feat: client hash cache

feat: add local config
feat: create a volume for data (for the future)
format: unname unused vars

1 files changed, 46 insertions, 0 deletions

diff --git a/internal/router/client-cache.go b/internal/router/client-cache.go
new file mode 100644
index 0000000..192d2ed
--- /dev/null
+++ b/internal/router/client-cache.go
@@ -0,0 +1,46 @@
+package router
+
+import (
+	"log/slog"
+	"sync"
+
+	"golang.org/x/crypto/argon2"
+)
+
+type ClientCache struct {
+	hashMap  map[string][]byte
+	mutexMap map[string]*sync.Mutex
+	salt     []byte
+}
+
+var CCache *ClientCache
+
+func NewClientCache(salt []byte) *ClientCache {
+	return &ClientCache{
+		hashMap:  make(map[string][]byte),
+		mutexMap: make(map[string]*sync.Mutex),
+		salt:     salt,
+	}
+}
+
+func (c *ClientCache) GetHash(id string) []byte {
+	if val, ok := c.hashMap[id]; ok {
+		slog.Debug("gave an old hash", slog.String("hash", string(val)))
+		return val
+	}
+
+	if _, ok := c.mutexMap[id]; !ok {
+		c.mutexMap[id] = &sync.Mutex{}
+	}
+	c.mutexMap[id].Lock()
+	defer c.mutexMap[id].Unlock()
+
+	if val, ok := c.hashMap[id]; ok {
+		slog.Debug("gave a newly generated hash", slog.String("hash", string(val)))
+		return val
+	}
+
+	c.hashMap[id] = argon2.IDKey([]byte(id), c.salt, 1, 64*1024, 4, 32)
+	slog.Debug("generated hash", slog.String("hash", string(c.hashMap[id])))
+	return c.hashMap[id]
+}