| 1 | package assetcache |
| 2 | |
| 3 | import ( |
| 4 | "errors" |
| 5 | "fmt" |
| 6 | "os" |
| 7 | "sync" |
| 8 | "testing" |
| 9 | "time" |
| 10 | ) |
| 11 | |
| 12 | // fakeFS is a settable free-space source. Tests using it are not acceptance: |
| 13 | // the real FS is covered by TestStatfsReportsTheTempDir. |
| 14 | type fakeFS struct { |
| 15 | mu sync.Mutex |
| 16 | total, free uint64 |
| 17 | err error |
| 18 | } |
| 19 | |
| 20 | func (f *fakeFS) Space(string) (uint64, uint64, error) { |
| 21 | f.mu.Lock() |
| 22 | defer f.mu.Unlock() |
| 23 | return f.total, f.free, f.err |
| 24 | } |
| 25 | |
| 26 | func (f *fakeFS) setFree(v uint64) { |
| 27 | f.mu.Lock() |
| 28 | f.free = v |
| 29 | f.mu.Unlock() |
| 30 | } |
| 31 | |
| 32 | const worstReserve = 2*MaxBody + metaReserve |
| 33 | |
| 34 | // fillStore opens a Store over a real temporary directory with a fake FS that |
| 35 | // has plenty of room, and a budget big enough for many worst-case fills. |
| 36 | func fillStore(t *testing.T) (*Store, *fakeFS, string) { |
| 37 | t.Helper() |
| 38 | dir := t.TempDir() |
| 39 | fs := &fakeFS{total: 64 << 30, free: 64 << 30} |
| 40 | cfg := testConfig(dir) |
| 41 | cfg.Budget = 4 << 30 |
| 42 | cfg.FS = fs |
| 43 | s, err := Open(cfg) |
| 44 | if err != nil { |
| 45 | t.Fatal(err) |
| 46 | } |
| 47 | return s, fs, dir |
| 48 | } |
| 49 | |
| 50 | // TestReserveWorstCaseWithUnknownLength is not acceptance: it uses a fake FS. |
| 51 | func TestReserveWorstCaseWithUnknownLength(t *testing.T) { |
| 52 | s, _, _ := fillStore(t) |
| 53 | f, err := s.Reserve(testKey("shop", "/a.css"), -1) |
| 54 | if err != nil { |
| 55 | t.Fatal(err) |
| 56 | } |
| 57 | defer f.Abort() |
| 58 | if got, want := s.Stats().Reserved, int64(2*MaxBody+64<<10); got != want { |
| 59 | t.Fatalf("Reserved = %d, want %d", got, want) |
| 60 | } |
| 61 | } |
| 62 | |
| 63 | // TestReserveUsesContentLength is not acceptance: it uses a fake FS. |
| 64 | func TestReserveUsesContentLength(t *testing.T) { |
| 65 | s, _, _ := fillStore(t) |
| 66 | f, err := s.Reserve(testKey("shop", "/a.css"), 1000) |
| 67 | if err != nil { |
| 68 | t.Fatal(err) |
| 69 | } |
| 70 | defer f.Abort() |
| 71 | if got, want := s.Stats().Reserved, int64(2*1000+metaReserve); got != want { |
| 72 | t.Fatalf("Reserved = %d, want %d", got, want) |
| 73 | } |
| 74 | } |
| 75 | |
| 76 | // TestReserveRefusesTooLarge is not acceptance: it uses a fake FS. |
| 77 | func TestReserveRefusesTooLarge(t *testing.T) { |
| 78 | s, _, dir := fillStore(t) |
| 79 | if _, err := s.Reserve(testKey("shop", "/big"), MaxBody+1); !errors.Is(err, ErrTooLarge) { |
| 80 | t.Fatalf("err = %v, want ErrTooLarge", err) |
| 81 | } |
| 82 | f, err := s.Reserve(testKey("shop", "/max"), MaxBody) |
| 83 | if err != nil { |
| 84 | t.Fatalf("a body of exactly MaxBody: %v", err) |
| 85 | } |
| 86 | f.Abort() |
| 87 | if got := s.Stats().Reserved; got != 0 { |
| 88 | t.Fatalf("Reserved = %d after refusals and abort, want 0", got) |
| 89 | } |
| 90 | if got := listDir(t, dir); len(got) != 0 { |
| 91 | t.Fatalf("files left: %v", got) |
| 92 | } |
| 93 | } |
| 94 | |
