add impl for lru sized cache

go.mod

@@ -35,6 +35,7 @@ require (
 	github.com/coinbase/waas-client-library-go v1.0.8
 	github.com/couchbase/gocb/v2 v2.9.2
 	github.com/crewjam/rfc5424 v0.1.0
+	github.com/dgraph-io/ristretto v1.0.0
 	github.com/dustin/go-humanize v1.0.1
 	github.com/elastic/go-elasticsearch/v8 v8.15.0
 	github.com/envoyproxy/protoc-gen-validate v1.1.0

go.sum

@@ -220,6 +220,10 @@ github.com/danieljoos/wincred v1.1.2/go.mod h1:GijpziifJoIBfYh+S7BbkdUTU4LfM+QnG
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/dgraph-io/ristretto v1.0.0 h1:SYG07bONKMlFDUYu5pEu3DGAh8c2OFNzKm6G9J4Si84=
+github.com/dgraph-io/ristretto v1.0.0/go.mod h1:jTi2FiYEhQ1NsMmA7DeBykizjOuY88NhKBkepyu1jPc=
+github.com/dgryski/go-farm v0.0.0-20200201041132-a6ae2369ad13 h1:fAjc9m62+UWV/WAFKLNi6ZS0675eEUC9y3AlwSbQu1Y=
+github.com/dgryski/go-farm v0.0.0-20200201041132-a6ae2369ad13/go.mod h1:SqUrOPUnsFjfmXRMNPybcSiG0BgUW2AuFH8PAnS2iTw=
 github.com/dimchansky/utfbom v1.1.1 h1:vV6w1AhK4VMnhBno/TPVCoK9U/LP0PkLCS9tbxHdi/U=
 github.com/dimchansky/utfbom v1.1.1/go.mod h1:SxdoEBH5qIqFocHMyGOXVAybYJdr71b1Q/j0mACtrfE=
 github.com/distribution/reference v0.6.0 h1:0IXCQ5g4/QMHHkarYzh5l+u8T3t73zM5QvfrDyIgxBk=

pkg/cache/decorator.go

@@ -0,0 +1,64 @@
+package cache
+
+// WithMetrics is a decorator that adds metrics collection to any Cache implementation.
+type WithMetrics[T any] struct {
+	wrapped   Cache[T]
+	metrics   BaseMetricsCollector
+	cacheName string
+}
+
+// NewCacheWithMetrics creates a new WithMetrics decorator that wraps the provided Cache
+// and collects metrics using the provided BaseMetricsCollector.
+// The cacheName parameter is used to identify the cache in the collected metrics.
+func NewCacheWithMetrics[T any](wrapped Cache[T], metrics BaseMetricsCollector, cacheName string) *WithMetrics[T] {
+	return &WithMetrics[T]{
+		wrapped:   wrapped,
+		metrics:   metrics,
+		cacheName: cacheName,
+	}
+}
+
+// Set sets the value for the given key in the cache. It also records a set metric
+// for the cache using the provided metrics collector and cache name.
+func (c *WithMetrics[T]) Set(key string, val T) {
+	c.metrics.RecordSet(c.cacheName)
+	c.wrapped.Set(key, val)
+}
+
+// Get retrieves the value for the given key from the underlying cache. It also records
+// a hit or miss metric for the cache using the provided metrics collector and cache name.
+func (c *WithMetrics[T]) Get(key string) (T, bool) {
+	val, found := c.wrapped.Get(key)
+	if found {
+		c.metrics.RecordHit(c.cacheName)
+	} else {
+		c.metrics.RecordMiss(c.cacheName)
+	}
+	return val, found
+}
+
+// Exists checks if the given key exists in the cache. It records a hit or miss metric
+// for the cache using the provided metrics collector and cache name.
+func (c *WithMetrics[T]) Exists(key string) bool {
+	found := c.wrapped.Exists(key)
+	if found {
+		c.metrics.RecordHit(c.cacheName)
+	} else {
+		c.metrics.RecordMiss(c.cacheName)
+	}
+	return found
+}
+
+// Delete removes the value for the given key from the cache. It also records a delete metric
+// for the cache using the provided metrics collector and cache name.
+func (c *WithMetrics[T]) Delete(key string) {
+	c.wrapped.Delete(key)
+	c.metrics.RecordDelete(c.cacheName)
+}
+
+// Clear removes all entries from the cache. It also records a clear metric
+// for the cache using the provided metrics collector and cache name.
+func (c *WithMetrics[T]) Clear() {
+	c.wrapped.Clear()
+	c.metrics.RecordClear(c.cacheName)
+}

