| 1 | package host |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "errors" |
| 6 | "testing" |
| 7 | |
| 8 | "github.com/carlosframework/platform/internal/release" |
| 9 | ) |
| 10 | |
| 11 | // bsGetCounter counts reads, so a test can see a write that needed none. |
| 12 | type bsGetCounter struct { |
| 13 | release.Store |
| 14 | gets int |
| 15 | } |
| 16 | |
| 17 | func (c *bsGetCounter) Get(ctx context.Context, key string) ([]byte, string, error) { |
| 18 | c.gets++ |
| 19 | return c.Store.Get(ctx, key) |
| 20 | } |
| 21 | |
| 22 | func countingBuildStates(t *testing.T) (*buildStates, *bsGetCounter) { |
| 23 | t.Helper() |
| 24 | b, s, _ := testBuildStates(t) |
| 25 | cs := &bsGetCounter{Store: s} |
| 26 | b.storeFor = storesOf(map[string]release.Store{"hib": cs}) |
| 27 | return b, cs |
| 28 | } |
| 29 | |
| 30 | // The state this agent last wrote is the one a conditional write can go |
| 31 | // on: a wake's record is then one round trip, not a read and a write. |
| 32 | func TestBuildStateWritesOnItsOwnLastCopyWithoutARead(t *testing.T) { |
| 33 | b, cs := countingBuildStates(t) |
| 34 | ctx := context.Background() |
| 35 | if err := put(t, b, ctx, "a.example.com", release.BuildState{LastExecuted: "v1", Completed: 1}); err != nil { |
| 36 | t.Fatal(err) |
| 37 | } |
| 38 | cs.gets = 0 |
| 39 | got, err := b.update(ctx, "a.example.com", bump) |
| 40 | if err != nil { |
| 41 | t.Fatal(err) |
| 42 | } |
| 43 | if cs.gets != 0 { |
| 44 | t.Errorf("the write read the object %d time(s); its own last copy was current", cs.gets) |
| 45 | } |
| 46 | if got.Completed != 2 || got.LastExecuted != "v1" { |
| 47 | t.Errorf("state = %+v, want the cached copy bumped", got) |
| 48 | } |
| 49 | cur, _, err := getState(ctx, cs.Store, "inst/a.example.com/build-state.json", "a.example.com") |
| 50 | if err != nil || cur == nil || cur.Completed != 2 { |
| 51 | t.Fatalf("object = %+v, %v", cur, err) |
| 52 | } |
| 53 | } |
| 54 | |
| 55 | // Another writer moved the object on: the conditional write fails, and the |
| 56 | // write reads it and merges on what is really there. |
| 57 | func TestBuildStateCopyThatMovedOnIsReadAgain(t *testing.T) { |
| 58 | b, cs := countingBuildStates(t) |
| 59 | ctx := context.Background() |
| 60 | if err := put(t, b, ctx, "a.example.com", release.BuildState{LastExecuted: "v1", Completed: 1}); err != nil { |
| 61 | t.Fatal(err) |
| 62 | } |
| 63 | key := "inst/a.example.com/build-state.json" |
| 64 | if _, err := cs.Store.Put(ctx, key, []byte(`{"schema":1,"host":"a.example.com","last_executed":"v9","completed":5}`), mustEtag(t, cs.Store, key)); err != nil { |
| 65 | t.Fatal(err) |
| 66 | } |
| 67 | cs.gets = 0 |
| 68 | got, err := b.update(ctx, "a.example.com", bump) |
| 69 | if err != nil { |
| 70 | t.Fatal(err) |
| 71 | } |
| 72 | if cs.gets == 0 { |
| 73 | t.Error("the write did not read an object that had moved on") |
| 74 | } |
| 75 | if got.Completed != 6 || got.LastExecuted != "v9" { |
| 76 | t.Errorf("state = %+v, want the other writer's state bumped", got) |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | // A merge that refuses on the cached copy is asked again on a fresh read: |
| 81 | // the copy may be stale, and a refusal on stale state would be wrong. |
| 82 | func TestBuildStateRefusalOnTheCachedCopyIsCheckedAgainstAFreshRead(t *testing.T) { |
| 83 | b, cs := countingBuildStates(t) |
| 84 | ctx := context.Background() |
| 85 | if err := put(t, b, ctx, "a.example.com", release.BuildState{LastExecuted: "v1", Completed: 1}); err != nil { |
| 86 | t.Fatal(err) |
| 87 | } |
| 88 | key := "inst/a.example.com/build-state.json" |
| 89 | if _, err := cs.Store.Put(ctx, key, []byte(`{"schema":1,"host":"a.example.com","last_executed":"v1","completed":2}`), mustEtag(t, cs.Store, key)); err != nil { |
| 90 | t.Fatal(err) |
| 91 | } |
| 92 | errStale := errors.New("stale") |
| 93 | got, err := b.write(ctx, "a.example.com", func(cur *release.BuildState) (release.BuildState, bool, error) { |
| 94 | if cur != nil && cur.Completed == 1 { |
| 95 | return release.BuildState{}, false, errStale |
| 96 | } |
| 97 | return *cur, true, nil |
| 98 | }, nil) |
| 99 | if err != nil { |
| 100 | t.Fatalf("write = %v; the refusal came from the cached copy, not the object", err) |
| 101 | } |
| 102 | if got.Completed != 2 { |
| 103 | t.Errorf("state = %+v", got) |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | // An object that no longer parses is never written over (R-BS-CORRUPT), |
| 108 | // cached copy or not: the conditional write fails and the read refuses. |
| 109 | func TestBuildStateCachedCopyNeverWritesOverACorruptObject(t *testing.T) { |
| 110 | b, cs := countingBuildStates(t) |
| 111 | ctx := context.Background() |
| 112 | if err := put(t, b, ctx, "a.example.com", release.BuildState{LastExecuted: "v1"}); err != nil { |
| 113 | t.Fatal(err) |
| 114 | } |
| 115 | key := "inst/a.example.com/build-state.json" |
| 116 | if _, err := cs.Store.Put(ctx, key, []byte("{"), mustEtag(t, cs.Store, key)); err != nil { |
| 117 | t.Fatal(err) |
| 118 | } |
| 119 | if _, err := b.update(ctx, "a.example.com", bump); err == nil { |
| 120 | t.Fatal("wrote over an object that does not parse") |
| 121 | } |
| 122 | raw, _, err := cs.Store.Get(ctx, key) |
| 123 | if err != nil || string(raw) != "{" { |
| 124 | t.Fatalf("object = %q, %v", raw, err) |
| 125 | } |
| 126 | } |
| 127 | |
amadan