| 95 | // TestReserveRefusesBelowTheFloor is not acceptance: it uses a fake FS. It is |
| 96 | // spec section 7's sixteen-fill case reduced to its rule: free space minus |
| 97 | // outstanding reservations minus this one must stay at the 15% floor. |
| 98 | func TestReserveRefusesBelowTheFloor(t *testing.T) { |
| 99 | s, fs, _ := fillStore(t) |
| 100 | fs.total = 8 << 30 |
| 101 | fs.free = 8<<30*15/100 + worstReserve // exactly one reservation above the floor |
| 102 | first, err := s.Reserve(testKey("shop", "/a"), -1) |
| 103 | if err != nil { |
| 104 | t.Fatalf("first reservation: %v", err) |
| 105 | } |
| 106 | defer first.Abort() |
| 107 | if _, err := s.Reserve(testKey("blog", "/b"), -1); !errors.Is(err, ErrBelowFloor) { |
| 108 | t.Fatalf("second concurrent reservation: err = %v, want ErrBelowFloor", err) |
| 109 | } |
| 110 | if got := s.Stats().Reserved; got != worstReserve { |
| 111 | t.Fatalf("Reserved = %d after a refusal, want %d", got, int64(worstReserve)) |
| 112 | } |
| 113 | // Once the first is released the room is back. |
| 114 | first.Abort() |
| 115 | again, err := s.Reserve(testKey("blog", "/b"), -1) |
| 116 | if err != nil { |
| 117 | t.Fatalf("after abort: %v", err) |
| 118 | } |
| 119 | again.Abort() |
| 120 | } |
| 121 | |
| 122 | // TestReserveRefusesWhenSomethingElseFillsTheDisk is not acceptance: it uses a |
| 123 | // fake FS. Free space drops between two calls, as when logs fill the disk. |
| 124 | func TestReserveRefusesWhenSomethingElseFillsTheDisk(t *testing.T) { |
| 125 | s, fs, _ := fillStore(t) |
| 126 | fs.total = 8 << 30 |
| 127 | fs.setFree(4 << 30) |
| 128 | f, err := s.Reserve(testKey("shop", "/a"), -1) |
| 129 | if err != nil { |
| 130 | t.Fatal(err) |
| 131 | } |
| 132 | defer f.Abort() |
| 133 | fs.setFree(8 << 30 * 15 / 100) // the floor itself, nothing to spare |
| 134 | if _, err := s.Reserve(testKey("shop", "/b"), 10); !errors.Is(err, ErrBelowFloor) { |
| 135 | t.Fatalf("err = %v, want ErrBelowFloor", err) |
| 136 | } |
| 137 | // The fill in flight is untouched and still writes up to its reservation. |
| 138 | if _, err := f.Write([]byte("still fine")); err != nil { |
| 139 | t.Fatalf("in-flight write: %v", err) |
| 140 | } |
| 141 | } |
| 142 | |
| 143 | // TestReserveRefusesWithAnFSError is not acceptance: it uses a fake FS. |
| 144 | func TestReserveRefusesWithAnFSError(t *testing.T) { |
| 145 | s, fs, _ := fillStore(t) |
| 146 | boom := errors.New("statfs failed") |
| 147 | fs.err = boom |
| 148 | if _, err := s.Reserve(testKey("shop", "/a"), 10); !errors.Is(err, boom) { |
| 149 | t.Fatalf("err = %v, want the FS error", err) |
| 150 | } |
| 151 | if got := s.Stats().Reserved; got != 0 { |
| 152 | t.Fatalf("Reserved = %d after an FS error", got) |
| 153 | } |
| 154 | s.mu.Lock() |
| 155 | boxFills := s.fills |
| 156 | s.mu.Unlock() |
| 157 | if boxFills != 0 { |
| 158 | t.Fatalf("fill slots held after an FS error: %d", boxFills) |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | // TestReserveRefusesOverBudget is not acceptance: it uses a fake FS. |
| 163 | func TestReserveRefusesOverBudget(t *testing.T) { |
| 164 | dir := t.TempDir() |
| 165 | cfg := testConfig(dir) |
