-here>
+
+    # in our example
+
+    swarm --bzzaccount 2f1cd699b0bf461dcfbf0098ad8f5587b038f0f1
+
+
+### Verifying that your local Swarm node is running
+
+When running, Swarm is accessible through an HTTP API on port 8500.
+
+Confirm that it is up and running by pointing your browser to http://localhost:8500
+
+### Ethereum Name Service resolution
+
+The Ethereum Name Service is the Ethereum equivalent of DNS in the classic web. In order to use ENS to resolve names to Swarm content hashes (e.g. `bzz://theswarm.eth`), `swarm` has to connect to a `geth` instance, which is synced with the Ethereum mainnet. This is done using the `--ens-api` flag.
+
+    swarm --bzzaccount <your-account-here> \
+          --ens-api '$HOME/.ethereum/geth.ipc'
+
+    # in our example
+
+    swarm --bzzaccount 2f1cd699b0bf461dcfbf0098ad8f5587b038f0f1 \
+          --ens-api '$HOME/.ethereum/geth.ipc'
+
+For more information on usage, features or command line flags, please consult the Documentation.
+
 
 ## Documentation
 
 Swarm documentation can be found at [https://swarm-guide.readthedocs.io](https://swarm-guide.readthedocs.io).
 
 
-## Contribution
+## Developers Guide
+
+### Go Environment
+
+We assume that you have Go v1.10 installed, and `GOPATH` is set.
+
+You must have your working copy under `$GOPATH/src/github.com/ethereum/go-ethereum`.
+
+Most likely you will be working from your fork of `go-ethereum`, let's say from `github.com/nirname/go-ethereum`. Clone or move your fork into the right place:
+
+```
+git clone git@github.com:nirname/go-ethereum.git $GOPATH/src/github.com/ethereum/go-ethereum
+```
+
+
+### Vendored Dependencies
+
+All dependencies are tracked in the `vendor` directory. We use `govendor` to manage them.
+
+If you want to add a new dependency, run `govendor fetch <import-path>`, then commit the result.
+
+If you want to update all dependencies to their latest upstream version, run `govendor fetch +v`.
+
+
+### Testing
+
+This section explains how to run unit, integration, and end-to-end tests in your development sandbox.
+
+Testing one library:
+
+```
+go test -v -cpu 4 ./swarm/api
+```
+
+Note: Using options -cpu (number of cores allowed) and -v (logging even if no error) is recommended.
+
+Testing only some methods:
+
+```
+go test -v -cpu 4 ./eth -run TestMethod
+```
+
+Note: here all tests with prefix TestMethod will be run, so if you got TestMethod, TestMethod1, then both!
+
+Running benchmarks:
+
+```
+go test -v -cpu 4 -bench . -run BenchmarkJoin
+```
+
+
+### Profiling Swarm
+
+This section explains how to add Go `pprof` profiler to Swarm
+
+If `swarm` is started with the `--pprof` option, a debugging HTTP server is made available on port 6060.
+
+You can bring up http://localhost:6060/debug/pprof to see the heap, running routines etc.
+
+By clicking full goroutine stack dump (clicking http://localhost:6060/debug/pprof/goroutine?debug=2) you can generate trace that is useful for debugging.
+
+
+### Metrics and Instrumentation in Swarm
+
+This section explains how to visualize and use existing Swarm metrics and how to instrument Swarm with a new metric.
+
+Swarm metrics system is based on the `go-metrics` library.
+
+The most common types of measurements we use in Swarm are `counters` and `resetting timers`. Consult the `go-metrics` documentation for full reference of available types.
+
+```
+# incrementing a counter
+metrics.GetOrRegisterCounter("network.stream.received_chunks", nil).Inc(1)
+
+# measuring latency with a resetting timer
+start := time.Now()
+t := metrics.GetOrRegisterResettingTimer("http.request.GET.time"), nil)
+...
+t := UpdateSince(start)
+```
+
+#### Visualizing metrics
+
+Swarm supports an InfluxDB exporter. Consult the help section to learn about the command line arguments used to configure it:
+
+```
+swarm --help | grep metrics
+```
+
+We use Grafana and InfluxDB to visualise metrics reported by Swarm. We keep our Grafana dashboards under version control at `./swarm/grafana_dashboards`. You could use them or design your own.
+
+We have built a tool to help with automatic start of Grafana and InfluxDB and provisioning of dashboards at https://github.com/nonsense/stateth , which requires that you have Docker installed.
+
+Once you have `stateth` installed, and you have Docker running locally, you have to:
+
+1. Run `stateth` and keep it running in the background
+```
+stateth --rm --grafana-dashboards-folder $GOPATH/src/github.com/ethereum/go-ethereum/swarm/grafana_dashboards --influxdb-database metrics
+```
+
+2. Run `swarm` with at least the following params:
+```
+--metrics \
+--metrics.influxdb.export \
+--metrics.influxdb.endpoint "http://localhost:8086" \
+--metrics.influxdb.username "admin" \
+--metrics.influxdb.password "admin" \
+--metrics.influxdb.database "metrics"
+```
+
+3. Open Grafana at http://localhost:3000 and view the dashboards to gain insight into Swarm.
+
+
+## Public Gateways
+
+Swarm offers a local HTTP proxy API that Dapps can use to interact with Swarm. The Ethereum Foundation is hosting a public gateway, which allows free access so that people can try Swarm without running their own node.
+
+The Swarm public gateways are temporary and users should not rely on their existence for production services.
+
+The Swarm public gateway can be found at https://swarm-gateways.net and is always running the latest `stable` Swarm release.
+
+## Swarm Dapps
+
+You can find a few reference Swarm decentralised applications at: https://swarm-gateways.net/bzz:/swarmapps.eth
+
+Their source code can be found at: https://github.com/ethersphere/swarm-dapps
+
+## Contributing
 
