chore(pgs): configurable max items for lru

Author: neurosnap

.env.example

@@ -102,6 +102,7 @@ PGS_PROTOCOL=http
 PGS_STORAGE_DIR=.storage
 PGS_DEBUG=1
 PGS_CACHE_TTL=600s
+PGS_CACHE_MAX_ITEMS=0
 
 PICO_CADDYFILE=./caddy/Caddyfile.pico
 PICO_V4=

pkg/apps/pgs/config.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"log/slog"
 	"path/filepath"
+	"strconv"
 	"time"
 
 	pgsdb "github.com/picosh/pico/pkg/apps/pgs/db"
@@ -13,6 +14,7 @@ import (
 
 type PgsConfig struct {
 	CacheTTL           time.Duration
+	CacheMaxItems      int
 	Domain             string
 	MaxAssetSize       int64
 	MaxSize            uint64
@@ -74,12 +76,18 @@ func NewPgsConfig(logger *slog.Logger, dbpool pgsdb.PgsDB, st storage.StorageSer
 	if err != nil {
 		cacheTTL = 600 * time.Second
 	}
+	cacheMaxItemsStr := shared.GetEnv("PGS_CACHE_MAX_ITEMS", "")
+	cacheMaxItems := 0
+	if cacheMaxItemsStr != "" {
+		cacheMaxItems, _ = strconv.Atoi(cacheMaxItemsStr)
+	}
 
 	sshHost := shared.GetEnv("PGS_SSH_HOST", "0.0.0.0")
 	sshPort := shared.GetEnv("PGS_SSH_PORT", "2222")
 
 	cfg := PgsConfig{
 		CacheTTL:           cacheTTL,
+		CacheMaxItems:      cacheMaxItems,
 		Domain:             domain,
 		MaxAssetSize:       maxAssetSize,
 		MaxSize:            maxSize,

pkg/apps/pgs/web.go

@@ -112,7 +112,7 @@ func (p *PromCacheMetrics) AddUpstreamRequest() {
 func NewPgsHttpCache(cfg *PgsConfig, upstream http.Handler) *httpcache.HttpCache {
 	ttl := cfg.CacheTTL
 	metrics := NewPromCacheMetrics(cfg.Logger, prometheus.DefaultRegisterer)
-	cache := expirable.NewLRU(0, metrics.EvictCacheItem, ttl)
+	cache := expirable.NewLRU(cfg.CacheMaxItems, metrics.EvictCacheItem, ttl)
 	httpCache := &httpcache.HttpCache{
 		Ttl:      ttl,
 		Logger:   cfg.Logger,
@@ -124,7 +124,12 @@ func NewPgsHttpCache(cfg *PgsConfig, upstream http.Handler) *httpcache.HttpCache
 		},
 		CacheMetrics: metrics,
 	}
-	httpCache.Logger.Info("httpcache initiated", "ttl", httpCache.Ttl, "storage", "lru")
+	httpCache.Logger.Info(
+		"httpcache initiated",
+		"storageType", "expirable.LRU",
+		"ttl", ttl,
+		"maxItems", cfg.CacheMaxItems,
+	)
 	return httpCache
 }