| 166 | cfg.Budget = 2*500 + metaReserve + 10 // room for one 500-byte fill, not two |
| 167 | cfg.FS = &fakeFS{total: 64 << 30, free: 64 << 30} |
| 168 | s, err := Open(cfg) |
| 169 | if err != nil { |
| 170 | t.Fatal(err) |
| 171 | } |
| 172 | a, err := s.Reserve(testKey("shop", "/a"), 500) |
| 173 | if err != nil { |
| 174 | t.Fatal(err) |
| 175 | } |
| 176 | defer a.Abort() |
| 177 | if _, err := s.Reserve(testKey("shop", "/b"), 500); !errors.Is(err, ErrNoRoom) { |
| 178 | t.Fatalf("err = %v, want ErrNoRoom", err) |
| 179 | } |
| 180 | } |
| 181 | |
| 182 | // TestReserveBoundsFillsPerBoxAndPerApp is not acceptance: it uses a fake FS. |
| 183 | func TestReserveBoundsFillsPerBoxAndPerApp(t *testing.T) { |
| 184 | s, _, _ := fillStore(t) |
| 185 | var fills []*Fill |
| 186 | defer func() { |
| 187 | for _, f := range fills { |
| 188 | f.Abort() |
| 189 | } |
| 190 | }() |
| 191 | reserve := func(app string, i int) (*Fill, error) { |
| 192 | f, err := s.Reserve(testKey(app, fmt.Sprintf("/%d", i)), 100) |
| 193 | if err == nil { |
| 194 | fills = append(fills, f) |
| 195 | } |
| 196 | return f, err |
| 197 | } |
| 198 | |
| 199 | // Four fills for one app are fine, the fifth is busy. |
| 200 | for i := 0; i < maxFillsPerApp; i++ { |
| 201 | if _, err := reserve("shop", i); err != nil { |
| 202 | t.Fatalf("fill %d for shop: %v", i, err) |
| 203 | } |
| 204 | } |
| 205 | if _, err := reserve("shop", 99); !errors.Is(err, ErrBusy) { |
| 206 | t.Fatalf("5th fill for one app: err = %v, want ErrBusy", err) |
| 207 | } |
| 208 | // Another app is not held up by it. |
| 209 | for i := 0; i < maxFillsPerApp; i++ { |
| 210 | if _, err := reserve("blog", i); err != nil { |
| 211 | t.Fatalf("fill %d for blog: %v", i, err) |
| 212 | } |
| 213 | } |
| 214 | // Fill the box to 16 with further apps, then the 17th is busy. |
| 215 | for a := 0; len(fills) < maxFillsPerBox; a++ { |
| 216 | if _, err := reserve(fmt.Sprintf("app%d", a), 0); err != nil { |
| 217 | t.Fatalf("fill %d: %v", len(fills), err) |
| 218 | } |
| 219 | } |
| 220 | if _, err := reserve("other", 0); !errors.Is(err, ErrBusy) { |
| 221 | t.Fatalf("17th fill on the box: err = %v, want ErrBusy", err) |
| 222 | } |
| 223 | // Releasing one frees a slot for the box and for that app. |
| 224 | fills[0].Abort() |
| 225 | fills = fills[1:] |
| 226 | if _, err := reserve("shop", 100); err != nil { |
| 227 | t.Fatalf("after abort: %v", err) |
| 228 | } |
| 229 | } |
| 230 | |
| 231 | // TestWritePastTheReservationFails is not acceptance: it uses a fake FS. |
| 232 | func TestWritePastTheReservationFails(t *testing.T) { |
| 233 | s, _, _ := fillStore(t) |
| 234 | f, err := s.Reserve(testKey("shop", "/a"), 10) |
| 235 | if err != nil { |
| 236 | t.Fatal(err) |
| 237 | } |
| 238 | defer f.Abort() |
| 239 | if n, err := f.Write([]byte("0123456789")); err != nil || n != 10 { |
| 240 | t.Fatalf("write of exactly the reservation: n=%d err=%v", n, err) |
| 241 | } |
| 242 | if n, err := f.Write([]byte("x")); !errors.Is(err, ErrTooLarge) || n != 0 { |
| 243 | t.Fatalf("write past the reservation: n=%d err=%v, want 0 and ErrTooLarge", n, err) |
| 244 | } |
