cache_test.go

     1  // Copyright 2017 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package cache
     6  
     7  import (
     8  	"bytes"
     9  	"encoding/binary"
    10  	"fmt"
    11  	"os"
    12  	"path/filepath"
    13  	"testing"
    14  	"time"
    15  )
    16  
    17  func init() {
    18  	verify = false // even if GODEBUG is set
    19  }
    20  
    21  func TestBasic(t *testing.T) {
    22  	dir, err := os.MkdirTemp("", "cachetest-")
    23  	if err != nil {
    24  		t.Fatal(err)
    25  	}
    26  	defer os.RemoveAll(dir)
    27  	_, err = Open(filepath.Join(dir, "notexist"))
    28  	if err == nil {
    29  		t.Fatal(`Open("tmp/notexist") succeeded, want failure`)
    30  	}
    31  
    32  	cdir := filepath.Join(dir, "c1")
    33  	if err := os.Mkdir(cdir, 0777); err != nil {
    34  		t.Fatal(err)
    35  	}
    36  
    37  	c1, err := Open(cdir)
    38  	if err != nil {
    39  		t.Fatalf("Open(c1) (create): %v", err)
    40  	}
    41  	if err := c1.putIndexEntry(dummyID(1), dummyID(12), 13, true); err != nil {
    42  		t.Fatalf("addIndexEntry: %v", err)
    43  	}
    44  	if err := c1.putIndexEntry(dummyID(1), dummyID(2), 3, true); err != nil { // overwrite entry
    45  		t.Fatalf("addIndexEntry: %v", err)
    46  	}
    47  	if entry, err := c1.Get(dummyID(1)); err != nil || entry.OutputID != dummyID(2) || entry.Size != 3 {
    48  		t.Fatalf("c1.Get(1) = %x, %v, %v, want %x, %v, nil", entry.OutputID, entry.Size, err, dummyID(2), 3)
    49  	}
    50  
    51  	c2, err := Open(cdir)
    52  	if err != nil {
    53  		t.Fatalf("Open(c2) (reuse): %v", err)
    54  	}
    55  	if entry, err := c2.Get(dummyID(1)); err != nil || entry.OutputID != dummyID(2) || entry.Size != 3 {
    56  		t.Fatalf("c2.Get(1) = %x, %v, %v, want %x, %v, nil", entry.OutputID, entry.Size, err, dummyID(2), 3)
    57  	}
    58  	if err := c2.putIndexEntry(dummyID(2), dummyID(3), 4, true); err != nil {
    59  		t.Fatalf("addIndexEntry: %v", err)
    60  	}
    61  	if entry, err := c1.Get(dummyID(2)); err != nil || entry.OutputID != dummyID(3) || entry.Size != 4 {
    62  		t.Fatalf("c1.Get(2) = %x, %v, %v, want %x, %v, nil", entry.OutputID, entry.Size, err, dummyID(3), 4)
    63  	}
    64  }
    65  
    66  func TestGrowth(t *testing.T) {
    67  	dir, err := os.MkdirTemp("", "cachetest-")
    68  	if err != nil {
    69  		t.Fatal(err)
    70  	}
    71  	defer os.RemoveAll(dir)
    72  
    73  	c, err := Open(dir)
    74  	if err != nil {
    75  		t.Fatalf("Open: %v", err)
    76  	}
    77  
    78  	n := 10000
    79  	if testing.Short() {
    80  		n = 10
    81  	}
    82  
    83  	for i := 0; i < n; i++ {
    84  		if err := c.putIndexEntry(dummyID(i), dummyID(i*99), int64(i)*101, true); err != nil {
    85  			t.Fatalf("addIndexEntry: %v", err)
    86  		}
    87  		id := ActionID(dummyID(i))
    88  		entry, err := c.Get(id)
    89  		if err != nil {
    90  			t.Fatalf("Get(%x): %v", id, err)
