refactor: optimize slice capacity handling

Author: bartventer

internal/log.go

@@ -42,7 +42,6 @@ func TraceIDFromContext(ctx context.Context) (string, bool) {
 
 type (
 	LogEntry struct {
-		CacheStatus  string
 		URLKey       string
 		MiscProvider MiscProvider
 		Error        error
@@ -75,6 +74,9 @@ func (m Misc) LogValue() slog.Value {
 	if m.RefIndex >= 0 && m.RefIndex < len(m.Refs) {
 		attrs = append(attrs, slog.Any("ref", m.Refs[m.RefIndex]))
 	}
+	if cap(attrs) > len(attrs) {
+		attrs = slices.Clip(attrs)
+	}
 	return slog.GroupValue(attrs...)
 }
 
@@ -143,7 +145,6 @@ func (l *Logger) LogCacheHit(req *http.Request, urlKey string, mp MiscProvider)
 		"Hit; served from cache.",
 		LogFunc(func() (CacheStatus, *http.Request, LogEntry) {
 			return CacheStatusHit, req, LogEntry{
-				CacheStatus:  CacheStatusHit.Value,
 				URLKey:       urlKey,
 				MiscProvider: mp,
 				Error:        nil,
@@ -159,7 +160,6 @@ func (l *Logger) LogCacheMiss(req *http.Request, urlKey string, mp MiscProvider)
 		"Miss; served from origin.",
 		LogFunc(func() (CacheStatus, *http.Request, LogEntry) {
 			return CacheStatusMiss, req, LogEntry{
-				CacheStatus:  CacheStatusMiss.Value,
 				URLKey:       urlKey,
 				MiscProvider: mp,
 				Error:        nil,
@@ -175,7 +175,6 @@ func (l *Logger) LogCacheStale(req *http.Request, urlKey string, mp MiscProvider
 		"Stale; served from cache.",
 		LogFunc(func() (CacheStatus, *http.Request, LogEntry) {
 			return CacheStatusStale, req, LogEntry{
-				CacheStatus:  CacheStatusStale.Value,
 				URLKey:       urlKey,
 				MiscProvider: mp,
 				Error:        nil,
@@ -191,7 +190,6 @@ func (l *Logger) LogCacheStaleIfError(req *http.Request, urlKey string, mp MiscP
 		"Stale; served from cache; stale-if-error policy applied.",
 		LogFunc(func() (CacheStatus, *http.Request, LogEntry) {
 			return CacheStatusStale, req, LogEntry{
-				CacheStatus:  CacheStatusStale.Value,
 				URLKey:       urlKey,
 				MiscProvider: mp,
 				Error:        nil,
@@ -207,7 +205,6 @@ func (l *Logger) LogCacheStaleRevalidate(req *http.Request, urlKey string, mp Mi
 		"Stale; served from cache; revalidating.",
 		LogFunc(func() (CacheStatus, *http.Request, LogEntry) {
 			return CacheStatusStale, req, LogEntry{
-				CacheStatus:  CacheStatusStale.Value,
 				URLKey:       urlKey,
 				MiscProvider: mp,
 				Error:        nil,
@@ -223,7 +220,6 @@ func (l *Logger) LogCacheRevalidated(req *http.Request, urlKey string, mp MiscPr
 		"Revalidated; served cached response.",
 		LogFunc(func() (CacheStatus, *http.Request, LogEntry) {
 			return CacheStatusRevalidated, req, LogEntry{
-				CacheStatus:  CacheStatusRevalidated.Value,
 				URLKey:       urlKey,
 				MiscProvider: mp,
 				Error:        nil,
@@ -239,7 +235,6 @@ func (l *Logger) LogCacheBypass(msg string, req *http.Request, urlKey string, mp
 		msg,
 		LogFunc(func() (CacheStatus, *http.Request, LogEntry) {
 			return CacheStatusBypass, req, LogEntry{
-				CacheStatus:  CacheStatusBypass.Value,
 				URLKey:       urlKey,
 				MiscProvider: mp,
 				Error:        nil,
@@ -261,7 +256,6 @@ func (l *Logger) LogCacheError(
 		msg,
 		LogFunc(func() (CacheStatus, *http.Request, LogEntry) {
 			return CacheStatus{Value: "error"}, req, LogEntry{
-				CacheStatus:  "error",
 				URLKey:       urlKey,
 				MiscProvider: mp,
 				Error:        err,
@@ -293,7 +287,7 @@ func (l *Logger) logCache(ctx context.Context, level slog.Level, msg string, lp
 			slog.String("host", req.Host),
 		),
 		groupAttrs("cache",
-			slog.String("status", cl.CacheStatus),
+			slog.Any("status", event),
 			slog.String("url_key", cl.URLKey),
 		),
 	)

