Files
pixa/internal/imgcache/stats_internal_test.go
T
clawbot d178113b45
check / check (push) Waiting to run
Remove the unused cache lifetime setting (closes #69)
CacheConfig.CacheTTL was set to DefaultCacheTTL (24 hours) and never
read, so cached images never expired. Remove the field, the constant
and the line that set it. Cached source and transformed images stay
until eviction removes them to keep the cache within cache_max_bytes.

Existing tests lose only the CacheTTL line of their cache config; no
test's checks change.

Model: opus-5-5
2026-10-13 01:31:00 +00:00

495 lines
12 KiB
Go

package imgcache
import (
"bytes"
"context"
"database/sql"
"image/color"
"io"
"io/fs"
"log/slog"
"math"
"strings"
"testing"
"time"
"sneak.berlin/go/pixa/internal/database"
"sneak.berlin/go/pixa/internal/httpfetcher"
)
func setupStatsTestDB(t *testing.T) *sql.DB {
t.Helper()
db, err := sql.Open("sqlite", ":memory:")
if err != nil {
t.Fatal(err)
}
err = database.ApplyMigrations(context.Background(), db, nil)
if err != nil {
t.Fatal(err)
}
t.Cleanup(func() { _ = db.Close() })
return db
}
func TestStats_HitRateIsRatio(t *testing.T) {
t.Parallel()
db := setupStatsTestDB(t)
dir := t.TempDir()
cache, err := NewCache(db, CacheConfig{
StateDir: dir,
NegativeTTL: 5 * time.Minute,
})
if err != nil {
t.Fatal(err)
}
ctx := context.Background()
// Set some hit/miss counts and a transform_count
_, err = db.ExecContext(ctx, `
UPDATE cache_stats
SET hit_count = 75, miss_count = 25, transform_count = 9999
WHERE id = 1
`)
if err != nil {
t.Fatal(err)
}
stats, err := cache.Stats(ctx)
if err != nil {
t.Fatal(err)
}
if stats.HitCount != 75 {
t.Errorf("HitCount = %d, want 75", stats.HitCount)
}
if stats.MissCount != 25 {
t.Errorf("MissCount = %d, want 25", stats.MissCount)
}
// HitRate should be 0.75, NOT 9999 (transform_count)
expectedRate := 0.75
if math.Abs(stats.HitRate-expectedRate) > 0.001 {
t.Errorf("HitRate = %f, want %f (was it scanning transform_count?)",
stats.HitRate, expectedRate)
}
}
func TestStats_ZeroCounts(t *testing.T) {
t.Parallel()
db := setupStatsTestDB(t)
dir := t.TempDir()
cache, err := NewCache(db, CacheConfig{
StateDir: dir,
NegativeTTL: 5 * time.Minute,
})
if err != nil {
t.Fatal(err)
}
stats, err := cache.Stats(context.Background())
if err != nil {
t.Fatal(err)
}
// With zero hits and misses, HitRate should be 0, not some garbage value
if stats.HitRate != 0.0 {
t.Errorf("HitRate = %f, want 0.0 for zero counts", stats.HitRate)
}
}
// TestStats_LogsFailedCountQueries verifies that a failed item count query
// and a failed size query are each logged at warn and Stats still succeeds.
func TestStats_LogsFailedCountQueries(t *testing.T) {
t.Parallel()
db := setupStatsTestDB(t)
var logBuf bytes.Buffer
cache, err := NewCache(db, CacheConfig{
StateDir: t.TempDir(),
NegativeTTL: 5 * time.Minute,
Logger: slog.New(slog.NewJSONHandler(&logBuf, nil)),
})
if err != nil {
t.Fatal(err)
}
_, err = db.ExecContext(t.Context(),
`DROP TABLE source_content; DROP TABLE variant_content`)
if err != nil {
t.Fatal(err)
}
_, err = cache.Stats(t.Context())
if err != nil {
t.Fatalf("Stats() error = %v, want nil", err)
}
for _, msg := range []string{
"failed to count cache items for stats",
"failed to sum cache size for stats",
} {
want := `"level":"WARN","msg":"` + msg + `"`
if !strings.Contains(logBuf.String(), want) {
t.Errorf("log missing %s; got %q", want, logBuf.String())
}
}
}
// TestIncrementStats_LogsFailedUpdates verifies that a failed hit or miss
// count update and a failed upstream fetch count update are each logged at
// warn.
func TestIncrementStats_LogsFailedUpdates(t *testing.T) {
t.Parallel()
db := setupStatsTestDB(t)
var logBuf bytes.Buffer
cache, err := NewCache(db, CacheConfig{
StateDir: t.TempDir(),
NegativeTTL: 5 * time.Minute,
Logger: slog.New(slog.NewJSONHandler(&logBuf, nil)),
})
if err != nil {
t.Fatal(err)
}
_, err = db.ExecContext(t.Context(), `DROP TABLE cache_stats`)
if err != nil {
t.Fatal(err)
}
cache.IncrementStats(t.Context(), false, 1024)
for _, msg := range []string{
"failed to count cache hit or miss",
"failed to count upstream fetch",
} {
want := `"level":"WARN","msg":"` + msg + `"`
if !strings.Contains(logBuf.String(), want) {
t.Errorf("log missing %s; got %q", want, logBuf.String())
}
}
}
// TestStats_TotalsCountSourcesAndVariants verifies that TotalItems and
// TotalSizeBytes cover the stored source images and processed variants.
