cmd/swarm, swarm/api/client: add HTTP API client and 'swarm ls' command (#3742)

This adds a swarm ls command which lists files and directories stored in a
manifest. Rather than listing all files, it uses "directory prefixes" in case there are a
lot of files in a manifest but you just want to traverse it.

This also includes some refactoring to the tests and the introduction of a
swarm/api/client package to make things easier to test.

swarm/api/client/client_test.go

@@ -0,0 +1,105 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package client
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"reflect"
+	"sort"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/swarm/testutil"
+)
+
+func TestClientManifestFileList(t *testing.T) {
+	srv := testutil.NewTestSwarmServer(t)
+	defer srv.Close()
+
+	dir, err := ioutil.TempDir("", "swarm-client-test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	files := []string{
+		"file1.txt",
+		"file2.txt",
+		"dir1/file3.txt",
+		"dir1/file4.txt",
+		"dir2/file5.txt",
+		"dir2/dir3/file6.txt",
+		"dir2/dir4/file7.txt",
+		"dir2/dir4/file8.txt",
+	}
+	for _, file := range files {
+		path := filepath.Join(dir, file)
+		if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
+			t.Fatalf("error creating dir for %s: %s", path, err)
+		}
+		if err := ioutil.WriteFile(path, []byte("data"), 0644); err != nil {
+			t.Fatalf("error writing file %s: %s", path, err)
+		}
+	}
+
+	client := NewClient(srv.URL)
+
+	hash, err := client.UploadDirectory(dir, "")
+	if err != nil {
+		t.Fatalf("error uploading directory: %s", err)
+	}
+
+	ls := func(prefix string) []string {
+		entries, err := client.ManifestFileList(hash, prefix)
+		if err != nil {
+			t.Fatal(err)
+		}
+		paths := make([]string, len(entries))
+		for i, entry := range entries {
+			paths[i] = entry.Path
+		}
+		sort.Strings(paths)
+		return paths
+	}
+
+	tests := map[string][]string{
+		"":                    []string{"dir1/", "dir2/", "file1.txt", "file2.txt"},
+		"file":                []string{"file1.txt", "file2.txt"},
+		"file1":               []string{"file1.txt"},
+		"file2.txt":           []string{"file2.txt"},
+		"file12":              []string{},
+		"dir":                 []string{"dir1/", "dir2/"},
+		"dir1":                []string{"dir1/"},
+		"dir1/":               []string{"dir1/file3.txt", "dir1/file4.txt"},
+		"dir1/file":           []string{"dir1/file3.txt", "dir1/file4.txt"},
+		"dir1/file3.txt":      []string{"dir1/file3.txt"},
+		"dir1/file34":         []string{},
+		"dir2/":               []string{"dir2/dir3/", "dir2/dir4/", "dir2/file5.txt"},
+		"dir2/file":           []string{"dir2/file5.txt"},
+		"dir2/dir":            []string{"dir2/dir3/", "dir2/dir4/"},
+		"dir2/dir3/":          []string{"dir2/dir3/file6.txt"},
+		"dir2/dir4/":          []string{"dir2/dir4/file7.txt", "dir2/dir4/file8.txt"},
+		"dir2/dir4/file":      []string{"dir2/dir4/file7.txt", "dir2/dir4/file8.txt"},
+		"dir2/dir4/file7.txt": []string{"dir2/dir4/file7.txt"},
+		"dir2/dir4/file78":    []string{},
+	}
+	for prefix, expected := range tests {
+		actual := ls(prefix)
+		if !reflect.DeepEqual(actual, expected) {
+			t.Fatalf("expected prefix %q to return paths %v, got %v", prefix, expected, actual)
+		}
+	}
+}