| 245 | if _, err := f.Write(nil); !errors.Is(err, ErrTooLarge) { |
| 246 | t.Fatalf("a failed fill keeps failing: err = %v", err) |
| 247 | } |
| 248 | } |
| 249 | |
| 250 | // TestWritePastMaxBodyFails is not acceptance: it uses a fake FS. With an |
| 251 | // unknown length the identity half is MaxBody, and the fill stops there. |
| 252 | func TestWritePastMaxBodyFails(t *testing.T) { |
| 253 | s, _, _ := fillStore(t) |
| 254 | f, err := s.Reserve(testKey("shop", "/a"), -1) |
| 255 | if err != nil { |
| 256 | t.Fatal(err) |
| 257 | } |
| 258 | defer f.Abort() |
| 259 | chunk := make([]byte, 1<<20) |
| 260 | for i := 0; i < MaxBody>>20; i++ { |
| 261 | if _, err := f.Write(chunk); err != nil { |
| 262 | t.Fatalf("chunk %d: %v", i, err) |
| 263 | } |
| 264 | } |
| 265 | if _, err := f.Write([]byte("x")); !errors.Is(err, ErrTooLarge) { |
| 266 | t.Fatalf("byte past MaxBody: err = %v, want ErrTooLarge", err) |
| 267 | } |
| 268 | } |
| 269 | |
| 270 | // TestAbortReleasesEverything is not acceptance: it uses a fake FS. |
| 271 | func TestAbortReleasesEverything(t *testing.T) { |
| 272 | s, _, dir := fillStore(t) |
| 273 | f, err := s.Reserve(testKey("shop", "/a"), 100) |
| 274 | if err != nil { |
| 275 | t.Fatal(err) |
| 276 | } |
| 277 | if _, err := f.Write([]byte("some bytes")); err != nil { |
| 278 | t.Fatal(err) |
| 279 | } |
| 280 | if len(listDir(t, dir)) == 0 { |
| 281 | t.Fatal("expected a temporary while the fill is open") |
| 282 | } |
| 283 | f.Abort() |
| 284 | if got := s.Stats().Reserved; got != 0 { |
| 285 | t.Fatalf("Reserved = %d after Abort", got) |
| 286 | } |
| 287 | if got := listDir(t, dir); len(got) != 0 { |
| 288 | t.Fatalf("files left after Abort: %v", got) |
| 289 | } |
| 290 | s.mu.Lock() |
| 291 | boxFills, appFills := s.fills, len(s.fillsByApp) |
| 292 | s.mu.Unlock() |
| 293 | if boxFills != 0 || appFills != 0 { |
| 294 | t.Fatalf("slots after Abort: box %d, apps %d, want 0 and 0", boxFills, appFills) |
| 295 | } |
| 296 | if _, err := f.Write([]byte("x")); err == nil { |
| 297 | t.Fatal("write after Abort succeeded") |
| 298 | } |
| 299 | } |
| 300 | |
| 301 | // TestAbortTwiceIsSafe is not acceptance: it uses a fake FS. A second Abort |
| 302 | // must not release another fill's reservation. |
| 303 | func TestAbortTwiceIsSafe(t *testing.T) { |
| 304 | s, _, _ := fillStore(t) |
| 305 | a, err := s.Reserve(testKey("shop", "/a"), 100) |
| 306 | if err != nil { |
| 307 | t.Fatal(err) |
| 308 | } |
| 309 | b, err := s.Reserve(testKey("shop", "/b"), 100) |
| 310 | if err != nil { |
| 311 | t.Fatal(err) |
| 312 | } |
| 313 | defer b.Abort() |
| 314 | a.Abort() |
| 315 | a.Abort() |
| 316 | if got, want := s.Stats().Reserved, int64(2*100+metaReserve); got != want { |
| 317 | t.Fatalf("Reserved = %d, want %d (b's alone)", got, want) |
| 318 | } |
| 319 | } |
| 320 | |
| 321 | // TestReserveAndAbortConcurrently is not acceptance: it uses a fake FS. Run |
| 322 | // with -race: counters must come back to zero. |
| 323 | func TestReserveAndAbortConcurrently(t *testing.T) { |
| 324 | s, _, dir := fillStore(t) |
| 325 | var wg sync.WaitGroup |
| 326 | for g := 0; g < 8; g++ { |
| 327 | wg.Add(1) |