func TestStats_TotalsCountSourcesAndVariants(t *testing.T) {
t.Parallel()
cache, _ := newEvictionTestCache(t, 1<<30)
storeEvictionTestSource(t, cache, testHostCDN, testPathCat,
bytes.Repeat([]byte{0xAA}, 1000))
storeEvictionTestVariant(t, cache, testVariantKeyOne,
bytes.Repeat([]byte{0xAB}, 500))
storeEvictionTestVariant(t, cache, testVariantKeyTwo,
bytes.Repeat([]byte{0xAC}, 250))
stats, err := cache.Stats(t.Context())
if err != nil {
t.Fatalf("Stats() error = %v", err)
}
if stats.TotalItems != 3 {
t.Errorf("TotalItems = %d, want 3 (1 source, 2 variants)", stats.TotalItems)
}
if stats.TotalSizeBytes != 1750 {
t.Errorf("TotalSizeBytes = %d, want 1750 (1000+500+250)",
stats.TotalSizeBytes)
}
}
// TestStats_DisabledCacheReportsNoItems verifies that a disabled disk cache
// reports no items and no size, even when its database still holds the
// rows of an earlier run with the disk cache enabled.
func TestStats_DisabledCacheReportsNoItems(t *testing.T) {
t.Parallel()
enabled, _ := newEvictionTestCache(t, 1<<30)
storeEvictionTestSource(t, enabled, testHostCDN, testPathCat,
bytes.Repeat([]byte{0xAA}, 1000))
storeEvictionTestVariant(t, enabled, testVariantKeyOne,
bytes.Repeat([]byte{0xAB}, 500))
disabled, err := NewCache(enabled.db, CacheConfig{
StateDir: t.TempDir(),
NegativeTTL: 5 * time.Minute,
DisableDiskCache: true,
})
if err != nil {
t.Fatal(err)
}
stats, err := disabled.Stats(t.Context())
if err != nil {
t.Fatalf("Stats() error = %v", err)
}
if stats.TotalItems != 0 || stats.TotalSizeBytes != 0 {
t.Errorf("TotalItems = %d, TotalSizeBytes = %d, want 0 and 0",
stats.TotalItems, stats.TotalSizeBytes)
}
}
// cacheStatsCounters holds the counters of the cache_stats row, in column
// order.
type cacheStatsCounters struct {
hitCount int64
missCount int64
upstreamFetchCount int64
upstreamFetchBytes int64
transformCount int64
}
// readCacheStatsCounters reads the counters of the cache_stats row.
func readCacheStatsCounters(t *testing.T, cache *Cache) cacheStatsCounters {
t.Helper()
var got cacheStatsCounters
err := cache.db.QueryRowContext(t.Context(), `
SELECT hit_count, miss_count, upstream_fetch_count,
upstream_fetch_bytes, transform_count
FROM cache_stats WHERE id = 1
`).Scan(&got.hitCount, &got.missCount, &got.upstreamFetchCount,
&got.upstreamFetchBytes, &got.transformCount)
if err != nil {
t.Fatalf("failed to read cache_stats: %v", err)
}
return got
}
// TestService_Get_CountsStats walks Get through a miss that fetches the
// source, a hit, a miss that reuses the cached source, and two misses whose
// source cannot be used, checking every cache_stats counter after each.
func TestService_Get_CountsStats(t *testing.T) {
t.Parallel()
svc, fixtures := SetupTestService(t)
// NewTestFS builds the same files the test service's fetcher serves.
testFS, _ := NewTestFS(t)
photo, err := fs.ReadFile(testFS, fixtures.GoodHostJPEG)
if err != nil {
t.Fatal(err)
}
fake, err := fs.ReadFile(testFS, fixtures.InvalidFile)
if err != nil {
t.Fatal(err)
}
photoBytes, fakeBytes := int64(len(photo)), int64(len(fake))
// want is hits, misses, upstream fetches, upstream bytes, transforms.
