From 15b7a6b5691571cfe08e7471f0e2b2cf90b6596b Mon Sep 17 00:00:00 2001
From: Ashish Naware <ashishnaware3@gmail.com>
Date: Fri, 13 Sep 2024 13:46:41 -0700
Subject: [PATCH] review comments: added metrics docs, licence header and made
 cache struct private

---
 docs/content/en/docs/reference/metrics.md | 20 ++++++++++++++++++++
 pkg/observer/cache.go                     | 17 ++++++++++-------
 pkg/observer/data.go                      |  4 ++--
 3 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/docs/content/en/docs/reference/metrics.md b/docs/content/en/docs/reference/metrics.md
index b3b750fc593..72ca585368f 100644
--- a/docs/content/en/docs/reference/metrics.md
+++ b/docs/content/en/docs/reference/metrics.md
@@ -29,6 +29,26 @@ Build information about tetragon
 | `modified` | `false` |
 | `time ` | `2022-05-13T15:54:45Z` |
 
+### `tetragon_data_cache_capacity`
+
+The capacity of the data cache.
+
+### `tetragon_data_cache_evictions_total`
+
+Number of data cache LRU evictions.
+
+### `tetragon_data_cache_misses_total`
+
+Number of data cache misses.
+
+| label | values |
+| ----- | ------ |
+| `operation` | `get, remove` |
+
+### `tetragon_data_cache_size`
+
+The size of the data cache
+
 ### `tetragon_data_event_size`
 
 The size of received data events.
diff --git a/pkg/observer/cache.go b/pkg/observer/cache.go
index 296d67bbc6d..63384282fb9 100644
--- a/pkg/observer/cache.go
+++ b/pkg/observer/cache.go
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright Authors of Tetragon
+
 package observer
 
 import (
@@ -7,14 +10,14 @@ import (
 	lru "github.com/hashicorp/golang-lru/v2"
 )
 
-type Cache struct {
+type cache struct {
 	cache *lru.Cache[dataapi.DataEventId, []byte]
 	size  int
 }
 
-func NewCache(
+func newCache(
 	dataCacheSize int,
-) (*Cache, error) {
+) (*cache, error) {
 	lruCache, err := lru.NewWithEvict(
 		dataCacheSize,
 		func(_ dataapi.DataEventId, _ []byte) {
@@ -24,14 +27,14 @@ func NewCache(
 	if err != nil {
 		return nil, err
 	}
-	cache := &Cache{
+	cache := &cache{
 		cache: lruCache,
 		size:  dataCacheSize,
 	}
 	return cache, nil
 }
 
-func (c *Cache) get(dataEventId dataapi.DataEventId) ([]byte, error) {
+func (c *cache) get(dataEventId dataapi.DataEventId) ([]byte, error) {
 	data, ok := c.cache.Get(dataEventId)
 	if !ok {
 		dataCacheMisses.WithLabelValues("get").Inc()
@@ -40,7 +43,7 @@ func (c *Cache) get(dataEventId dataapi.DataEventId) ([]byte, error) {
 	return data, nil
 }
 
-func (c *Cache) add(id dataapi.DataEventId, msgData []byte) bool {
+func (c *cache) add(id dataapi.DataEventId, msgData []byte) bool {
 	evicted := c.cache.Add(id, msgData)
 	if !evicted {
 		dataCacheTotal.Inc()
@@ -48,7 +51,7 @@ func (c *Cache) add(id dataapi.DataEventId, msgData []byte) bool {
 	return evicted
 }
 
-func (c *Cache) remove(desc dataapi.DataEventDesc) bool {
+func (c *cache) remove(desc dataapi.DataEventDesc) bool {
 	present := c.cache.Remove(desc.Id)
 	if present {
 		dataCacheTotal.Dec()
diff --git a/pkg/observer/data.go b/pkg/observer/data.go
index 00decab608a..4d0b82e4b5d 100644
--- a/pkg/observer/data.go
+++ b/pkg/observer/data.go
@@ -19,12 +19,12 @@ func init() {
 }
 
 var (
-	dataCache *Cache
+	dataCache *cache
 )
 
 func InitDataCache(size int) error {
 	var err error
-	dataCache, err = NewCache(size)
+	dataCache, err = newCache(size)
 	return err
 }