 Thank you for considering to help out with the source code! We welcome contributions from
 anyone on the internet, and are grateful for even the smallest of fixes!

swarm/api/http/response.go

@@ -29,14 +29,12 @@ import (
 	"github.com/ethereum/go-ethereum/swarm/api"
 )
 
-//metrics variables
 var (
 	htmlCounter      = metrics.NewRegisteredCounter("api.http.errorpage.html.count", nil)
 	jsonCounter      = metrics.NewRegisteredCounter("api.http.errorpage.json.count", nil)
 	plaintextCounter = metrics.NewRegisteredCounter("api.http.errorpage.plaintext.count", nil)
 )
 
-//parameters needed for formatting the correct HTML page
 type ResponseParams struct {
 	Msg       template.HTML
 	Code      int
@@ -45,7 +43,7 @@ type ResponseParams struct {
 	Details   template.HTML
 }
 
-//ShowMultipeChoices is used when a user requests a resource in a manifest which results
+// ShowMultipleChoices is used when a user requests a resource in a manifest which results
 // in ambiguous results. It returns a HTML page with clickable links of each of the entry
 // in the manifest which fits the request URI ambiguity.
 // For example, if the user requests bzz:/<hash>/read and that manifest contains entries
@@ -66,7 +64,6 @@ func ShowMultipleChoices(w http.ResponseWriter, r *http.Request, list api.Manife
 	}
 
 	uri.Scheme = "bzz-list"
-	//request the same url just with bzz-list
 	msg += fmt.Sprintf("Disambiguation:<br/>Your request may refer to multiple choices.<br/>Click <a class=\"orange\" href='"+"/"+uri.String()+"'>here</a> if your browser does not redirect you within 5 seconds.<script>setTimeout(\"location.href='%s';\",5000);</script><br/>", "/"+uri.String())
 	RespondTemplate(w, r, "error", msg, http.StatusMultipleChoices)
 }
@@ -86,7 +83,6 @@ func RespondError(w http.ResponseWriter, r *http.Request, msg string, code int)
 	RespondTemplate(w, r, "error", msg, code)
 }
 
-//evaluate if client accepts html or json response
 func respond(w http.ResponseWriter, r *http.Request, params *ResponseParams) {
 	w.WriteHeader(params.Code)
 
