WIP: Archive command which is much faster

common/archive/ar/ar_test.go

Index: common/archive/ar/ar_test.go
diff --git a/common/archive/ar/ar_test.go b/common/archive/ar/ar_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..c607e0c72f823aa546d2e11369c43f5f7f5dd64a
--- /dev/null
+++ b/common/archive/ar/ar_test.go
@@ -0,0 +1,185 @@
+// Copyright 2016 The LUCI Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
+package ar
+
+import (
+	"bytes"
+	"github.com/maruel/ut"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path"
+	"strings"
+	"testing"
+	"time"
+)
+
+var (
+	TestFile1 = ("" +
+		// ar file header
+		"!<arch>\n" +
+		// filename len	- 16 bytes
+		"#1/9            " +
+		// modtime		- 12 bytes
+		"1447140471  " +
+		// owner id		- 6 bytes
+		"1000  " +
+		// group id		- 6 bytes
+		"1000  " +
+		// file mode	- 8 bytes
+		"100640  " +
+		// Data size	- 10 bytes
+		"15        " +
+		// File magic	- 2 bytes
+		"\x60\n" +
+		// File name	- 9 bytes
+		"filename1" +
+		// File data	- 6 bytes
+		"abc123" +
+		// Padding		- 1 byte
+		"\n" +
+		"")
+)
+
+func TestWriterCreatesTestFile1(t *testing.T) {
+	b := &bytes.Buffer{}
+	data := []byte("abc123")
+
+	ar := NewWriter(b)
+	if err := ar.Add("filename1", data); err != nil {
+		t.Fatalf("Add: %v", err)
+	}
+	if err := ar.Close(); err != nil {
+		t.Fatalf("Close: %v", err)
+	}
+
+	ut.AssertEqual(t, []byte(TestFile1), b.Bytes())
+}
+
+func TestReaderOnTestFile1(t *testing.T) {
+	r := strings.NewReader(TestFile1)
+
+	ar, err := NewReader(r)
+	if err != nil {
+		t.Fatalf("NewReader: %v", err)
+	}
+
+	h, err := ar.Next()
+	if err != nil {
+		t.Fatalf("Header: %v", err)
+	}
+
+	ut.AssertEqual(t, "filename1", h.Name())
+	ut.AssertEqual(t, int64(6), h.Size())
+	ut.AssertEqual(t, time.Unix(1447140471, 0), h.ModTime())
+
+	data := make([]byte, 6)
+	n, err := ar.Read(data)
+	if err != nil {
+		t.Fatalf("Data: %v", err)
+	}
+	ut.AssertEqual(t, 6, n)
+	ut.AssertEqual(t, []byte("abc123"), data)
+
+	if err := ar.Close(); err != nil {
+		t.Fatalf("Close: %v", err)
+	}
+}
+
+func TestWithSystemArCommandList(t *testing.T) {
+	if _, err := exec.LookPath("ar"); err != nil {
+		t.Skipf("ar command not found: %v", err)
+	}
+
+	// Write out to an archive file
+	tmpfile, err := ioutil.TempFile("", "go-ar-test.")
+	if err != nil {
+		t.Fatalf("unable to create temp file: %v", err)
+	}
+	defer os.Remove(tmpfile.Name()) // clean up
+	ar := NewWriter(tmpfile)
+	ar.Add("file1.txt", []byte("file1 contents"))
+	ar.Add("file2.txt", []byte("file2 contents"))
+	ar.Add("dir1/file3.txt", []byte("file3 contents"))
+	ar.Close()
+
+	// Use the ar command to list the file
+	cmd_list := exec.Command("ar", "t", tmpfile.Name())
+	var cmd_list_out_buf bytes.Buffer
+	cmd_list.Stdout = &cmd_list_out_buf
+	if err := cmd_list.Run(); err != nil {
+		t.Fatalf("ar command failed: %v\n%s", err, cmd_list_out_buf.String())
+	}
+
+	cmd_list_actual_out := cmd_list_out_buf.String()
+	cmd_list_expect_out := `file1.txt
+file2.txt
+dir1/file3.txt
+`
+	ut.AssertEqual(t, cmd_list_expect_out, cmd_list_actual_out)
+}
+
+func TestWithSystemArCommandExtract(t *testing.T) {
+	arpath, err := exec.LookPath("ar")
+	if err != nil {
+		t.Skipf("ar command not found: %v", err)
+	}
+
+	// Write out to an archive file
+	tmpfile, err := ioutil.TempFile("", "go-ar-test.")
+	if err != nil {
+		t.Fatalf("unable to create temp file: %v", err)
+	}
+	defer os.Remove(tmpfile.Name()) // clean up
+	ar := NewWriter(tmpfile)
+	ar.Add("file1.txt", []byte("file1 contents"))
+	ar.Add("file2.txt", []byte("file2 contents"))
+	ar.Close()
+
+	// Extract the ar
+	tmpdir, err := ioutil.TempDir("", "go-ar-test.")
+	defer os.RemoveAll(tmpdir)
+	cmd_extract := exec.Cmd{
+		Path: arpath,
+		Args: []string{"ar", "x", tmpfile.Name()},
+		Dir:  tmpdir,
+	}
+	var cmd_extract_out_buf bytes.Buffer
+	cmd_extract.Stdout = &cmd_extract_out_buf
+	if err := cmd_extract.Run(); err != nil {
+		t.Fatalf("ar command failed: %v\n%s", err, cmd_extract_out_buf.String())
+	}
+
+	// Compare the directory output
+	dir_contents, err := ioutil.ReadDir(tmpdir)
+	if err != nil {
+		t.Fatalf("Unable to read the output directory: %v", err)
+	}
+	for _, fi := range dir_contents {
+		if fi.Name() != "file1.txt" && fi.Name() != "file2.txt" {
+			t.Errorf("Found unexpected file '%s'", fi.Name())
+		}
+	}
+
+	file1_contents, err := ioutil.ReadFile(path.Join(tmpdir, "file1.txt"))
+	file1_expected := []byte("file1 contents")
+	if err != nil {
+		t.Errorf("%v", err)
+	} else {
+		if bytes.Compare(file1_contents, file1_expected) != 0 {
+			t.Errorf("file1.txt content incorrect. Got:\n%v\n%v\n", file1_contents, file1_expected)
+		}
+	}
+
+	file2_contents, err := ioutil.ReadFile(path.Join(tmpdir, "file2.txt"))
+	file2_expected := []byte("file2 contents")
+	if err != nil {
+		t.Errorf("%v", err)
+	} else {
+		if bytes.Compare(file2_contents, file2_expected) != 0 {
+			t.Errorf("file2.txt content incorrect. Got:\n%v\n%v\n", file2_contents, file2_expected)
+		}
+	}
+}