steps := []struct {
name string
path string
size int
wantErr bool
want cacheStatsCounters
}{
{"miss that fetches the source", testPathPhoto, 50, false,
cacheStatsCounters{0, 1, 1, photoBytes, 1}},
{"hit", testPathPhoto, 50, false,
cacheStatsCounters{1, 1, 1, photoBytes, 1}},
{"miss that reuses the cached source", testPathPhoto, 25, false,
cacheStatsCounters{1, 2, 1, photoBytes, 2}},
{"miss whose source fails the magic byte check", "/images/fake.jpg", 50, true,
cacheStatsCounters{1, 3, 2, photoBytes + fakeBytes, 2}},
{"miss whose source is not found", "/images/nonexistent.jpg", 50, true,
cacheStatsCounters{1, 4, 2, photoBytes + fakeBytes, 2}},
}
for _, step := range steps {
resp, err := svc.Get(t.Context(), &ImageRequest{
SourceHost: fixtures.GoodHost,
SourcePath: step.path,
Size: Size{Width: step.size, Height: step.size},
Format: FormatJPEG,
Quality: 85,
FitMode: FitCover,
})
if (err != nil) != step.wantErr {
t.Fatalf("%s: Get() error = %v, want error %t", step.name, err, step.wantErr)
}
if err == nil {
_ = resp.Content.Close()
}
got := readCacheStatsCounters(t, svc.cache)
if got != step.want {
t.Fatalf("after the %s: counters = %+v, want %+v", step.name, got, step.want)
}
}
}
// fakeUpstream answers every fetch with itself as a JPEG body. The body
// serves data, then calls cancel, when set, and returns err; io.EOF ends
// the body normally.
type fakeUpstream struct {
data *bytes.Reader
cancel context.CancelFunc
err error
}
func (u *fakeUpstream) Fetch(
context.Context, string,
) (*httpfetcher.FetchResult, error) {
return &httpfetcher.FetchResult{
Content: io.NopCloser(u),
ContentLength: -1,
ContentType: testContentTypeJPEG,
}, nil
}
func (u *fakeUpstream) Read(p []byte) (int, error) {
if u.data.Len() > 0 {
return u.data.Read(p)
}
if u.cancel != nil {
u.cancel()
}
return 0, u.err
}
// TestService_Get_CountsInterruptedMisses checks every cache_stats counter
// after a miss whose request context ends during or after the upstream
// fetch, and after a miss whose upstream body is over the size limit.
func TestService_Get_CountsInterruptedMisses(t *testing.T) {
t.Parallel()
photo := generateTestJPEG(t, 100, 100, color.RGBA{255, 0, 0, 255})
half := len(photo) / 2
// want is hits, misses, upstream fetches, upstream bytes, transforms.
tests := []struct {
name string
served int // bytes of the photo the upstream body serves
cancel bool // whether the body then ends the request context
readErr error // what the body then returns
wantErr bool
want cacheStatsCounters
}{
{"request context ends during the fetch", half, true, context.Canceled, true,
cacheStatsCounters{0, 1, 1, int64(half), 0}},
{"request context ends after the fetch", len(photo), true, io.EOF, false,
cacheStatsCounters{0, 1, 1, int64(len(photo)), 1}},
{"upstream body over the size limit", half, false,
httpfetcher.ErrResponseTooLarge, true,
cacheStatsCounters{0, 1, 1, int64(half), 0}},
}
for _, tc := range tests {
t.Run(tc.name, func(t *testing.T) {
t.Parallel()
svc, fixtures := SetupTestService(t)
ctx, cancel := context.WithCancel(t.Context())
defer cancel()
upstream := &fakeUpstream{
data: bytes.NewReader(photo[:tc.served]),
err: tc.readErr,
}
if tc.cancel {
upstream.cancel = cancel
}
svc.fetcher = upstream
resp, err := svc.Get(ctx, &ImageRequest{
SourceHost: fixtures.GoodHost,
SourcePath: testPathPhoto,
Size: Size{Width: 50, Height: 50},
Format: FormatJPEG,
Quality: 85,
FitMode: FitCover,
})
t.Logf("Get() error = %v", err)
if (err != nil) != tc.wantErr {
t.Fatalf("Get() error = %v, want error %t", err, tc.wantErr)
}
if err == nil {
_ = resp.Content.Close()
}
got := readCacheStatsCounters(t, svc.cache)
if got != tc.want {
t.Errorf("counters = %+v, want %+v", got, tc.want)
}
})
}
}
// TestService_Get_CountsHitAfterRequestEnds checks every cache_stats counter
// after a hit served with a request context that has already ended: only
// the hit count moves.
func TestService_Get_CountsHitAfterRequestEnds(t *testing.T) {
t.Parallel()
svc, fixtures := SetupTestService(t)
req := &ImageRequest{
SourceHost: fixtures.GoodHost,
SourcePath: testPathPhoto,
Size: Size{Width: 50, Height: 50},
Format: FormatJPEG,
Quality: 85,
FitMode: FitCover,
}
// A first request caches the variant.
resp, err := svc.Get(t.Context(), req)
if err != nil {
t.Fatalf("first Get() error = %v", err)
}
_ = resp.Content.Close()
want := readCacheStatsCounters(t, svc.cache)
want.hitCount++
ctx, cancel := context.WithCancel(t.Context())
cancel()
resp, err = svc.Get(ctx, req)
if err != nil {
t.Fatalf("Get() with an ended request context: error = %v", err)
}
_ = resp.Content.Close()
if resp.CacheStatus != CacheHit {
t.Fatalf("CacheStatus = %v, want %v", resp.CacheStatus, CacheHit)
}
got := readCacheStatsCounters(t, svc.cache)
if got != want {
t.Errorf("counters = %+v, want %+v", got, want)
}
}