@@ -108,7 +104,6 @@ func respond(w http.ResponseWriter, r *http.Request, params *ResponseParams) {
 	}
 }
 
-//return a HTML page
 func respondHTML(w http.ResponseWriter, r *http.Request, params *ResponseParams) {
 	htmlCounter.Inc(1)
 	log.Debug("respondHTML", "ruid", GetRUID(r.Context()))
@@ -118,7 +113,6 @@ func respondHTML(w http.ResponseWriter, r *http.Request, params *ResponseParams)
 	}
 }
 
-//return JSON
 func respondJSON(w http.ResponseWriter, r *http.Request, params *ResponseParams) error {
 	jsonCounter.Inc(1)
 	log.Debug("respondJSON", "ruid", GetRUID(r.Context()))
@@ -126,7 +120,6 @@ func respondJSON(w http.ResponseWriter, r *http.Request, params *ResponseParams)
 	return json.NewEncoder(w).Encode(params)
 }
 
-//return plaintext
 func respondPlaintext(w http.ResponseWriter, r *http.Request, params *ResponseParams) error {
 	plaintextCounter.Inc(1)
 	log.Debug("respondPlaintext", "ruid", GetRUID(r.Context()))

swarm/api/http/server_test.go

@@ -909,7 +909,6 @@ func TestMethodsNotAllowed(t *testing.T) {
 
 }
 
-// HTTP convenience function
 func httpDo(httpMethod string, url string, reqBody io.Reader, headers map[string]string, verbose bool, t *testing.T) (*http.Response, string) {
 	// Build the Request
 	req, err := http.NewRequest(httpMethod, url, reqBody)
@@ -942,11 +941,10 @@ func httpDo(httpMethod string, url string, reqBody io.Reader, headers map[string
 }
 
 func TestGet(t *testing.T) {
-	// Setup Swarm
 	srv := testutil.NewTestSwarmServer(t, serverFunc)
 	defer srv.Close()
 
-	testCases := []struct {
+	for _, testCase := range []struct {
 		uri                string
 		method             string
 		headers            map[string]string
@@ -955,25 +953,22 @@ func TestGet(t *testing.T) {
 		verbose            bool
 	}{
 		{
-			// Accept: text/html GET / -> 200 HTML, Swarm Landing Page
 			uri:                fmt.Sprintf("%s/", srv.URL),
 			method:             "GET",
 			headers:            map[string]string{"Accept": "text/html"},
 			expectedStatusCode: 200,
-			assertResponseBody: "<a href=\"/bzz:/theswarm.eth\">Swarm</a>: Serverless Hosting Incentivised peer-to-peer Storage and Content Distribution",
+			assertResponseBody: "Swarm: Serverless Hosting Incentivised Peer-To-Peer Storage And Content Distribution",
 			verbose:            false,
 		},
 		{
-			// Accept: application/json GET / -> 200 'Welcome to Swarm'
 			uri:                fmt.Sprintf("%s/", srv.URL),
 			method:             "GET",
 			headers:            map[string]string{"Accept": "application/json"},
 			expectedStatusCode: 200,
-			assertResponseBody: "Welcome to Swarm!",
+			assertResponseBody: "Swarm: Please request a valid ENS or swarm hash with the appropriate bzz scheme",
 			verbose:            false,
 		},
 		{
-			// GET /robots.txt -> 200
 			uri:                fmt.Sprintf("%s/robots.txt", srv.URL),
 			method:             "GET",
 			headers:            map[string]string{"Accept": "text/html"},
@@ -982,62 +977,54 @@ func TestGet(t *testing.T) {
 			verbose:            false,
 		},
 		{
-			// GET /path_that_doesnt exist -> 400
 			uri:                fmt.Sprintf("%s/nonexistent_path", srv.URL),
 			method:             "GET",
 			headers:            map[string]string{},
-			expectedStatusCode: 400,
+			expectedStatusCode: 404,
 			verbose:            false,
 		},
 		{
-			// GET bzz-invalid:/ -> 400
 			uri:                fmt.Sprintf("%s/bzz:asdf/", srv.URL),
 			method:             "GET",
 			headers:            map[string]string{},
-			expectedStatusCode: 400,
+			expectedStatusCode: 404,
 			verbose:            false,
 		},
 		{
-			// GET bzz-invalid:/ -> 400
 			uri:                fmt.Sprintf("%s/tbz2/", srv.URL),
 			method:             "GET",
 			headers:            map[string]string{},
-			expectedStatusCode: 400,
+			expectedStatusCode: 404,
 			verbose:            false,
 		},
 		{
-			// GET bzz-invalid:/ -> 400
 			uri:                fmt.Sprintf("%s/bzz-rack:/", srv.URL),
 			method:             "GET",
 			headers:            map[string]string{},
-			expectedStatusCode: 400,
+			expectedStatusCode: 404,
 			verbose:            false,
 		},
 		{
-			// GET bzz-invalid:/ -> 400
 			uri:                fmt.Sprintf("%s/bzz-ls", srv.URL),
 			method:             "GET",
 			headers:            map[string]string{},
-			expectedStatusCode: 400,
+			expectedStatusCode: 404,
 			verbose:            false,
 		},
-	}
+	} {
-
-	for _, testCase := range testCases {
 		t.Run("GET "+testCase.uri, func(t *testing.T) {
 			res, body := httpDo(testCase.method, testCase.uri, nil, testCase.headers, testCase.verbose, t)
 			if res.StatusCode != testCase.expectedStatusCode {
-				t.Fatalf("expected %s %s to return a %v but it didn't", testCase.method, testCase.uri, testCase.expectedStatusCode)
+				t.Fatalf("expected status code %d but got %d", testCase.expectedStatusCode, res.StatusCode)
 			}
 			if testCase.assertResponseBody != "" && !strings.Contains(body, testCase.assertResponseBody) {
-				t.Fatalf("expected %s %s to have %s within HTTP response body but it didn't", testCase.method, testCase.uri, testCase.assertResponseBody)
+				t.Fatalf("expected response to be: %s but got: %s", testCase.assertResponseBody, body)
 			}
 		})
 	}
 }
 