| 328 | go func(g int) { |
| 329 | defer wg.Done() |
| 330 | for i := 0; i < 50; i++ { |
| 331 | f, err := s.Reserve(testKey([]string{"shop", "blog"}[g%2], fmt.Sprintf("/%d/%d", g, i)), 64) |
| 332 | if err != nil { |
| 333 | if !errors.Is(err, ErrBusy) { |
| 334 | t.Errorf("unexpected error: %v", err) |
| 335 | } |
| 336 | continue |
| 337 | } |
| 338 | if _, err := f.Write([]byte("body")); err != nil { |
| 339 | t.Errorf("write: %v", err) |
| 340 | } |
| 341 | f.Abort() |
| 342 | } |
| 343 | }(g) |
| 344 | } |
| 345 | wg.Wait() |
| 346 | if got := s.Stats().Reserved; got != 0 { |
| 347 | t.Fatalf("Reserved = %d after all aborted", got) |
| 348 | } |
| 349 | if got := listDir(t, dir); len(got) != 0 { |
| 350 | t.Fatalf("files left: %v", got) |
| 351 | } |
| 352 | } |
| 353 | |
| 354 | // TestAbortKeepsLeftoverBytesCountedAndRetries is not acceptance: it uses a |
| 355 | // fake FS. When the temporaries cannot be removed (the directory is not |
| 356 | // writable), the bytes still on disk stay counted, the fill slot is released, |
| 357 | // and a second Abort removes the files and releases the bytes. |
| 358 | func TestAbortKeepsLeftoverBytesCountedAndRetries(t *testing.T) { |
| 359 | if os.Geteuid() == 0 { |
| 360 | t.Skip("root ignores directory permissions") |
| 361 | } |
| 362 | s, _, dir := fillStore(t) |
| 363 | f, err := s.Reserve(testKey("shop", "/a"), 100) |
| 364 | if err != nil { |
| 365 | t.Fatal(err) |
| 366 | } |
| 367 | if _, err := f.Write([]byte("ten bytes!")); err != nil { |
| 368 | t.Fatal(err) |
| 369 | } |
| 370 | if err := os.Chmod(dir, 0o500); err != nil { |
| 371 | t.Fatal(err) |
| 372 | } |
| 373 | t.Cleanup(func() { os.Chmod(dir, 0o700) }) |
| 374 | |
| 375 | f.Abort() |
| 376 | if got := s.Stats().Reserved; got != 10 { |
| 377 | t.Fatalf("Reserved = %d after a failed cleanup, want the 10 bytes still on disk", got) |
| 378 | } |
| 379 | if got := listDir(t, dir); len(got) != 1 { |
| 380 | t.Fatalf("files after a failed cleanup: %v, want the one body temporary", got) |
| 381 | } |
| 382 | s.mu.Lock() |
| 383 | boxFills, appFills := s.fills, len(s.fillsByApp) |
| 384 | s.mu.Unlock() |
| 385 | if boxFills != 0 || appFills != 0 { |
| 386 | t.Fatalf("slots after a failed cleanup: box %d, apps %d, want 0 and 0", boxFills, appFills) |
| 387 | } |
| 388 | f.Abort() // still failing: nothing changes, nothing is released twice |
| 389 | if got := s.Stats().Reserved; got != 10 { |
| 390 | t.Fatalf("Reserved = %d after a second failed cleanup, want 10", got) |
| 391 | } |
| 392 | |
| 393 | if err := os.Chmod(dir, 0o700); err != nil { |
| 394 | t.Fatal(err) |
| 395 | } |
| 396 | f.Abort() |
| 397 | if got := s.Stats().Reserved; got != 0 { |
| 398 | t.Fatalf("Reserved = %d after the retry, want 0", got) |
| 399 | } |
| 400 | if got := listDir(t, dir); len(got) != 0 { |
| 401 | t.Fatalf("files after the retry: %v", got) |
| 402 | } |
| 403 | f.Abort() // and a further Abort is a no-op |
| 404 | if got := s.Stats().Reserved; got != 0 { |
| 405 | t.Fatalf("Reserved = %d after a third Abort", got) |
| 406 | } |
| 407 | } |
| 408 | |
| 409 | // TestReserveResamplesWhenACommitLandsAfterItsSample is not acceptance: it |
