1 # This is a regression test for #652435. It checks that we don't generate
2 # multiple action entry ids for the same index file. That was happening
3 # previously because we sometimes generated the action id with unclean
4 # paths (and the rest of the time with clean paths) for the same package.
5 # This test will use a go program ('check') to check the cache that there are
6 # no two action entry files that point to the same object id.
7
8 sleep 2s # Sleep so that the unpacked files are > 2 seconds old. The index won't be used if the modified times on the files are newer.
9 go build -o check$GOEXE check.go
10 cd mod
11 env GOCACHE=$WORK/newcache # Run list command in a clean cache.
12 go list all
13 exec ../check$GOEXE
14
15 -- mod/go.mod --
16 module example.com/foo
17 -- mod/foo.go --
18 package foo
19 -- check.go --
20 package main
21
22 import (
23 "errors"
24 "log"
25 "os"
26 "path/filepath"
27 "strings"
28 )
29
30 func main() {
31 cachedir := os.Getenv("GOCACHE")
32 if cachedir == "" {
33 log.Fatal("GOCACHE env var is empty; expected it to be set")
34 }
35
36 // Read the top level cache directory. The cache directory contains directories with
37 // each of the possible two hex digit prefixes (00-FF) of a cache entry's id.
38 // Those directories in turn contain files with the hex id followed by either
39 // "-a" for the action entries or "-d" for the object entries. We want to check
40 // if two action entries point to the same object entry so we'll iterate through
41 // all the "-a" files and see if any two of them refer to the same object id
42 // (corresponding to a "-d" file).
43 dirs, err := os.ReadDir(cachedir)
44 if err != nil {
45 log.Fatal(err)
46 }
47
48 seen := map[string]string{} // object id -> action id
49
50 for _, entry := range dirs {
51 if entry.IsDir() && len(entry.Name()) == 2 {
52 prefixdir := filepath.Join(cachedir, entry.Name())
53 entries, err := os.ReadDir(prefixdir)
54 if err != nil {
55 log.Fatal(err)
56 }
57
58 for _, entry := range entries {
59 if !strings.HasSuffix(entry.Name(), "-a") {
60 // not an action id entry
61 continue
62 }
63 actionEntryFile := filepath.Join(prefixdir, entry.Name())
64 objid, err := objectid(actionEntryFile)
65 if err != nil {
66 log.Fatal(err)
67 }
68 if other, ok := seen[objid]; ok {
69 log.Printf("found two action entry files (%s, %s) pointing to the same object id: %s", other, entry.Name(), objid)
70 os.Exit(1)
71 }
72 seen[objid] = entry.Name()
73 }
74 }
75 }
76 }
77
78 // objectid returns the object id that the given actionEntryFile points to.
79 func objectid(actionEntryFile string) (string, error) {
80 // See cmd/go/internal/cache.(*DiskCache).get for the code that reads
81 // from the action entry files. The following is based on that function.
82 const (
83 HashSize = 32
84 hexSize = HashSize * 2
85 entrySize = 2 + 1 + hexSize + 1 + hexSize + 1 + 20 + 1 + 20 + 1
86 )
87
88 entry, err := os.ReadFile(actionEntryFile)
89 if err != nil {
90 return "", err
91 }
92 if len(entry) < entrySize {
93 return "", errors.New("entry file incomplete")
94 }
95 if entry[0] != 'v' || entry[1] != '1' || entry[2] != ' ' || entry[3+hexSize] != ' ' || entry[3+hexSize+1+hexSize] != ' ' || entry[3+hexSize+1+hexSize+1+20] != ' ' || entry[entrySize-1] != '\n' {
96 return "", errors.New("invalid header")
97 }
98 return string(entry[3+hexSize+1 : 3+hexSize+1+hexSize]), nil
99 }
100
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