 func TestModify(t *testing.T) {
-	// Setup Swarm and upload a test file to it
 	srv := testutil.NewTestSwarmServer(t, serverFunc)
 	defer srv.Close()
 
@@ -1057,7 +1044,7 @@ func TestModify(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	testCases := []struct {
+	for _, testCase := range []struct {
 		uri                   string
 		method                string
 		headers               map[string]string
@@ -1068,7 +1055,6 @@ func TestModify(t *testing.T) {
 		verbose               bool
 	}{
 		{
-			// DELETE bzz:/hash -> 200 OK
 			uri:                fmt.Sprintf("%s/bzz:/%s", srv.URL, hash),
 			method:             "DELETE",
 			headers:            map[string]string{},
@@ -1077,7 +1063,6 @@ func TestModify(t *testing.T) {
 			verbose:            false,
 		},
 		{
-			// PUT bzz:/hash -> 405 Method Not Allowed
 			uri:                fmt.Sprintf("%s/bzz:/%s", srv.URL, hash),
 			method:             "PUT",
 			headers:            map[string]string{},
@@ -1085,7 +1070,6 @@ func TestModify(t *testing.T) {
 			verbose:            false,
 		},
 		{
-			// PUT bzz-raw:/hash -> 405 Method Not Allowed
 			uri:                fmt.Sprintf("%s/bzz-raw:/%s", srv.URL, hash),
 			method:             "PUT",
 			headers:            map[string]string{},
@@ -1093,7 +1077,6 @@ func TestModify(t *testing.T) {
 			verbose:            false,
 		},
 		{
-			// PATCH bzz:/hash -> 405 Method Not Allowed
 			uri:                fmt.Sprintf("%s/bzz:/%s", srv.URL, hash),
 			method:             "PATCH",
 			headers:            map[string]string{},
@@ -1101,7 +1084,6 @@ func TestModify(t *testing.T) {
 			verbose:            false,
 		},
 		{
-			// POST bzz-raw:/ -> 200 OK
 			uri:                   fmt.Sprintf("%s/bzz-raw:/", srv.URL),
 			method:                "POST",
 			headers:               map[string]string{},
@@ -1111,7 +1093,6 @@ func TestModify(t *testing.T) {
 			verbose:               false,
 		},
 		{
-			// POST bzz-raw:/encrypt -> 200 OK
 			uri:                   fmt.Sprintf("%s/bzz-raw:/encrypt", srv.URL),
 			method:                "POST",
 			headers:               map[string]string{},
@@ -1120,19 +1101,17 @@ func TestModify(t *testing.T) {
 			assertResponseHeaders: map[string]string{"Content-Length": "128"},
 			verbose:               false,
 		},
-	}
+	} {
-
-	for _, testCase := range testCases {
 		t.Run(testCase.method+" "+testCase.uri, func(t *testing.T) {
 			reqBody := bytes.NewReader(testCase.requestBody)
 			res, body := httpDo(testCase.method, testCase.uri, reqBody, testCase.headers, testCase.verbose, t)
 