internal/normalization.go

@@ -192,6 +192,9 @@ outer:
 			}
 			slices.Sort(params)
 		}
+		if cap(params) > len(params) {
+			params = slices.Clip(params)
+		}
 		qualityParts = append(qualityParts, qualityValue{
 			main:   main,
 			q:      q,

roundtripper.go

@@ -218,6 +218,12 @@ func (r *transport) handleUnrecognizedMethod(
 			return nil, err
 		}
 		internal.CacheStatusBypass.ApplyTo(resp.Header)
+		r.logger.LogCacheBypass(
+			"Bypass; unrecognized (safe) method, served from upstream.",
+			req,
+			urlKey,
+			nil,
+		)
 		return resp, nil
 	}
 	resp, err := r.upstream.RoundTrip(req)
@@ -229,7 +235,12 @@ func (r *transport) handleUnrecognizedMethod(
 		r.ci.InvalidateCache(req.URL, resp.Header, refs, urlKey)
 	}
 	internal.CacheStatusBypass.ApplyTo(resp.Header)
-	r.logger.LogCacheBypass("Bypass; unrecognized method, served from upstream.", req, urlKey, nil)
+	r.logger.LogCacheBypass(
+		"Bypass; unrecognized (unsafe) method, served from upstream.",
+		req,
+		urlKey,
+		nil,
+	)
 	return resp, nil
 }
 
@@ -241,6 +252,17 @@ func (r *transport) handleCacheMiss(
 ) (*http.Response, error) {
 	ccReq := internal.ParseCCRequestDirectives(req.Header)
 	if ccReq.OnlyIfCached() {
+		r.logger.LogCacheMiss(
+			req,
+			urlKey,
+			internal.MiscFunc(func() internal.Misc {
+				return internal.Misc{
+					CCReq:    ccReq,
+					Refs:     refs,
+					RefIndex: refIndex,
+				}
+			}),
+		)
 		return make504Response(req)
 	}
 	resp, start, end, err := r.roundTripTimed(req)

store/fscache/fscache.go

@@ -57,6 +57,7 @@ import (
 	"net/url"
 	"os"
 	"path/filepath"
+	"slices"
 	"strings"
 	"time"
 
@@ -174,11 +175,11 @@ func WithBaseDir(base string) Option {
 }
 
 func fromURL(u *url.URL) (*fsCache, error) {
-	opts := make([]Option, 0, 4)
-	var appname string
-	if appname = u.Query().Get("appname"); appname == "" {
+	appname := u.Query().Get("appname")
+	if appname == "" {
 		return nil, ErrMissingAppName
 	}
+	opts := make([]Option, 0, 4)
 	if u.Path != "" && u.Path != "/" {
 		opts = append(opts, WithBaseDir(u.Path))
 	}
@@ -192,6 +193,9 @@ func fromURL(u *url.URL) (*fsCache, error) {
 		key := cmp.Or(u.Query().Get("encrypt_key"), os.Getenv("FSCACHE_ENCRYPT_KEY"))
 		opts = append(opts, WithEncryption(key))
 	}
+	if cap(opts) > len(opts) {
+		opts = slices.Clip(opts)
+	}
 	return Open(appname, opts...)
 }
 
@@ -452,5 +456,8 @@ func (c *fsCache) keys(prefix string) ([]string, error) {
 	if err != nil {
 		return nil, err
 	}
+	if cap(keys) > len(keys) {
+		keys = slices.Clip(keys)
+	}
 	return keys, nil
 }