plugin: introduce the cache system to speed up the plugin with big node

Changelog-Fixed: introduce the cache system to speed up the plugin with big node

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>

.gitignore

@@ -3,3 +3,5 @@ vendor
 go-lnmetrics
 
 *.out
+
+.idea/

go.mod

@@ -3,7 +3,7 @@ module github.com/LNOpenMetrics/go-lnmetrics.reporter
 go 1.17
 
 require (
-	github.com/LNOpenMetrics/lnmetrics.utils v0.0.3
+	github.com/LNOpenMetrics/lnmetrics.utils v0.0.6
 	github.com/elastic/go-sysinfo v1.7.1
 	github.com/kinbiko/jsonassert v1.0.2
 	github.com/robfig/cron/v3 v3.0.1

go.sum

@@ -6,6 +6,8 @@ github.com/LNOpenMetrics/lnmetrics.utils v0.0.2 h1:USJE6C1dhiNUjiQ29iQ3MHxxZt9Y0
 github.com/LNOpenMetrics/lnmetrics.utils v0.0.2/go.mod h1:6PC0XEUljl08AHdHdMQtR2tGJ1o9Jzg8yt7nioTnlE4=
 github.com/LNOpenMetrics/lnmetrics.utils v0.0.3 h1:emd43at2elU8FDAeJhTDNkMF1/cbYR0lFS0iyka34Go=
 github.com/LNOpenMetrics/lnmetrics.utils v0.0.3/go.mod h1:6PC0XEUljl08AHdHdMQtR2tGJ1o9Jzg8yt7nioTnlE4=
+github.com/LNOpenMetrics/lnmetrics.utils v0.0.6 h1:fO6nTbMsLzJDEHRRfyS+QUSEzmyXHCaOWOpmttlYGrE=
+github.com/LNOpenMetrics/lnmetrics.utils v0.0.6/go.mod h1:6PC0XEUljl08AHdHdMQtR2tGJ1o9Jzg8yt7nioTnlE4=
 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=

internal/cache/cache_manager.go

@@ -0,0 +1,124 @@
+package cache
+
+import (
+	"encoding/json"
+	"fmt"
+	db "github.com/LNOpenMetrics/lnmetrics.utils/db/leveldb"
+	"github.com/LNOpenMetrics/lnmetrics.utils/log"
+	"strings"
+)
+
+// cacheManager is the internal rappresentation
+// of the cache manager, that contains all the utils
+// function to manage the cache
+type cacheManager struct {
+	prefix   string
+	cacheIdx string
+	cache    map[string]*string
+}
+
+func GetInstance() *cacheManager {
+	return &cacheManager{
+		prefix:   "cache",
+		cacheIdx: "cache/idx",
+		cache:    nil,
+	}
+}
+
+func (instance *cacheManager) buildID(key string) string {
+	return strings.Join([]string{instance.prefix, key}, "/")
+}
+
+func (instance *cacheManager) initCache() error {
+	instance.cache = make(map[string]*string)
+	arrJson, err := json.Marshal(instance.cache)
+	if err != nil {
+		return err
+	}
+	if err := db.GetInstance().PutValueInBytes(instance.cacheIdx, arrJson); err != nil {
+		log.GetInstance().Errorf("%s", err)
+		return err
+	}
+	return nil
+}
+
+func (instance *cacheManager) getCacheIndex() (map[string]*string, error) {
+	if instance.cache == nil {
+		if err := instance.initCache(); err != nil {
+			return nil, err
+		}
+		return instance.getCacheIndex()
+	}
+	value, err := db.GetInstance().GetValueInBytes(instance.cacheIdx)
+	if err != nil {
+		return nil, err
+	}
+	if err := json.Unmarshal(value, &instance.cache); err != nil {
+		return nil, err
+	}
+	return instance.cache, nil
+}
+
+func (instance *cacheManager) addToCache(key string) error {
+	idx := instance.cache
+	if idx == nil {
+		tmpIdx, err := instance.getCacheIndex()
+		if err != nil {
+			return err
+		}
+		idx = tmpIdx
+	}
+	if _, ok := idx[key]; !ok {
+		idx[key] = &key
+	}
+	return nil
+}
+
+func (instance *cacheManager) IsInCache(key string) bool {
+	if instance.cache != nil {
+		_, ok := instance.cache[key]
+		if ok {
+			return ok
+		}
+		// otherwise, continue and check with the database
+	}
+	key = instance.buildID(key)
+	_, err := db.GetInstance().GetValue(key)
+	if err != nil {
+		log.GetInstance().Errorf("Error inside the cache: %s", err)
+		return false
+	}
+	return true
+}
+
+// GetFromCache  retrieval the information that are in the cache in bytes
+func (instance *cacheManager) GetFromCache(key string) ([]byte, error) {
+	if instance.IsInCache(key) {
+		key = instance.buildID(key)
+		return db.GetInstance().GetValueInBytes(key)
+	}
+	return nil, fmt.Errorf("no value with key %s in the cache", key)
+}
+
+// PutToCache put the value in the json form inside the cache with the key specified
+func (instance *cacheManager) PutToCache(key string, value interface{}) error {
+	jsonValue, err := json.Marshal(value)
+	if err != nil {
+		return err
+	}
+	key = instance.buildID(key)
+	if err := db.GetInstance().PutValueInBytes(key, jsonValue); err != nil {
+		return err
+	}
+	return instance.addToCache(key)
+}
+
+// CleanCache clean the index from the database
+func (instance *cacheManager) CleanCache() error {
+	for key := range instance.cache {
+		if err := db.GetInstance().DeleteValue(key); err != nil {
+			return err
+		}
+	}
+	return nil
+}

internal/cache/cache_model.go

@@ -0,0 +1,16 @@
+// Package cache package implement the basic block to implement the
+// cache persistence
+package cache
+
+import (
+	"github.com/vincenzopalazzo/glightning/glightning"
+)
+
+// NodeInfoCache implement the interface to
+// store the node information inside the cache.
+type NodeInfoCache struct {
+	ID       string
+	Alias    string
+	Color    string
+	Features *glightning.Hexed
+}