pkg/cache/metrics.go

@@ -0,0 +1,107 @@
+package cache
+
+import (
+	"sync"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+// BaseMetricsCollector defines the interface for recording cache metrics.
+// Each method corresponds to a specific cache-related operation.
+type BaseMetricsCollector interface {
+	RecordHit(cacheName string)
+	RecordMiss(cacheName string)
+	RecordSet(cacheName string)
+	RecordDelete(cacheName string)
+	RecordClear(cacheName string)
+}
+
+// MetricsCollector encapsulates all Prometheus metrics with labels.
+// It holds Prometheus counters for cache operations, which help track
+// the performance and usage of the cache.
+type MetricsCollector struct {
+	// Base metrics.
+	hits    *prometheus.CounterVec
+	misses  *prometheus.CounterVec
+	sets    *prometheus.CounterVec
+	deletes *prometheus.CounterVec
+	clears  *prometheus.CounterVec
+}
+
+var (
+	collectorOnce sync.Once // Ensures that the collector is initialized only once.
+	collector     *MetricsCollector
+)
+
+// InitializeMetrics initializes the singleton MetricsCollector.
+// It sets up Prometheus counters for cache operations (hits, misses, sets, deletes, clears).
+// Should be called once at the start of the application.
+func InitializeMetrics(namespace, subsystem string) {
+	collectorOnce.Do(func() {
+		collector = &MetricsCollector{
+			hits: promauto.NewCounterVec(prometheus.CounterOpts{
+				Namespace: namespace,
+				Subsystem: subsystem,
+				Name:      "hits_total",
+				Help:      "Total number of cache hits.",
+			}, []string{"cache_name"}),
+
+			misses: promauto.NewCounterVec(prometheus.CounterOpts{
+				Namespace: namespace,
+				Subsystem: subsystem,
+				Name:      "misses_total",
+				Help:      "Total number of cache misses.",
+			}, []string{"cache_name"}),
+
+			sets: promauto.NewCounterVec(prometheus.CounterOpts{
+				Namespace: namespace,
+				Subsystem: subsystem,
+				Name:      "sets_total",
+				Help:      "Total number of cache set operations.",
+			}, []string{"cache_name"}),
+
+			deletes: promauto.NewCounterVec(prometheus.CounterOpts{
+				Namespace: namespace,
+				Subsystem: subsystem,
+				Name:      "deletes_total",
+				Help:      "Total number of cache delete operations.",
+			}, []string{"cache_name"}),
+
+			clears: promauto.NewCounterVec(prometheus.CounterOpts{
+				Namespace: namespace,
+				Subsystem: subsystem,
+				Name:      "clears_total",
+				Help:      "Total number of cache clear operations.",
+			}, []string{"cache_name"}),
+		}
+	})
+}
+
+// GetMetricsCollector returns the singleton MetricsCollector instance.
+// It panics if InitializeMetrics has not been called to ensure metrics are properly initialized.
+// Must be called after InitializeMetrics to avoid runtime issues.
+// If you do it before, BAD THINGS WILL HAPPEN.
+func GetMetricsCollector() *MetricsCollector {
+	if collector == nil {
+		panic("MetricsCollector not initialized. Call InitializeMetrics first.")
+	}
+	return collector
+}
+
+// Implement BaseMetricsCollector interface methods.
+
+// RecordHit increments the counter for cache hits, tracking how often cache lookups succeed.
+func (m *MetricsCollector) RecordHit(cacheName string) { m.hits.WithLabelValues(cacheName).Inc() }
+
+// RecordMiss increments the counter for cache misses, tracking how often cache lookups fail.
+func (m *MetricsCollector) RecordMiss(cacheName string) { m.misses.WithLabelValues(cacheName).Inc() }
+
+// RecordSet increments the counter for cache set operations, tracking how often items are added/updated.
+func (m *MetricsCollector) RecordSet(cacheName string) { m.sets.WithLabelValues(cacheName).Inc() }
+
+// RecordDelete increments the counter for cache delete operations, tracking how often items are removed.
+func (m *MetricsCollector) RecordDelete(cacheName string) { m.deletes.WithLabelValues(cacheName).Inc() }
+
+// RecordClear increments the counter for cache clear operations, tracking how often the cache is completely cleared.
+func (m *MetricsCollector) RecordClear(cacheName string) { m.clears.WithLabelValues(cacheName).Inc() }

pkg/cache/sizedlru/metrics.go

@@ -0,0 +1,69 @@
+package sizedlru
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+
+	"github.com/trufflesecurity/trufflehog/v3/pkg/cache"
+)
+
+// MetricsCollector should implement the collector interface.
+var _ collector = (*MetricsCollector)(nil)
+
+// MetricsCollector extends the BaseMetricsCollector with Sized LRU specific metrics.
+// It provides methods to record cache hits, misses, and evictions.
+type MetricsCollector struct {
+	// BaseMetricsCollector is embedded to provide the base metrics functionality.
+	cache.BaseMetricsCollector
+
+	totalHits   *prometheus.GaugeVec
+	totalMisses *prometheus.GaugeVec
+	totalEvicts *prometheus.GaugeVec
+}
+
+// NewSizedLRUMetricsCollector initializes a new MetricsCollector with the provided namespace and subsystem.
+func NewSizedLRUMetricsCollector(namespace, subsystem string) *MetricsCollector {
+	base := cache.GetMetricsCollector()
+
+	totalHits := prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: namespace,
+		Subsystem: subsystem,
+		Name:      "total_hits",
+		Help:      "Total number of cache hits.",
+	}, []string{"cache_name"})
+
+	totalMisses := prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: namespace,
+		Subsystem: subsystem,
+		Name:      "total_misses",
+		Help:      "Total number of cache misses.",
+	}, []string{"cache_name"})
+
+	totalEvicts := prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: namespace,
+		Subsystem: subsystem,
+		Name:      "total_evicts",
+		Help:      "Total number of cache evictions.",
+	}, []string{"cache_name"})
+
+	return &MetricsCollector{
+		BaseMetricsCollector: base,
+		totalHits:            totalHits,
+		totalMisses:          totalMisses,
+		totalEvicts:          totalEvicts,
+	}
+}
+
+// RecordHits updates the total hits metric for the given cache name.
+func (c *MetricsCollector) RecordHits(cacheName string, hits uint64) {
+	c.totalHits.WithLabelValues(cacheName).Set(float64(hits))
+}
+
+// RecordMisses updates the total misses metric for the given cache name.
+func (c *MetricsCollector) RecordMisses(cacheName string, misses uint64) {
+	c.totalMisses.WithLabelValues(cacheName).Set(float64(misses))
+}
+
+// RecordEvictions updates the total evictions metric for the given cache name.
+func (c *MetricsCollector) RecordEvictions(cacheName string, evictions uint64) {
+	c.totalEvicts.WithLabelValues(cacheName).Set(float64(evictions))
+}