 			if res.StatusCode != testCase.expectedStatusCode {
-				t.Fatalf("expected %s %s to return a %v but it returned a %v instead", testCase.method, testCase.uri, testCase.expectedStatusCode, res.StatusCode)
+				t.Fatalf("expected status code %d but got %d", testCase.expectedStatusCode, res.StatusCode)
 			}
 			if testCase.assertResponseBody != "" && !strings.Contains(body, testCase.assertResponseBody) {
 				t.Log(body)
-				t.Fatalf("expected %s %s to have %s within HTTP response body but it didn't", testCase.method, testCase.uri, testCase.assertResponseBody)
+				t.Fatalf("expected response %s but got %s", testCase.assertResponseBody, body)
 			}
 			for key, value := range testCase.assertResponseHeaders {
 				if res.Header.Get(key) != value {

swarm/api/manifest.go

@@ -164,7 +164,7 @@ func (m *ManifestWalker) Walk(walkFn WalkFn) error {
 }
 
 func (m *ManifestWalker) walk(trie *manifestTrie, prefix string, walkFn WalkFn) error {
-	for _, entry := range trie.entries {
+	for _, entry := range &trie.entries {
 		if entry == nil {
 			continue
 		}
@@ -313,7 +313,7 @@ func (mt *manifestTrie) addEntry(entry *manifestTrieEntry, quitC chan bool) {
 }
 
 func (mt *manifestTrie) getCountLast() (cnt int, entry *manifestTrieEntry) {
-	for _, e := range mt.entries {
+	for _, e := range &mt.entries {
 		if e != nil {
 			cnt++
 			entry = e
@@ -367,7 +367,7 @@ func (mt *manifestTrie) recalcAndStore() error {
 	buffer.WriteString(`{"entries":[`)
 
 	list := &Manifest{}
-	for _, entry := range mt.entries {
+	for _, entry := range &mt.entries {
 		if entry != nil {
 			if entry.Hash == "" { // TODO: paralellize
 				err := entry.subtrie.recalcAndStore()

trie/node.go

@@ -55,7 +55,7 @@ var nilValueNode = valueNode(nil)
 func (n *fullNode) EncodeRLP(w io.Writer) error {
 	var nodes [17]node
 
-	for i, child := range n.Children {
+	for i, child := range &n.Children {
 		if child != nil {
 			nodes[i] = child
 		} else {
@@ -98,7 +98,7 @@ func (n valueNode) String() string  { return n.fstring("") }
 
 func (n *fullNode) fstring(ind string) string {
 	resp := fmt.Sprintf("[\n%s  ", ind)
-	for i, node := range n.Children {
+	for i, node := range &n.Children {
 		if node == nil {
 			resp += fmt.Sprintf("%s: <nil> ", indices[i])
 		} else {

trie/trie.go

@@ -356,7 +356,7 @@ func (t *Trie) delete(n node, prefix, key []byte) (bool, node, error) {
 		// value that is left in n or -2 if n contains at least two
 		// values.
 		pos := -1
-		for i, cld := range n.Children {
+		for i, cld := range &n.Children {
 			if cld != nil {
 				if pos == -1 {
 					pos = i