    91  		}
    92  		if entry.OutputID != dummyID(i*99) || entry.Size != int64(i)*101 {
    93  			t.Errorf("Get(%x) = %x, %d, want %x, %d", id, entry.OutputID, entry.Size, dummyID(i*99), int64(i)*101)
    94  		}
    95  	}
    96  	for i := 0; i < n; i++ {
    97  		id := ActionID(dummyID(i))
    98  		entry, err := c.Get(id)
    99  		if err != nil {
   100  			t.Fatalf("Get2(%x): %v", id, err)
   101  		}
   102  		if entry.OutputID != dummyID(i*99) || entry.Size != int64(i)*101 {
   103  			t.Errorf("Get2(%x) = %x, %d, want %x, %d", id, entry.OutputID, entry.Size, dummyID(i*99), int64(i)*101)
   104  		}
   105  	}
   106  }
   107  
   108  func TestVerifyPanic(t *testing.T) {
   109  	os.Setenv("GODEBUG", "gocacheverify=1")
   110  	initEnv()
   111  	defer func() {
   112  		os.Unsetenv("GODEBUG")
   113  		verify = false
   114  	}()
   115  
   116  	if !verify {
   117  		t.Fatal("initEnv did not set verify")
   118  	}
   119  
   120  	dir, err := os.MkdirTemp("", "cachetest-")
   121  	if err != nil {
   122  		t.Fatal(err)
   123  	}
   124  	defer os.RemoveAll(dir)
   125  
   126  	c, err := Open(dir)
   127  	if err != nil {
   128  		t.Fatalf("Open: %v", err)
   129  	}
   130  
   131  	id := ActionID(dummyID(1))
   132  	if err := c.PutBytes(id, []byte("abc")); err != nil {
   133  		t.Fatal(err)
   134  	}
   135  
   136  	defer func() {
   137  		if err := recover(); err != nil {
   138  			t.Log(err)
   139  			return
   140  		}
   141  	}()
   142  	c.PutBytes(id, []byte("def"))
   143  	t.Fatal("mismatched Put did not panic in verify mode")
   144  }
   145  
   146  func dummyID(x int) [HashSize]byte {
   147  	var out [HashSize]byte
   148  	binary.LittleEndian.PutUint64(out[:], uint64(x))
   149  	return out
   150  }
   151  
   152  func TestCacheTrim(t *testing.T) {
   153  	dir, err := os.MkdirTemp("", "cachetest-")
   154  	if err != nil {
   155  		t.Fatal(err)
   156  	}
   157  	defer os.RemoveAll(dir)
   158  
   159  	c, err := Open(dir)
   160  	if err != nil {
   161  		t.Fatalf("Open: %v", err)
   162  	}
   163  	const start = 1000000000
   164  	now := int64(start)
   165  	c.now = func() time.Time { return time.Unix(now, 0) }
   166  
   167  	checkTime := func(name string, mtime int64) {
   168  		t.Helper()
   169  		file := filepath.Join(c.dir, name[:2], name)
   170  		info, err := os.Stat(file)
   171  		if err != nil {
   172  			t.Fatal(err)
   173  		}
   174  		if info.ModTime().Unix() != mtime {
   175  			t.Fatalf("%s mtime = %d, want %d", name, info.ModTime().Unix(), mtime)
   176  		}
   177  	}
   178  
   179  	id := ActionID(dummyID(1))
   180  	c.PutBytes(id, []byte("abc"))
   181  	entry, _ := c.Get(id)
   182  	c.PutBytes(ActionID(dummyID(2)), []byte("def"))
   183  	mtime := now
   184  	checkTime(fmt.Sprintf("%x-a", id), mtime)
   185  	checkTime(fmt.Sprintf("%x-d", entry.OutputID), mtime)
   186  
   187  	// Get should not change recent mtimes.
