feat: add cache implementation

internal/cache/cache.go

@@ -0,0 +1,38 @@
+package cache
+
+import (
+	"log/slog"
+
+	"github.com/grassrootseconomics/celo-tracker/internal/chain"
+)
+
+type (
+	Cache interface {
+		Purge() error
+		Exists(string) bool
+		Add(string) bool
+		Size() int
+	}
+
+	CacheOpts struct {
+		Logg      *slog.Logger
+		Chain     *chain.Chain
+		CacheType string
+	}
+)
+
+func New(o CacheOpts) Cache {
+	var (
+		cache Cache
+	)
+
+	switch o.CacheType {
+	case "map":
+		cache = NewMapCache()
+	default:
+		cache = NewMapCache()
+	}
+	o.Logg.Debug("bootstrapping cache")
+
+	return cache
+}

internal/cache/map.go

@@ -0,0 +1,39 @@
+package cache
+
+import (
+	"log/slog"
+
+	"github.com/puzpuzpuz/xsync/v3"
+)
+
+type (
+	MapCache struct {
+		mapCache *xsync.Map
+		logg     *slog.Logger
+	}
+)
+
+func NewMapCache() *MapCache {
+	return &MapCache{
+		mapCache: xsync.NewMap(),
+	}
+}
+
+func (c *MapCache) Purge() error {
+	c.mapCache.Clear()
+	return nil
+}
+
+func (c *MapCache) Exists(key string) bool {
+	_, ok := c.mapCache.Load(key)
+	return ok
+}
+
+func (c *MapCache) Add(key string) bool {
+	c.mapCache.Store(key, nil)
+	return true
+}
+
+func (c *MapCache) Size() int {
+	return c.mapCache.Size()
+}