Push code

cache/MemCache.go

@@ -0,0 +1,79 @@
+package cache
+
+import "sync"
+
+// DNSCache is a simple in-memory cache for DNS records
+type DNSCache struct {
+	mu    sync.RWMutex
+	cache map[string]string // key: "fqdn:provider" -> value: IP
+}
+
+var globalCache *DNSCache
+
+func init() {
+	globalCache = &DNSCache{
+		cache: make(map[string]string),
+	}
+}
+
+// GetCache returns the global cache instance
+func GetCache() *DNSCache {
+	return globalCache
+}
+
+// makeKey creates a unique cache key from FQDN and provider
+func (c *DNSCache) makeKey(fqdn, provider string) string {
+	return fqdn + ":" + provider
+}
+
+// NeedsUpdate checks if the record needs updating
+// Returns true if IP is different or not in cache
+func (c *DNSCache) NeedsUpdate(fqdn, provider, newIP string) bool {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	key := c.makeKey(fqdn, provider)
+	cachedIP, exists := c.cache[key]
+
+	if !exists {
+		return true // Not in cache, needs update
+	}
+
+	return cachedIP != newIP // Update if IP changed
+}
+
+// Set updates the cache with the new IP
+func (c *DNSCache) Set(fqdn, provider, ip string) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	key := c.makeKey(fqdn, provider)
+	c.cache[key] = ip
+}
+
+// Get retrieves the cached IP
+func (c *DNSCache) Get(fqdn, provider string) (string, bool) {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	key := c.makeKey(fqdn, provider)
+	ip, exists := c.cache[key]
+	return ip, exists
+}
+
+// Clear removes a specific entry from cache
+func (c *DNSCache) Clear(fqdn, provider string) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	key := c.makeKey(fqdn, provider)
+	delete(c.cache, key)
+}
+
+// ClearAll removes all entries from cache
+func (c *DNSCache) ClearAll() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	c.cache = make(map[string]string)
+}