1// SPDX-License-Identifier: MIT
2
3package git
4
5import (
6 "bytes"
7 "context"
8 "fmt"
9 "math/rand"
10 "os"
11 "os/exec"
12 "path"
13 "path/filepath"
14 "slices"
15 "sort"
16 "strings"
17 "sync"
18 "testing"
19)
20
21// realWalkRepo clones the repository named by ERMITE_GIT_BENCH_REPO (bare,
22// no hardlinks, so the source is never touched) and writes a split
23// commit-graph with changed-path Bloom filters. The clone is shared by the
24// tests and benchmarks of the run.
25type realWalk struct {
26 dir string
27 r *Repo
28 head ObjectID
29}
30
31var (
32 realWalkOnce sync.Once
33 realWalkFx *realWalk
34 realWalkErr error
35)
36
37func getRealWalk(tb testing.TB) *realWalk {
38 tb.Helper()
39 src := os.Getenv("ERMITE_GIT_BENCH_REPO")
40 if src == "" {
41 tb.Skip("ERMITE_GIT_BENCH_REPO is not set")
42 }
43 requireGit(tb)
44 realWalkOnce.Do(func() {
45 dir, err := os.MkdirTemp("", "ermite-walk-*")
46 if err != nil {
47 realWalkErr = err
48 return
49 }
50 clone := filepath.Join(dir, "clone.git")
51 for _, args := range [][]string{
52 {"clone", "--quiet", "--bare", "--no-local", src, clone},
53 {"-C", clone, "commit-graph", "write", "--reachable", "--changed-paths", "--split"},
54 } {
55 cmd := exec.Command("git", args...)
56 cmd.Env = gitEnv()
57 if out, err := cmd.CombinedOutput(); err != nil {
58 realWalkErr = fmt.Errorf("git %v: %v\n%s", args, err, out)
59 return
60 }
61 }
62 r, err := Open(clone)
63 if err != nil {
64 realWalkErr = err
65 return
66 }
67 head, err := exec.Command("git", "-C", clone, "rev-parse", "HEAD").Output()
68 if err != nil {
69 realWalkErr = err
70 return
71 }
72 id, err := ParseID(strings.TrimSpace(string(head)))
73 if err != nil {
74 realWalkErr = err
75 return
76 }
77 realWalkFx = &realWalk{dir: clone, r: r, head: id}
78 })
79 if realWalkErr != nil {
80 tb.Fatal(realWalkErr)
81 }
82 return realWalkFx
83}
84
85func (x *realWalk) git(tb testing.TB, args ...string) string {
86 tb.Helper()
87 cmd := exec.Command("git", append([]string{"-C", x.dir}, args...)...)
88 cmd.Env = gitEnv()
89 var errb bytes.Buffer
90 cmd.Stderr = &errb
91 out, err := cmd.Output()
92 if err != nil {
93 tb.Fatalf("git %v: %v\n%s", args, err, errb.String())
94 }
95 return string(out)
96}
97
98// cleanupRealWalk is called by TestMain.
99func cleanupRealWalk() {
100 if realWalkFx != nil {
101 _ = realWalkFx.r.Close()
102 _ = os.RemoveAll(filepath.Dir(realWalkFx.dir))
103 }
104}
105
106func TestWalkRealRepository(t *testing.T) {
107 x := getRealWalk(t)
108 head := x.head.String()
109
110 // Full history.
111 want := lines(x.git(t, "log", "--format=%H", head))
112 got := walkIDs(t, x.r, x.head, WalkOptions{})
113 if !slices.Equal(got, want) {
114 t.Fatalf("full history differs: %d commits, git has %d", len(got), len(want))
115 }
116 t.Logf("full history: %d commits", len(got))
117 for _, win := range [][2]int{{5000, 100}, {1, 1}, {len(want) - 3, 10}} {
118 exp := window(want, win[0], win[1])
119 if g := walkIDs(t, x.r, x.head, WalkOptions{Skip: win[0], Limit: win[1]}); !slices.Equal(g, exp) {
120 t.Errorf("skip %d limit %d differs", win[0], win[1])
121 }
122 }
123
124 // 20 sampled paths: files and directories, deterministic.
125 files := lines(x.git(t, "ls-tree", "-r", "--name-only", head))
126 dirSet := map[string]bool{}
127 for _, f := range files {
128 for d := path.Dir(f); d != "."; d = path.Dir(d) {
129 dirSet[d] = true
130 }
131 }
132 dirs := make([]string, 0, len(dirSet))
133 for d := range dirSet {
134 dirs = append(dirs, d)
135 }
136 sort.Strings(dirs)
137 rng := rand.New(rand.NewSource(42))
138 var paths []string
139 for len(paths) < 14 {
140 paths = append(paths, files[rng.Intn(len(files))])
141 }
142 for len(paths) < 20 && len(dirs) > 0 {
143 paths = append(paths, dirs[rng.Intn(len(dirs))])
144 }
145 paths = append(paths, "go.mod", "pkg/gui/")
146 for _, p := range paths {
147 want := lines(x.git(t, "log", "--format=%H", head, "--", p))
148 got := walkIDs(t, x.r, x.head, WalkOptions{Path: p})
149 if !slices.Equal(got, want) {
150 t.Errorf("path %q: %d commits, git has %d", p, len(got), len(want))
151 continue
152 }
153 if len(want) > 7 {
154 if g := walkIDs(t, x.r, x.head, WalkOptions{Path: p, Skip: 3, Limit: 4}); !slices.Equal(g, want[3:7]) {
155 t.Errorf("path %q: skip/limit differ", p)
156 }
157 }
158 }
159 t.Logf("%d paths compared", len(paths))
160}
161
162func TestLastCommitsRealRepository(t *testing.T) {
163 x := getRealWalk(t)
164 head := x.head.String()
165 // The root and three subdirectories, the biggest ones among the first.
166 dirs := []string{""}
167 for _, d := range []string{"pkg/gui", "pkg/commands", "docs"} {
168 if x.git(t, "ls-tree", head, d+"/") != "" {
169 dirs = append(dirs, d)
170 }
171 }
172 for _, dir := range dirs {
173 spec := head
174 if dir != "" {
175 spec += ":" + dir
176 }
177 names := lines(x.git(t, "ls-tree", "--name-only", spec))
178 if len(names) > 120 {
179 names = names[:120]
180 }
181 got, err := x.r.LastCommits(context.Background(), x.head, dir, names)
182 if err != nil {
183 t.Fatal(err)
184 }
185 for i, n := range names {
186 p := path.Join(dir, n)
187 exp := strings.TrimSpace(x.git(t, "log", "-n", "1", "--format=%H", head, "--", p))
188 if got[i].String() != exp {
189 t.Errorf("%q: got %s want %s", p, got[i], exp)
190 }
191 }
192 t.Logf("dir %q: %d entries compared", dir, len(names))
193 }
194}