| 410 | // uses a fake FS. A fill commits between another Reserve's free-space sample |
| 411 | // and its decision. The committed bytes have left the reservation counter |
| 412 | // and are not in the sample either, so a decision that combined the two |
| 413 | // would count them nowhere. The numbers make that stale combination pass |
| 414 | // the floor and a fresh sample fail it. |
| 415 | func TestReserveResamplesWhenACommitLandsAfterItsSample(t *testing.T) { |
| 416 | s, fs, _ := fillStore(t) |
| 417 | const total = 8 << 30 |
| 418 | floor := uint64(total) * floorPercent / 100 |
| 419 | body := make([]byte, 1<<20) |
| 420 | onDisk := uint64(len(body)) + 4096 // what the fake disk loses when a commits |
| 421 | start := floor + worstReserve + onDisk/2 |
| 422 | fs.total = total |
| 423 | fs.setFree(start) |
| 424 | |
| 425 | a := fill(t, s, testKey("blog", "/a.css"), body) |
| 426 | samples := 0 |
| 427 | s.afterSample = func() { |
| 428 | samples++ |
| 429 | if samples > 1 { |
| 430 | return |
| 431 | } |
| 432 | if err := a.Commit(Meta{Header: cssHeader("1"), Lifetime: time.Hour, Expires: testNow.Add(time.Hour)}, false); err != nil { |
| 433 | t.Errorf("Commit: %v", err) |
| 434 | } |
| 435 | fs.setFree(start - onDisk) |
| 436 | } |
| 437 | f, err := s.Reserve(testKey("shop", "/b.css"), -1) |
| 438 | if err == nil { |
| 439 | f.Abort() |
| 440 | } |
| 441 | if !errors.Is(err, ErrBelowFloor) { |
| 442 | t.Fatalf("Reserve after a commit landed behind its sample: err = %v, want ErrBelowFloor", err) |
| 443 | } |
| 444 | if samples < 2 { |
| 445 | t.Fatalf("free space sampled %d times, want a second sample after the commit", samples) |
| 446 | } |
| 447 | if st := s.Stats(); st.Reserved != 0 || st.Entries != 1 { |
| 448 | t.Fatalf("Stats = %+v, want a's entry and nothing reserved", st) |
| 449 | } |
| 450 | } |
| 451 | |
| 452 | // TestReserveDecidesUnderTheLockWhenReleasesKeepComing is not acceptance: it |
| 453 | // uses a fake FS. Every unlocked sample is overtaken by a release, so after |
| 454 | // sampleTries of them Reserve samples with the store locked, where nothing |
| 455 | // can move the counter, and decides on that. |
| 456 | func TestReserveDecidesUnderTheLockWhenReleasesKeepComing(t *testing.T) { |
| 457 | s, _, _ := fillStore(t) |
| 458 | var others []*Fill |
| 459 | for i := 0; i < sampleTries; i++ { |
| 460 | others = append(others, fill(t, s, testKey("blog", fmt.Sprintf("/%d", i)), []byte("x"))) |
| 461 | } |
| 462 | samples := 0 |
| 463 | s.afterSample = func() { |
| 464 | if samples < len(others) { |
| 465 | others[samples].Abort() |
| 466 | } |
| 467 | samples++ |
| 468 | } |
| 469 | f, err := s.Reserve(testKey("shop", "/a.css"), 10) |
| 470 | if err != nil { |
| 471 | t.Fatalf("Reserve: %v", err) |
| 472 | } |
| 473 | f.Abort() |
| 474 | if samples != sampleTries { |
| 475 | t.Fatalf("unlocked samples = %d, want %d and then one under the lock", samples, sampleTries) |
| 476 | } |
| 477 | if st := s.Stats(); st.Reserved != 0 { |
| 478 | t.Fatalf("Reserved = %d after every fill aborted", st.Reserved) |
| 479 | } |
| 480 | } |
| 481 | |
amadan