   188  	now = start + 10
   189  	c.Get(id)
   190  	checkTime(fmt.Sprintf("%x-a", id), mtime)
   191  	checkTime(fmt.Sprintf("%x-d", entry.OutputID), mtime)
   192  
   193  	// Get should change distant mtimes.
   194  	now = start + 5000
   195  	mtime2 := now
   196  	if _, err := c.Get(id); err != nil {
   197  		t.Fatal(err)
   198  	}
   199  	c.OutputFile(entry.OutputID)
   200  	checkTime(fmt.Sprintf("%x-a", id), mtime2)
   201  	checkTime(fmt.Sprintf("%x-d", entry.OutputID), mtime2)
   202  
   203  	// Trim should leave everything alone: it's all too new.
   204  	c.Trim()
   205  	if _, err := c.Get(id); err != nil {
   206  		t.Fatal(err)
   207  	}
   208  	c.OutputFile(entry.OutputID)
   209  	data, err := os.ReadFile(filepath.Join(dir, "trim.txt"))
   210  	if err != nil {
   211  		t.Fatal(err)
   212  	}
   213  	checkTime(fmt.Sprintf("%x-a", dummyID(2)), start)
   214  
   215  	// Trim less than a day later should not do any work at all.
   216  	now = start + 80000
   217  	c.Trim()
   218  	if _, err := c.Get(id); err != nil {
   219  		t.Fatal(err)
   220  	}
   221  	c.OutputFile(entry.OutputID)
   222  	data2, err := os.ReadFile(filepath.Join(dir, "trim.txt"))
   223  	if err != nil {
   224  		t.Fatal(err)
   225  	}
   226  	if !bytes.Equal(data, data2) {
   227  		t.Fatalf("second trim did work: %q -> %q", data, data2)
   228  	}
   229  
   230  	// Fast forward and do another trim just before the 5 day cutoff.
   231  	// Note that because of usedQuantum the cutoff is actually 5 days + 1 hour.
   232  	// We used c.Get(id) just now, so 5 days later it should still be kept.
   233  	// On the other hand almost a full day has gone by since we wrote dummyID(2)
   234  	// and we haven't looked at it since, so 5 days later it should be gone.
   235  	now += 5 * 86400
   236  	checkTime(fmt.Sprintf("%x-a", dummyID(2)), start)
   237  	c.Trim()
   238  	if _, err := c.Get(id); err != nil {
   239  		t.Fatal(err)
   240  	}
   241  	c.OutputFile(entry.OutputID)
   242  	mtime3 := now
   243  	if _, err := c.Get(dummyID(2)); err == nil { // haven't done a Get for this since original write above
   244  		t.Fatalf("Trim did not remove dummyID(2)")
   245  	}
   246  
   247  	// The c.Get(id) refreshed id's mtime again.
   248  	// Check that another 5 days later it is still not gone,
   249  	// but check by using checkTime, which doesn't bring mtime forward.
   250  	now += 5 * 86400
   251  	c.Trim()
   252  	checkTime(fmt.Sprintf("%x-a", id), mtime3)
   253  	checkTime(fmt.Sprintf("%x-d", entry.OutputID), mtime3)
   254  
   255  	// Half a day later Trim should still be a no-op, because there was a Trim recently.
   256  	// Even though the entry for id is now old enough to be trimmed,
   257  	// it gets a reprieve until the time comes for a new Trim scan.
   258  	now += 86400 / 2
   259  	c.Trim()
   260  	checkTime(fmt.Sprintf("%x-a", id), mtime3)
   261  	checkTime(fmt.Sprintf("%x-d", entry.OutputID), mtime3)
   262  
   263  	// Another half a day later, Trim should actually run, and it should remove id.
   264  	now += 86400/2 + 1
   265  	c.Trim()
   266  	if _, err := c.Get(dummyID(1)); err == nil {
   267  		t.Fatal("Trim did not remove dummyID(1)")
   268  	}
   269  }
   270
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